Bladder Cancer
Bladder cancer accounts for approximately 90% of cancers of the urinary tract (renal pelvis, ureters, bladder, and urethra). Bladder cancer usually originates in the bladder lining, which consists of a mucous layer of surface cells that expand and deflate, smooth muscle, and a fibrous layer. Tumors are categorized as low-stage (superficial) or high-stage (muscle invasive).
Bladder cancer is two to three times more common in men and the incidence of bladder cancer increases with age. People over the age of 70 develop the disease two to three times more often than those aged 55-69 and 15 go 20 times more often than those aged 30-54.
*Information provided by Urology Channel.
What is Bladder Cancer?
- Bladder cancer originates in the tissues of the bladder, most commonly in the urothelial cells lining the bladder wall.
- The most common type is Urothelial carcinoma (transitional cell carcinoma) – 90% of cases in developed countries.
Other types:
- Squamous cell carcinoma, adenocarcinoma, small cell carcinoma (very rare).
What are the risk factors of Bladder Cancer?
- Smoking is the most significant modifiable risk factor.
- Occupational exposure to aromatic amines (dyes, rubber, textiles)
- Chronic bladder inflammation/infections (Schistosomiasis – associated with squamous cell carcinoma)
- Age > 55 years
- Male sex (3-4x more common than in females)
- Prior radiation therapy or chemotherapy (cyclophosphamide)
Clinical Features:
- Painless gross hematuria (most common presenting symptom)
- Dysuria, urgency, frequency (less common; seen in carcinoma in situ)
- Recurrent urinary tract infections
- Flank pain (if obstruction occurs)
Diagnosis:
- Urinalysis and urine cytology
- Cytoscopy with biopsy (gold standard)
- Imaging: CT urogram, MRI, or ultrasound to assess local invasion and metastases
Staging (TNM System):
Tis: Carcinoma in situ (non-invasive flat tumor)
Ta: Non-invasive papillary tumor
T1: Invades subepithelial connective tissue
T2: Invades muscularis propria
T3: Invades perivesical tissue
T4: Invades surrounding organs (e.g., prostate uterus)
Management:
- Non-muscle-invasive (Ta, T1, Tis):
- Transurethral resection of bladder tumor (TURBT)
- Intravesical therapy (e.g., BCG immunotherapy or mitomycin C)
Muscle-invasive:
- Radical cystectomy with urinary diversion
- Neoadjuvant chemotherapy often recommended
- Bladder-sparing: TURBT + chemo-radiation (in selected cases)
Metastatic disease:
- Systematic chemotherapy (e.g., cisplatin-based)
- Immunotherapy (e.g, checkpoint inhibitors – atezolizumab, pembrolizumab)
Prognosis:
- Depends on stage, grade, and response to treatment
- Non-muscle-invasive: good prognosis but high recurrence rate.
- Muscle-invasive: worse prognosis; 5-year survival ~ 50%