There is no evidence that close contact or having sex, kissing, touching, sharing meals or breathing the same air as someone with cancer can give you cancer. A person's cancer cells cannot usually survive in the body of another healthy person because their immune system would destroy the foreign cancer cells.
In rare cases, organ transplants from people with cancer have been able to cause cancer in the person who got the organ. This is because people who get organ transplants must take medicine that weakens their immune system - this stops their immune system from destroying the transplanted organ, but it also allows transplanted cancer cells to survive.
Having cancer during pregnancy could, in rare cases, be a health risk for the unborn baby. There has been only one study showing that cancer cells may be passed from a mother to an unborn baby and may possibly increase the baby's risk of developing a similar type of cancer.
Although cancer is not contagious, certain bacteria and viruses that can increase the risk of cancer are contagious. These bacteria and viruses can be passed between people by sex, kissing, touching or sharing meals.
Cancer sometimes occurs more often in certain families, but it doesn't mean that family members have spread cancer to each other. This can happen because family members:
In addition, there may be clusters of cancer cases among unrelated people when they are exposed to a common source of a cancer-causing substance such as tobacco smoke.
A clinical trial led by the Society’s NCIC Clinical Trials group found that men with prostate cancer who are treated with intermittent courses of hormone therapy live as long as those receiving continuous therapy.