Is an oncogene the same as a genetic marker that indicates cancer?
An oncogene is a gene that is commonly mutated (changed) in tumors and is thought to be one of the driving forces behind the tumor’s growth. Oncogenes are almost always mutated only in the tumor, not in the normal cells of the body. Genes that are mutated in normal cells (called “germline mutations”) can also be associated with a high risk of cancer. One of these is the BRCA family of genes. Mutations that turn off the BRCA gene (called “loss-of-function mutations”) can lead to a high risk of breast and ovarian cancers. Sometimes the mutations found in the tumor can be used to see whether treatment has worked, especially once the tumor is no longer visible. We can test patients for these mutations, e.g. the BCR-Abl translocation in chronic myelogenous leukemia, to see whether there is any evidence of disease remaining after what looks to be successful treatment.
