Bladder Cancer: Types, Staging and Management

Bladder cancer is a broad term used to describe all types of cancers affecting the urinary bladder. It includes several distinct types, each with unique characteristics, risk factors, and treatment approaches. Below, we provide a comprehensive overview of bladder cancer based on the latest medical knowledge.

Types of Bladder Cancer

1. Transitional Cell Carcinoma (TCC):
   • Also called urothelial cell carcinoma (UCC), TCC is the most common primary neoplasm of the bladder and the entire urinary system.
   • It can be superficial (70-80% of cases) or invasive (20-30%). Superficial tumors are often papillary, while invasive tumors may spread into deeper layers of the bladder wall.
2. Squamous Cell Carcinoma (SCC):
   • Accounts for 3-8% of bladder cancers.
   • More common in regions where schistosomiasis infections are prevalent.
   • Often associated with chronic irritation, such as from bladder stones or indwelling catheters.
3. Adenocarcinoma:
   • Rare, accounting for about 1% of bladder cancers.
   • Often linked to chronic irritation, bladder exstrophy, or persistent urachal remnants.
4. Small Cell Carcinoma:
   • Extremely rare, with a poor prognosis.
   • Often diagnosed at an advanced stage.

Staging and Diagnosis of bladde cancer

The Vesical Imaging-Reporting and Data System (VI-RADS) was introduced in 2018 to standardize bladder cancer staging using multiparametric MRI. It assigns a score from 1 to 5 based on imaging findings:

• VI-RADS 1: Muscle invasion is highly unlikely.
• VI-RADS 2: Muscle invasion is unlikely.
• VI-RADS 3: Muscle invasion is equivocal.
• VI-RADS 4: Muscle invasion is likely.
• VI-RADS 5: Invasion of muscle and beyond the bladder is very likely.

Diagnostic Tools:

• Cystoscopy and Biopsy: Primary methods for diagnosis and local tumor staging.
• Imaging:
  • CT: Useful for assessing tumor size, nodal status, and distant metastases.
  • MRI: Superior for local staging, especially in distinguishing T1 from T2 tumors.
  • Ultrasound: Limited role in diagnosis or staging.
  • PET: Not suitable for primary diagnosis due to urinary excretion of FDG but useful for evaluating metastases.

Clinical Presentation of bladder cancer

• Hematuria (blood in the urine) is the most common symptom, which may be macroscopic or microscopic.
• Tumors near the vesicoureteric junction may cause ureteral obstruction and hydronephrosis, presenting as flank pain.
• Tumors near the urethral orifice may lead to bladder outlet obstruction and urinary retention.
• Systemic symptoms of metastatic disease may also be present in advanced cases.

Pathology and Risk Factors of bladder cancer

• Pathology of bladder cancer:
  • Superficial TCCs are often papillary, while invasive TCCs may involve deeper layers of the bladder wall.
  • SCC and adenocarcinoma are often associated with chronic irritation or infection.
• Risk Factors:
  • Smoking (aromatic amines in tobacco smoke).
  • Exposure to industrial chemicals (e.g., arylamines, polycyclic aromatic hydrocarbons).
  • Chronic bladder irritation (e.g., from stones, catheters, or infections).
  • Chemotherapy agents like cyclophosphamide.

Radiographic Features of bladder cancer

• CT:
  • Bladder TCCs appear as focal wall thickening or masses protruding into the lumen.
  • Calcifications may be present.
  • CT can distinguish T3b (stranding/nodules in perivesical fat) and T4 tumors (invasion of adjacent structures).
• MRI:
  • T1: Isointense to muscle.
  • T2: Slightly hyperintense to muscle; useful for assessing muscle layer integrity.
  • T1 C+ (Gd): Shows enhancement.
• Urography:
  • Useful for assessing the entire urinary tract for synchronous tumors.

Treatment and Prognosis of bladder cancer

• Superficial Tumors:
  • Treated with transurethral resection (TURBT) and intravesical therapy (e.g., BCG or mitomycin C).
  • High recurrence rate (70% within 3 years), but excellent prognosis with a 5-year survival rate of 94%.
• Invasive Tumors:
  • Require radical cystectomy, often combined with chemotherapy or radiotherapy.
  • Prognosis is poorer, with a 5-year survival rate of 6% for metastatic disease.
• Recurrence:
  • 2-4% of patients with bladder TCC may develop TCCs in the renal pelvis or ureter.

Differential Diagnosis of bladder cancer

• Other bladder tumors (e.g., squamous cell carcinoma, adenocarcinoma).
• Benign prostatic hypertrophy or prostate cancer.
• Ureteric jets (may simulate a filling defect).
• Cystitis glandularis.

Specifics of Rare Bladder Cancers

1. Squamous Cell Carcinoma (SCC):
   • Often solitary and large at diagnosis, with muscular wall invasion common.
   • Associated with schistosomiasis, chronic irritation, or infection.
2. Adenocarcinoma:
   • Subclassified as primary (non-urachal or urachal) or secondary (metastatic).
   • Urachal adenocarcinoma is characterized by a midline, infraumbilical mass with peripheral calcification.
3. Small Cell Carcinoma:
   • Rare, with a poor prognosis (<10% 5-year survival for localized disease).
   • Imaging findings overlap with TCC.

Conclusion

Bladder cancer is a diverse group of malignancies with varying presentations, risk factors, and treatment options. Accurate diagnosis and staging, particularly using the VI-RADS system, are critical for effective management. If you or a loved one is experiencing symptoms or has been diagnosed with bladder cancer, consult a specialist to discuss the best treatment plan tailored to your specific condition.