Health A to Z — 7 minutes
Cervical cancer: Pap test replaced by an HPV test
The Quebec Ministry of Health will replace the traditional Pap test for primary screening of cervical cancer with a test for human papillomavirus (HPV). Doing so will be in line with the recommendations of the Institut national d’excellence en santé et en services sociaux du Québec (INESSS), which considers the HPV test a more effective tool than the Pap test.
Quebec is joining a growing number of countries, including Australia and the Netherlands, and some Canadian provinces, such as Ontario and British Columbia, where this approach is being studied or implemented.
HPV, the primary cause of cervical cancer
Cervical cancer is almost always the result of infection with the human papillomavirus (HPV), which is usually transmitted sexually. Health Canada estimates that 1,440 Canadian women will develop cervical cancer in 2021, and 380 will die from it. In Quebec, this represents 280 new cases and 80 deaths.
While an HPV infection typically clears up within 18 to 24 months for most individuals, some strains of the virus can cause changes (dysplasia) in the cervix cells that can develop into cancer. In particular, HPV 16 and HPV 18 alone account for 70% of all cervical cancers.
The Pap test: A long-standing tool
Cervical cancer survival has improved dramatically in industrialized countries over the past 50 years. For example, from 1972 to 2006 in Canada, the survival rate increased by 70%. This improvement is partly due to cytological screening, the famous Pap test developed by the Greek physician George Papanicolaou in 1943.
A Pap test is used to detect abnormal cells on the cervix. If the result is positive, a colposcopy, a more precise visual examination of the cervix and suspicious tissue, is performed, possibly followed by a biopsy for further diagnostic evaluation.
For decades, these tests have been the mainstay of Quebec’s cervical cancer screening program. The problem is that the Pap test is not as effective as the HPV test, which was made possible by the development of DNA analysis technologies in the 1980s.
Benefits and limitations of HPV testing
According to a Canadian study, HPV testing has a 94.6% success rate in detecting pre-cancerous lesions, compared to 55.4% for Pap testing. With direct detection of HPV DNA, the results are much more accurate.
Because it generates fewer false negatives, HPV testing could be performed every five years instead of the two or three years required for Pap testing.
However, HPV testing lacks specificity. It detects the presence of the different types of the virus even in the absence of pre-cancerous or cancerous lesions (this could be called a false positive). Since HPV is present in 75% of sexually active young women, a positive HPV result in this population would generate a high number of colposcopies with ultimately negative results.
On the other hand, the Pap test is very specific: 97% of patients with a positive result actually have suspicious cells, which significantly reduces “unnecessary” colposcopies. That is why the INESS recommends a Pap test before ordering a colposcopy if HPV testing detects lower-risk viruses. People who test positive for HPV 16 and 18 should be referred directly for a colposcopy.
A new feature under study: Self-collection
While Pap tests require specimens to be taken from specific areas of the cervix, which a health care professional must do, HPV testing requires only a simple cervical or vaginal swab and can be done by self-collection.
Most studies show that the accuracy of HPV detection in self-collected specimens is as good as those performed by a clinician.
According to the INESSS, self-collection would increase the participation rate of currently under-screened people (indigenous people, immigrant women, the LGTBQ+ community, etc.), especially if users can send the kit and sample by mail.
In fact, the vast majority of women find self-care acceptable, even beneficial. It is easy to perform, painless and does not require a clinic visit. Women also appreciate that it is private and that they can take control of their health. A pilot project in the Eastern Townships in April 2022 clearly demonstrates that Quebec women are interested in this method: all 400 self-testing kits were distributed in a single day.
Until the change in screening method is official, sexually active women (or women who have been sexually active) should continue to get a Pap test every two to three years.
For professional support, we’re here.
We provide a wide range of services related to HPV and other STBBIs. Test results for chlamydia, gonorrhea, syphilis, hepatitis B and HIV are available within 24 hours. A doctor's prescription is required.
- Gynecological Cytology
- HPV molecular detection test
- Gynecological cytology cascade
- Molecular HPV cascade
Do you have a medical prescription for any of these tests? Book an appointment online or contact Biron Health Group’s customer service at 1 833 590-2712.
- Isabelle Paré (May 31, 2022). “Pap test replaced by an HPV test,” (translation) Le Devoir, https://www.ledevoir.com/societe/sante/717126/sante-le-test-pap-remplace-par-un-test-de-detection-du-vph
- Institut national d’excellence en santé et en services sociaux (2022). Cervical cancer screening in Quebec: recommendations for implementing the human papillomavirus test (HPV test) as a primary screening test. (translation) INESSS, Quebec, 182 p. https://www.inesss.qc.ca/fileadmin/doc/INESSS/Rapports/Oncologie/INESSS_Cancer_col_uterus_Avis.pdf
- Canadian Cancer Statistics Advisory Committee, in collaboration with the Canadian Cancer Society, Statistics Canada and the Public Health Agency of Canada (2021). Canadian Cancer Statistics 2021. Canadian Cancer Society, Toronto, 95 p. https://cdn.cancer.ca/-/media/files/research/cancer-statistics/2021-statistics/2021-pdf-en-final.pdf
- J. A. Dickinson, A. Stankiewicz, C. Popadiuk et al. (2012) “Reduced cervical cancer incidence and mortality in Canada: national data from 1932 to 2006,” BMC Public Health, 12(992), https://doi.org/10.1186/1471-2458-12-992
- Marie-Hélène Mayrand, Eliane Duarte-Franco, Isabel Rodrigues, Stephen D. Walter, James Hanley, Alex Ferenczy, Sam Ratnam, François Coutlée, Eduardo L. Franco (2007). “Human Papillomavirus DNA versus Papanicolaou Screening Tests for Cervical Cancer,” The New England Journal of Medicine, 357:1579-1588, https://www.nejm.org/doi/full/10.1056/nejmoa071430
- Claude Plante (Apr. 5, 2022). “Cervical cancer self-screening: all kits have been distributed” (translation), La Voix de l’Est, https://www.lavoixdelest.ca/2022/04/05/autodepistage-du-cancer-du-col-de-luterus--toutes-les-trousses-ont-ete-distribuees-498fa631f31f2dced7dd054e09b10820