Cervical Cancer Screening Participation

Key findings

In 2013–2015, approximately 2.7 million Ontario women aged 21 to 69 (61% of eligible women) were screened for cervical cancer with a Pap test. This represents a decrease of 5 percentage points from 2004–2006, when 66% of eligible women were screened.

The number of women eligible for screening through the Ontario Cervical Screening Program (OCSP) has continued to increase, from 3.9 million women in 2004–2006 to 4.4 million women in 2013–2015.

In 2008, 84% of the women who had a normal Pap test that year returned for a subsequent Pap test within 42 months. Sixty-six percent of Ontario women who had a normal Pap test result in 2012 returned for another Pap test within 42 months, which represents a decrease of 18 percentage points.

It is important to note that Cancer Care Ontario revised its cervical cancer screening guidelines in 2012, which included increasing the recommended screening interval to once every 3 years; changes to the Ontario Health Insurance Plan fee schedule were made as a result of the new recommendations. Women screened in 2011 and 2012 would be expected to be re-screened in 2014 and 2015, respectively, achieving a total of 1 screening test in the 42-month period following their 2011 or 2012 Pap test. This change in the OCSP-recommended screening interval may have contributed to the decrease in screening participation observed from 2008–2011 to 2013–2015.

Measure	Desired Direction	As of this Report
Participation: Percentage of Ontario screen-eligible women, aged 21 to 69, who completed at least 1 Pap test in a 42-month period
Retention: Percentage of Ontario screen-eligible women, aged 21 to 66, who had a subsequent Pap test within 42 months of a normal Pap test result
See Methodology and Approach to find out how the ratings are calculated.

What is cervical cancer screening (Pap test)?

• A screening test identifies people in a healthy, asymptomatic population who may be at risk for disease. It is not a diagnostic test. The purpose of cervical screening is to prevent cervical cancer by identifying pre-cancerous changes to the cells of the cervix using the Pap test. Ontario operates screening programs for 3 types of cancer: breast, cervical and colorectal.
• Changes in the cervix that lead to cancer—called precursor or precancerous lesions—usually develop slowly over many years, accounting for a long period of time when abnormal cell changes are present and can be found by a Pap test before cervical cancer appears.
• Colposcopy is a diagnostic procedure performed after an abnormal Pap test result. This procedure allows a colposcopist to take tissue samples (biopsies) of cervical abnormalities so a pathologist can make a definitive diagnosis and a doctor can develop a treatment plan¹.
• After the diagnostic process is complete, a woman with a precursor lesion requiring treatment may undergo a loop electrical excision procedure, laser therapy or cold knife cone biopsy¹. Treating precursor lesions can prevent cervical cancer from developing.
• Cancer Care Ontario updated its cervical cancer screening guidelines in 2012. It now recommends cervical cancer screening every 3 years for women aged 21 to 69 who are, or who have ever been, sexually active. Women can stop screening at age 70 if they have had 3 or more normal tests within the previous 10 years².

What do the results show?

Cervical cancer screening participation decreased in 2013–2015 (Figure 1).

• Provincial cervical cancer screening participation in 2013–2015 (61%) was lower than in 2007–2009 (67%) and falls short of the 85% target.
• Approximately 2.6 million Ontario women aged 21 to 69 were screened for cervical cancer in 2013–2015.
• In 2013–2015, the Local Health Integration Network (LHIN) with the highest cervical screening participation was Champlain (65%). The Toronto Central and North East LHINs had the lowest participation (57%) over the same time period.

Cervical cancer screening participation varies by age group (Figure 2).

• In 2013–2015, participation in cervical cancer screening was highest in women aged 30 to 39 and 40 to 49 (65%), and lowest in women aged 60 to 69 (53%). Participation decreased in all age groups from 2010–2012 to 2013–2015.
• Cervical cancer incidence rates in Ontario are highest in women aged 35 to 44 and 55 to 64.³

Cervical cancer screening retention needs improvement (Figure 3, 4).

• Approximately 741,000 women who had a normal Pap test in 2012 returned for a Pap test within 42 months (66% of eligible women).
• In 2008, 84% of the women who had a normal Pap that year returned for a subsequent Pap test within 42 months. Sixty-six percent of Ontario women who had a normal Pap test result in 2012 returned for another Pap test within 42 months, a decrease of 18 percentage points.
• The Central LHIN had the highest retention of women with a normal Pap test in 2012 (68%). The Central West LHIN had the lowest retention of women with a normal Pap test in 2012 (61%).
• Retention has decreased for each cohort of women since 2008 and in all LHINs.
• Among women who had a normal Pap test in 2012 and returned for a Pap test within 42 months, retention was highest in those aged 40 to 49 and 50 to 59 (67%), and lowest in those aged 20 to 29 (63%). A similar pattern can be seen in previous years.

Why is this important to Ontarians?

Cervical cancer screening has reduced cervical cancer incidence and mortality.

• Through regular screening and the appropriate and timely follow-up of abnormal results, it is possible to prevent cervical cancer from developing or to find it early, when treatment and outcomes are better.
• Organized cervical cancer screening significantly reduces cervical cancer incidence (i.e. new cancer cases) and mortality (i.e. deaths)^4–6. Long-term reductions in cervical cancer incidence and mortality in Ontario are related to regular screening with appropriate and timely follow-up.
• In 2016, it is estimated that 630 Ontario women were diagnosed with cervical cancer in 2016 and roughly 150 women died of the disease⁷. These low rates are a measure of success of Ontario’s screening system, but they also reflect the need for improvement in prevention and early detection of this essentially preventable disease.
• Virtually all cervical cancers and their precursor lesions are caused by persistent infection with high-risk oncogenic (i.e. cancer-causing) human papillomavirus (HPV) types, especially types 16 and 18^8–10. HPV is transmitted through intimate sexual contact and is common among sexually active men and women^11,12. Most sexually active men and women will get an HPV infection in their lifetime^12–14. HPV infections rarely cause symptoms and most will go away, or clear, without causing harm. The reasons some high-risk HPV infections clear on their own and some persist are not well understood.
• Persistent high-risk HPV infections are a necessary factor in the development of cervical cancer and pre-cancerous changes in the cervix.
• Because pre-cancerous cervical changes rarely cause symptoms, screening is the only way to find early cell changes that could lead to cervical cancer.

Cervical cancer screening needs to continue despite HPV vaccination.

• Vaccines are now available to prevent infection with the major oncogenic strains of HPV that have been linked to the development of the majority of cervical cancer cases¹⁵.
• Vaccinated women should continue to get regularly screened for cervical cancer. While current vaccines target the majority of oncogenic types, other oncogenic types exist. Moreover, vaccines do not provide protection for people who get infected with high-risk HPV before immunization.

How does Ontario compare with other jurisdictions?

• Ensuring that the data and measures from other jurisdictions are comparable to Ontario’s is a challenge. Caution should be used when comparing Ontario’s indicator results to those from other jurisdictions due to potential differences in data definitions, methodologies and time periods. Cross-jurisdictional comparison is still useful, however, for providing a rough indication of how well Ontario is doing compared to other jurisdictions.
• Australia’s cervical cancer screening participation in 2013–2014 was 58%, which is lower than Ontario’s (61%). However, Australia uses a measurement period of 2 years, compared to 42 months in Ontario¹⁶.
• For more information on comparisons of cervical cancer screening participation among jurisdictions, see CSQI’s screening comparison section.

Next steps

• Cancer Care Ontario’s updated guidelines recommend HPV testing as the primary screening test for cervical cancer. Cancer Care Ontario is working with the Ministry of Health and Long-Term Care to implement HPV testing in the OCSP.
• In the interim, the OCSP supports continuing to use cervical cytology as the primary cervical screening test.
• Cancer Care Ontario has developed an online Primary Care Screening Activity Report (PC SAR) for all 3 screening programs (cervical, breast and colorectal cancer). This tool (accessed online) allows physicians in a patient enrolment model practice to see the complete screening status of each of their enrolled age-eligible patients, including those due for screening and follow-up. Next steps include working with the Regional Primary Care Leads to identify barriers to adoption of the tool, and to promote and encourage use of the PC SAR.
• Cancer Care Ontario is developing evidence-informed strategies to increase access, align processes, improve practices and enhance the quality of colposcopy services in the province. The OCSP recently released evidence-informed clinical guidelines for the delivery of colposcopy services in Ontario¹⁷. Next steps include working with regional partners to encourage implementation of these guidelines.
• The OCSP correspondence program, which supports cervical screening participation and retention, began in the fall of 2013. Eligible women are mailed letters inviting them to get screened for cervical cancer, advising them of their test results and reminding them when it is time to return for screening.

View Notes

1. Cancer Care Ontario [Internet]. Toronto: Cancer Care Ontario. Insight on cancer: news and information on cervical cancer; 2005 Oct [cited 2015 Dec 18]. Available from: https://cancercare.on.ca/common/pages/UserFile.aspx?fileId=13802
2. Cancer Care Ontario. Ontario Cancer Screening Performance Report 2016. Toronto: Cancer Care Ontario; 2016.
3. Cancer Care Ontario. Ontario Cancer Statistics 2016. Toronto: Cancer Care Ontario; 2016.
4. Pettersson F, Björkholm E, Näslund I. Evaluation of screening for cervical cancer in Sweden: trends in incidence and mortality 1958–1980. Int J Epidemiol. 1985 Dec; 14(4):521–7.
5. Lynge E, Madsen M, Engholm G. Effect of organized screening on incidence and mortality of cervical cancer in Denmark. Cancer Res. 1989 Apr 15; 49(8):2157–60.
6. Quinn M, Babb P, Jones J, Allen E. Effect of screening on incidence of and mortality from cancer of the cervix in England: evaluation based on routinely collected statics. BMJ. 1999 Apr 3; 318(7188):904–8.
7. Canadian Cancer Society. Canadian cancer statistics, 2016. Toronto: Canadian Cancer Society, Steering Committee on Cancer Statistics; 2016.
8. Kwong J, Crowcoft N, Campitelli MA, Ratnasingham S, Daneman N, Deeks SL, et al. Ontario burden of infectious disease study (ONBOIDS). Toronto: Ontario Agency for Health Protection and Promotion, Institute for Clinical Evaluative Sciences; 2010.
9. Walboomers JM, Jacobs MV, Manos MM, Bosch FX, Kummer JA, Shah KV, et al. Human papillomavirus is a necessary cause of invasive cervical cancer worldwide. J Pathol. 1999 Sep; 189(1):12–9.
10. Franco EL, Schlecht NF, Saslow D. The epidemiology of cervical cancer. The Cancer Journal. 2003 Oct; 9(5):348–59.
11. Yabroff KR, Mandelblatt JS, Kerner JF. Effectiveness of interventions to improve follow-up after abnormal cervical cancer screening. Prev Med. 2000 Oct; 31(4):429–39.
12. Brown DR, Shew ML, Qadadri B, Neptune N, Vargas M, Tu W, et al. A longitudinal study of genital human papillomavirus infection in a cohort of closely followed adolescent women. J Infect Dis. 2005 Jan 15; 191(2):182–92.
13. Koutsky L. Epidemiology of genital human papillomavirus infection. Am J Med. 1997 May 5; 102(5A):3–8.
14. Bosch FX, de Sanjosé S. Human papillomavirus and cervical cancer: burden and assessment of causality. J Natl Cancer Inst Monogr. 2003; 31:3–13.
15. Smith JS, Lindsay L, Hoots B, Keys J, Franceschi S, Winer R, et al. Human papillomavirus type distribution in invasive cervical cancer and high-grade cervical lesions: a meta-analysis update. Int J Cancer. 2007 Aug 1; 121(3):621–32.
16. Australian Institute of Health and Welfare. Cervical cancer screening in Australia 2013–2014. Cancer screening series no. 97. Cat. no. CAN 95. Canberra: Australian Institute of Health and Welfare; 2016.
17. Cancer Care Ontario [Internet]. Clinical guidance: recommended best practices for delivery of colposcopy services in Ontario; 2016 June [cited 27 Jan 2017]. Available from: https://cancercare.on.ca/common/pages/UserFile.aspx?fileId=361450