Site Editor
William J. Gradishar, MD, FACP, FASCO
William J. Gradishar, MD, FACP, FASCO
Posted: Thursday, June 9, 2022
Women aged at least 55 years with grade 1 or 2 T1 N0 luminal A breast cancer who underwent breast-conserving surgery and adjuvant endocrine therapy alone experienced very low rates of local recurrence at 5 years, according to Timothy Joseph Whelan, BM, BCh, FRCPC, FASCO, of McMaster University, Hamilton, Ontario, and colleagues. The results of the prospective multicenter LUMINA study, which were presented during the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract LBA501), suggested these older women may be candidates for omission of radiotherapy.
“Traditional clinical pathologic factors alone are limited in their ability to identify women with a low enough risk of local recurrence to omit radiotherapy,” the investigators remarked. “Molecular-defined intrinsic subtypes of breast cancer provide additional prognostic information, with luminal A having the lowest risk of recurrence.”
Between August 2013 and July 2017, 501 patients with estrogen receptor–positive, progesterone receptor–positive, HER2-negative breast cancer who had a Ki67 of less than or equal to 13.25% were classified as luminal A and enrolled in this study. The median age was 67, and the median tumor size was 1.1 cm. After undergoing breast-conserving surgery, the patients were not administered radiotherapy. Follow-up data were provided for a median of 5 years.
A total of 10 events of local recurrence, as well as 8 contralateral breast cancers, 12 relapse-free survival, 47 disease-free survival, and 13 overall survival events, were reported at 5 years. The 5-year rates of these outcomes were 2.3%, 1.9%, 97.3%, 89.9%, and 97.2%, respectively; according to the investigators, at this time point, the rate of local recurrence satisfied the prespecified boundary.
“This exciting data is very reassuring and could impact a large number of patients with cancer who have very low chances of their breast cancer returning even without radiation therapy,” said ASCO expert in radiation oncology Corey Wayne Speers, MD, PhD, of the University of Michigan Rogel Cancer Center.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.
JNCCN Spotlights
