Bladder Cancer

Bladder cancer is a malignant tumor that arises in the bladder. About 90% of cases are urothelial carcinoma (also called transitional cell carcinoma), which develops from the cells lining the inside of the bladder. Less common types include squamous cell carcinoma, adenocarcinoma, and sarcoma.

Bladder cancer is classified into three major categories:

• Non–muscle-invasive bladder cancer (NMIBC, superficial) – confined to the inner lining or just beneath it
• Muscle-invasive bladder cancer (MIBC) – extends into the bladder muscle layer
• Metastatic bladder cancer – spreads to distant organs

The disease is most common in people in their 60s and 70s, and men are 3–4 times more likely than women to develop it.

Hematuria (blood in the urine)

• the most common symptom is painless hematuria. blood may be visible to the eye or detectable only under a microscope. It can appear intermittently and may be mild or, in severe cases, include blood clots. Importantly, the severity of hematuria does not always reflect the stage of cancer.

Urinary symptoms

• Frequent urination, urgency, and painful urination may occur. These are also common in urinary tract infections (UTIs), so persistent or recurrent symptoms should raise suspicion for bladder cancer.

Advanced disease symptoms

• When the cancer progresses, symptoms depend on the site of spread. Weight loss and pain are common. Bone metastasis may cause bone pain, while obstruction of the urinary tract (hydronephrosis) may result in flank pain.

Several factors are linked to the development and progression of bladder cancer:

Occupational exposures

• Workers in industries involving rubber, petrochemicals, leather, dyes, paints, printing, and road construction have higher risk.

Smoking

• The leading risk factor. Smokers are about three times more likely to develop bladder cancer; 25–60% of patients with bladder cancer are smokers.

Age

• Rare under age 40; about 90% of cases occur in people over 55.

Chronic bladder conditions

• Long-term catheter use, bladder stones, or chronic infections increase risk. Infection with the parasite Schistosoma haematobium is also associated.

Prior cancer treatment

• Certain chemotherapy drugs (e.g., cyclophosphamide) and pelvic radiation therapy increase risk.