Patients typically undergo radiotherapy after breast-conserving surgery to minimize the risk of local recurrence. However, the side effects and costs of radiation are no easy burden to bear.
Researchers are looking to explore alternative options for some patients—and they may have found one.
A new analysis in the New England Journal of Medicine looked into whether patients with luminal A breast cancer can skip extra radiation treatments after breast-conserving surgery.[1] The team behind the study believe their results could reshape treatment protocols going forward.
Luminal A breast cancer is characterized by distinct hormone receptor and growth factor receptor statuses. The study focused on women aged 55 or above who had undergone breast-conserving surgery for T1N0 (tumor size <2 cm and node negative), grade 1 or 2, all of whom had luminal A breast cancer subtype.
Conducted between August 2013 and July 2017, 740 patients met the eligibility criteria. Out of these, 500 were enrolled. Patients with a Ki67 index of 13.25% or less were included. The median patient age was 67.1 years, with tumor sizes ranging from 0.7 to 1.4 cm. Patients enrolled in the study had also received adjuvant endocrine therapy, including aromatase inhibitors or tamoxifen.
At the five-year mark, the study observed a local recurrence rate of 2.3% in the breast among the enrolled patients, which aligns with the acceptable risk threshold. Notably, contralateral breast cancer occurred in 1.9% of patients, and an overall recurrence rate of 2.7% was observed. Typically, breast cancer recurrence rates are as high as 6% within the first five years.
The study's authors noted that limiting radiotherapy after breast-conserving surgery would allow physicians to offer more patient-friendly treatment approaches instead. However, they warned that there are limitations to these findings.
“We selected a group of women at low risk on the basis of traditional clinicopathologic factors and a molecular biomarker, and we carefully treated and followed patients prospectively. Our results are generalizable to this group and should not be extrapolated to other groups,” wrote Timothy J. Whelan, BM, BCh, with the department of oncology at McMaster University, and colleagues.
While further research and validation are required, these findings contribute to the ongoing conversation about individualized breast cancer treatment, highlighting the role of evidence-based research in customizing medical treatment plans for specific patient populations.
The study was funded by the Canadian Cancer Society and the Canadian Breast Cancer Foundation.
Chad is an award-winning writer and editor with over 15 years of experience working in media. He has a decade-long professional background in healthcare, working as a writer and in public relations.