Bladder cancer refers to any malignant growth that originates in the bladder. The cancer begins in the cells lining the inside of the bladder, known as urothelial cells. The cancer cells can proliferate, forming a tumour and possibly spreading to other parts of the body.
Types of Bladder Cancer
Bladder cancer is typically classified into several types, largely dependent on the cells in which it originates. Each type demonstrates unique characteristics, affecting the treatment approach and overall prognosis.
- Transitional Cell Carcinoma (Urothelial Carcinoma): Transitional Cell Carcinoma is the most common type, making up about 90% of all bladder cancers. It starts in the urothelial cells, the innermost lining of the bladder. These cells can stretch when the bladder is full and shrink when it is emptied. This cancer can be non-muscle invasive, where it’s limited to the inner layer of the bladder, or muscle-invasive, where it has spread to the bladder’s muscular wall.
- Squamous Cell Carcinoma: Squamous cells are flat, thin cells that can form in the bladder as a response to long-term infection or irritation, accounting for about 1-2% of all bladder cancers. Squamous cell carcinoma arises when these cells become malignant over time due to prolonged infection or irritation. This form of bladder cancer is more common in regions where parasitic infections in the bladder are common. These infections can lead to chronic bladder inflammation, promoting squamous cell transformation and eventually, carcinoma.
- Adenocarcinoma: Adenocarcinoma is a rare type of bladder cancer, contributing to less than 1% of all cases. It originates in the glandular (secretory) cells located in the bladder lining, which produce and release mucus. This type of cancer may develop from prolonged inflammation and irritation, or from a congenital condition known as exstrophy that affects bladder development. Adenocarcinoma of the bladder often presents a challenge in treatment, owing to its typical discovery at advanced stages.
Understanding the different types of bladder cancer impacts both treatment options and outcomes. A urologist will be able to provide guidance based on the specific type and stage of bladder cancer diagnosed.
Get an Accurate Diagnosis & Proper Treatment
for Your Condition
Non-Muscle Invasive and Muscle Invasive Bladder Cancers
Bladder cancer can be broadly categorised into two main types: Muscle Invasive Bladder Cancer (MIBC) and Non-Muscle Invasive Bladder Cancer (NMIBC). Each type has distinct characteristics, treatment approaches, and prognostic factors.
Muscle Invasive Bladder Cancer (MIBC)
MIBC is a type of bladder cancer where the abnormal cells have infiltrated the muscle layer of the bladder. MIBC is more aggressive and has a higher potential to spread to other parts of the body compared to NMIBC.
Key points about MIBC:
Subtypes of MIBC: The most common subtype of MIBC is urothelial carcinoma, which arises from the transitional cells lining the bladder. Other less common subtypes include squamous cell carcinoma and adenocarcinoma.
Diagnosis and Staging of MIBC: The diagnosis of MIBC involves various tests and procedures. Imaging tests, such as CT scans and MRIs, help evaluate the extent of tumour infiltration. A biopsy of the bladder tissue confirms the presence of cancer cells. Staging systems, such as the TNM classification, are used to determine the stage of MIBC and guide treatment decisions.
Non-Muscle Invasive Bladder Cancer (NMIBC)
NMIBC is a type of bladder cancer where the abnormal cells are confined to the innermost lining of the bladder and have not invaded the muscle layer. NMIBC is considered less aggressive and has a lower risk of spreading beyond the bladder.
Key points about NMIBC:
Subtypes of NMIBC: NMIBC includes several subtypes, the most common of which are papillary tumours and carcinoma in situ (CIS). Papillary tumours grow as projections from the bladder lining, while CIS refers to the presence of flat, high-grade cancer cells.
Diagnosis and Staging of NMIBC: The diagnosis of NMIBC involves various diagnostic procedures, such as urine tests (cytology, NMP22, FISH) to detect abnormal cells shed in the urine. Cystoscopy, a procedure where a thin tube with a camera is inserted into the bladder, allows visual examination of the bladder lining. Biopsy samples may be taken during cystoscopy to confirm the presence of cancer cells. Staging systems, such as the TNM classification, help determine the stage and extent of NMIBC.
Conclusion
Increasing awareness and knowledge about these distinct types of bladder cancer can help individuals make informed decisions regarding prevention, early detection, and appropriate treatment strategies.
