When early-stage breast cancer patients have a lumpectomy or unilateral mastectomy, they are typically invited for annual mammograms after their treatment. This can understandably be a big source of stress for the survivor, but is screening of this frequency necessary? A new study finds it might not be, for some patients.
According to research presented at the recent San Antonio Breast Cancer Symposium, for certain survivors, getting a mammogram every two or three years after early-stage breast cancer surgery is not linked with worse outcomes than getting an annual screening. This was among women who were diagnosed at the age of 50 or older and were several years past their surgery.
The researchers say the best approach to screening hasn’t been extensively researched in large trials, but there may be benefits to less frequent mammograms if it doesn’t cause additional risk.
Dr. Janet Dunn, professor of clinical trials at the University of Warwick in England, says, “De-escalation of mammographic surveillance reduces the burden on the health care system, decreases the inconvenience for women having to undergo these mammograms, and reduces the associated stress of waiting for results.”
To test whether this de-escalation is still safe, the researchers enrolled 5,235 women into their phase III Mammo-50 trial. All of them had undergone breast cancer surgery, were 50 or older when diagnosed, and had been cancer-free for three years after the surgery.
The women were split evenly into a group that had annual mammograms and a group that was screened every two or three years, two for those who had a lumpectomy and three for those who had a mastectomy.
After five years of follow-up, the annual screeners had a 98.1% breast cancer survival rate and a 94.7% overall survival rate, compared with 98.3% and 94.5% in the de-escalated screening group. Meanwhile, there was breast cancer recurrence in 5.9% of the first group and 5.5% of the second. A sub-study measuring quality of life was conducted at the same time, finding that there were no differences in mental wellbeing, distress, or other concerns.
The findings indicate that less frequent screening may be beneficial for some patients, though the researchers note that the study was limited to women diagnosed when they were at least 50 and who were already recurrence-free for three years.
However, Dr. Dunn says, “The trial demonstrated that the outcomes from undergoing less frequent mammograms were no worse than undergoing annual mammograms for this group of women. It is important to carry out these types of trials to streamline services where possible while not disadvantaging patients.”
Current guidelines in the United Kingdom call for annual mammograms for five years after early-stage breast cancer surgery, while in the United States, it’s recommended indefinitely.
According to the American Cancer Society, annual mammograms should not be needed when a patient has a double mastectomy, though if only one breast is removed, screening is still needed in the other one.