Is cancer contagious?

Three people wearing medical face masks

The claim

You can “catch” cancer from someone else.
Three people wearing medical face masks

The truth

There is no evidence that close contact (including kissing, touching, having sex, sharing meals or breathing the same air) with someone who has cancer can give you cancer. A person's cancer cells would not usually survive in the body of another healthy person because their immune system would destroy the foreign cancer cells.

2 rare instances when cancer can be spread to another person

Organ transplants
In rare cases, organ transplants from people with cancer have caused cancer in the person who got the organ. This is because people who get organ transplants must take medicine that weakens their immune system. The medicine stops their immune system from attacking the transplanted organ, but it could also allow transplanted cancer cells to survive.
Having cancer during pregnancy could be a health risk for the baby, but it’s rare. There has been only one study showing that cancer cells may be passed from a pregnant woman to her baby, possibly increasing the baby's risk of developing a similar cancer.

You should know

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 through kissing, touching, having sex or sharing meals.

The Canadian Cancer Society is committed to sharing important information about cancer risk to Canadians and will continue to monitor research in this area.