Bladder cancer typically refers to cancer that starts in the urothelial cells that line the bladder. The bladder is a hollow muscular organ in your lower abdomen that stores urine.
It is the most common type of cancer in the urinary tract. The predominant type of bladder cancer is transitional cell carcinoma (TCC). While not as common, TCC can also occur in the kidneys, pelvis, ureters or urethra as these structures are also lined by the same urothelial cells that line the bladder.
There are other types of bladder cancers that are rare:
- Squamous cells carcinoma
- Small cell carcinoma
This article will be focusing on TCC.
Bladder cancer is classified into non-muscle-invasive and muscle-invasive types based on the depth of invasion from the innermost lining towards the outer layers of the bladder. Approximately 70% of newly diagnosed urothelial bladder cancers are classified as non-muscle invasive.