• 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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Breast Cancer Screening Quality and Efficiency

 
Measure Desired DirectionAs of this Report
PPV: Percentage of women, aged 50 to 74, who had an abnormal OBSP screening mammogram resultand were diagnosed with breast cancer (ductal carcinoma in situ or invasive) after diagnostic workupBlack Arrow UpGreen Arrow Level
Early return: Percentage of Ontario women, aged 50 to 72, who were screened through the OBSP with a biennial (every 2 years) screening recall recommendation and had a subsequent program mammogram within 18 months of the previous mammogramBlack Arrow DownYellow Arrow Down
Confirmed high risk by genetic assessment: Percentage of Ontario women, aged 30 to 69, who were referred to the OBSP and were confirmed to be at high risk for breast cancer by genetic assessment (counselling and/or testing)Black Arrow UpGreen Arrow Down
Screened within 90 days of confirmation of high risk status: Percentage of Ontario women aged 30 to 69 screened through the High Risk OBSP within 90 days of confirmation of high risk statusBlack Arrow UpRed Arrow Down
See Methodology and Approach to find out how the ratings are calculated.

Key findings

In 2015, the positive predictive value (PPV) of breast cancer screening in the Ontario Breast Screening Program (OBSP) was 6.4%. A PPV of 6.4% means that 3,244 of the 51,016 women aged 50 to 74 who had an abnormal OBSP screening mammogram were diagnosed with breast cancer. The PPV for mammograms in Ontario has remained steady at around 6% since 2012.

Approximately 19,300 Ontario women aged 50 to 72 who were screened through the OBSP in 2014 and who received a 2-year screening recall recommendation had a subsequent program mammogram within 18 months, an indicator of screening participation behaviour that falls outside recommended guidelines. Early return increased from 4.7% in women who had an OBSP mammogram with a 2-year recall recommendation in 2010, to 5% in women who had a mammogram in 2014. Considerable regional variation was present for this indicator.

In 2015, approximately 7,500 women aged 30 to 69 who were referred to the High Risk OBSP completed a genetic assessment (counselling or testing) to determine whether they were at high risk for breast cancer. Of the women who completed an assessment, approximately 2,300 (31%) were determined to be at high risk, compared to 29% in 2011–2012 (the start of the High Risk OBSP). The proportion of women at high risk for breast cancer who were screened in the OBSP with mammography, plus magnetic resonance imaging (MRI) or ultrasound, within 90 days of confirmation of their high risk status was 47% in 2015, which is down from 65% in 2011–2012.

What is breast cancer screening?

  • 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 breast screening is to find cancer at an early stage, when it is easier to treat. Ontario operates screening programs for 3 types of cancer: breast, cervical and colorectal.
  • A mammogram uses low-dose X-rays to produce images of the breast1. A breast MRI uses magnetic waves and an intravenous contrast agent (e.g. dye) to create cross-sectional images of the breast2. Both tests can show changes in the breasts that may be early signs of breast cancer, even when the changes are too small for a woman or her doctor to feel or see.
  • Breast cancer screening with mammography is recommended every 2 years for average-risk women aged 50 to 741.
  • Breast cancer screening with mammography and breast MRI is recommended every year for women aged 30 to 69 identified as being at high risk for breast cancer1.
  • Most women with an abnormal mammogram result will not have breast cancer1. More tests are needed after an abnormal mammogram result to determine whether a cancer is present.
  • Diagnostic assessment includes additional radiological or surgical procedures, such as diagnostic mammography, ultrasonography, and core and/or open surgical biopsy.
  • In Ontario, breast cancer screening occurs through the OBSP (an organized province-wide screening program) and through non-OBSP sites. For a map of locations, visit the Breast Cancer Screening Participation section.

What is Positive Predictive Value (PPV)?

  • Positive predictive value (PPV) is a quality measure that assesses the accuracy of breast cancer screening in finding breast cancer. It is influenced by the abnormal call rate (i.e. the percentage of women referred for further testing due to an abnormal screening mammogram), cancer detection rates and the underlying incidence (i.e. new cases) of breast cancer.
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Close Graph

What do the results show?

The PPV of breast screening in the OBSP has remained steady over time, but it varies by age group and among Local Health Integration Networks (LHINs) (Figures 1 and 2).

  • The PPV of OBSP mammograms overall in 2015 was 6.4%. Mammogram PPV has remained steady at approximately 6% since 2012.
  • In 2015, 3,244 of the over 50,000 Ontario women aged 50 to 74 who had an abnormal OBSP screening mammogram result went on to be diagnosed with breast cancer.
  • Some variation in mammogram PPV by LHIN was present. The LHIN with the highest PPV in 2015 was Champlain (9.3%). The LHINs with the lowest PPV in 2015 were Central West (4.9%) and Mississauga Halton (4.8%).
  • PPV increases with age. In 2015, the PPV of OBSP mammograms was highest in women aged 70 to 74 (12.1%) and lowest in women aged 50 to 54 (3.3%). A similar pattern can be seen in previous years. Positive predictive value increases with subsequent screens, which is why PPV is higher in older age groups.
  • PPV is reported as a single measure for first and subsequent screens to be consistent with Ontario’s cervical and colorectal cancer screening programs. National breast screening guidelines have 2 separate PPV targets for first screens (≥5%) and subsequent screens (≥6%)2,3.

Considerable regional variation exists in early return among LHINs (Figure 3).

  • Early return increased from 4.7% in women who had an OBSP mammogram and a 2-year screening recall recommendation in 2010 to 5% in women who had an OBSP mammogram in 2014.
  • Of the approximately 384,000 women aged 50 to 72 who were screened through the OBSP in 2014 and given a recommendation to re-screen in 24 months (2 years), approximately 19,300 (5%) had a subsequent program mammogram within 18 months.
  • The LHINs with the lowest (i.e. better) early return for women with an OBSP mammogram and 2-year recall recommendation in 2014 were South East and North East (both 1.4%). The LHINs with the highest early return for the same time period were Toronto Central and Central (both 9.1%). Early return has increased in Ontario for every cohort of women with biennial screening recall recommendations since 2011. In particular, early return increased in most LHINs from 2013 to 2014. The LHINs with the greatest increases were Central West and North Simcoe Muskoka (an increase of 0.7 percentage points). Early return decreased (improved) in South West and North East (improvement of 0.3 percentage points for both) during the same time period.
  • Early return will continue to provide direction for Cancer Care Ontario in its work with its regional partners to promote adherence to risk-appropriate screening intervals across the province.

Early return for breast cancer screening varies by age group (Figure 4).

  • In 2014, the percentage of women with a biennial screening recall recommendation returning for a subsequent program mammogram within 18 months of a previous mammogram was lowest (4.5%) in women aged 70 to 72 and highest (5.4%) in the youngest age group (women aged 50 to 54). A similar pattern can be seen in previous years.

The proportion of women referred for genetic assessment who are subsequently confirmed to be at high risk decreased for the first time since the start of the High Risk OBSP, although with some regional variation (Figure 5).

  • The proportion of women who were referred to the High Risk OBSP and were confirmed to be at high risk after referral decreased to 31% in 2015 (from 34% in 2014).
  • Some regional variation is present for this indicator. In 2015, the LHIN with the highest percentage of women confirmed to be at high risk for breast cancer after genetic assessment was Mississauga Halton (43%). The LHIN with the lowest percentage of women confirmed to be at high risk for breast cancer after genetic assessment was North West (18%).
  • The OBSP has set a provincial target of 30% or greater for this indicator, meaning that approximately 1 in 3 women who are referred for genetic assessment are confirmed to be at high risk for breast cancer1.
  • Monitoring this indicator allows Cancer Care Ontario to see if the high risk referral criteria are interpreted correctly by primary care providers, and to ensure that the criteria appropriately identify women who may be at increased risk for breast cancer.

The proportion of women screened in the High Risk OBSP within 90 days of confirmation of their high risk status has decreased since the start of the program with considerable regional variation (Figure 6).

  • In 2011–2012, at the start of the High Risk OBSP, 65% of women were screened using a mammogram, plus MRI or ultrasound, within 90 days of confirmation of their high risk status, compared to 47% in 2015.
  • The OBSP has set a provincial target of 90% or greater for this indicator, meaning that about 9 in 10 women should be screened within 90 days of confirmation of their high risk status.
  • Considerable regional variation exists for this indicator. In 2015, the LHIN with the highest percentage of women screened within 90 days of confirmation of their high risk status was South East (72%). The LHIN with the lowest percentage of women screened within 90 days was Hamilton Niagara Haldimand Brant (17%).
  • The decrease in women screened within the 90-day recommendation may be partly related to increasing wait times for MRIs. Current wait times are available at ontariowaittimes.com.

Why is this important to Ontarians?

Mammography is important for the early detection of breast cancer, but it is not perfect.

  • Finding breast cancer early increases the number of treatment options available, and it can lead to better treatment outcomes and survival rates4.
  • A Canadian study on mammography effectiveness in screening programs found that mammograms are associated with a 21% reduction in breast cancer mortality in average-risk women aged 50 to 69, compared to no screening5.
  • Women without breast cancer who receive abnormal mammogram results (false-positives) may unnecessarily undergo additional imaging and biopsies. The likelihood of a false-positive result is lower for re-screens than for initial screens because previous mammograms can be used for comparison6.
  • Even with a mammogram, some breast cancers are not found (false-negatives). Dense breast tissue and current use of hormone replacement therapy are associated with an increased risk of breast cancer being missed by screening7.
  • The PPV of a screening test depends on the underlying prevalence of disease (i.e. all people alive who currently have a specific disease) in the population being screened, which may help to explain the variation observed across LHINs and age groups.

Organized screening offers important advantages for women and physicians.

  • The OBSP provides high-quality screening for women at average risk of developing breast cancer through mammography and for women at high risk through mammography, plus MRI or ultrasound.
  • Communication to women and healthcare providers includes:
    • women eligible for screening through the OBSP are sent invitations to get screened, along with information about breast cancer screening and details on how to find an OBSP site;
    • normal result letters are sent to women after their screening visits;
    • women screened through the OBSP are sent recall and reminder letters when they are due for their next round of screening; and
    • OBSP sites follow up on abnormal screening results and communicate normal and abnormal results to a woman’s healthcare provider.
  • Coordination and navigation includes:
    • arranging genetic assessment (if appropriate) for women who have been referred to the High Risk OBSP;
    • booking mammography and screening breast MRI (or, if appropriate, screening ultrasound) appointments via OBSP sites;
    • suggesting an appropriate screening recall interval based on a woman’s screening result and risk factors; and
    • having OBSP assessment sites coordinate follow-up tests, track test results and provide navigation from abnormal screen to final diagnosis for women with abnormal screening results.

The OBSP is continually evaluated and improved to maximize benefits and minimize limitations.

  • Women are encouraged to get screened through the OBSP. As an organized screening program, it offers important benefits, such as inviting women to participate in screening, reminding participants when it is time for their next screening test, notifying participants of screening results, tracking participants throughout the screening process, and evaluating program quality and performance.
  • A robust quality assurance and performance monitoring framework is in place for the OBSP.
  • All OBSP screening sites are accredited by the Canadian Association of Radiologists (CAR) Mammography Accreditation Program (MAP). The CAR MAP guidelines cover radiologist and medical radiation technologist (MRT) qualifications, equipment, quality control, quality assurance, image quality and radiation dose8.
  • Feedback on performance, which is then compared to national targets and quality standards, is provided annually to all OBSP screening and assessment sites, as well as to individual radiologists.
  • The OBSP funds regular physical inspections of mammography equipment at OBSP sites.

Next steps

  • The OBSP’s quality assurance program will continue to provide performance feedback to individual OBSP sites, radiologists and MRTs, as well as identify opportunities for improvement (where necessary).
  • The OBSP continues to expand, with new sites being brought into the program in 2016 and 2017.

View Notes

  1. Cancer Care Ontario. Ontario Cancer Screening Performance Report 2016. Toronto: Cancer Care Ontario; 2016.
  2. Canadian Partnership Against Cancer. Report from the evaluation indicators working group: guidelines for monitoring breast cancer screening program performance. 3rd Edition. Toronto: Canadian Partnership Against Cancer; 2013.
  3. Canadian Partnership Against Cancer. Breast cancer screening in Canada: monitoring and evaluation of quality indicators—results report, January 2009–December 2010. Toronto: Canadian Partnership Against Cancer; 2015.
  4. Nelson H, Tyne K, Naik A, Bougatsos C, Chan B, Humphrey L. Screening for breast cancer: an update for the U.S. Preventive Services Task Force. Ann Intern Med. 2009 Nov 17; 151(10):727–37.
  5. Canadian Task Force on Preventive Health Care, Tonelli M, Gorber CS, Joffres M, Dickinson J, Singh H, et al. Recommendations on screening for breast cancer in average-risk women aged 40–74 years. CMAJ. 2011 Nov 22; 183(17):1991–2001. Chiarelli AM, Halapy E, Nadalin V, Shumak R, O’Malley F, Mai V. Performance measures from 10 years of breast screening in the Ontario Breast Screening Program, 1990/91 to 2000. Eur J Cancer Prev. 2006 Feb; 15(1):34–42.
  6. Chiarelli AM, Kirsh VA, Klar NS, Shumak R, Jong R, Fishell E, et al. Influence of patterns of hormone replacement therapy use and mammographic density on breast cancer detection. Cancer Epidemiol Biomarkers Prev. 2006 Oct; 15(10):1856–62.
  7. The Canadian Association of Radiologists [Internet]. Ottawa: the Canadian Association of Radiologists; c2009. Mammography accreditation program (MAP); [cited 2015 Dec 17]. Available from: http://www.car.ca/en/accreditation/map.aspx.