For women who've overcome cervical cancer, new research from MUSC Hollings Cancer Center points to another health risk that may not be on their radar: anal cancer.
Led by Hollings researchers Haluk Damgacioglu, Ph.D. , and Ashish Deshmukh, Ph.D. , co-leader of the Cancer Prevention and Control Research Program , the study sheds light on an under-recognized risk facing women with a history of cervical cancer – and highlights the need for updated screening guidelines. The paper was published in JAMA Network Open.
Cervical cancer is one of the most preventable cancers: Thanks to routine screening and the HPV vaccine, it has a survival rate of over 90% when found early. But clinical guidelines have not addressed what comes next for these patients, who may be at high risk for a related type of cancer.
"We've known for a long time that both cervical and anal cancers are caused by HPV, the human papillomavirus," Deshmukh said. "But what hasn't been well-understood is how that shared risk might connect the two diseases over a woman's lifetime."
Currently, anal cancer screening is recommended for certain high-risk groups, such as people living with HIV, organ transplant recipients and women with a history of vulvar cancer. But there are no clear screening guidelines for women with cervical cancer.
One problem has been a lack of long-term data on their risk and how that risk changes with age and over time. This study helps to fill that gap using high-quality, population-based data.
The researchers turned to the National Cancer Institute's SEER (Surveillance, Epidemiology and End Results) program – a comprehensive set of registries that tracks cancer diagnoses across the U.S. They analyzed data from more than 85,000 women diagnosed with cervical cancer, tracking them over two decades to see how many went on to develop anal cancer and when those diagnoses occurred.
What they found was striking. Compared with the general population, women with a history of cervical cancer had nearly twice the risk of developing anal cancer.
Anal cancer rates increased with age and over time, with the most diagnoses found in women ages 65 to 74 who were more than 15 years out from their original diagnosis. For women in this age group, the rate of anal cancer diagnoses was so high that it surpassed a widely accepted threshold for recommending routine screening.
"Our study shows that the risk doesn't go away – it actually increases with age and over time," Damgacioglu said.
Why the delay? HPV-related cancers often take years, sometimes decades, to develop. In some cases, the virus may linger undetected or have spread from another part of the body.
"It's a slow process," Deshmukh said, "and that's part of why it's been so hard to detect. By the time symptoms show up, the cancer is often advanced."
While anal cancer screening is not as routine as screening for other cancers, reliable methods do exist, including anal cytology (a kind of Pap screen) and anoscopy. Unfortunately, access to specialized screening remains limited. In South Carolina, for example, there is currently only one provider trained to perform high-resolution anoscopy.
That is why it is so important to identify and prioritize the highest-risk groups.
"These results tell us that women who had cervical cancer years ago should be considered for routine anal cancer screening," Damgacioglu said. "Right now, that's not happening."
This study could be a first step in changing that.
Deshmukh and his team are already building on the findings in a newly funded project that will evaluate how best to screen this group. That work, which is a collaboration with MD Anderson Cancer Center and the Icahn School of Medicine at Mount Sinai, will help to determine how and how often screening should occur.
"We don't have the resources to screen everyone," Deshmukh said. "But we can use these data to be strategic. Screening based on risk ensures we help the people who need it most."
For now, the team hopes their research raises awareness and sparks conversations between patients and providers.
"This is about helping long-term cancer survivors protect their health," Damgacioglu said. "They've already fought one cancer – we want to help prevent a second."
