No guidelines exist for the treatment of precancerous anal lesions that might ultimately develop into anal cancer, leaving physicians to make a best guess about whether to remove them or wait and watch to see if they go away on their own. A study led by a University of Florida researcher offers recommendations for treating the lesions in a high-risk group that could lower patients’ risk of developing anal cancer by 80 percent.
“We currently have no national anal cancer screening guidelines. One reason for this is that the long-term benefits of treating lesions detected through screening are unknown,” said the study’s lead investigator Ashish A. Deshmukh, Ph.D., M.P.H., an assistant professor in the department of health services research, management and policy in the UF College of Public Health and Health Professions. “Our study is the first to determine age-specific recommendations for treating these lesions.”
The study findings, which offer recommendations for monitoring or removing the lesions based on the patient’s age, appear today in the journal Cancer (http://bit.ly/2wO0Byb).
“We believe our findings will help set future guidelines for precancer treatment and they represent an important step toward our ultimate goal of informing national anal cancer prevention policies and potentially helping to decrease anal cancer burden for patients and the health care system,” Deshmukh said.
The American Cancer Society estimates about 8,200 Americans will receive an anal cancer diagnosis this year. Human papillomavirus, or HPV, the same virus that causes most cases of cervical cancer, is responsible for 93 percent of anal cancer cases. Sometimes anal lesions heal naturally as the body’s immune system fights the virus, but other times the lesions develop into cancer. Lesions can be removed surgically, but the treatment is painful for many patients, the lesions frequently come back within a year and patients still have a small chance of developing anal cancer. A large multisite clinical trial led by researchers at the University of California San Francisco is expected to answer questions about anal lesion treatment and monitoring, but study results are still several years away.
Deshmukh and his colleagues designed a study to help give physicians information now. The team developed a mathematical model to simulate a patient population of men with HIV who have sex with men.
“About half of these men will experience precancerous anal lesions and their risk of developing anal cancer is more than 100 times higher than the general population,” Deshmukh said. “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.”
Using the best available data, including patient health outcomes, cancer risk, treatment cost and impact on quality of life, the team built a computer model that acts like a virtual randomized clinical trial to track 100,000 simulated patients over the course of their lifetimes.
Taking into account the risk of lesions developing into cancer, treatment costs and the quality of life issues surrounding side effects of lesion removal, the researchers determined that patients younger than 38 would benefit most from conservative management of anal lesions, rather than surgical removal. After 38, as cancer risk starts to increase with age, the researchers recommend removing anal lesions, which can reduce anal cancer risk by nearly one-third without compromising quality of life. Pairing lesion removal with administration of the HPV vaccine, a relatively new treatment approach, has the potential to offer extra protection, decreasing the risk of anal cancer and mortality by almost 80 percent, Deshmukh said.
“Our study highlights the importance of decision-analytic modeling as an approach to inform clinical questions that otherwise could take years and be prohibitively expensive,” said the study’s senior author Jagpreet Chhatwal, Ph.D., an assistant professor at Harvard Medical School and Massachusetts General Hospital. “Our analysis can help inform future clinical trials and minimize patient harm by recognizing which patients could benefit from anal cancer treatment.”
Future research can further define other anal cancer screening questions such as screening and treatment frequency, said study co-author Elizabeth Chiao, M.D., M.P.H., an associate professor of medicine in the infectious diseases section at the Baylor College of Medicine.
“However, our age-specific findings are the first step in identifying a rational, cost-effective approach for anal cancer screening in this population,” she said.
In another recent study published by Deshmukh and colleagues in the journal Vaccine (http://bit.ly/2w2ZhSI), they conclude that treatment plus HPV vaccination is also the most valuable strategy for treating precancerous anal lesions, saving health care dollars that may otherwise be spent on treating recurrent lesions and anal cancer.
The current study was supported by funding from the Janice Davis Gordon Memorial Postdoctoral Fellowship at The University of Texas MD Anderson Cancer Center, the National Institutes of Health and the National Cancer Institute.