The groundbreaking ANCHOR study showed that early detection and treatment of anal HSIL (anal precancer) reduces cancer progression by 57%. Today, the study and results were published in the New England Journal of Medicine. The study was conceived by Anal Cancer Foundation scientific advisory board member Dr. Joel Palefsky, and supported through advocacy efforts by the Foundation.
WHAT IS THE ANCHOR STUDY?
The ANCHOR Study hoped to improve patient outcomes for people with anal precancer and cancer by finding the best way to stop anal precancer from progressing to cancer.
ANCHOR stands for Anal Cancer HSIL Outcomes Research and the study investigated if treating anal cancer precursor lesions reduced cancer risk for people living with HIV. The incidence of anal cancer is highest in people living with HIV which is why they were chosen for this study.
ANCHOR aimed to recruit 5,000 people living with HIV and randomized participants into two groups: a group who received treatment for anal precancer, and a control group.
WHO CONDUCTED ANCHOR?
ANCHOR occurred in 25 locations around the United States. It was conceived and led by Anal Cancer Foundation Scientific Advisory Board Member Dr. Joel Palefsky.
WHAT WAS ANCHOR RESEARCHING?
Prevention and early detection are essential to ending anal cancer. Yet, despite its growing incidence and mortality, there are no national screening guidelines for anal cancer or precancer. We know that rates of cervical cancer reduced by 80% once doctors started screening for, and treating, cervical precancer.
The hope was that the ANCHOR study would illustrate that treating anal precancer reduces the risk of anal cancer—and it has now done so!
The Anchor study had two main objectives: to determine the effectiveness of screening for and treating anal precancer to reduce the incidence of anal cancer in HIV-positive men and women, and to create a bank of blood, anal swab, and tissue specimens to support critical scientific studies on how anal cancer progresses.
There were two arms in the study: one arm that received treatment for anal precancer and a control arm that did not.
Ninety percent of anal cancer is caused by the human papillomavirus (HPV), which can cause changes to the skin around and inside the anus. These changes are called "high-grade squamous intraepithelial lesions" or HSIL. About half of HIV+ men who have sex with men have anal HSIL. The study discovered that nearly half of HIV+ women do as well. Not all anal HSIL will develop into cancer. Most HSIL will go away on its own, but some becomes cancer over time and can eventually spread to other parts of the body.
WHAT DID THEY LEARN?
Most importantly, the study found a 57% reduction of anal cancer in people whose precancer was treated.
As this was the first study of this size and purpose, the researchers sought to discover additional information about HSIL and anal cancer. Additional findings include:
- A higher prevalence of HSIL than anticipated. This was most surprising in women. They were expecting 10% prevalence but found 47.2%.
- The study diagnosed 17 people with cancer, which was higher than expected.
- There was a younger median age at diagnosis than expected.
- There was no real difference in age, race, or gender in those who progressed to cancer, but a large difference in cancer progression in smokers as compared to nonsmokers.
WHY DID THE STUDY LOOK AT TREATMENT SOLEY IN HIV-POSITIVE PEOPLE?
They are at the highest risk for anal HSIL and anal cancer.
WHY DID THEY STUDY HSIL TO PREVENT ANAL CANCER?
We know that treating cervical HSIL (precancer) is an effective way to reduce the risk of developing cervical cancer. Anal cancer and cervical cancer are similar enough that cervical is a good cancer prevention model to follow.
HOW DID THE STUDY WORK?
There were two arms: a treatment arm and a monitoring arm. In those randomly assigned to the treatment arm, when patients showed up with evidence of HSIL they were treated immediately with hyfrecation (burning off skin lesions), infrared coagulation (using infrared light as a heat source to cut off blood supply to internal hemorrhoids), fuorouracil (5-Fu) cream, or imiquimod cream. Whichever the provider chose, they had to follow a very specific treatment algorithm.
In the active monitoring arm, HSIL was monitored closely but with no treatment. The ultimate goal was to get rid of as much HSIL as possible.
WHAT ROLE DID ACF PLAY?
The Anal Cancer Foundation built and led the coalition of organizations that supported and pushed for the study. As part of its advocacy, ACF submitted testimony on behalf of the organizations in 2011 and 2012. At the time it was called the HOST study.
WHAT DOES THIS MEAN FOR THE ANAL CANCER COMMUNITY?
Anal cancer is rapidly increasing at 3% a year. More people are being diagnosed with late-stage anal cancer than ever before.
The study proved that treating anal precancer in people living with HIV, the group at highest risk for developing anal cancer, reduces their cancer risk. The researchers also found there is room for improvement in how we treat anal lesions and a great need for new medical training programs to address screening and early treatment. We need standard methods to find it early.
The Anal Cancer Foundation sees the ANCHOR trial as a critical step toward ending anal cancer. It is the first definitive evidence that early screening makes a difference. The next steps are ensuring screening becomes standard for people living with HIV, and focusing on how we can leverage these results to help people at risk for anal cancer who were not in the study population. It is also clear that we must support efforts to better train medical physicians to find and treat anal cancer before it ever becomes cancer.
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