Treating precursor anal cancer lesions significantly reduces anal cancer risk in people living with HIV, according to a groundbreaking study of nearly 4,500 people at elevated risk for the cancer.
The discovery that anal pre-cancer lesions can be detected and easily treated early to prevent the often deadly cancer is similar to what happened with cervical cancer prevention, when scientists proved that finding and treating cervical pre-cancer lesions could significantly reduce cervical cancer incidence.
“The ANCHOR study shows that what we can offer for anal canal cancer prevention is a similar algorithm to the standard of care for cervical cancer prevention,” said Isabella Rosa-Cunha, M.D., principal investigator of the ANCHOR study sites at Sylvester Comprehensive Cancer Center and Jackson Memorial Hospital and associate professor of infectious diseases at the University of Miami Miller School of Medicine.
“We do an anal pap smear, and we can look into the anal canal for abnormal areas using a microscope called a colposcope. We biopsy abnormal areas to determine the presence of high-grade squamous intraepithelial lesions (HSIL), the pre-cancer lesions that can potentially progress to anal cancer. If we find those lesions, we can treat them, often in an in-office procedure.”The study shows that screening and treatment of high-risk lesions can significantly reduce chances of progression to anal cancer in people living with HIV and, possibly, in many other patient populations at risk for anal cancer as well, Dr. Rosa-Cunha said.
“While anal cancer is not as common as other cancer types—it affects approximately 2% of the general population—it is much more common in some patient populations,” she explained. “These include individuals living with HIV, women with a history of vulvar or cervical cancer, men who have sex with men who are HIV-negative, and men and women who have immunosuppression for reasons other than HIV infection.”
ANCHOR changes the landscape of cancer prevention, offering a new opportunity to reduce the burden of anal cancer globally, according to Erin Kobetz, Ph.D., M.P.H., vice provost for research and scholarship and associate director, population sciences and cancer disparity, at Sylvester.
“We are so proud of Sylvester’s role in this trial, the leadership of Dr. Rosa-Cunha and the commitment of study participants to making this discovery possible,” Dr. Kobetz said. “As a National Cancer Institute (NCI)-designated cancer center, Sylvester prioritizes research studies, such as ANCHOR, where the focus of inquiry aligns with our local cancer burden and the unique needs of the multicultural community that we serve.”
The 21 sites of the ANCHOR (Anal Cancer/HSIL [high-grade squamous intraepithelial lesions] Outcomes Research) study were led nationally by Joel Palefsky, M.D., professor of medicine at UC San Francisco. Dr. Palefsky established the world’s first clinic devoted to anal cancer prevention in 1991 at UCSF. He trained Dr. Rosa-Cunha in high-resolution anoscopy for the identification and treatment of precancerous lesions in the anal canal.
“I started the first anal dysplasia program at our medical campus in 2011,” Dr. Rosa-Cunha said. “There are not many sites in the U.S. that offer comprehensive screening, treatment and management of anal dysplasia (or pre-cancer). Today we have a comprehensive clinic that ranks among the best in the country.”
Sylvester began enrollment for the ANCHOR study in 2016, recruiting individuals living with HIV patients 35 years and older who were diagnosed with having HSIL but had not yet had anal cancer. The participants were randomized into two groups: treatment of the lesion or active monitoring of the lesion without treatment to determine if treatment influenced cancer risk.
The trial was so successful that it was stopped in late September 2021 so that all patients in the study could receive treatment of their high-risk lesions. Results are being prepared for peer-reviewed publication and are being shared now because of the public health importance of the findings, according to Dr. Rosa-Cunha.
“Asignificant number of women were enrolled in the study, which proved that access to screening for women living with HIV is essential for early detection and prevention of anal cancer,” said ANCHOR co-investigator JoNell Potter, Ph.D., A.P.R.N., FAAN, vice chair and professor of Clinical Obstetrics, Gynecology and Reproductive Sciences at the Miller School. “The women who volunteered for this study should be proud of their contribution to the outcome of this study, which will certainly change screening practices and prevention efforts for all women at risk for anal cancer.”