Illustration: anchorstudy.org
A groundbreaking new study in which researchers from Winship Cancer Institute of Emory University and Emory Center for AIDS Research contributed, finds that routinely screening and treating precancerous anal lesions greatly decreases the likelihood of progression to anal cancer, much like the approach to preventing cervical cancer in women. The Anal Cancer/HSIL Outcomes Research (ANCHOR) study was published June 16, 2022, in the New England Journal of Medicine.
The seven-year National Cancer Institute-funded ANCHOR study, conducted under the auspices of the AIDS Malignancy Consortium, an NCI-supported clinical trials group, was led by University of California San Francisco infectious disease expert Joel Palefsky, MD. At 25 sites across the United States, the phase 3 clinical trial tested 4446 men, women, transgender and nonbinary individuals living with HIV and at high risk for developing anal cancer.
Routine screening for cervical cancer with HPV and/or Pap testing and removing cervical high-grade squamous intraepithelial lesions (HSIL) has been shown to prevent many cases of cervical cancer. But it has been unclear whether treating anal HSIL found through screening likewise prevents anal cancer.
Anal cancer is fairly rare in the general population but is the fourth most common cancer among people living with HIV. Although HPV vaccination can prevent new anal HPV infections, there have been no evidence-based recommendations to guide screening for and treatment of anal HSIL.
"By showing that treatment for HSIL reduces the risk of anal cancer, this study also provides a rationale for screening for anal HSIL in people with HIV," says Robert Yarchoan, MD, director of NCI's Office of HIV and AIDS Malignancy.
Winship gynecologist Lisa Flowers, MD, MPH, FACOG, served as the principal investigator for the study site at Grady Health Systems. A member of Winship's Discovery and Developmental Therapeutics program, professor in the Department of Gynecology & Obstetrics at the Emory University School of Medicine, director of colposcopy and anoscopy services at Grady Cancer Center and president of the American Society for Colposcopy and Cervical Pathology, Flowers says the critical question the study answered is that there is a benefit to screening and treating precancerous lesions. "That was a big deal for us to find out," she says.
Another big deal was what Flowers calls the "remarkable" 80% retention rate of study participants at the Grady site. "This is considerable," she says, "considering that this was largely a population of color in a clinical trial. It was successful, and they were able to participate in something that is going to change the future."
Flowers points out that there are still questions to answer—including whether all patients with HSIL should be treated, who might need immediate treatment and who can be observed, and what is the most preferable treatment in terms of patients' compliance with it. "We need more data and information to figure out what will be the best tools to identify patients who are at high risk and who should have anoscopy and receive treatment," says Flowers. "I am sure moving forward we will have more answers in additional studies."
For the time being, however, Flowers says, "This is groundbreaking. This is going to change the standard of care for anal cancer screening. It's going to change the perspective of a cancer that was pretty much neglected to one where we can have a high impact if we do screening. It is literally changing the face of this disease."