Bladder cancer

Bladder cancer
Transitional cell carcinoma of the bladder. The white in the bladder is contrast.
Specialty	Oncology, urology
Symptoms	Blood in the urine, pain with urination
Usual onset	65 to 84 years old
Types	Transitional cell carcinoma, squamous cell carcinoma, adenocarcinoma
Risk factors	Smoking, family history, prior radiation therapy, frequent bladder infections, certain chemicals
Diagnostic method	Cystoscopy with tissue biopsies
Treatment	Surgery, radiation therapy, chemotherapy, immunotherapy
Prognosis	Five-year survival rates ~77% (US)
Frequency	549,000 new cases (2018)
Deaths	200,000 (2018)

Bladder cancer is any of several types of cancer arising from the tissues of the urinary bladder. Symptoms include blood in the urine, pain with urination, and low back pain. It is caused when epithelial cells that line the bladder become malignant.

Risk factors for bladder cancer include smoking, family history, prior radiation therapy, frequent bladder infections, and exposure to certain chemicals. The most common type is transitional cell carcinoma. Other types include squamous cell carcinoma and adenocarcinoma. Diagnosis is typically by cystoscopy with tissue biopsies. Staging of the cancer is determined by transurethral resection and medical imaging.

Treatment depends on the stage of the cancer. It may include some combination of surgery, radiation therapy, chemotherapy, or immunotherapy. Surgical options may include transurethral resection, partial or complete removal of the bladder, or urinary diversion. The typical five-year survival rates in the United States is 77%, Canada is 75%, and Europe is 68%.

Bladder cancer, as of 2018, affected about 1.6 million people globally with 549,000 new cases and 200,000 deaths. Age of onset is most often between 65 and 84 years of age. Males are more often affected than females. In 2018, the highest rate of bladder cancer occurred in Southern and Western Europe followed by North America with rates of 15, 13, and 12 cases per 100,000 people. The highest rates of bladder cancer deaths were seen in Northern Africa and Western Asia followed by Southern Europe.

Signs and symptoms

Location of bladder cancer

The most common symptom of bladder cancer is visible blood in the urine (haematuria) despite painless urination. This affects around 75% of people eventually diagnosed with the disease. Some instead have "microscopic haematuria" – small amounts of blood in the urine that can only be seen under a microscope during urinalysis – pain while urinating, or no symptoms at all (their tumors are detected during unrelated medical imaging). Less commonly, a tumor can block the flow of urine into the bladder, causing pain along the flank of the body (between the ribs and the hips). Most people with blood in the urine do not have bladder cancer; up to 22% of those with visible haematuria and 5% with microscopic haematuria are diagnosed with the disease. Women with bladder cancer and haematuria are often misdiagnosed with urinary tract infections, delaying appropriate diagnosis and treatment.

People with advanced disease may have pelvic or bony pain, lower-extremity swelling, or flank pain. Rarely, a palpable mass can be detected on physical examination.

Causes

Bladder cancer is caused by genetic damage to the DNA of bladder cells. These changes can be random, or can be induced by exposure of the bladder to toxic substances such as those from consuming tobacco. The accumulation of this genetic damage disrupts the normal functioning of bladder cells, causing them to grow uncontrollably and form a tumor.

Smoking

Tobacco smoking is the main known contributor to urinary bladder cancer; in most populations, smoking is associated with over half of bladder cancer cases in men and one-third of cases among women, however these proportions have reduced over recent years since there are fewer smokers in Europe and North America. There is an almost linear relationship between smoking duration (in years), pack years and bladder cancer risk. A risk plateau at smoking about 15 cigarettes a day can be observed (meaning that those who smoke 15 cigarettes a day are approximately at the same risk as those smoking 30 cigarettes a day). Smoking in any form (cigar, cigarette, pipe, Egyptian waterpipe and smokeless tobacco) increases the risk for bladder cancer. Quitting smoking reduces the risk. Risk of bladder cancer decreases by 30% within 1–4 years and continues to decrease by 60% at 25 years after smoking cessation. However, former smokers will most likely always be at a higher risk of bladder cancer compared to people who have never smoked. Passive smoking also appears to be a risk.

Opium consumption increases the risk of bladder cancer threefold, while concurrent use of opium and tobacco increases the risk of bladder cancer fivefold when compared to the general population.

Occupational exposure

Thirty percent of bladder tumors probably result from occupational exposure in the workplace to carcinogens. Occupational or circumstantial exposure to the following substances has been implicated as a cause of bladder cancer; benzidine (dyes manufacturing), 4-aminobiphenyl (rubber industry), 2-naphtylamine (azo dyes manufacturing, foundry fumes, rubber industry, cigarette smoke and cancer research), phenacetin (analgesic), arsenic and chlorinated aliphatic hydrocarbons in drinking water, auramine (dye manufacturing), magenta (dye manufacturing), ortho-toluidine (dye manufacturing), epoxy and polyurethane resin hardening agents (plastics industry), chlornaphazine, coal-tar pitch. Occupations at risk are bus drivers, rubber workers, painters, motor mechanics, leather (including shoe) workers, blacksmiths, machine setters, and mechanics. Hairdressers are thought to be at risk as well because of their frequent exposure to permanent hair dyes.

Infection

Infection with Schistosoma haematobium (bilharzia or schistosomiasis) may cause bladder cancer, particularly of the squamous cell type. Schistosoma eggs induces a chronic inflammatory state in the bladder wall resulting in tissue fibrosis. Higher levels of N-nitroso compounds has been detected in urine samples of people with schistosomiasis. N-Nitroso compounds have been implicated in the pathogenesis of schistosomiasis related bladder cancer. They cause alkylation DNA damage, specially Guanine to Adenine transition mutations in the HRAS and p53 tumor suppressor gene. Mutations of p53 are detected in 73% of the tumors, BCL-2 mutations accounting for 32% and the combination of the two accounting for 13%. Other causes of squamous cell carcinoma of the bladder include chronic catheterizations in people with a spinal cord injury and history of treatment with cyclophosphamide.

Diet

The American Institute for Cancer Research have stated that there is strong evidence that drinking water containing arsenic increases the risk of bladder cancer.

High consumption of animal fat and dietary cholesterol increases bladder cancer risk in men.

Ingestion of aristolochic acid present in many Chinese herbal medications has been shown to cause urothelial carcinoma and kidney failure. Aristolochic acid activates peroxidase in the urothelium and causes transversion mutation in the TP53 tumor suppressor gene.

Other

People who undergo external beam radiotherapy (EBRT) for prostate cancer have a higher risk of developing invasive bladder cancer.

In addition to these major risk factors there are also numerous other modifiable factors that are less strongly (i.e. 10–20% risk increase) associated with bladder cancer, for example, obesity. Although these could be considered as minor effects, risk reduction in the general population could still be achieved by reducing the prevalence of a number of smaller risk factor together.

Genetics

Mutations in FGFR3, TP53, PIK3CA, KDM6A, ARID1A, KMT2D, HRAS, TERT, KRAS, CREBBP, RB1 and TSC1 genes may be associated with some cases of bladder cancer. Deletions of parts or whole of chromosome 9 is common in bladder cancer. Low grade cancer are known to harbor mutations in RAS pathway and the fibroblast growth factor receptor 3 (FGFR3) gene, both of which play a role in the MAPK/ERK pathway. p53 and RB gene mutations are implicated in high-grade muscle invasive tumors. Eighty nine percent of muscle invasive cancers have mutations in chromatin remodeling and histone modifying genes. Deletion of both copies of the GSTM1 gene has a modest increase in risk of bladder cancer. GSTM1 gene product glutathione S-transferase M1 (GSTM1) participates in the detoxification process of carcinogens such as polycyclic aromatic hydrocarbons found in cigarette smoke. Similarly, mutations in NAT2 (N-acetyltransferase) is associated with increased risk for bladder cancer. N-acetyltransferase helps in detoxification of carcinogens like aromatic amines (also present in cigarette smoke). Various single-nucleotide polymorphisms in PSCA gene present on chromosome 8 have shown to increase the risk for bladder cancer. PSCA gene promoter region has an androgen response region. Loss of reactivity of this region to androgens is hypothesized as a cause of more aggressive tumors in women (unlike in men who have higher amount of androgen).

Muscle invasive bladder cancer are heterogeneous in nature. In general, they can be genetically classified into basal and luminal subtypes. Basal subtype show alterations involving RB and NFE2L2 and luminal type show changes in FGFR3 and KDM6A genes. Basal subtype are subdivided into basal and claudin low-type group and are aggressive and show metastasis at presentation, however they respond to platinum based chemotherapy. Luminal subtype can be subdivided into p53-like and luminal. p53-like tumors of luminal subtype although not as aggressive as basal type, show resistance to chemotherapy

Diagnosis

Bladder wall thickening due to cancer

Bladder tumor in FDG PET due to the high physiological FDG-concentration in the bladder, furosemide was supplied together with 200 MBq FDG. The uptake cranial to the lesion is a physiological uptake in the colon.

Those suspected of having bladder cancer can undergo several tests to assess the presence and extent of any tumors. First, many undergo a physical examination that can involve a digital rectal exam and pelvic exam, where a doctor feels the pelvic area for unusual masses that could be tumors. Severe bladder tumors often shed cells into the urine; these can be detected by urine cytology, where cells are collected from a urine sample, and viewed under a microscope. Cytology can detect around two thirds of high-grade tumors, but detects just 1 in 8 low-grade tumors. Additional urine tests can be used to detect molecules associated with bladder cancer. Some detect the proteins bladder tumor antigen or NMP22 that tend to be elevated in the urine of those with bladder cancer; some detect mRNA of tumor-associated genes; some use fluorescence microscopy to detect cancerous cells more sensitively than regular cytology.

Many also undergo cystoscopy, wherein a flexible camera is threaded up the urethra and into the bladder to visually inspect for cancerous tissue. Cystoscopy is most sensitive to papillary tumors (tumors with a finger-like shape that grow into the urine-holding part of the bladder); it is less sensitive to small, low-lying carcinoma in situ (CIS). CIS detection is improved by blue light cystoscopy, where a dye (hexaminolevulinate) that accumulates in cancer cells is injected into the bladder during cystoscopy. The dye fluoresces when the cystoscope shines blue light on it, allowing for more sensitive detection of small tumors.

The upper urinary tract (ureters and kidney) is also imaged for tumors that could cause blood in the urine. This is typically done by injecting a dye into the blood that the kidneys will filter into the urinary tract, then imaging by computed tomography scanning. Those whose kidneys are not functioning well enough to filter the dye may instead be scanned by magnetic resonance imaging.

Suspected tumors are removed by threading a device up the urethra in a process called "transurethral resection of bladder tumor" (TURBT). All tumors are removed, as well as a piece of the underlying bladder muscle. Removed tissue is examined by a pathologist to determine if it is cancerous.

Classification

Histopathology of urothelial carcinoma of the urinary bladder. Transurethral biopsy. H&E stain

Type	Relative incidence	Subtypes
Transitional cell carcinoma	95%	Papillary (70%)
		Non-papillary (30%)
Non-transitional cell carcinoma	5%	Squamous cell carcinomas, adenocarcinomas, sarcomas, small cell carcinomas, and secondary deposits from cancers elsewhere in the body.

Non-papillary carcinoma includes carcinoma in situ (CIS), microinvasive carcinoma and frankly invasive carcinoma. Carcinoma in situ (CIS) invariably consists of cytologically high-grade tumour cells.

Transitional cell carcinoma can undergo differentiation (25%) into its variants. When seen under a microscope, papillary transitional cell carcinoma can present in its typical form or as one of its variations (squamous, glandular differentiation or micropapillary variant). Different variations of non-papillary transitional cell carcinoma are listed below.

Variant	Histology	Percentage of non-papillary cases	Implications
Squamous differentiation	Presence of intercellular bridges or keratinization	60%	Outcomes similar to conventional transitional cell carcinoma
Glandular differentiation	Presence of true glandular spaces	10%
Sarcomatoid foci	Presence of both epithelial and mesenchymal differentiation	7%	Clinically aggressive
Micropapillary variant	Resembles papillary serous carcinoma of the ovary or resembling micropapillary carcinoma of breast or lung	3.7%	Clinically aggressive, early cystectomy recommended
Urothelial carcinoma with small tubules and microcystic form	Presence of cysts with a size range of microscopic to 1-2mm	Rare
Lymphoepithelioma-like carcinoma	Resembles lymphoepithelioma of the nasopharynx
Lymphoma-like and plasmacytoid variants	Malignant cells resemble cells of malignant lymphoma or plasmacytoma
Nested variant	Histologically look similar to von Brunn's nests		Can be misdiagnosed as benign von Brunn's nests or non-invasive low-grade papillary urothelial carcinoma
Urothelial carcinoma with giant cells	Presence of epithelial tumour giant cells and looks similar to giant cell carcinoma of the lung
Trophoblastic differentiation	Presence of syncytiotrophoblastic giant cells or choriocarcinomatous differentiation, may express HCG
Clear cell variant	Clear cell pattern with glycogen-rich cytoplasm
Plasmacytoid	Cells with abundant lipid content, mimic signet ring cell adenocarcinoma of stomach/ lobular breast cancer		Clinically aggressive, propensity for peritoneal spread
Unusual stromal reactions	Presence of following; pseudosarcomatous stroma, stromal osseous or cartilaginous metaplasia, osteoclast-type giant cells, lymphoid infiltrate

Staging

Diagram showing the T stages of bladder cancer

Stage N1 bladder cancer

Advanced bladder cancer (M1b)

Lymph nodes in the pelvis. Bladder cancer commonly spreads to obturator and internal iliac (not labelled)

Lymphatic drainage of the bladder (lateral view).Tumors on the superolateral bladder wall spread to external iliac lymph nodes

Bladder cancer is staged (classified by the extent of spread of the cancer) and graded (how abnormal and aggressive the cells appear under the microscope) to determine treatment and predict outcomes. Staging is usually performed with transurethral resection of bladder tumor (TURBT) and radiologic imaging (CT and MRI). Papillary tumors confined to the mucosa or which invade the lamina propria are classified as Ta or T1. Flat lesions that do not invade the basement membrane of the bladder mucosa are termed Tis (in situ). All three categories (Tis, Ta and T1) are grouped together as non-muscle invasive disease for therapeutic purposes and in most cases they are offered cystoscopic resection with TURBT without the need for radical resection of the entire urinary bladder. Tumors in the remaining categories (T2, T3 and T4) are termed muscle-invasive disease and are associated with less favorable prognosis.

In the TNM staging system (8th Edn. 2017) for bladder cancer:

T (Primary tumour)

• TX Primary tumour cannot be assessed
• T0 No evidence of primary tumour
• Ta Non-invasive papillary carcinoma
• Tis Carcinoma in situ ('flat tumour')
• T1 Tumour invades subepithelial connective tissue
• T2a Tumour invades superficial muscle (inner half of the detrusor muscle)
• T2b Tumour invades deep muscle (outer half of the detrusor muscle)
• T3 Tumour invades perivesical tissue:
  • T3a Microscopically
  • T3b Macroscopically (extravesical mass)
• T4a Tumour invades prostate, uterus or vagina
• T4b Tumour invades pelvic wall or abdominal wall

N (Lymph nodes)

• NX Regional lymph nodes cannot be assessed
• N0 No regional lymph node metastasis
• N1 Metastasis in a single lymph node in true pelvis (hypogastric, obturator, external iliac, or presacral nodes)
• N2 Metastasis in multiple lymph nodes in true pelvis (hypogastric, obturator, external iliac, or presacral nodes)
• N3 Metastasis in common iliac lymph nodes

M (Distant metastasis)

• MX Distant metastasis cannot be assessed
• M0 No distant metastasis
• M1 Distant metastasis.
  • M1a: The cancer has spread only to lymph nodes outside of the pelvis.
  • M1b: The cancer has spread other parts of the body.

The most common sites for bladder cancer metastases are the lymph nodes, bones, lung, liver, and peritoneum. The most common sentinel lymph nodes draining bladder cancer are obturator and internal iliac lymph nodes. The location of lymphatic spread depends on the location of the tumors. Tumors on the superolateral bladder wall spread to external iliac lymph nodes. Tumors on the neck, anterior wall and fundus spread commonly to the internal iliac lymph nodes. From the regional lymph nodes (i.e. obturator, internal and external lymph nodes) the cancer spreads to distant sites like the common iliac lymph nodes and paraaortic lymph nodes. Skipped lymph node lesions are not seen in bladder cancer.

Numerical
The stages above can be integrated into a numerical staging (with Roman numerals) as follows:

Stage	Tumor	Nodes	Metastasis	5-year survival in the US
Stage 0a	Ta	N0	M0	98%
Stage 0is	Tis	N0	M0	95%
Stage I	T1	N0	M0	63%
Stage II	T2a	N0	M0
	T2b
Stage IIIA	T3a	N0	M0	35%
	T3b
	T4a
	T1-4a	N1
Stage IIIB	T1-4a	N2	M0
		N3
Stage IVA	T4b	Any N	M0
	Any T		M1a
Stage IVB	Any T	Any N	M1b	5%

Grading

According to WHO classification (1973) bladder cancers are histologically graded into:

• G1 – Well differentiated,
• G2 – Moderately differentiated
• G3 – Poorly differentiated

WHO classification (2004/2016)

• Papillary lesions
  • Urothelial Papilloma
  • Papillary urothelial neoplasm of low malignant potential (PUNLMP)
  • Low Grade
  • High Grade
• Flat lesions
  • Urothelial proliferation of uncertain malignant potential
  • Reactive atypia
  • Atypia of unknown significance
  • Urothelial dysplasia
  • Urothelial CIS (always high grade)
    • Primary
    • Secondary
    • Concurrent

Risk stratification

People with non-muscle invasive bladder cancer (NMIBC), are risk-stratified based on clinical and pathological factors so that they are treated appropriately depending on their probability of having progression and/or recurrence. People with non-muscle invasive tumors are categorized into low-risk, intermediate-risk and high-risk or provided with a numerical risk score. Risk-stratification framework is provided by American Urology Association/Society of Urological Oncology (AUA/SUO stratification), European Association of Urology (EAU) guidelines, European Organization for Research and Treatment of Cancer (EORTC) risk tables and Club Urológico Español de Tratamiento Oncológico (CUETO) scoring model.

AUA risk stratification for non-muscle invasive bladder cancer

Low risk	Intermediate risk	High risk
Low grade solitary Ta tumor, smaller than 3 cm	Recurrence within 1 year, Low grade Ta tumor	High grade T1
Papillary urothelial neoplasm of low malignant potential	Solitary low grade Ta tumor, bigger than 3 cm	Any recurrent tumor or any high grade Ta
	Low grade Ta, multifocal tumors	High grade Ta, bigger than 3 cm (or multifocal)
	High grade Ta, smaller than 3 cm	Any carcinoma in situ
	Low grade T1	Any BCG failure in high grade tumors
		Any variant histology
		Any lymphovascular invasion
		Any high grade prostatic urethral involvement

The EORTC and CUETO model use a cumulative score obtained from individual prognostic factors, which are then converted into risk of progression and recurrence. The six prognostic factors included in the EORTC model are number of tumors, recurrence rate, T-stage, presence of carcinoma-in-situ and grade of the tumor. Scoring for recurrence in the CUETO model incorporates 6 variables; age, gender, grade, tumor status, number of tumors and presence of tis. For progression scoring the previous 6 variables plus T stage is used.

EORTC/CUETO risk of recurrence depending on the cumulative score

Model	Cumulative score for recurrence	Recurrence at 1-year (%)	Recurrence at 5-year (%)
EORTC	0	15	31
	1-4	24	46
	5-9	38	62
	10-17	61	78
CUETO	0-4	8.2	21
	5-6	12	36
	7-9	25	48
	10-16	42	68

EORTC/CUETO risk of progression depending on the cumulative score

Model	Cumulative score for progression	Progression at 1-year (%)	Progression at 5-year (%)
EORTC	0	0.2	0.8
	2-6	1	6
	7-13	5	17
	12-23	17	45
CUETO	0-4	1.2	3.7
	5-6	3	12
	7-9	5.5	21
	10-16	14	34

Prevention

Diet

As of 2019, there is limited high level evidence to suggest that eating vegetable and fruits decreases the risk of bladder cancer. Fruit and yellow-orange vegetables, particularly carrots and those containing selenium, citrus fruits and cruciferous vegetables have been identified as having a possibly protective effect.

While it is suggested that the polyphenol compounds in tea may have an inhibitory effect on bladder tumor formation and growth, there is limited evidence to suggesting drinking tea decreases bladder cancer risk. A 2022 review found that a Mediterranean diet has a protective effect on bladder cancer risk. Higher consumption of monounsaturated fat and plant-based oils decrease bladder cancer risk in women. Higher consumption of total dietary fiber and whole grains is associated with a reduced risk of bladder cancer.

Screening

As of 2019 there is insufficient evidence to determine if screening for bladder cancer in people without symptoms is effective or not.

Treatment

Flow chart of treatment

The treatment of bladder cancer depends on how deeply the tumor invades into the bladder wall.

Treatment strategies for bladder cancer include:

• Non-muscle invasive: transurethral resection of bladder tumor (TURBT) with or without intravesical chemotherapy or immunotherapy
• Muscle invasive
  • Stage II/Stage IIIA: radical cystectomy plus neoadjuvant chemotherapy (multimodal therapy, preferred) or transurethral resection with chemoradiation (trimodal therapy, highly selected people) or partial cystectomy plus neoadjuvant chemotherapy (in highly selected people)
  • Stage IIIB/IVA: cisplatin-based chemotherapy followed by radical cystectomy or chemoradiation or observation depending on treatment response
  • Stage IVB (locally advanced; unresectable tumors): palliative radiotherapy
• Metastatic disease: cisplatin-based chemotherapy
• Metastatic disease but unfit for cisplatin-based chemotherapy: carboplatin-based chemotherapy
• Metastatic disease with contraindication for chemotherapy: checkpoint inhibitors if programmed death ligand 1 (PD L1) positive
• Squamous cell carcinoma or adenocarcinoma of bladder: radical cystectomy

Non-muscle invasive

Transurethral resection

Non-muscle invasive bladder cancer (those not entering the muscle layer of the bladder) can be "shaved off" using an electrocautery device attached to a cystoscope, which in that case is called a resectoscope. The procedure is called transurethral resection of bladder tumor (TURBT) and serves primarily for pathological staging. In case of non-muscle invasive bladder cancer the TURBT is in itself the treatment, but in case of muscle invasive cancer, the procedure is insufficient for final treatment. Additionally, blue light cystoscopy with optical-imaging agent Hexaminolevulinate (HAL) is recommended at initial TURBT to increase lesion detection (especially carcinoma in situ) and improve resection quality thereby reducing recurrence. It is important to assess the quality of the resection: if there is evidence of incomplete resection, or if there is no muscle in the specimen (without which muscle invasiveness cannot be determined), then a second TURBT is strongly recommended. Moreover, nearly half of the people with high-grade noninvasive disease have residual tumor after primary TURBT; in such cases a second TURBT is important for avoiding under-staging. At this point classifying people into risk groups is recommended. Treatment and surveillance for different risk groups is indicated in the table below.

Another method for reducing recurrence of tumors is medication after TURBT surgery. The two most common medicines used for this purpose are Bacillus Calmette–Guérin (BCG) and mitomycin. For people who have already had a TURBT procedure, BCG may lead to similar risk of death and may reduce the risk of tumor recurrence. However, this medication may increase the risk of serious unwanted side effects. More research is needed to confirm these results.

Chemotherapy

Drug treatment (chemotherapy) into the bladder(Intravesical)

A single instillation of chemotherapy into the bladder after primary TURBT has shown benefit in deceasing recurrence by 35% in non-muscle invasive disease. Medications which can be used for this purpose are mitomycin C (MMC), epirubicin, pirarubicin and gemcitabine. Instillation of post-operative chemotherapy should be conducted within first few hours after TURBT. As time progress residual tumor cells are known to adhere firmly and are covered by extracellular matrix which decrease the efficacy of the instillation. The most common side effect is chemical cystitis and skin irritation. If there is a suspicion of bladder perforation during TURBT, chemotherapy should not be instilled into the bladder as serious adverse events are known to occur due to drug extravasation. Studies have shown that efficacy of chemotherapy is increased by the use of Device assisted chemotherapy . These technologies use different mechanisms to facilitate the absorption and action of a chemotherapy drug instilled directly into the bladder. Another technology – electromotive drug administration (EMDA) – uses an electric current to enhance drug absorption after surgical removal of the tumor. Another technology, thermotherapy, uses radio-frequency energy to directly heat the bladder wall, which together with chemotherapy (chemohyperthermia) shows a synergistic effect, enhancing each other's capacity to kill tumor cells.

Immunotherapy

Attenuated strain of M. bovis used in the treatment of bladder cancer

Immunotherapy by Bacillus Calmette–Guérin (BCG) delivery into the bladder is also used to treat and prevent the recurrence of NMIBC. BCG is a vaccine against tuberculosis that is prepared from attenuated (weakened) live bovine tuberculosis bacillus, Mycobacterium bovis, that has lost its virulence in humans. BCG immunotherapy is effective in up to 2/3 of the cases at this stage, and in randomized trials has been shown to be superior to standard chemotherapy. The exact mechanism by which BCG prevents recurrence is unknown. However, it has been shown that the bacteria are taken up by the cancer cells. The infection of these cells in the bladder may trigger a localized immune reaction which clears residual cancer cells.

BCG is delivered as induction and a maintenance course. The induction course consists of 6-week course of intravesical and percutaneous BCG. This is followed by a maintenance course. There is no consensus regarding the maintenance schedule, however the most commonly followed is the Southwestern Oncology Group (SWOG) schedule. The SWOG maintenance schedule consists of intravesical and percutaneous BCG every week for 3 weeks given at 3, 6, 12, 18, 24, 30 and 36 months. Three weekly maintenance regimen with induction has shown complete response rate of 84% compared to 69% in people who received 6-week induction BCG only at 6 months. Many studies have explored alternate treatment schedules and regimes of BCG but has shown no clinical significance. Efficacy of different strains of BCG (Connaught, TICE, Pasteur, Tokio-172) has been shown not to be different however, there is no high-level evidence.

Side effects of BCG therapy include cystitis, prostatitis, epididymo-orchitis, balanitis, ureteral obstruction, bladder contraction, mycobacterial osteomyelitis, reactive arthritis, mycobacterial pneumonia, granulomatous hepatitis, granulomatous nephritis, interstitial nephritis, infectious vasculitis and disseminated infection.

Local infection (i.e. prostatitis, epididymo-orchitis, balanitis) because of BCG should be treated with triple tubercular therapy, with one of the drug being fluoroquinolone for 3 to 6 months. In people with systemic infections, BCG therapy should be stopped and anti-tubercular multidrug treatment for at-least 6 months should be started. Medications that can be used for this treatment are INH, rifampicin, ethambutol, fluoroquinolones, clarithromycin, aminoglycosides, and doxycycline. BCG strains are not sensitive to pyrazinamide therefore, it should not be a part of anti-tubercular treatment.

Nogapendekin alfa inbakicept (Anktiva), used in combination with Bacillus Calmette-Guérin was approved for medical use in the United States in April 2024.

BCG treatment failure

BCG treatment failure can be classified into 3 groups; BCG relapse, BCG-refractory and BCG-intolerant. In BCG relapse, tumor reoccurs after a disease free period. BCG-refractory tumors are the ones which do not respond to induction and maintenance doses of BCG or which progress during therapy. In BCG-intolerant, tumor reoccurs due to incomplete treatment as the person receiving it is unable to tolerate an induction course of BCG. Around 50% of the people fail BCG treatment and would require further treatment.

People whose tumors recurred after treatment with BCG or who were unresponsive to treatment, are more difficult to treat. In such people a radical cystectomy is recommendation In people who do not show response to BCG therapy and are unfit or unwilling to undergo radical cystectomy, salvage therapies can be considered. Salvage therapy include intravesical chemotherapy with agents such as valrubicin, gemcitabine or docetaxel, chemoradiation or chemohyperthermia.

Treatment and follow-up after primary TURBT

Risk	Other considerations	Chemotherapy	Immunotherapy (BCG)	Cystoscopy (surveillance)	Imaging (surveillance)
Low				at 3-months followed by cystoscopy at 12-months, then yearly for 5-years	CT/MR urography and CT/MRI of abdomen and pelvis at baseline
Intermediate	Primary tumor with history of chemotherapy	Intravesical chemotherapy for 1 year OR Intravesical BCG for 1 year (preferred)		at 3-months with cytology followed by once every 3–6 months for 5-years and then yearly	CT/MR urography and CT/MRI of abdomen and pelvis at baseline
	Recurrent tumors with history of previous chemotherapy		Intravesical BCG for 1 year
High			Intravesical BCG for 3 year (as tolerated)	at 3-months with cytology followed by once every 3-months for 2-years after that, 6 monthly for 5 years then yearly	CT/MR urography and CT/MRI of abdomen and pelvis at baseline, CT/MR urography 1-2 yearly for 10 years
	T1G3/High grade, Lymphovascular invasion, Presence of variant histology	Consider radical cystectomy

Photodynamic Therapy

Photodynamic therapy (PDT) is a treatment option involving the administration of a photosensitizing agent, followed by the exposure of the bladder’s inner lining to a specific wavelength of light through a cystoscope. The light activation of the photosensitizer helps to destroy cancerous cells while sparing much of the surrounding healthy tissue.

PDT is particularly advantageous for patients who might be at high risk from surgery or those who prefer a less invasive option. The procedure is known for its precision and the ability to be repeated, which is important for managing the recurrent nature of NMIBC. Clinical trials and studies have shown that PDT can be effective in reducing tumor recurrence rates and is associated with a favorable safety profile, emphasizing its potential as a primary or adjuvant treatment modality.

Research continues to evaluate the long-term outcomes of PDT for bladder cancer and explore potential improvements in photosensitizers and light delivery systems to enhance the treatment’s efficacy and patient outcomes.

Muscle invasive

Surgical reconstruction (neobladder) of the bladder following removal.

Multimodal therapy (standard treatment)

Further information: Cystectomy

Untreated, non-muscle invasive tumors may gradually begin to infiltrate the muscular wall of the bladder (muscle invasive bladder cancer). Tumors that infiltrate the bladder wall require more radical surgery, where part (partial cystectomy) or all (radical cystectomy) of the bladder is removed (a cystectomy) and the urinary stream is diverted into an isolated bowel loop (called an ileal conduit or urostomy). In some cases, skilled surgeons can create a substitute bladder (a neobladder) from a segment of intestinal tissue, but this largely depends upon a person's preference, age of the person, renal function, and the site of the disease.

A bilateral pelvic lymphadenectomy should accompany radical cystectomy. At minimum, a standard template of lymphadenectomy should be followed by removing the external and internal iliac and obturator lymph node. When performing a lymphadenectomy, the surgeon can either remove lymph nodes from a smaller (standard) or from larger (extended) area. In comparison with a standard lymph node dissection, having an extended dissection may reduce a person's likelihood of death from any reason, including dying from bladder cancer. The extended procedure may lead to more serious unwanted effects and may or may not influence the likelihood of the cancer recurring over time. The rate of not-so-serious side effects may be similar for both surgeries.

Radical cystectomy has a significant morbidity associated with it. About 50-65% of the people experience complication within 90 days of surgery. Mortality rates was 7% within 90 days of surgery. High volume centers have better outcomes than low volume centers. Some centers are implementing Enhanced Recovery After Surgery (ERAS) society recommendations to decrease morbidity after radical cystectomy. However, due to lack of specific evidence in urologic surgery, ERAS protocol has not been widely incorporated in urologic clinical care.

Even after surgical removal of bladder, 50% of the people with muscle invasive disease (T2-T4) develop metastatic disease within two years due to micrometastasis. In such, neoadjuvant chemotherapy (chemotherapy before main treatment, i.e. surgery) has shown to increase overall survival at 5 years from 45% to 50% with an absolute survival benefit of 5%. Currently the two most used chemotherapy regimens for neoadjuvant chemotherapy are platinum based; methotrexate, vinblastine, doxorubicin, cisplatin (MVAC) and gemcitabine with cisplatin (GC). Other regimens include dose dense MVAC (DDMVC) and cisplatin, methotrexate and vinblastine (CMV). Although, the optimal regimen has not been established, the preferred regimen for neoadjuvant therapy is MVAC.

Role of adjuvant chemotherapy (chemotherapy after main treatment) is limited to people with high grade tumours (pT3/T4and/or N+) and who have not been treated with neoadjuvant therapy. Adjuvant radiation therapy has not shown any advantage in bladder cancer treatment.

Dosage and schedule of chemotherapy regimens for neoadjuvant and adjuvant chemotherapy

MVAC	DDMVAC	Gemcitabine + cisplatin
Methotrexate (30 mg/m2 IV) - day 1,15,22 Vinblastine (3 mg/m2 IV) - day 2, 15, 22 Doxorubicin (30 mg/m2 IV) - day 2 Cisplatin (70 mg/m2 IV) - day 2 Repeat every 4 weeks for 3 cycles	Methotrexate (30 mg/m2 IV) - day 1 Vinblastine (3 mg/m2 IV) - day 2 Doxorubicin (30 mg/m2 IV) - day 2 Cisplatin (70 mg/m2 IV) - day 2 Granulocyte colony-stimulating factor (G-CSF) (240μg/m2 SC) - day 4-10 Repeat every 2 weeks for 3–4 cycles	Gemcitabine (1,000 mg/m2 IV) - day 1,8,15 Cisplatin (70 mg/m2) - day 2 Repeat every 4 weeks for 4 cycles

Trimodal therapy (alternative treatment)

A combination of radiation and chemotherapy (chemoradiation) in conjunction with transurethral (endoscopic) bladder tumor resection can be used as an alternative in certain people. Review of available large data series on this so-called trimodality therapy has indicated similar long-term cancer specific survival rates, with improved overall quality of life as for people undergoing radical cystectomy with urinary reconstruction. However, currently no randomized control trials are available which has compared trimodal therapy with radical cystectomy. People who undergo trimodal therapy are usually highly selected and generally have T2 disease without hydronephrosis and/or carcinoma in-situ. Five year cancer specific survival and overall survival after trimodal therapy is between 50% to 82% and 36% to 74%.

In trimodal therapy, a maximal TURBT is conducted followed by chemoradiation therapy. Radiation sensitizing chemotherapy regimens consisting of cisplatin or 5-flurouracil and mitomycin C are used. Radiation therapy is via external bean radiotherapy (EBRT) with a target curative dose of 64-66 Gy. Surveillance for progression or recurrence should conducted with the aid of CT scans, cystoscopies and urine cytology. Side effects of chemoradiation include nausea, vomiting, loss of appetite, hair loss, mouth sores, diarrhea, constipation, increased risk of infections and bleeding and fatigue.

In people who fail trimodal therapy, radical cystectomy is considered if there is muscle invasive or recurrent tumors. Around 25-30% fail treatment and undergo salvage radical cystectomy. TURBT with intravesical therapy is indicated after treatment failure for non-muscle invasive disease.

Partial cystectomy

In people with solitary tumor without concurrent carcinoma in situ in an area where a clean surgical margins can be achieved, a partial cystectomy with lymphadenectomy can be considered. Management plan including partial cystectomy should be accompanied with neoadjuvant chemotherapy. In people with urachal adenocarcinoma of the bladder, a partial cystectomy with en-bloc resection of urachal ligament and umbilicus can be considered.

Metastatic disease

First line treatment

Cisplatin-containing combination chemotherapy is the standard of care for metastatic bladder care. Fitness for receiving cisplatin based chemotherapy is assessed before treatment. A person is deemed unfit if anyone of the following is true.

• Eastern Cooperative Oncology Group performance status of 2
• Creatinine clearance < 60 mL/min
• Grade ≥ 2 hearing loss
• Grade ≥ 2 neuropathy
• New York Heart Association Class III heart failure

People who are deemed fit receive platinum based regimens; methotrexate, vinblastine, doxorubicin, with cisplatin (MVAC) or gemcitabine with cisplatin (GC). Alternative regimens include paclitaxel with gemcitabine and cisplatin (PCG, triple therapy) and cisplatin, methotrexate and vinblastine (CMV). Response rate for cisplatin-based combination ranges from 39 to 65% and complete response is seen in 12-35% of the people. MVAC is better tolerated if it is combined with granulocyte colony-stimulating factor and the regimen is known as dose dense MVAC regimen (DDMVAC). This combination has shown to decease all cause mortality. MVAC regimen is aggressive. Febrile neutropenia (fever due to decrease in white blood cells) occurs in 10 to 14% and death due to toxicity in about 3-4%. Common side effects of MVAC include suppression of bone marrow, fever due to decrease in white blood cells, sepsis, mucositis, and nausea and vomiting. In contrast, the GC regimen has shown lower rates of neutropenic sepsis and grade 3/4 mucositis compared to MVAC. Efforts have been made to increase tolerance of cisplatin-based regimen by replacing it with carboplatin-based chemotherapy. However, cisplatin-based therapy is superior to carboplatin-based chemotherapy in achieving overall and complete response. Nevertheless, nearly half of the people with metastatic disease are "unfit" for cisplatin-based therapy. In such persons a combination of carboplatin and gemcitabine (GemCarbo) can be used as first line chemotherapy. In people who are not eligible for any platinum based chemotherapy and have PD-L1 expression, Atezolizumab and Pembrolizumab can be used.

People with bone metastasis should receive bisphosphonates or denosumab to prevent skeletal related events (e.g. fractures, spinal cord compression, bone pain).

Dosage and schedule of first-line chemotherapy regimens for metastatic bladder cancer in cisplatin eligible people

DDMVAC	Gemcitabine + Cisplatin
Methotrexate (30 mg/m2 IV) - day 1 Vinblastine (3 mg/m2 IV) - day 2 Doxorubicin (30 mg/m2 IV) - day 2 Cisplatin (70 mg/m2 IV) - day 2 Granulocyte colony-stimulating factor (G-CSF) (240μg/m2 SC) - day 4-10 Repeat every 2 weeks for 3–4 cycles	Gemcitabine (1,000 mg/m2 IV) - day 1,8,15 Cisplatin (70 mg/m2) - day 2 Repeat every 4 weeks for 4 cycles

Dosage and schedule of first-line chemotherapy regimens for metastatic bladder cancer in cisplatin ineligible people

Atezolizumab (in PD-L1+)	Gemcitabine + Carboplatin	Pembrolizumab (in PD-L1+)
Atezolizumab (Atezolizumab 1200 mg IV) every 3 weeks	Gemcitabine (1,000 mg/m2 IV) - day 1,8 Carboplatin (4.5 × [glomerular filtration rate + 25]) - day 1 and every 3 weeks	Pembrolizumab 200 mg every 3 weeks

Second line treatment

Bladder cancer that is refractory or shows progression after platinum-based chemotherapy can be treated with second-line chemotherapy or immunotherapy.

The most commonly used second-line chemotherapy is single-agent regimes of Taxanes (Paclitaxel, nab-paclitaxel and Docetaxel). Other single-agent regimes include Vinflunine, a third generation vinca alkaloid (approved in Europe), Gemcitabine, Pemetrexed, Oxaliplatin, and Ifosfamide. Side effects of Vinflunine include neutropenia, constipation, fatigue and anemia and has limited its use as a second line agent. Response to second-line chemotherapy occurs in 5%–20% people. Median progression free survival with second-line chemotherapy is 3–4 months.

In people with fibroblast growth factor receptors (FGFR) mutations and fail standard platinum based chemotherapy erdafitinib can be used. Erdafitinib has shown a response rate of 40% in these patients.

Five immunotherapy agents have been approved in the US for use in metastatic bladder cancer. They act by inhibiting programmed cell-death protein 1 (PD-1) or programmed cell-death ligand 1 (PD-L1). Pembrolizumab and nivolumab, and are inhibitors of programmed cell-death ligand 1 (PD-1). Avelumab, atezolizumab and durvalumab are inhibitors of PD-L1.

Pembrolizumab probably improves overall survival a little and may slightly improve quality of life for people with urothelial cancer that has worsened after initial treatment when compared with continued chemotherapy. However, pembrolizumab may have only minimal effects on the rate of death resulting from treatment or the rate at which the cancer advances. Pembrolizumab may cause less serious side effects than chemotherapy.

Dosage and schedule of second-line immunotherapy regimens for metastatic bladder cancer(in PD-L1+).

Atezolizumab	Nivolumab	Pembrolizumab	Durvalumab	Avelumab
Atezolizumab 1200 mg IV every 3 weeks	Nivolumab 3 mg/kg IV every 2 weeks	Pembrolizumab 200 mg every 3 weeks	Durvalumab 10 mg/kg every 2 weeks for 12 months	Avelumab 10 mg/kg IV every 2 weeks

Surveillance and response

Contrast enhanced CT is used to monitor lung, liver, and lymph node metastases. A bone scan is used to detect and monitor bone metastasis. Treatment response is measured using the Response evaluation criteria in solid tumors (RECIST) into one of the following groups; response (complete or partial), stable disease and progressive disease.

Prognosis

People with non-muscle invasive tumors have a favorable outcome (5-year survival is 95% vs. 69% of muscle invasive bladder cancer). However, 70% of them will have a recurrence after initial treatment with 30% of them presenting with muscle invasive disease. Recurrence and progression to a higher disease stage have a less favorable outcome.

Survival after radical cystectomy and pelvic lymph node dissection is dependent on the pathological stage. If the disease has not spread to the lymph node and is limited to the bladder (T1 or T2, N0) the 5-year survival is 78%. If it has spread locally around the region of the bladder with no lymph node involved (T3, N0) then the 5-year survival drops to 47%. In disease with lymph node spread (N+, irrespective of T stage) the 5-year survival is 31%. Locally advanced and metastatic disease drastically decreases survival, with a median survival of 3–6 months without chemotherapy. Cisplatin-based chemotherapy has increased the median survival to 15-months. However, the 5-year survival is still 15%.

There are several prognostic factors which determine cancer specific survival after radical cystectomy. Factor with detrimental effect of cancer specific survival are old age, higher tumor grade and pathological stage, lymph node metastasis, presence of lymphovascular invasion and positive soft tissue margin. Lymph node density (positive lymph nodes/total lymph nodes observed in the specimen from surgery) is a predictor of survival in lymph node positive disease. Higher the density lower is the survival.

Quality of life

After radical cystectomy, urinary and sexual function remain inferior to the general population. People who have a neobladder have better emotional function and body image compared with ones with cutaneous diversion (who need to wear a bag to collect urine over their abdomen). Social factors such as family, relationships, health and finances contribute significantly for determining good quality of life in people who have been diagnosed with bladder cancer.

A high percentage of people with bladder cancer have anxiety and depression. People who are young, single and have advanced clinical disease have a high risk for getting diagnosed with a psychiatric illness post-treatment. People with psychiatric illness post treatment seem to have worse cancer specific and overall survival.

Epidemiology

Top countries by new cases of bladder cancer per 100,000 (2018)

Rank	Country	Overall	Men	Women
1	Lebanon	25	40	9
2	Greece	21	40	4
3	Denmark	18	29	8
4	Hungary	17	27	9
5	Albania	16	27	6
5	Netherlands	16	26	8
7	Belgium	16	27	6
8	Italy	15	27	6
9	Germany	15	26	6
10	Spain	15	27	6

Age-standardized death from bladder cancer per 100,000 inhabitants in 2004.

  no data

  less than 1.5

  1.5–3

  3–4.5

  4.5–6

  6–7.5

  7.5–9

  9–10.5

  10.5–12

  12–13.5

  13.5–15

  15–16.5

  more than 16.5

Around 500,000 people are diagnosed with bladder cancer each year, and 200,000 die of the disease. This makes bladder cancer the tenth most commonly diagnosed cancer, and the thirteenth cause of cancer deaths. Bladder cancer is most common in wealthier regions of the world, where exposure to certain carcinogens is highest. It is also common in places where schistosome infection is common, such as North Africa.

Bladder cancer is much more common in men than women; around 1.1% of men and 0.27% of women develop bladder cancer. This makes bladder cancer the sixth most common cancer in men, and the seventeenth in women. When women are diagnosed with bladder cancer, they tend to have more advanced disease and consequently a poorer prognosis. This difference in outcomes is attributed to numerous factors such as, difference in carcinogen exposure, genetics, social and quality of care. One of the common signs of bladder cancer is hematuria and is quite often misdiagnosed as urinary tract infection in women, leading to a delay in diagnosis. Smoking can only partially explain this higher rates in men in western hemisphere. In Africa, men are more prone to do field work and are exposed to infection with Schistosoma, this may explain to a certain extent the gap in incidence of squamous cell cancers in areas where bladder cancer is endemic.

As with most cancers, bladder cancer is more common in older people; the average person with bladder cancer is diagnosed at age 73.

Veterinary medicine

This section is an excerpt from Bladder cancer in cats and dogs.[edit]

Bladder cancer in cats and dogs usually is transitional cell carcinoma, which arises from the epithelial cells that line the bladder. Less often, cancer of the urinary bladder is squamous cell carcinoma, adenocarcinoma, or rhabdomyosarcoma.

References

Works cited

• Ahmadi H, Duddalwar V, Daneshmand S (June 2021). "Diagnosis and Staging of Bladder Cancer". Hematol Oncol Clin North Am. 35 (3): 531–541. doi:10.1016/j.hoc.2021.02.004. PMID 33958149.
• Dyrskjøt L, Hansel DE, Efstathiou JA, Knowles MA, Galsky MD, Teoh J, Theodorescu D (October 2023). "Bladder cancer". Nat Rev Dis Primers. 9 (1): 58. doi:10.1038/s41572-023-00468-9. PMC 11218610. PMID 37884563.
• Hahn NM (2022). "Chapter 86: Cancer of the Bladder and Urinary Tract". In Loscalzo J, Fauci A, Kasper D, et al. (eds.). Harrison's Principles of Internal Medicine (21st ed.). McGraw Hill. ISBN 978-1264268504.
• Lenis AT, Lec PM, Chamie K (November 2020). "Bladder Cancer: A Review". JAMA. 324 (19): 1980–1991. doi:10.1001/jama.2020.17598. PMID 33201207.