Cancer Causes

American Cancer SocietyThe following information was developed by the American Cancer Society, and is presented on Cancer.Net as part of a collaboration between the American Society of Clinical Oncology (ASCO) and the American Cancer Society. Both organizations have long shared a commitment to empowering people with information about cancer they can trust. Learn more about this collaboration and how it will help advance that goal. Used with permission. © 2022.

Is Cancer Contagious?

A healthy person cannot "catch" cancer from someone who has it. Cancer is not contagious.

Cancer Clusters

More than 1,000 suspected cancer clusters are reported to state health departments each year. But just what is a cancer cluster?

Known and Probable Human Carcinogens

Lists of substances and exposures that are known or suspected to cause cancer and information on how different agencies and groups test and classify possible carcinogens.