Thousands of women, particularly survivors of cervical cancer, may soon be offered screening for anal cancer, following a significant study that revealed an elevated risk years after their initial diagnosis. Anal cancer, though rare, is experiencing a rapid increase in incidence, especially among older women. Current medical guidelines already recommend screening for specific high-risk populations, such as individuals with HIV and women with a history of vulvar cancer. However, medical professionals are now advocating for the inclusion of cervical cancer survivors as a crucial, currently overlooked group, given the continued rise in anal cancer cases.

The rates of anal cancer are climbing most sharply among women over 65, with an approximate 4 percent annual increase in this demographic. Oncologists at the US National Cancer Institute caution that if this trend persists, the number of cases could double in less than two decades.

A pivotal study, led by Dr. Haluk Damgacioglu, an expert in disease modeling at the Medical University of South Carolina, focused on this issue. Researchers tracked over 85,500 women diagnosed with cervical cancer between 1975 and 2021 for an average of nine years. The study excluded women who had already been diagnosed with anal cancer or developed it within two months of their cervical cancer diagnosis. Among the remaining participants, 64 women subsequently developed anal cancer, with the risk significantly increasing 10 to 15 years after their cervical cancer treatment. Notably, nearly 60 percent of anal cancer cases in women aged 65 to 74 occurred more than 15 years post-cervical cancer diagnosis. The study identified rates of 17.6 cases per 100,000 in this age group, which surpasses the 17 cases per 100,000 threshold typically used to justify screening programs.

Writing in the journal JAMA Network Open, Dr. Damgacioglu emphasized these findings, stating, 'These findings support the need for age-based and duration-based anal cancer screening recommendations for women with a cervical cancer history.' He added that the study provides 'critical data to inform anal cancer screening recommendations among a high-risk population of women with a history of cervical cancer.' The research team is now calling for further studies to assess the risks and benefits of such screening and to determine the optimal age for its introduction.

Both cervical and anal cancers are strongly linked to infection with high-risk strains of the human papillomavirus (HPV), which is primarily transmitted through sexual contact. HPV is believed to be responsible for at least 90 percent of anal cancers and 99 percent of cervical cancers. While over 100 types of HPV exist, only about 30 can affect the genital area. Many individuals infected with HPV remain asymptomatic, and most infections clear up without intervention. However, in some cases, persistent HPV infection can lead to abnormal tissue growth, eventually developing into cancer over many years.

Early detection is crucial for improving outcomes. If anal cancer is diagnosed early, the chance of surviving at least five years is approximately 95 percent. Conversely, this survival rate plummets to just 15 percent if the disease is detected late, after it has spread to other parts of the body. Cervical cancer itself remains a significant cause of mortality, with around two women in the UK dying from it daily. It is often referred to as a 'silent killer' because its symptoms can be easily mistaken for less serious issues like period pain and fatigue. Despite regular invitations for cervical screening (smear tests) for women aged 25 to 49 in the UK, uptake remains low, with only about 70 percent of eligible women attending their scheduled tests.

Approximately 1,600 people are diagnosed with anal cancer in the UK each year, with women forming the majority. High-profile cases have brought some attention to the disease, including American actress Farrah Fawcett, a 1970s TV icon, who revealed her anal cancer diagnosis in 2006. Her diagnosis regrettably sparked tabloid speculation about her sex life due to the societal stigma surrounding the disease. Fawcett died in 2009 at age 62 after the cancer metastasized. More recently, 'Desperate Housewives' star Marcia Cross was diagnosed with anal cancer in 2017, which she attributes to an HPV strain that may have also caused her husband's throat cancer.

Common symptoms of anal cancer include bleeding from the anus, pain in or around the area, small lumps felt around the anus, changes in bowel habits, and passing mucus. While these symptoms can also be indicative of more common conditions like hemorrhoids or anal fissures, any persistent or unusual symptoms should always be promptly investigated by a doctor. The call for enhanced screening also aligns with broader public health efforts, as health chiefs are currently urging under-25s who missed out on the life-saving HPV cancer vaccine during school to come forward for immunization.