|Measure ||Desired Direction||As of this Report |
|Percentage of stage I breast cancer patients who received imaging tests to detect distant metastasis |
| See Methodology and Approach to find out how the ratings are calculated. |
The majority of Ontario women with early stage breast cancer undergo imaging for staging to detect metastases. Practice guidelines, however, do not recommend routine imaging to detect metastatic disease in patients with no symptoms. Efforts should focus on improving awareness among physicians and patients and knowledge translation to increase guideline adherence.
What type of tests are used for metastatic staging in breast cancer?
In my words
For cancer care to be efficient, the time between someone being sent for the first test to the final diagnosis must be much quicker. Waiting for tests and results has both an emotional and physical impact on the patient. The longer the wait, the greater the fear, the more the cancer can grow.
- Most women with a new diagnosis of breast cancer present with early stage disease (stages I and II)1. In early stage breast cancer, the disease is confined to the breast tissue. This is in contrast to late stage breast cancer, where the disease has spread to other organs and tissues. These tumour deposits are known as metastases.
- Baseline imaging tests to detect metastases include bone scanning, liver ultrasonography, chest radiography (X-ray) and computed tomography (CT)3,4.
- The likelihood of tests detecting metastases in stage I or II breast cancer patients with no symptoms of spread are 0.2% and 1.2% respectively2. For this reason, most guidelines (both national and international) do not recommend imaging for early stage breast cancer patients who have no symptoms of metastatic disease3,4.
- Imaging tests in patients without symptoms may identify findings unrelated to breast cancer that are of no clinical significance. This, in turn, may result in unnecessary further testing and needless patient anxiety.
- A disease pathway map for the screening and diagnosis of breast cancer , outlines evidence-based best practices for when these and other tests should be ordered.
- Imaging equipment and resources to run the technologies are expensive and should be used appropriately whenever possible.
- In 2012, the American Board of Internal Medicine launched the Choosing Wisely® campaign with a goal of improving the dialogue around avoiding unnecessary or harmful medical tests, treatments and procedures. Choosing Wisely Canada (CWC) was promoted by a team of leading Canadian physicians in partnership with the Canadian Medical Association (CMA). CWC has endorsed the Choosing Wisely® recommendations and investigated additional opportunities to use resources more efficiently and effectively. For more information on CWC, visit their website.
- In particular, Choosing Wisely® suggests the following:
- “Imaging with PET, CT or radionuclide bone scans can be useful in the staging of specific cancer types. However, these tests are often used in the staging evaluation of low-risk cancers, despite a lack of evidence suggesting they improve detection of metastatic disease or survival.”
- “In breast cancer, for example, there is a lack of evidence demonstrating a benefit for the use of PET, CT or radionuclide bone scans in asymptomatic individuals with newly identified ductal carcinoma in situ (DCIS), or clinical stage I or II disease.”
- “Unnecessary imaging can lead to harm through unnecessary invasive procedures, over-treatment, unnecessary radiation exposure and misdiagnosis.”
What is efficiency?
- Efficiency is a dimension of health service quality that tracks whether we are making the best use of our existing resources (such as types of treatment, machines, staff and hospital beds) to achieve desired outcomes.
- The results tell us about the proportion of patients being treated according to guidelines. They also help us consider the utilization of these unique technologies in order to identify whether they are being used to their maximum potential—or whether there is opportunity to better use the capacity of a limited resource for those patients who need it most.
What do the results show?
The number of patients receiving unnecessary tests (as defined by guidelines) is higher than expected and includes regional variation (Figures 1 and 2).
- Figure 1 shows that the majority of women diagnosed with early stage breast cancer may be receiving unnecessary imaging tests for staging. The average number of stage I patients receiving these tests has decreased slightly each year since 2012, the year Choosing Wisely® was launched.
- Women with stage II breast cancer are undergoing more tests than women with stage I breast cancer. This may partly be due to variations in guideline recommendations: the current Cancer Care Ontario guidance document indicates bone scanning for stage II patients4, but Choosing Wisely® does not recommend this test3. On average, stage II patients are receiving 34% more bone scans than stage I patients (data not shown).
- Modalities included in this analysis are ultrasound, CT, MRI, X-Ray, and bone scan. These tests were performed on any of the following: skeleton (excluding skeletal MRI if performed on the same day as breast MRI), thorax (excluding pre-operative chest X-ray) abdomen, and pelvis.
- Figure 2 shows that in 2014, the proportion of stage I breast cancer patients who had staging tests for metastatic disease showed some regional variation (from 47% to 76%). A similar range was seen for 2012 (from 47% to 80%) and 2013 (from 51% to 80%), but the regional rankings were different, so there is no clear region with best or worst practices.
- The reasons for a discrepancy between guideline recommendations and practice are likely a combination of patient-related and physician-related factors. Patients have reported that additional testing gives them peace of mind and that they would be uncomfortable if their doctor, in concordance with the local Cancer Care Ontario guidelines, did not perform imaging for metastatic disease4,5. Physicians, however, have reported that clinical findings or suspicious clinical history is what prompts referral for staging tests (as opposed to patient preference)6.
- Some early stage breast cancer patients will present with symptoms and comorbidities that require staging tests. Clinical consensus and recent evidence says that these patients only account for 5% to 10% of the early stage breast cancer population, yet in 2014, 58% of stage I patients received imaging tests for staging7. Of the 5,068 distinct tests performed on stage I patients in 2014, 4,561 (90%) may have been unnecessary.
- The cost of each scan depends on the modality, and it includes a physician fee, technician fee and facility overhead costs. A CT scan of the abdomen, for example, costs around $220i to the system8,9. A recent study published in the journal Current Oncology found that the cost of all imaging on early stage breast cancer patients in Ontario ranged from $4.4 million to $6.8 million over a 5-year period, depending on guideline recommendations (figures are cumulative and in Canadian dollars)10.
- These tests have downstream implications on the system because they may lead to follow-up examinations and (in the case of false positive tests) unnecessary treatment. If unnecessary tests were eliminated, it might increase test availability for other patients.
- For Fiscal Year (FY) 2014–2015, the median adult wait times in Ontario for patients with known or suspected invasive cancer (non-aggressive, non-emergency) were 8 days for CT scans and 10 days for MRI scans. The 90th percentile adult wait times for the province were 22 days for CT scans and 38 days for MRI scans11. For more information on wait times, see Ontario Wait Times website..
i $108.30 (X126: CT abdomen, with or without IV contrast)8; $19.63 (NOC 3215: medical radiation technologists median wage $38.11; assume 0.5hour for CT9; $92.54 (institutional internal overhead cost).
days for MRI scans11.
Why is this important for patient care?
Appropriate testing is a quality issue and a limited system resource issue.
- One of the main purposes of staging is to rule out metastasis. Staging may occur before surgery, but it is more commonly performed after surgery at the hospital where primary therapy is given2.
- Staging tests are time-consuming and anxiety-provoking. Occasionally, false-positive results lead to other expensive tests. Unnecessary imaging can lead to harm through unnecessary invasive procedures, over-treatment, unnecessary radiation exposure and misdiagnosis3.
- Each test is associated with a wait time. Unnecessary testing delays definitive treatment (surgery or systemic) and is not likely to provide benefit to the patient.
- Imaging is a limited resource. Increases in use of diagnostic imaging in Canada have far exceeded population growth: from 1993 to 2004 there was a 3-fold increase in the number of CT scans and a 7-fold increase in the number of MRI scans12. The high demand for these services contributes to longer wait times. When patients who do not need a test are removed from the queue, there is more timely capacity for those patients who do need the tests.
How does Ontario compare?
- An Ontario study, published in the Canadian Medical Association Journal in 2015, demonstrated similar results presented here13. Overall, there was a higher imaging utilization rate (86%) for early stage breast cancer patients (stage I and II) than those presented in this section (71% of stage I and II patients). The lower numbers reported in the Cancer System Quality Index (CSQI) may be attributed to the exclusion of pre-operative chest X-ray from these data (as per the CWC anesthesiology recommendations)14. The Ontario study in the Canadian Medical Association Journal also assessed data from 2007 to 2012, prior to any effects that the Choosing Wisely® recommendations would have had on diagnostic testing.
- A study from the United States demonstrated that only 15% of early stage breast cancer patients from 2 separate facilities had at least 1 imaging test during the staging window. Investigators conducted chart-level audits and found that approximately half of the imaging tests were ordered in response to a sign or symptom7.
- A Canadian study assessed the consistency of radiological staging for breast cancer in an academic oncology setting and found that 59% of stage I patients and 58% of stage II patients were over-investigated. The study estimated that the cost of non-adherence is in the range of $78 (Canadian dollars) per new, early stage breast cancer patient who is seen at the centre15.
Find out more
- Cancer Care Ontario. Ontario breast screening program: 2011 report [Internet]. Toronto: Cancer Care Ontario: 2011 [cited 2016 Mar 7]. Available from: https://cancercare.on.ca/common/pages/UserFile.aspx?fileId=288834.
- Brennan ME, Houssami N. Evaluation of the evidence on staging imaging for detection of asymptomatic distant metastasis in newly diagnosed breast cancer. Breast. 2012; 21(2):112–23.
- Schnipper LE, et al. American Society of Clinical Oncology identifies five key opportunities to improve care and reduce costs: the top five list for oncology. J Clin Oncol. 2012; 14(30):1715–1724.
- Cancer Care Ontario. Baseline staging tests in primary breast cancer [Internet]. Toronto: Cancer Care Ontario; 2011 [cited 2016 Mar 7]. Available from: https://cancercare.on.ca/common/pages/UserFile.aspx?fileId=13866.
- Simos et al. Patient perceptions and expectations regarding imaging for metastatic disease in early stage breast cancer. SpringerPlus. 2014; 3:176.
- Simos D, Hutton B, Graham ID, Arnaout A, Caudrelier JM, Clemons M. Imaging for metastatic disease in patients with newly diagnosed breast cancer: are doctor's perceptions in keeping with the guidelines? J Eval Clin Pract. 2015; 21:67–73.
- Hahn EE, Tang T, Lee JS, Munoz-Plaza C, Adesina JO, Shen E, et al. Use of imaging for staging of early stage breast cancer in two integrated health care systems: adherence with a choosing wisely recommendation. J Oncol Pract. 2015; 11(3):320–328.
- Ministry of Health and Long-Term Care (MOHLTC). Schedule of benefits: physician services under the Health Insurance Act [Internet]. Toronto: MOHLTC [cited 2016 Mar 1]. Available from: http://www.health.gov.on.ca/english/providers/program/ohip/sob/physserv/sob_master20160229.pdf.
- Jobbank.ca [Internet]. Ottawa: Government of Canada. Explore careers—wage report; 2015 Oct 23 [cited 2015 Nov 16]. Available from: http://www.jobbank.gc.ca/LMI_report_bynoc.do?&noc=3215&reportOption=wage .
- Thavorn K, Wang Z, Fergusson D, van Katwyk S, Arnaout A, Clemons M. Cost implications of unwarranted imaging for distant metastasis in women with early stage breast cancer in Ontario. Curr Oncol. 2016; 23(Suppl 1):s52–55.
- Ontario Ministry of Health and Long-Term Care [Internet]. Toronto: Queen’s Printer for Ontario: 2008. Ontario wait times, surgery and diagnostic imaging results; 2016 Mar 3 [cited 2016 Mar 8]. Available from: http://www.ontariowaittimes.com/SurgeryDI/EN/Data.aspx?View=1&Type=0&Modality=3&ModalityType=23,26&LHIN=7&city=&pc=&dist=0&hosptID=0&str=&period=0 .
- Tu JV, Pinfold PS, McColgan P, Laupacis A, editors. Access to health services in Ontario, ICES Atlas. 2nd edition [Internet].Toronto: ICES; May 2006 [cited 2016 March 8]. Available from: http://www.ices.on.ca/~/media/Files/Atlases-Reports/2006/Access-to-health-services-in-Ontario-2nd-edition/Full%20report.ashx.
- Simos D, Catley C, van Walraven C, Arnaout A, Booth CM, McInnes M, et al. Imaging for distant metastases in women with early stage breast cancer: a population-based cohort study. CMAJ. 2015. doi: 0.1503/cmaj.150003
- Choosing Wisely Canada [Internet]. Anesthesiology: five things physicians and patients should question; 2015 Sept 17 [cited 2016 Mar 8]. Available from: http://www.choosingwiselycanada.org/recommendations/anesthesiology/.
- Han D, Hogeveen S, Goldstein MS, George R, Brezden-Masley C, Hoch J, et al. Is knowledge translation adequate? A quality assurance study of staging investigations in early stage breast cancer patients. Breast Cancer Res Tr. 2012; 132(1):1–7.