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. 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. 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.

Bladder cancer characteristically causes blood in the urine, which may be visible or detectable only by microscope. Blood in the urine is the most common symptom in bladder cancer, and is painless. Visible blood in the urine may be of only short duration, and a urine test may be required to confirm non visible blood. Between 80–90% of people with bladder cancer initially presented with visible blood. Blood in the urine may also be caused by other conditions, such as bladder or ureteric stones, infection, kidney disease, kidney cancers or vascular malformations, though these conditions (except kidney cancers) would typically be painful.

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.

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.

If invasive or high grade (includes carcinoma in situ) cancer is detected on TURBT, an MRI and/or CT scan of the abdomen and pelvis or urogram and CT chest or x-ray chest should be conducted for disease staging and to look for cancer spread (metastasis). Increase in alkaline phosphatase levels without evidence of liver disease should be evaluated for bone metastasis by a bone scan. Although ^{18F-fluorodeoxyglucose} (FDG)-positron emission tomography (PET)/CT has been explored as a viable method for staging, there is no consensus to support its role in routine clinical evaluations.

Regards
Amalia
Managing Editor
Journal of Clinical Oncology and Cancer Research.