Study outlines recommendations for precancerous treatment of anal lesions
Currently, no guidelines exist for screening and treatment of precancerous anal lesions or for anal cancer screening because enough is not known about the effectiveness of treating lesions detected through screening. A new study published today by researchers at Baylor College of Medicine and the University of Florida uses a computer model to offer recommendations for monitoring and/or treating these lesions based on a patient's age. Their report appears in the journal Cancer.
HIV-positive men who have sex with men are at a disproportionately high risk for anal cancer. High-grade squamous intraepithelial lesions are precursors for anal cancer, and evidence suggests that administering the HPV vaccine after treating these lesions improves the effectiveness of the treatment. Researchers aimed to determine the optimal age-specific strategy to treat these lesions considering clinical effectiveness and cost-effectiveness and to identify the optimal age to initiate management.
"We hope our new study will influence the anal cancer screening guidelines by identifying the optimal age for screening initiation and the optimal treatment response rates," said Dr. Elizabeth Y. Chiao, associate professor of medicine in the section of infectious diseases at Baylor and with the Houston VA Center for Innovations in Quality, Effectiveness and Safety.
To address the question, they developed a computer model, which acts like a randomized clinical trial, to track more than 100,000 simulated patients over the course of their lifetimes. The patient model consists of men with HIV who have sex with men.
"We know that cases of anal cancer among people with HIV are on the rise, and while the exact causes are unknown, we suspect HIV may hinder the body's ability to fight HPV infection," said the study's lead investigator, Dr. Ashish A. Deshmukh, assistant professor in the Department of Health Services Research, Management and Policy in the University of Florida College of Public Health and Health Professions. "Our ultimate goal is to help expedite the formation of national anal cancer prevention policies and reduce anal cancer burden among these high risk groups."
The researchers' analyses demonstrated that men younger than 38 years of age benefitted most from conservative management (no treatment) of the lesions rather than surgical removal, whereas men over the age of 38 benefitted from removal of anal lesions, which can reduce the risk of anal cancer by one-third without compromising quality of life. In addition, pairing the removal with administration of the HPV vaccine potentially decreases the risk of mortality by almost 80 percent.
"Our findings demonstrate that a conservative approach for management of these lesions in younger HIV-positive men who have sex with men is the most cost-effective. We found that the treatment in younger patients is not effective when we considered the long-term outcomes, and may not be cost-effective from the societal perspective," Chiao said. "Our age-specific findings are the first step in identifying a rational, cost-effective approach for anal cancer screening in this population."