The benefit of adjuvant radiotherapy after breast conserving surgery in older patients with low risk breast cancer- a meta-analysis of randomized trials

Abstract

Purpose/Objective(s)It is currently unclear whether patients with low risk breast cancer receiving adjuvant endocrine therapy need adjuvant radiation therapy after breast conserving surgery. The data of randomized trials are available.Materials/MethodsIn a database search 5 randomized trials including in total 3766 mostly elderly patients with early stage breast cancer treated either with adjuvant endocrine therapy or with endocrine therapy and additional whole breast radiation after breast conserving surgery were identified. Published hazard ratios for time to local recurrence were the basis of our meta-analysis. Meta-analysis of the effect sizes on local recurrence was performed using a random effects model based on parameter estimates of log hazard ratios in Cox models and their standard errors. Furthermore, overall survival was examined.ResultsAdjuvant hormone therapy alone in mostly older patients with low risk breast cancer resulted in significantly shorter time to local relapse compared to radiation therapy combined with hormone therapy (Hazard Ratio: 6.8, 95% CI: 4.23–10.93, p < 0.0001) . There was no significant difference for overall survival.ConclusionAdditional radiation therapy to hormone therapy did improve local relapse in breast cancer patients but did not show significant impact on overall survival.

Male breast cancer in the United States: Treatment patterns and prognostic factors in the 21st century

“…In older women with early‐stage, ER+ tumors who are treated with BCS and hormonal therapy, additional radiotherapy may not improve overall survival, but in older men with similar disease, we noted a nonsignificant trend toward improved survival with radiotherapy (see Supporting Fig. 6B).…”

COVID-19: Global radiation oncology’s targeted response for pandemic preparedness

“…Patients with non-invasive disease who gain no survival benefit from breast radiotherapy should discuss omitting radiotherapy altogether [27]. Older patients with low risk disease who have minimal survival benefit from breast radiotherapy and much greater risk of mortality from COVID-19 should also consider omitting radiotherapy altogether [28] [29]. Patients with estrogen receptor positive breast cancer may also delay their radiotherapy treatment for up to 5 months with relative confidence if they are established on endocrine therapy and have received prior chemotherapy [30].…”

Changing practice patterns of adjuvant radiation among elderly women with early stage breast cancer in the United States from 2004 to 2014

“…However, these studies tend to include women younger than 70 years of age. More recently, the benefit of RT in older women has been called into question by several studies, including large randomized controlled trials (RCTs) . Two well‐powered prospective RCT addressing radiation in older women are the CALGB 9343 trial from 1994 to 1999 and the more recent larger PRIME II trial from 2003 to 2009 .…”