How Do Genes Affect Cancer Growth?

The discovery of certain types of genes that contribute to cancer has been an extremely important development for cancer research. Over 90% of cancers are observed to have some type of genetic alteration. Some of these alterations are inherited, while others are sporadic, which means they occur by chance or occur from environmental exposures (usually over many years).

There are three main types of genes that can affect cell growth, and are altered (mutated) in certain types of cancers, including the following:

  • Oncogenes: These genes regulate the normal growth of cells. Scientists commonly describe oncogenes as similar to a cancer "switch" that most people have in their bodies. What "flips the switch" to make these oncogenes suddenly become unable to control the normal growth of cells and allowing abnormal cancer cells to begin to grow, is unknown.
  • Tumor suppressor genes: These genes are able to recognize abnormal growth and reproduction of damaged cells, or cancer cells, and can interrupt their reproduction until the defect is corrected. If the tumor suppressor genes are mutated, however, and they do not function properly, tumor growth may occur.
  • Mismatch-repair genes: These genes help recognize errors when DNA is copied to make a new cell. If the DNA does not "match" perfectly, these genes repair the mismatch and correct the error. If these genes are not working properly, however, errors in DNA can be transmitted to new cells, causing them to be damaged.

Usually the number of cells in any of our body tissues is tightly controlled so that new cells are made for normal growth and development, as well as to replace dying cells. Ultimately, cancer is a loss of this balance due to genetic alterations that "tip the balance" in favor of excessive cell growth.

Clinical Trials

Clinical trials are research studies that evaluate a new medical approach, device, drug, or other treatment. As a Stanford Health Care patient, you have access to the latest, advanced clinical trials.

Open trials refer to studies currently accepting participants. Closed trials are not currently enrolling, but may open in the future.

Before beginning treatment, ask your doctor about any clinical trials you should consider. Learn more about clinical trials for cancer patients.

Our Clinic

CANCER GENETICS PROGRAM

Expert care in a location convenient for you. Visit our clinic to make an appointment.

Call 650-498-6000 to make an appointment