As there are multiple organs that make up the genitourinary system, the genitourinary cancers are a broad category for the cancers that can arise in any of these organs. They arise as a result of uncontrolled growth and proliferation of the cells that are found in any of these organs.
The types of cancers that arise in the genitourinary system are categorised based on the organ and the cell type from where it begins.
Renal cancer (cancer of the kidney)
In Singapore, renal cancers account for 1 to 2 percent of all cancers. Cancers of the kidney are classified based on the cell type they arise from, as well as their appearance under the microscope. The main cell type of the kidney are the renal cells. Renal cell carcinomas are the most common type of cancers that arise out of the kidney. Also known as renal cell adenocarcinoma, about 9 of 10 renal cancers are of this type. Cancers of the kidney include:
- Renal cell carcinoma (RCC)
- Clear cell renal cell carcinoma – most common, 70 percent of patients with RCC have this subtype
- Non-clear cell renal cell carcinoma
- Papillary renal cell carcinoma – second most common subtype of RCC, makes up 10 percent of RCC
- Chromophobe renal cell carcinoma – makes up about 5 percent of RCCs
- Transitional cell carcinoma – accounts for about 5 percent of renal cancers. It is also known as urothelial carcinomas, and originates not from the kidney, but the lining of the renal pelvis. The renal pelvis is where the ureters meet the kidney, and the cells lining this area are known as transitional cells. They look less like renal cells, and instead more like the cells of the ureter and bladder.
- Wilm’s tumour – also known as nephroblastoma, these tumours arise in children and rarely in adults.
- Renal sarcoma – a rare type of cancer of the kidney, sarcomas arise from the blood vessels and connective tissue of the kidney.
In Singapore, bladder cancer is one of the ten most common cancers among males. In its early stages, it can often be cured. Although most common in the bladder, bladder cancer can also occur in other parts of the urinary tract. Cancers of the bladder include:
- Urothelial carcinoma (transitional cell carcinoma) – the most common type of bladder cancer, arising from the urothelial cells which line the urinary tract. Also can be found in the renal pelvis of the kidney
- Squamous cell carcinoma – much less common than urothelial carcinoma. Microscopically the cells of this cancer look like the flat cells found on the surface of the skin
- Adenocarcinoma – less common, accounting for about 1 percent of bladder cancers. These cancers arise from gland-forming cells
- Small cell carcinoma – less common, accounting for about 1 percent of bladder cancers. This cancer begins in the neuroendocrine cells of the bladder (nerve-like cells)
- Sarcoma – very rare.These cancers begin in the muscle cells of the bladder
These above lists contain just a few examples of the different cancers that can develop in the organs of the genitourinary system (see also: prostate and gynaecological cancers). The different types of cancer have different prognoses and outlooks, as well as treatment plans.