Bladder Cancer

Basics

Description

  • Primary malignant neoplasms arising in the urinary bladder
  • There are three types that begin in cells in the lining of the bladder: transitional cell carcinoma, squamous cell carcinoma, and adenocarcinoma.
  • Most common type is transitional cell carcinoma (90%) (1).
  • The spectrum of bladder cancer includes nonmuscle invasive, muscle invasive, and metastatic disease.
  • Rhabdomyosarcoma of the bladder may occur in children.

Epidemiology

Incidence

  • Increases with age (median age at diagnosis is 73 years) (2)
  • More common in Caucasians than in Asians or African Americans
  • Male > female (4:1); but in smokers, risk is 1:1.
  • 34.2/100,000 men per year (2)
  • 8.5/100,000 women per year
  • 19.7/100,000 men and women per year (2)

Prevalence
In 2018, 723,745 cases in the United States (2)

Etiology and Pathophysiology

Unknown, other than related to risk factors:

  • 75% is nonmuscle invasive (in lamina propria or mucosa) (3):
    • Usually highly differentiated with long survival
    • Initial event seems to be the activation of an oncogene on chromosome 9 in superficial cancers (1).
  • 25% of tumors are muscle invasive (deeper than lamina propria) at presentation (3):
    • Tend to be high grade with worse prognosis
    • Associated with other chromosome deletions

Genetics
Genetic effects may play a direct role in the initiation and progression of bladder cancer. Most studies showed a small increase in risk in relatives of those with bladder cancer. Patients with Lynch syndrome has up to 20% lifetime risk of developing bladder cancer.

Risk Factors

  • Smoking is the single greatest risk factor (increases risk 4-fold) and increases risk equally for men and women (4).
  • There is a slight but significant increased risk with the use of pioglitazone, possibly in a dose- and time-dependent manner; may also be present with other thiazolidinediones (5)
  • Other risk factors (4):
    • Positive family history, especially in relatives diagnosed before age 60 years
    • Occupational carcinogens in dye, rubber, paint, plastics, metal, carbon black dust, petroleum, and automotive exhaust
    • Schistosomiasis in Mediterranean (squamous cell) cancer
    • Arsenic in well water
    • History of bladder radiation, pelvic irradiation, or certain anticancer drugs like cyclophosphamide or ifosfamide
    • Chronic lower UTI
    • Chronic indwelling urinary catheter
    • Cyclophosphamide exposure
ALERT
Any smoker who presents with microscopic or gross hematuria or irritative voiding symptoms such as urgency and frequency not clearly due to UTI should be evaluated by cystoscopy for the presence of a bladder neoplasm.

General Prevention

  • Avoid smoking and other risk factors.
  • Counseling of individuals with occupational exposure
  • The U.S. Preventive Services Task Force has concluded that there is insufficient evidence to determine the balance between risk and harm of screening for bladder cancer.

Commonly Associated Conditions

Smoking

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