Is cancer contagious?

While some animal cancers have been found to be contagious, no human form has yet been found to be contagious. However, certain contagious diseases can cause cancer in humans. These diseases are not transmitted through cancer cells but through the viruses that cause the disease. Additionally, some behaviors are thought to be contagious, or at least may cause exposure to cancer-causing agents. In this case, the cancer cells are not contagious, but the behaviors that cause them, such as smoking, may be more likely in family groups.

Some viruses have a direct link to certain types of cancer. For example, some forms of human papillomavirus (HPV) are now listed as the leading cause of all cervical cancers, and can also cause penile cancer. There are only a few types of HPV that cause such illnesses, and not everyone who has the virus will get cancer. All types of HPV that can cause it are sexually transmitted.

Another sexually transmitted disease that is indicated in a form of cancer is the human herpes virus 8 (HHV8). It has been linked to the development of Kaposi's sarcoma and is almost always incorrectly identified as being caused by AIDS. This misunderstanding occurs because people with HIV and AIDS are at much higher risk of contracting HHV8.

Certain behaviors can predispose people to certain types of cancer and diseases. For example, those who smoke are not only at risk of lung cancer, but may also increase the risk for others around whom they smoke. Also, children of parents who smoke are more likely to smoke themselves. So, in a non-traditional sense, this behavior can be thought of as "contagious."

Alcoholism is another form of indirectly "contagious" behavior that increases the risk of stomach and liver cancer. Children of alcoholics are more likely to become alcoholics. While this may be partly behavioral, there may also be genetic factors that predispose people to addiction. In these cases, behavior passed down from one generation to the next can increase the risk of certain forms of cancer.

In the traditional sense of "contagious," most forms of cancer cannot be spread to another person. However, the recent discovery of HPV's role in cervical cancer raises questions about whether others may be the result of exposure to certain viruses or bacteria. Scientists continue to research this area in hopes of finding more ways to cure and prevent these diseases.

Go up