Cancer is NOT contagious. There is no evidence that close contact or things like sex, kissing, touching, sharing meals, or breathing the same air can spread cancer from one person to another. Cancer cells from one person are generally unable to live in the body of another healthy person. Cancer transfer during organ transplant There have been some cases in which organ transplants from people with cancer have been able to cause cancer in the person who got the organ.
This seems to be the main reason that cancer in a transplanted organ can, in rare cases, give cancer to the person who gets the organ. Organ donors are carefully screened to reduce this risk.
This also appears to be due to the drugs that are given to reduce the risk of transplant rejection.
Research has shown that the longer and more intensely the immune system is suppressed after transplant, the higher the risk of cancer. The drugs that allow the body to accept the organ also make the immune system less able to recognize and attack pre-cancer cells and the viruses that can cause cancer. Cancer transfer during pregnancy Even if a woman has cancer during pregnancy, the cancer rarely affects the fetus directly. Some cancers can spread from the mother to the placenta the organ that connects the mother to the fetus , but most cancers cannot affect the fetus itself.
In a few very rare cases, melanoma a form of skin cancer has been found to spread to the placenta and the fetus. We know that germs especially bacteria and viruses can be passed from person to person through sex, kissing, touching, and sharing or preparing food.
Some can even be spread by breathing the same air. But germs are much more likely to be a threat to a person with cancer than to a healthy person. They may not be able to fight off infections very well. Germs can increase cancer risk. There are some germs that can play a role in the development of certain types of cancer. Certain types of human papilloma viruses HPVs are linked to cancers of the cervix, vagina, vulva, penis, anus, and some cancers of the mouth, throat, head, and neck. But smoking, drinking, and other factors increase the risk of these cancers, too.
Epstein-Barr virus EBV is linked to nose and throat nasopharyngeal cancer, lymphoma of the stomach, Hodgkin lymphoma, and Burkitt lymphoma. Hepatitis B virus HBV and hepatitis C virus HCV are linked to long-term chronic liver infections, which can raise the risk of liver cancer hepatocellular carcinoma. A few may get Kaposi sarcoma if they are taking medicines that weaken their immune systems such as those used after an organ transplant. Invasive cervical cancer, Kaposi sarcoma, and certain lymphomas are much more common in people who are infected with the human immunodeficiency virus HIV , the virus that weakens the immune system and causes AIDS.
These viruses can be passed from person to person usually through blood or sex , but the viral infection alone usually does not lead to cancer. A weakened immune system, other infections, other risk factors such as smoking , and other health problems allow cancer to develop more readily.
Bacteria Bacteria can also promote cancer. Helicobacter pylori is a common bacterium now known to be linked to certain kinds of cancer in the stomach. Long-term infection with these bacteria can damage the inner layer of the stomach and increase the risk of stomach cancer. Parasites Certain parasitic worms that can live inside the human body can also increase the risk of developing some kinds of cancer.
Parasites that can cause cancer are rarely found in the United States or other developed countries, but they are linked with cancer of the bladder and the bile ducts, and possibly other cancers, too.
Cancer develops because the DNA in a cell changes. Most cancers do not appear to be caused or affected by infectious agents. These changes may be inherited or develop during life. Some changes happen for no known reason, while others are due to environmental exposures, such as sun UV damage or cigarette smoke.
Some viruses are known to directly cause mutations in DNA that can develop into cancer. Scientific studies of cancer causes show that cancer does not spread like a contagious disease. If cancer were contagious, we would have cancer epidemics just as we have flu epidemics — cancer would spread like measles, polio, or the common cold. We would expect a high rate of cancer among the families and friends of cancer patients and among health professionals because of their exposure to the disease.
This is not the case. The fact that cancer might happen more often in certain families does not mean that the family members have spread cancer to each other. There are other reasons this can happen: Family members share the same genes. Families may have similar unhealthy lifestyles diet and smoking, for example. Family members may all be exposed to the same cancer-causing agent. But scientists have found that these clusters almost never reflect a greater incidence of cancer than would be found in a random survey of the general public.
People with cancer need to be around other people. Even today, families, friends, and co-workers of people with cancer sometimes stay away when they learn about the disease. As a result, people with cancer often say they feel isolated and alone. They need your visits and support.