What is Kidney Cancer?

What are cancer cells?
Cancer cells are abnormal versions of healthy cells. In some ways they grow like normal cells but do so at abnormal rates with irregular shapes.
Kidney Cancer
  Kidney Cancer is a disease where cells in the tissues of the kidney start to grow uncontrollably and form tumors. Renal cell carcinoma (RCC) occurs in the epithelial cell (the cells lining the kidneys) and is the most common type of kidney cancer.
How do they grow and spread?
A single RCC cell grows and divides to form 2 cells. Theses 2 cells then form 4 cells and continue to repeat the process over and over. Unlike the healthy cells, these cancer cells do NOT respond to the body telling them to stop multiplying. A tumor is formed and can be detected when enough cancer cells are made. Some cancer cells may enter the bloodstream, causing it to spread to other parts of the body. When new tumors appear in other areas or organs, it is called metastatic. In other words, it has spread to other regions of the body. No matter where the cancer spreads it is still called Kidney cancer.
How do Epithelial cells differ from other cells?
  • Capillaries do not reside within epithelial cell tissues.
  • Endings of neurons are present within epithelial cell tissues.
  • Perceive external stimulus.
  • Slough off and glide in order to replace dead cells. This function allows epithelial cells to maintain a closed barrier to the external environment.
Renal Cell Carcinoma starts in the Epithelial cells
Epithelium (Epithelial tissue shown here) is a type of tissue of which many glands are formed. Functions of epithelial cells include secretion, absorption, transcellular transport, sensation detection and selective permeability. In the adult kidney epithelial cells from the cortical collecting duct are differentiated in two ways:principal cells are involved in water, sodium, and potassium transport and intercalated cells mediate acid base transport. The principal characteristics associated with epithelial cells are to defend the underlying cellular elements from harmful x-rays, different toxic compounds or potential physical injury. Other functions include intracellular transport, secretion of certain enzymes, and hormone release into vascular system.
Common Among Cancers
Also known as renal cell cancer (RCC) is the most common type of kidney cancer. About 9 out of 10 kidney cancers are renal cell carcinomas. Although RCC usually grows as a single mass (tumor) sometimes there 2 or more.
Main Types of Renal Cell Carcinomas
Clear Cell

Clear Cell

  • Clear cell RCCs are the most common, accounting for 75 – 85% of these tumors. The cells within the tumor are mostly clear.
  • Papillary cell RCCs are the second most common type, accounting for 10 – 15%. Papillary cells are distinguished by small rounded protuberances on the surface.
  • Chromophobe cell RCCs are the third common form, accounting for 3 – 5%. These cells do not take colored stain very easily.
  • Wilms’ tumor is a rapidly developing cancer found in children.
Papillary Cell

Papillary Cell

Do We Know the Cause?
Many risk factors may increase the chance of developing kidney cancer, however, it is not known exactly what causes kidney cells to become cancerous.
Changes (mutations) in genes
Researchers are beginning to understand how certain changes in DNA can cause normal kidney cells to become cancerous.  However, we must fund research for the scientists to move forward.