Key clinical point: Omission of radiotherapy after breast-conserving surgery (BCS) increased local recurrence rates but did not affect distant recurrence rates or overall survival (OS) outcomes in women aged ≥65 years with low-risk, hormone receptor-positive (HR+), early breast cancer (BC).
Major finding: In patients who did not vs did receive radiotherapy, the cumulative incidence of local recurrence within 10 years was significantly higher (9.5% vs 0.9%; hazard ratio, 10.4; P < .001), but the 10-year cumulative incidence of distant recurrence (1.6% vs 3.0%) and OS (80.8% vs 80.7%) were not worsened.
Study details : Findings are from the phase 3, PRIME II trial including 1326 older patients with HR+, early BC who received adjuvant endocrine therapy after BCS and were randomly assigned to receive whole breast irradiation or no irradiation.
Disclosures: This study was supported by the Chief Scientist Office of the Scottish Government and other sources. DA Cameron declared serving as a consultant for several sources.
Source: Kunkler IH et al. Breast-conserving surgery with or without irradiation in early breast cancer. N Engl J Med. 2023;388(7):585-594 (Feb 16). Doi: 10.1056/NEJMoa2207586