• 2,300 women
    women were determined to be at high risk for breast cancer by the High Risk Screening Program in Ontario in 2015
  • 86%
    of cancer patients saw a registered dietitian at a regional cancer centre within 14 days of referral in 2016
  • 71%
    of stage III colon cancer patients received chemotherapy within 60 days of after surgery in 2014
  • 86%
    of all cancer surgery patients received their consult within the recommended wait time in 2016, and 87% received their surgery within the recommend wait time
  • Over 43,000
    patients were discussed at comprehensive multidisciplinary cancer conferences (MCCs) in fiscal year 2016/2017
  • About 13%
    of patients who undergo lung, prostate and colorectal surgery have an unplanned hospital visit following surgery
  • 79%
    of breast cancer patients had a guideline-recommended mammogram in the first follow-up year
  • 74%
    of colorectal cancer patients diagnosed in 2013 had a surveillance colonoscopy within 18 months of surgery
  • Over 100
    patient and family advisors, who vary by their type of cancer and experiences, represent diverse regions and work with Cancer Care Ontario to ensure a person-centred cancer system
  • 383,023
    unique patients were screened for symptom severity using Your Symptoms Matter – General Symptoms (YSM-General) in 2016
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Cervical Cancer Screening Quality

Measure Desired Direction As of this Report
PPV: Percentage of screen-eligible Ontario women, aged 21–69, with an abnormal Pap test result who were diagnosed with a pre-invasive cervical lesion after a follow-up colposcopy or surgical procedure Black Arrow Level Grey Arrow Up
Screening history in cases of invasive cervical cancer: Percentage of Ontario women, aged 21 and older, who were diagnosed with invasive cervical cancer and were screened with a Pap test up to 10 years before their cancer diagnosis Black Arrow Down Grey Arrow Null
See Methodology and Approach to find out how the ratings are calculated.

Key findings

Of the 37,021 women who had an abnormal Pap test result in 2014, 2,563 were diagnosed with pre-invasive cervical cancer, which is a positive predictive value (PPV) of 6.9%. The PPV of the Pap test in Ontario has increased over time, from 4.6% in 2011 to 6.9% in 2014, although there was some regional variation.

From 2012 to 2015, nearly 80% of women aged 21 and older who were diagnosed with invasive cervical cancer had not had a Pap test within the recommended 3-year screening interval, and 39% had not had a Pap test within the 10 years before their diagnosis.

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, so there is 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 plan.1
  • 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 is Positive Predictive Value (PPV)?

  • Positive predictive value (PPV) is a quality measure that assesses the chance of having pre-invasive (i.e. changes to the cells of the cervix that may develop into cancer) cervical cancer with an abnormal Pap test result. It is influenced by the proportion of abnormal Pap test results and the prevalence (i.e. all people alive who currently have a specific disease) of pre-invasive cervical cancer in screen-eligible women.
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What do the results show?

The PPV of the Pap test for pre-cancerous lesions has increased since 2010 (Figure 1).

  • The PPV of the Pap test increased in Ontario, rising from 4.6% in 2011 to 6.9% in 2014.
  • Some regional variation was present for this indicator. In 2014, the Local Health Integration Network (LHIN) with the highest PPV for pre-invasive lesions was South West (8.7%). The LHIN with the lowest PPV was South East (4.8%).
  • The PPV for Pap test detection of invasive cervical cancer was low and consistent across the LHINs (data not shown).
  • It is important to note that the Pap test is not designed to find invasive cervical cancer, nor does it perform well in the detection of invasive cervical cancer. The Pap test performs most efficiently in the detection of pre-invasive abnormalities that may develop into cervical cancer if not treated.

PPV of the Pap test varies by age (Figure 2).

  • In 2014, the PPV of the Pap test for pre-invasive abnormalities was highest in women aged 30 to 39 (9.5%), and lowest in women aged 50 to 59 (5.0%) and 60 to 69 (5.1%).

The majority of screening-aged women (aged 21 to 69) who were diagnosed with invasive cervical cancer in Ontario had not had a Pap test within the recommended screening interval (Figure 3).

  • Due to limitations in the Pap test history data, it is difficult to tell whether a Pap test was done for screening or diagnosis. Therefore, Pap tests performed within 2 years of the diagnosis were excluded because they may have been performed for diagnostic reasons.
  • Nearly 80% of Ontario women diagnosed with invasive cervical cancer from 2012 to 2015 had not had a Pap test within 3 years before their diagnosis.
  • Based on strong supporting evidence, Ontario’s recommended screening interval for cervical cancer is 3 years. Women over the age of 21 who are or have ever been sexually active should get screened for cervical cancer every 3 years.

Screening history in Ontario women diagnosed with invasive cervical cancer varied by age at diagnosis (Figure 3).

  • As the age at diagnosis increased, the length of time between Pap tests also increased:

    • Forty-seven percent of women diagnosed with cervical cancer aged 50 to 59 had not had a Pap test in the 10 years before their diagnosis, compared to 32% of women aged 40 to 49.
    • Sixty-three percent of women diagnosed with cervical cancer at age 70 or older had not had a Pap test in the 10 years before their diagnosis (264 women from 2012 to 2015).
  • The majority of women diagnosed with invasive cervical cancer were aged 40 to 49 (562 cases).

Why is this important to Ontarians?

  • An organized screening program offering regular cervical cancer screening and timely and appropriate follow-up of abnormal screening tests significantly reduces cervical cancer incidence (i.e. new cancer cases) and mortality (i.e. deaths)3–5.
  • The intention of cervical cancer screening is to find pre-cancerous changes so that cancer can be prevented. Despite having an organized screening program, it is estimated that 630 Ontario women were diagnosed with cervical cancer in 2016 and roughly 150 women died of the disease6 . In Ontario, cervical cancer incidence rates have been decreasing since the early 1980s due to the implementation of widespread cervical cancer screening6.
  • 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 187–9. HPV is transmitted through intimate sexual contact and is common among sexually active men and women10,11. Most sexually active men and women will get an HPV infection in their lifetime11–13. Most HPV infections 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.
  • Through regular screening and the appropriate and timely follow-up of abnormal results, it is possible to prevent cervical cancer from developing or to detect it early, when treatment and outcomes are better.

Next steps

  • Cancer Care Ontario is moving towards fully organized cervical cancer screening to improve the effectiveness of the Ontario Cervical Screening Program (OCSP). Screening participation rates remain a priority for the OCSP.
  • Cancer Care Ontario and the OCSP are working to improve cervical cancer screening participation and retention in eligible women, and are pursuing multiple strategies to engage populations where screening participation is low.
  • 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.
  • 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 Ontario14. Next steps include working with regional partners to encourage implementation of these guidelines.

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 Report 2016. Toronto: Cancer Care Ontario; 2016.
  3. 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.
  4. 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.
  5. 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.
  6. Canadian Cancer Society. Canadian Cancer Statistics 2016. Toronto: Canadian Cancer Society; 2016.
  7. 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.
  8. 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.
  9. Franco EL, Schlecht NF, Saslow D. The epidemiology of cervical cancer. The Cancer Journal. 2003 Oct; 9(5):348–59.
  10. 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.
  11. 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.
  12. Koutsky L. Epidemiology of genital human papillomavirus infection. Am J Med. 1997 May 5; 102(5A):3–8.
  13. Bosch FX, de Sanjosé S. Human papillomavirus and cervical cancer: burden and assessment of causality. J Natl Cancer Inst Monogr. 2003; 31:3–13.
  14. 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