(Reuters Health) – – When it’s unclear whether the potential benefit of breast cancer screening outweighs the possible harms, doctors should encourage women to make an informed decision based on their personal preferences, Canadian doctors recommend.
The new guidelines released today by the Canadian Task Force on Preventive Health Care are similar to recommendations released in 2011, researchers note in CMAJ. But the updated recommendations may encourage more women, particularly those under 50, to opt against screening mammograms, said vice-chair of the task force Dr. Ainsley Moore.
“The evidence continues to show a close balance between potential benefits and harms of breast cancer screening,” Moore said by email. “This balance appears to be less favorable for younger women.”
The goal of mammograms is to detect tumors before they can be felt in a physical breast exam, catching cancer sooner when it’s easier to treat. Ideally, this should mean fewer women are diagnosed when tumors are bigger, rapidly growing, and harder to control.
But a growing body of evidence suggests that widespread breast cancer screening may catch more small, slow-growing tumors that are unlikely to be fatal, without curbing the number of cancers that are diagnosed at a late stage. And catching more small, slow-growing tumors may needlessly expose women to invasive follow-up testing and treatments.
For the current recommendations, researchers examined the latest evidence on the outcomes from screening mammograms, which are done for women without symptoms and do not include patients who feel a lump in their breast. Among other things, researchers examined 29 studies assessing the value women place on the anticipated benefits and harms from screening.