STIs and Cancer

An African American woman looks pensively in the distance

There are a number of risk factors for cancer; increasingly of interest to researchers is the link between cancer and viral, bacterial, and parasitic infections. Some sexually transmitted infections are among those that can increase the risk for developing certain cancers:

  • HPV, or human papillomavirus, is most commonly associated with cervical cancer, but it can cause other types of cancers as well. HPV is thought to be responsible for more than 90% of anal cancers, about 70% of vaginal and vulvar cancers, and 60% of penile cancers. About 60% to 70% of cancers of the oropharynx (back of the throat) may be linked to HPV as well. One important way to prevent HPV-related cancer is to get vaccinated against HPV.

  • Chronic hepatitis B infection can cause complications such as cirrhosis (scarring of the liver) and even lead to liver cancer. The good news is that hepatitis B is preventable through vaccination. While not common, hepatitis C can be spread through vaginal or anal sex and infections can also cause liver cancer.

  • HIV patients are susceptible to several cancers including Kaposi sarcoma, a cancer targeting the lining of blood vessels

It’s important to note that most individuals with these infections won’t develop cancer but it’s a good idea to learn more about how to reduce your risk and take care of yourself. Both HPV and hepatitis B are preventable through vaccines, for example. Talk with your healthcare provider to see which vaccinations, tests and exams might be recommended for you.

The National Cancer Institute fact sheet is also a good resource to learn more about the link between infectious agents and cancer.

More to Explore

A stethoscope hangs over file folders

HPV Screening with Self Collection Endorsed by Two Organizations

At the end of 2025, the American Cancer Society released its new cervical cancer screening guidelines. In January 2026, the Health Resources and Services Administration endorsed a new set of guidelines as well. Both suggest HPV screening with self collected samples is an acceptable option.

Australia

Australia is Closer to Ending Cervical Cancer

Australia has been a leader in HPV-prevention and cervical cancer screening for decades. Because of this, it is now close to eliminating cervical cancer entirely. However, recent drops in vaccination and screening rates threaten this progress.

A stethoscope and a teal ribbon

ACS Releases New Cervical Cancer Screening Guidelines

The American Cancer Society (ACS) released new recommendations for cervical cancer screening that focus on HPV testing and approve the use of self-collected samples. The recommendations also clarify the age at which screening should start and stop.

A visual representation of herd immunity

Study Shows Herd Immunity for HPV is Possible

We’ve known for years that the HPV vaccine works. Now new research shows that widespread vaccination even protects those who haven’t gotten the shot. This study proves that it is possible to reach herd immunity for HPV.

A man hold on to his throat

HPV-Related Head and Neck Cancer

You have probably heard that HPV can cause cervical cancer. But did you know that it can also cause cancers of the mouth, tongue, and throat?