Study Finds Cervical Cancer Survivors Face Higher Risk of Anal Cancer, Prompting Calls for Screening Review
Researchers say women treated for cervical cancer may meet thresholds for anal cancer screening years later as cases rise among older women
A U.S. research team has found that women who survive cervical cancer face an elevated risk of developing anal cancer a decade or more after their initial diagnosis, a finding the authors say supports reconsideration of screening recommendations for this population.
The study, published in JAMA Network Open, followed more than 85,500 women diagnosed with cervical cancer between 1975 and 2021 and observed 64 subsequent anal cancer cases among those who were not diagnosed with anal cancer at or immediately after their cervical diagnosis. Risk rose most sharply 10 to 15 years after treatment, and nearly 60 percent of anal cancers in women aged 65 to 74 occurred more than 15 years after the cervical cancer diagnosis. In that age group the incidence reached 17.6 cases per 100,000 — just above the 17-per-100,000 threshold commonly used to justify screening programmes.
Human papillomavirus (HPV) is thought to cause the large majority of both cancers: researchers estimate HPV contributes to more than 90 percent of anal cancers and virtually all cervical cancers. Current screening guidance in many countries recommends targeted anal-cancer screening for groups considered at high risk, such as people with HIV or a history of vulvar cancer, but does not generally include cervical cancer survivors.
Lead author Haluk Damgacioglu, a disease modelling expert at the Medical University of South Carolina, said the findings support the development of age-based and duration-based anal cancer screening recommendations for women with prior cervical cancer. The study’s authors urged further research to weigh the potential benefits and harms of screening in this group and to determine the optimal age to begin testing.
Anal cancer remains uncommon compared with other cancers but incidence has been rising, particularly among older women. U.S. National Cancer Institute oncologists have warned that if current trends continue, cases could double within two decades. In the United Kingdom, roughly 1,600 people are diagnosed with anal cancer annually, and the majority of those cases occur in women.
Survival depends heavily on stage at diagnosis. When detected early, the five-year survival rate for anal cancer is about 95 percent; for cancers discovered after they have spread, five-year survival falls to about 15 percent. Common symptoms include rectal bleeding, pain around the anus, palpable lumps, changes in bowel habits and passing mucus. Medical experts note these symptoms can be caused by more common conditions such as haemorrhoids or fissures, and recommend that persistent or unusual symptoms be evaluated by a clinician.
The study excluded women who had anal cancer at the time of cervical diagnosis or within two months, and reports a median follow-up of nine years. The pattern of later-onset anal cancers among older survivors aligns with broader epidemiological data showing the fastest increases in anal cancer incidence among women over 65, at an annual rise of roughly 4 percent in some analyses.
The link between cervical and anal cancers is biologically plausible because both are associated with persistent infection by high-risk HPV strains, which are transmitted through sexual contact and can remain asymptomatic for many years. Vaccination against HPV has been shown to prevent infections that lead to cervical and other HPV-related cancers. Public health officials continue to encourage vaccination and screening: in the UK, women aged 25 to 49 are invited for cervical screening every three years, although uptake has been around 70 percent for eligible women.
Prominent public cases have highlighted the disease’s stigma and clinical impact. Actress Farrah Fawcett revealed an anal cancer diagnosis in 2006 and died in 2009 after the disease spread. Actress Marcia Cross disclosed an anal cancer diagnosis in 2017. Researchers and clinicians say such cases have helped raise awareness but that the condition remains little discussed.
The authors of the JAMA Network Open paper called for policy and clinical reviews to consider whether history of cervical cancer should be incorporated into anal cancer screening criteria, especially for older women and for survivors a decade or more out from treatment. They emphasised the need for studies to evaluate screening methods, intervals and ages for initiation, and to assess the balance of potential harms and benefits before changing public health guidance.
Health authorities are also urging young people who missed routine HPV vaccination while in school to seek the vaccine, as part of broader efforts to reduce the long-term burden of HPV-associated cancers.