Scientists do not know exactly what causes most adrenal cortical tumors. Over the past few years, they have made great progress in understanding how certain changes in a person's DNA can cause cells in the adrenal to become cancerous. DNA is the molecule that carries the instructions for nearly everything our cells do. We usually look like our parents because they are the source of our DNA. However, DNA affects more than our outward appearance. It also determines our risk for developing certain diseases, including some types of cancer.

Some genes (parts of our DNA) contain instructions for controlling when our cells grow and divide. Some genes that promote cell division are called oncogenes. Other genes that slow down cancer cell division or cause them to die are called tumor suppressor genes. We know that cancers can be caused by DNA mutations (changes) that turn on oncogenes or turn off tumor suppressor genes. Some people with cancer have DNA mutations they inherited from a parent, which increase their risk for developing the disease. But most DNA mutations that are seen in cancers happen during life rather than having been inherited. These mutations may result from exposure to radiation or carcinogens (cancer-causing chemicals). Most of these mutations, however, happen for no apparent reason.

The DNA mutations that cause tumors in people with the genetic syndromes discussed in the previous section have been identified. Defects in the gene that causes MEN-1 are responsible for most hereditary adrenal tumors.

The Li-Fraumeni syndrome is caused by inherited mutations that inactivate the p53 tumor suppressor gene. Only a small minority of adrenal cortical cancers are due to this syndrome. Many other adrenal cortical cancers have also been found to have abnormal p53 genes that were acquired after birth (not inherited).

Last Medical Review: 03/20/2009
Last Revised: 03/20/2009