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Patients with cancer are undergoing unnecessary screening tests for colorectal and breast cancer: study


Patients with cancer that has already spread are being screened for new cancers despite little benefit to the patient, according to new research by ICES and Sunnybrook Health Sciences Centre.

The study published today in CMAJ Open found that nearly one in 20 patients underwent tests for colorectal cancer and nearly one in 11 women underwent screening for breast cancer, within a year of receiving their diagnosis of metastatic cancer.

“Cancer screening is important in order to improve outcomes for patients. But the aim of screening is to detect disease early when treatment may improve the patient’s health. Our findings show that for patients with metastatic colorectal, lung, breast or prostate cancer, the benefit of cancer screening is limited,” says Dr. Simron Singh, author on the study and medical oncologist at the Odette Cancer Centre at Sunnybrook Health Sciences Centre, and adjunct scientist at ICES.

The study looked at data housed at ICES on 20,992 patients with metastatic lung, breast or prostate cancer and found 2.9 per cent, 6.3 per cent and 13.3 per cent of patients, respectively, underwent testing for colorectal cancer within one year of cancer diagnosis. Within three years of diagnosis, rates jumped to 4.1 per cent, 12.3 per cent and 27.5 per cent, respectively (8.5 per cent of all patients).

Among the 10,034 women with metastatic lung or colorectal cancer, 8.7 per cent and 8.0 per cent of patients, respectively, underwent breast cancer screening within one year of cancer diagnosis. Within three years of diagnosis, screening rates reached 10.2 per cent and 13.1 per cent, respectively.

“There are a number of reasons why cancer screening for patients who already have metastatic cancer is unnecessary. For the patients, they are being put through testing that may cause undue stress and financial burden in addition to potential risks that exist for some of the tests. But there is also the impact on our healthcare system at large, because unnecessary tests add to costs, as well as to wait times for others in the system,” says Dr. Matthew Cheung, author of the study, haematologist at the Odette Cancer Centre at Sunnybrook Health Sciences Centre and adjunct scientist at ICES.

Choosing Wisely campaigns, which operate in more than 20 countries worldwide, are dedicated to reducing the frequency of low-value care, which is defined as care that offers little to no patient benefit or a greater risk of harm. In 2013, the Choosing Wisely Canada campaign and a group of four national cancer associations issued an initial list of recommendations, including “Don’t perform routine cancer screening, or surveillance for a new primary cancer, in the majority of patients with metastatic disease”.

The researchers stress that the excessive screening may reflect the successful promotion of the cancer screening program in place in Ontario. The automated system sends letters to Ontarians in certain age groups to invite them to get screened for three types of cancer: breast, cervical and colorectal. But the researchers add that a shortfall of the program is the lack of individualized consideration, specifically for patients with metastatic cancer.

“Our study results illustrate the importance of communication between physicians and patients. When a patient with stage 4 cancer receives an invitation to get screened for cancer, it should spark a conversation about the benefits and risks of the screening with their doctor,” adds Singh.

“Screening for a new primary cancer in patients with existing metastatic cancer,” was published today in CMAJ Open.

Author block: Matthew C. Cheung, Jill Tinmouth, Peter C. Austin, Hadas D. Fischer, Kinwah Fung and Simron Singh.

ICES is an independent, non-profit organization that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. For the latest ICES news, follow us on Twitter: @ICESOntario


Deborah Creatura
Media Advisor, ICES
[email protected]
(o) 416-480-4780 or (c) 647-406-5996


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