Is Cancer Contagious?

Cancer is not transmitted from a person with cancer to healthy people. There is no evidence yet that it spreads through contact such as breathing the same air, shaking hands, kissing or sexual intercourse.

Can Cancer Spread Through Contact?

Even if cancer cells come into contact with a healthy person’s body, they cannot survive because the healthy person’s immune system destroys them and does not allow them to live.

Most cancer types arise from damage and mutations in a person’s DNA. These changes may result from environmental or hereditary factors. Although the causes of some DNA damage are unknown, some have carcinogenic triggers such as smoking, alcohol or sun exposure. Some viruses can directly affect DNA and cause mutations, while inflammation can also indirectly trigger cancer.

Can Cancer Be Transmitted Through Organ Transplantation?

Cancer has occurred in recipients after organ transplantation from people with cancer to people with organ failure. However, an important factor increasing this risk is that transplant recipients take medicines that weaken their immune systems. Donors are therefore checked for cancer to minimize this risk in organ donation.

Does Cancer During Pregnancy Affect the Baby?

Even if the mother has cancer during pregnancy, the fetus (the baby in the womb) is usually unaffected. Although cancer may rarely pass from the mother to the placenta (the organ connecting fetus and mother), most cancer types do not affect the fetus in the uterus.

Do Microbes Increase Cancer Risk?

Microbes are contagious. Bacteria and viruses in particular may spread between people through sexual intercourse, kissing or sharing food. Some can spread even through breathing the same air. Microbes pose a greater threat to people with cancer than to healthy individuals because patients’ immune systems are weakened, particularly during treatment. Their bodies may then be unable to cope with infections.

Metagenomicsis the science studying the role of microbes in cancer. Certain microbes play an important role in the development of some cancer types. This may be why people think cancer is contagious.

Viruses

Some viruses can trigger the development of specific cancer types.

For example:

• Some Human Papillomaviruses (HPV)may increase risks of cervical, vaginal, vulvar, penile, anal and head and neck cancers.
• Epstein-Barr virus (EBV) is associated with cancer of the upper throat (nasopharynx), gastric lymphoma, Hodgkin lymphoma and Burkitt lymphoma.
• Hepatitis B virus (HBV) and hepatitis C (HCV) are linked to long-term liver infections and may increase liver cancer risk.

Conditions weakening the immune system, such as AIDS caused by HIV, or immunosuppression following organ transplantation, may create a favorable environment for the growth and development of Kaposi sarcoma and certain lymphomas.

Bacteria

Bacteria can trigger cancer. Helikobacter pylori is a common bacterium known to be associated with certain stomach cancers. Long-term infection may damage the stomach lining and increase stomach cancer risk.

cancer is not a contagious disease

Scientific research suggests that cancer is not a disease transmitted directly from person to person. However, contagious viruses, bacteria and parasites can trigger its development. A healthy lifestyle, monogamy and regular checkups can reduce this risk. We therefore recommend that people with cancer avoid isolation and instead stay in contact with others.