Introduction to bladder cancer

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Introduction to bladder cancer

Introduction to bladder cancer

Introduction to bladder cancer

The bladder is an organ in the pelvis that stores urine before it leaves the body during urination. The other parts of the urinary tract are the kidneys, ureters, and urethra. The ureter is a tube that runs from each kidney into the bladder. The urethra is the tube that carries urine out of the body. In men, the prostate gland is also considered part of the urinary tract.

The bladder is lined with a layer of cells called the urothelium. Underneath this layer is a thin fibrous layer called lamina propria and then there is the muscle layer of the bladder.

Urinary bladder cancer (BCa) is one of the most common urological malignancies. It accounts for around 4 % of all cancer cases in men. The risk of this cancer increases with use of tobacco and exposure to certain industrial chemical. 

About bladder cancer

Bladder cancers start in the urothelium. Urothelium also forms the lining of the ureter and pelvis of the kidney. Cancer in the urothelium can start in the bladder, ureter or pelvis and are treated in the same way. Cancer has a natural tendency to spread away from where it starts.

Types of bladder cancer

There are three main types of bladder cancers.

  • Urothelial carcinoma. This is the most common type of bladder cancer. 90% of bladder cancer and 10% of kidney cancers are urothelial cancers. It begins in the urothelial cells found in the urinary tract. Urothelial carcinoma is sometimes also called transitional cell carcinoma or TCC.
  • Squamous cell carcinoma. Some times due to chronic irritation of bladder from stones can lead to change in lining of bladder to squamous cells and they can cause squamous cancer. About 4% of bladder cancer is squamous type
  • Adenocarcinoma. This type accounts for about 2% of all bladder cancers and develops from glandular cells.

Other rare type of bladder cancer includes  sarcoma of the bladder and small cell bladder cancer. Small cell bladder cancer is a rare type of bladder cancer that is likely to spread to other parts of the body.

Bladder cancer can spread deep into the bladder wall and can be -

  • Noninvasive – carcinoma in situ and papillary carcinoma of the bladder are very superficial and they only involve the urothelium
  • Non-muscle-invasive. Non-muscle-invasive bladder cancer typically has only grown into the lamina propria and not into muscle, also called stage I. Non-muscle-invasive cancer.
  • Muscle-invasive. Muscle-invasive bladder cancer has grown into the bladder's wall muscle and sometimes into the fatty layers or surrounding tissue outside the bladder.

If a bladder tumor has spread into the surrounding organs, like the uterus and vagina in women, the prostate in men, and/or nearby muscles, it is called locally advanced disease. Bladder cancer also often spreads to the lymph nodes in the pelvis. If it has spread into the liver, bones, lungs, lymph nodes outside the pelvis or other parts of the body, the cancer is called metastatic disease.

Dr. Rakesh Rai. MS, FRCS, MD, CCT, ASTS fellow (USA).