Squamous cell bladder cancer (SCC) represents a less frequently encountered form of bladder malignancy. This type of cancer originates from the thin, flat squamous cells that can line the bladder, differing from the more prevalent urothelial carcinoma, which arises from transitional cells. While urothelial carcinoma accounts for the vast majority of bladder cancer cases, SCC typically constitutes a smaller percentage, ranging from about 1% to 7% of diagnoses in Western countries.
Causes and Associated Risk Factors
Squamous cell bladder cancer is linked to chronic irritation and inflammation within the bladder lining. Prolonged exposure to inflammatory conditions can cause the bladder’s normal transitional cells to undergo a change, transforming into flat, scale-like squamous cells, a process known as squamous metaplasia. Over time, these altered cells can become cancerous, especially with continued irritation. Common factors include recurrent urinary tract infections (UTIs) and long-term indwelling urinary catheters. Bladder stones, causing persistent friction and inflammation, are also a risk factor for SCC.
Globally, a significant cause of SCC, particularly in certain regions like parts of Africa, is infection with Schistosoma haematobium, a parasitic flatworm that causes schistosomiasis (also known as bilharzia). This parasitic infection leads to severe chronic bladder inflammation, increasing the risk of SCC.
Recognizing the Symptoms
Signs of squamous cell bladder cancer involve changes in urinary patterns and urine appearance. A common indicator is hematuria, or blood in the urine, which may be visible (red or cola-colored) or detectable only through lab tests. Hematuria often prompts medical attention.
Individuals may also experience dysuria, characterized by pain or a burning sensation during urination. An increased need to urinate, along with a sense of urgency, can also be present. Some people report feeling a persistent urge to urinate without being able to pass much urine. As the disease progresses, individuals may develop pelvic pain or pain in the lower back or flank area. These symptoms are not exclusive to SCC and can be associated with other urinary conditions, necessitating a thorough medical evaluation.
The Diagnostic Process
Diagnosing squamous cell bladder cancer involves procedures to visualize the bladder, obtain tissue samples, and determine cancer extent. Cystoscopy is a primary diagnostic tool, using a thin, lighted tube (cystoscope) inserted through the urethra into the bladder. This allows direct examination of the bladder lining for abnormal areas like tumors. Fluid fills the bladder during cystoscopy for a clearer view.
If suspicious areas are identified during cystoscopy, a biopsy is performed, often via transurethral resection of bladder tumor (TURBT). The tissue is sent to a pathology laboratory for microscopic examination to confirm cancer cells and identify them as squamous cell carcinoma. This confirmation is important for accurate diagnosis and to differentiate SCC from other bladder cancer types.
Following biopsy, imaging tests assess cancer stage, indicating growth into the bladder wall or spread. Computed tomography (CT) scans of the abdomen and pelvis, magnetic resonance imaging (MRI), or ultrasounds visualize the bladder, surrounding tissues, and distant organs. These imaging modalities help determine the depth of tumor invasion into the bladder muscle and detect spread to lymph nodes or other distant sites, aiding treatment planning.
Treatment Modalities
Treatment for squamous cell bladder cancer is complex, tailored to the individual’s cancer stage and overall health. Surgery is often a primary treatment due to SCC’s invasive nature at diagnosis. Radical cystectomy, the complete removal of the bladder, is common for muscle-invasive SCC. After cystectomy, urinary diversion procedures create a new way for urine to exit, such as an ileal conduit or a neobladder.
Chemotherapy may be part of the treatment plan for SCC, though its effectiveness can differ from urothelial carcinoma. It can be administered before surgery (neoadjuvant) to shrink the tumor, or after surgery (adjuvant) to eliminate remaining cancer cells. The specific chemotherapy regimen depends on the individual case.
Radiation therapy is another option, sometimes used as a primary treatment if surgery is not feasible, or in combination with other therapies. Preoperative radiation before cystectomy may protect against pelvic recurrence, a common cause of death in SCC. Post-operative radiation may also be recommended for positive surgical margins or advanced disease.
Prognosis and Outlook
The outlook for squamous cell bladder cancer patients is largely influenced by the stage at diagnosis. Because SCC is often diagnosed after invading the bladder muscle or spreading, the prognosis can be more serious than other bladder cancers detected earlier.
Tumor growth depth into the bladder wall and spread to lymph nodes or distant sites significantly affect survival. Local pelvic recurrence is a common cause of mortality after initial SCC treatment.
Early detection and appropriate management are important for improving outcomes. While statistics vary, reported 5-year survival rates for SCC range from approximately 28% to 50%, reflecting challenges with its advanced presentation.