This fall, Ontario is lowering the minimum age for access to regular mammography screening from age 50 to 40. Eligible patients will be able to self-refer for breast cancer screening rather than needing a referral.
To help unpack the change, three Sunnybrook experts provide their perspectives. They say the change is welcome – but patients in their 40s should still speak with their primary care provider about whether early mammography is right for them.
Dr. Lisa Del Giudice is a family physician and the regional primary care cancer lead for the Toronto Regional Cancer Program.
Dr. Ellen Warner is a medical oncologist at Sunnybrook’s Odette Cancer Centre who led a practice-changing study of breast cancer screening for high-risk patients.
Dr. Martin Yaffe is a senior scientist, Physical Sciences at the Odette Cancer Research Program.
How will this change current screening protocols?
LISA: Currently, only patients age 50-74 can self-refer for a screening mammogram. This means they can book their own appointment directly through the Ontario Breast Cancer Screening Program without a doctor’s referral. Patients in this age bracket also receive a recall letter every one to two years inviting them to be re-screened for breast cancer.
The change coming into effect this fall will mean patients in their 40s will also be able to self-refer for a mammogram if they wish. They can also continue to seek guidance and a referral from their primary care provider if they prefer. This will be a big shift from the status quo, where currently people age 40-49 who want a screening mammogram must discuss it with their primary care provider first, who will then refer them for the procedure.
Until now, how commonly have family doctors referred patients in their 40s for a screening mammogram if asked?
ELLEN: I think most (but not all) patients in this age group who have asked for a mammogram got a referral. Having a mammogram at this earlier age should be a nuanced discussion between a patient and a doctor.
LISA: I have heard of the rare situation where patients were told they did not qualify because they weren’t 50. Not all family doctors are aware they should discuss the pros and cons with the patient but still refer them if they want to be screened; there is definitely some confusion and room for improvement.
In the months ahead, we also expect that health authorities and regional cancer programs will be offering educational programming for family doctors to increase their understanding around screening protocols. Several new patient resources will also highlight the benefits and risks of screening people age 40-49, especially for people who do not have easy access to a primary care provider.
What are the pros and cons of screening mammograms that patients in their 40s should consider?
MARTIN: In 2023, Canadian researchers compared data from provinces which regularly screen patients in their 40s with data from those that don’t and concluded that earlier mammography screening leads to improved breast cancer survival rates.
Lowering the age at which people can self-refer gives them more control over decisions around earlier detection to prevent advanced cancer. That’s important knowing that people diagnosed with breast cancer earlier face the possibility of more years of life lost.
Also, by treating cancers found earlier, you may reduce the need for extensive surgery or other aggressive treatments, like radiation or chemotherapy.
Among the cons is the need for a screening recall, which happens when the result isn’t clear and secondary imaging is needed. Even though only a small number of these recalls will result in a diagnosis of cancer, the process can cause anxiety. If after that recall imaging there is still some suspicion, a biopsy may be done. While that’s not surgery, it involves needles which can be stressful and uncomfortable. There is also the risk of overdiagnosis. That means finding a real cancer, but one that is very slow growing and might have otherwise caused no harm because it wasn’t serious. Despite the fact it doesn’t cause risk, that patient is now a cancer patient. The challenge is that until a cancer is found and evaluated, the doctor doesn’t know if it’s slow growing or one that will be more aggressive.
One way we could reduce the anxiety associated with screening is to reduce the time it takes for a patient to be told that ‘everything is okay’ after recall imaging or a biopsy.
LISA: For people in their 40s, there is an increased risk of ‘false positives’, or screening recalls that do not find cancer, due to factors such as having denser premenopausal breasts. As Martin noted, this process can then lead to biopsies and other tests which can be anxiety-provoking. Patients need to consider their tolerance for false positives and whether they will be okay if they have to wait to have further tests done.
It is also worth noting there is weaker evidence to support systematic breast cancer screening among people age 40-49 compared to those age 50-74. On the other hand, there are people in their 40s who may be at higher risk of developing breast cancer, such as those with a family history, certain ethnic groups, and those of late childbearing age.
When family doctors are discussing screening mammography with patients, they need to help them weigh out all their individual risks and benefits.
What do you think of the change to Ontario’s breast cancer screening protocols?
ELLEN: Patients who want a mammogram should be able to get one. But it shouldn’t be misinterpreted as an endorsement for every single patient in their 40s to get screening mammography.
LISA: Cancer screening has many potential benefits and people have wanted this for some time. But I have also seen a lot of anxiety that can come from a false positive; it happens to more patients than you might think. In a perfect world, primary care providers will have the time to thoroughly discuss the pros and cons with individual patients.
MARTIN: Primary care doctors are busy and some may not fully understand the issues around screening, so better educational tools will help them. It’s worth noting that having a screening mammogram is not mandatory at any age. Providing clear and accurate information will help patients make the decision that is best for them.
As I referred to above, researchers have found that earlier screening leads to improved survival rates. Overall, this is something I’ve been pushing towards for over 20 years, so I think it’s great news. And it brings Ontario in line with several other provinces where patients can self-refer for a mammogram starting at age 40.
Any other thoughts regarding breast cancer screening?
MARTIN: There are other groups, including Black patients and other ethnic and racial minorities, who are at a higher risk for breast cancer in their 40s. Right now, we don’t have any special considerations in place around reducing barriers to care and providing more equitable health care for these individuals. Moving screening to age 40 will help some of these patients.
ELLEN: Screening everyone the same way based on their age and sex isn’t a terribly efficient way to do things. It would be nice to approach this in a more nuanced way. That means screening patients with a family history and those with a first pregnancy after age 35. There are a lot of models that look at risk and can help predict those patients who are most likely to get breast cancer, and therefore benefit from earlier screening. Continuing to research these risk-prediction models would be helpful.
LISA: It’s important to note that screening mammograms are for people who do not have any symptoms. Anyone who feels a lump or notices changes in their breast(s) should be assessed by a doctor or nurse practitioner and get a diagnostic mammogram and possibly an ultrasound. A diagnostic mammogram provides more detailed views of the breast and does require a referral.
