What is Muscle-Invasive Bladder Cancer?

Muscle-Invasive Bladder Cancer (MIBC) is a type of bladder cancer where the tumor grows into the muscle layer of the bladder wall (the detrusor muscle). This is a more aggressive form of bladder cancer compared to non-muscle invasive types and typically requires more intensive treatment.

Causes and Risk Factors

Several factors can increase the risk of developing MIBC, including:

• Tobacco smoking: The most significant risk factor.
• Occupational exposures: Contact with chemicals such as aromatic amines in industries like dye, rubber, leather.
• Chronic bladder inflammation: From infections or long-term catheter use.
• Age and gender: More common in older adults and men.
• Previous bladder cancer history: Progression from non-muscle invasive disease.

Symptoms

MIBC symptoms can be similar to other types of bladder cancer and include:

• Visible blood in urine (hematuria)
• Painful or frequent urination
• Lower back or pelvic pain
• Urinary urgency or difficulty

Diagnosis

Diagnosis typically involves:

• Cystoscopy: Visual examination of the bladder using a scope.
• Biopsy and TURBT: Transurethral resection of bladder tumor to obtain tissue samples.
• Imaging: CT or MRI scans to assess tumor extent and lymph node involvement.
• Urine cytology: Checking for cancer cells in urine.

Treatment Options

Treatment for MIBC is more aggressive than for non-muscle invasive cancer and may include:

• Radical cystectomy: Surgical removal of the bladder and nearby lymph nodes.
• Neoadjuvant chemotherapy: Chemotherapy given before surgery to shrink tumors and improve outcomes.
• Radiation therapy: Sometimes used with chemotherapy for bladder preservation in select patients.
• Immunotherapy: Checkpoint inhibitors for advanced or metastatic disease.
• Urinary diversion: Creating an alternative way for urine to leave the body post bladder removal.

Prognosis

The prognosis depends on the stage and grade of the tumor at diagnosis and response to treatment. Early diagnosis and multimodal treatment improve survival rates.