What’s New in Anal Cancer Research?

Important research into anal cancer is now under way in many hospitals, medical centers, and other institutions around the world. Each year, scientists use clinical trials to find out more about what causes this disease, how to prevent it, and how to better treat it.

Looking at changes in anal cancer cells

We know that human papillomavirus (HPV) is a major cause of anal cancer. Researchers are now looking at how HPV affects molecules inside anal cells to cause them to become cancer. Improved understanding of the molecular changes inside anal cancer cells may lead to ways to prevent it and is also expected to help scientists find treatments using drugs that target these changes. Targeted drugs are different from standard chemotherapy drugs. They sometimes work when chemo drugs don’t, and they often have different (and less severe) side effects.

Screening for anal cancer

Ongoing research is being done on the value of screening tests for anal cancer, especially in people with major risk factors, such as HIV infection. (Screening is checking for a disease in people who don't have symptoms of it.) The test studied most is anal cytology, sometimes called the anal Pap test. This test may help find anal cancer when it's small, before it's causing symptoms and when it's easier to treat. Studies are also looking at whether the anal Pap test can help find  anal pre-cancer (called anal intraepithelial neoplasia, or AIN), so it can be treated before cancer even develops. 


Better treatments for anal cancer with fewer side effects and long-term changes in body function are areas of active research. For instance, photodynamic therapy is being looked at to see if it can help treat small tumors and pre-cancer changes. Drugs like 5-FU and imiquimod cream are also being used. These treatments are focused on the changed cells in the anus. They don't harm healthy cells in the anus or the rest of the body.

Immunotherapy is treatment that boosts the body’s immune response against cancer cells. Different kinds of immunotherapy are being study for use against anal cancer. Pembrolizumab (Keytruda®) is one example that's already used to treat other types of cancer. It's now being studied for use in treating anal cancers that have spread to other parts of the body and don't respond to other forms of treatment.

Radiation therapy is a common treatment for anal cancer. Doctors are looking at ways to give external radiation more accurately and effectively to decrease the effects on normal healthy tissues. Other research is being done to learn about the possible benefits of combining external radiation and internal radiation therapy to treat anal cancer.

Combining chemotherapy and radiation is another area of interest. Giving these treatments together might allow people to get lower doses of each one, which could lessen side effects. Different drug combinations, with different forms of radiation are being tested in clinical trials.

HPV vaccines are used today to prevent HPV infection, but they don't help treat HPV infections. Doctors are looking at whether these vaccines might be used to help treat high-grade pre-cancers and keep them from becoming cancer. Researchers are also working on new vaccines to treat women and men who already have HPV infections and HPV-related cancers like anal cancer or cervical cancer. These vaccines may help the immune system attack pre-cancers and even cancers that contain HPV.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: November 13, 2017 Last Revised: November 13, 2017

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.