Shifting Trends in Anal Cancer

Anal cancer is on the rise in the United States, with the most significant increases occurring among older women—particularly white and Hispanic women over age 65. This emerging trend challenges long-held assumptions about who is considered "high risk" and who should be screened.

Although the exact causes of this rise remain uncertain, one likely factor is that many older women were beyond the recommended age when the human papillomavirus (HPV) vaccine became widely available. Given that HPV is responsible for about 90% of anal cancer cases, this gap in vaccination coverage may be contributing to increased risk in this population.

Using data from the National Cancer Institute’s SEER database (2017–2021), researchers found:

• Overall, anal cancer rates rose 2.9% in women and 1.6% in men during the five-year study period.
• Among white women over 65, rates increased 4.3% annually, reaching 11.4 cases per 100,000 by 2021.
• If this trend continues, anal cancer incidence in this group could double in less than 17 years.
• Hispanic women over 65 had the second-highest rate—7.5 cases per 100,000—with a 1.7% annual increase.

Though anal cancer is still considered rare—comprising about 1% of all gastrointestinal cancers—these findings highlight an urgent need to reevaluate screening strategies. Current guidelines prioritize high-risk groups such as individuals with HIV, bone marrow transplant recipients, and others with compromised immune systems. Older women are not yet included, despite growing evidence that they may be at increasing risk.

This is where cancer registrars play a vital role.

The insights gained from cancer registry data—and the dedication of Oncology Data Specialists—are helping to uncover important shifts in cancer incidence, identify at-risk populations, and inform the future of screening and prevention.