What is cancer?
Cancer is a term used for diseases that are caused by the uncontrolled growth of abnormal cells. These abnormal cells divide without control and are able to invade other parts of the body.
Normal cells follow an orderly path of growth, division and death. However, sometimes this process goes wrong. If the genetic material of a cell has become damaged or changed, mutations affecting the life and death cycle may result. When this happens, cells do not die when they should and new cells form when the body does not need them. The extra cells can produce a mass of tissue, called a tumor (except in the case of leukemia, where cancer cells prohibit normal blood function).
There are over 200 types of cancers. Cancer can develop in almost any organ or tissue, such as lungs, kidneys, skin, bones or nerve tissue.
The kidneys are two bean shaped organs about the size of a fist located just below the ribcage, one on each side of the spine. They are responsible for flitering blood to remove excess water and waste. These elements then become urine. Urine travels from the kidneys to the bladder, where it is stored, through long slender tubes called ureters.
Kidney Cancer Facts:
Kidney cancer is not just one type of cancer, but rather many different types.
Renal Cell Carcinoma (RCC) is the most common type of kidney cancer (9 out of 10 cases). RCC usually begins as a tumor within a kidney; however, sometimes there can be more than one tumor or even tumors in both kidneys. These tumors can grow to be very large, but are usually found before they spead to other parts of the body.
Within the group of RCC, there are several subtypes based on how the cells appear under the microscope:
- Clear Cell Renal Cell Carcinoma is the most common subtype within RCC (7 out of 10). Cells of this type appear clear or pale under the microscope.
- Papillary Renal Cell Carcinoma is the second most common, making up 10%. This type produces "finger like" projections on the tumor.
- Chromophobe Renal Cell Carcinoma makes up around 5% of RCC cases. Cells of this type are also clear, but are much larger with other distinguishing features.
- Collecting Duct Renal Cell Carcinoma is very rare. These cells can form irregular tubes.
- Unclassified Renal Cell Carcinoma cases are uncommon, but happen when the cell type doesn't fit any other category or there is more than one type present.
Additional types of kidney cancer include:
Wilms tumors are almost always found in children.
Transitional cell carcinomas don't start in the kidney itself, but instead begin in the renal pelvis (where the urine goes before it enters the ureter).
Renal sarcomas are a rare type of kidney cancer that begin in the blood vessels or connective tissue of the kidney.