TCGA's Study of Adrenocortical Carcinoma
What is adrenocortical carcinoma?
Adrenocortical carcinoma is a rare cancer that develops in the outer layer of tissue of the adrenal glands, organs that lie on top of each kidney. This outer layer known as the adrenal cortex produces important hormones called steroids that help the body deal with stress, regulate blood pressure and the amount of salt in the blood, as well as cause the body to acquire masculine or feminine characteristics.1 A tumor of the adrenal cortex can produce either no hormones or excess hormones.
In the United States, an estimated 300 people are diagnosed with adrenocortical carcinoma each year.1 If detected at an early stage, this type of cancer can often be successfully treated. However, almost 70% of people are diagnosed with advanced adrenocortical carcinoma.2 For patients at the latest stage of this cancer, less than 20% survive five years after diagnosis. Additional information on adrenocortical carcinoma.
What have TCGA researchers learned about adrenocortical carcinoma?
- Chromosome copy number changes, wherein a cell has gained or lost sets of chromosomes, is a probable driver of adrenocortical carcinoma:
- Whole genome doubling occurred in 51% of adrenocortical carcinoma tumors studied.
- Hypoploidy, or the loss of a significant amount of the genome, was observed 31% of cases studied.
- Further evidence that overexpression of IGF2, a gene encoding a hormone involved in cell growth, and mutation of TP53, a very common tumor suppressor gene, are hallmarks of adrenocortical carcinoma.
- Novel mutations that likely contribute to the development of adrenocortical carcinoma include:
- Mutations in PRKAR1A, found in 8% of patients in the study, have previously been associated with tumors and other diseases of the adrenal cortex.
1American Cancer Society. Cancer Facts and Figures 2013. Atlanta: American Cancer Society, Inc. 2013.
2Phan AT. Adrenal cortical carcinoma—review of current knowledge and treatment practices. Hematol Oncol Clin North Am. 2007 Jun; 21(3):489-507.