Regular Screening Mammograms May Significantly Reduce Breast Cancer Mortality, Swedish Study Shows
Patients who regularly attend screening mammograms may have a reduced risk of breast cancer mortality, according to recent findings presented by Smith et al at the Radiological Society of North America (RSNA) 2023 Scientific Assembly and Annual Meeting (Abstract R1-SSBR10-4).
Early breast cancer detection, prior to the presence of symptoms, may be critical to survival. According to the American Cancer Society, patients between the ages of 45 and 54 should undergo mammograms every year and those aged 55 and older can switch to every other year or continue with annual mammograms. Skipping just one scheduled mammogram may result in a more advanced breast cancer diagnosis, significantly impacting a patient’s chance of survival.
“The purpose of [screening] is to detect breast cancer during the few years it can be seen on a mammogram, but before symptoms are apparent,” explained lead study author Robert A. Smith, PhD, Senior Vice President and Director of the American Cancer Society Center for Cancer Screening. “If [patients] unknowingly has breast cancer and misses or postpones [their] mammogram during this time—when [they have] no symptoms, but [their] breast cancer is growing and perhaps spreading—then the window for early detection will be lost,” he stressed.
Although regular mammograms are often an important factor in early breast cancer detection, there are still many barriers that restrict patients from receiving this preventive care, including access, work, or family obligations. “It is challenging to keep track of your schedule, and in the [United States], many [patients] do not receive reminders. Further, for all of us, the obligations of work and family compete with our scheduled health care,” Dr. Smith added.
Study Methods and Results
In the recent study, investigators analyzed the screening mammogram history of 37,079 patients with breast cancer who visited oncology centers across Sweden from 1992 to 2016—with the goal of determining the impact of missing a mammogram. The investigators used the Swedish Cause of Death Register to identify 4,564 breast cancer deaths among the patients involved in the study. They then tracked the patients’ participation in five or fewer of the most recent invitations for breast cancer mammograms prior to cancer diagnosis.
The investigators discovered that the patients who attended all invited mammograms had a survival rate of more than 80%, whereas those who did not participate in any screenings had a survival rate ranging from 59.1% to 77.6%.
Additionally, the patients who attended all five mammograms experienced a 72% reduction in the risk of breast cancer mortality compared with those who did not participate in any mammograms. Even after conservatively adjusting for potential self-selection factors, the investigators reported a significant 66% reduction in the risk of breast cancer mortality in those who attended their mammograms.
“[Patients] who attended all five previous [mammogram] examinations prior to a diagnosis of breast cancer were nearly three times less likely to die from breast cancer compared with [patients[ who had not attended any examinations—and each additional examination attended among the five previous examinations conferred an additive protective effect against dying from breast cancer,” Dr. Smith emphasized.
The investigators proposed that imaging facilities should prioritize encouraging patients to attend their mammograms at the earliest opportunities. This may be especially important when patients have to cancel their appointments, at which point, the facilities should reschedule these screenings for the next earliest available appointment.
“These findings show that as much as possible, adherence to regular [mammograms] is the very best insurance a [patient] has against being diagnosed with…advanced breast cancer that could be life-threatening,” Dr. Smith concluded.The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.