HPV-based screening key to eliminating cervical cancer in Canada

Implementing human papillomavirus (HPV)-based screening in British Columbia could eliminate cervical cancer in the province before 2040, according to a modeling study in CMAJ (Canadian Medical Association Journal) https://www.cmaj.ca/lookup/doi/10.1503/cmaj.231682.

More than 90% of cervical cancer cases worldwide are caused by 9 types of high-risk HPV. The World Health Organization and the Canadian Partnership Against Cancer (CPAC) have both set targets to eliminate cervical cancer by 2040, defined as an annual rate of less than 4 per 100 000 women.

The Pap test has been the primary screening tool for decades, but HPV-based screening shows better accuracy in detecting cervical precancer. As well, HPV-based screening can be performed on samples collected by the patient rather than a health care provider, increasing access and uptake.

“The option for self-collection may also reduce barriers to access and increase screening uptake among those who are never- or underscreened,” writes lead author Dr. Reka Pataky, Canadian Centre for Applied Research in Cancer Control and BC Cancer, Vancouver, BC, with coauthors.

Researchers used CPAC’s OncoSim-Cervical model to develop scenarios that would help BC achieve targets to eliminate cervical cancer. Using current Pap testing, with no changes to HPV vaccination rates or screening participation rates, BC would not reach the goal of 4 cases/100 000 until 2045. If it implemented HPV-based screening, BC would achieve the target by 2034 and prevent more than 900 cases of cervical cancer by 2050.

There are concerns about increased demand for colposcopy to investigate an abnormal result, and precancer treatments with implementation of HPV-based screening. The authors suggest that phased-in HPV testing by age could help reduce the burden on health care systems.

“Screening programs across Canada need to implement HPV-based cervix screening in strategic and innovative ways that increase access to screening services, enhance timely follow-up and treatment, and reduce health disparities across the population,” they conclude.

In a related editorialhttps://www.cmaj.ca/lookup/doi/10.1503/cmaj.240722, Dr. Shannon Charlebois, medical editor at CMAJ, and Dr. Sarah Kean, a gynecologic oncologist at the University of Manitoba, write that cervical cancer is increasing in younger populations and commonly affects equity-seeking groups.

“Invasive cervical cancer disproportionately affects equity-seeking populations,” they write. “Yet, those most at risk are the least likely to be screened, including 2SLGBTQI+ people, immigrants, those with a disability, Black and Indigenous people, and victims of sexual trauma. It is the most common cancer among females living with HIV.”

Self-sampling, which evidence shows is as accurate as physician-collected samples, will help increase access to cervical cancer screening for these groups.

“If Canada is to eliminate cervical cancer, which is entirely possible, every health system across the country should integrate self-sampling into their cervical cancer screening program.”