De-escalating adjuvant therapies in older patients with lower risk estrogen receptor-positive breast cancer treated with breast-conserving surgery: A systematic review and meta-analysis.

Abstract

PURPOSE:

Radiation therapy (RT) and endocrine therapy (ET) are standard treatments for hormone receptor-positive (HR+) breast cancer after breast-conserving surgery (BCS). However, many older patients are at greater risk of treatment-related toxicities and non-cancer related death, and less likely to benefit from these standard treatments. A systematic review was performed evaluating outcomes of omitting RT or ET in older patients aged ≥50 treated with BCS for lower-risk breast cancer.

METHODS:

Medline, Embase, and the Cochrane Register of Controlled Trials were queried from 1980 to April 30th, 2020 for randomized controlled studies (RCTs) and prospective cohort studies (PCSs) evaluating omission of RT and/or ET compared to RT plus ET in patients. Meta-analysis was performed using random-effects models with findings reported as risk ratios (RR) with 95% confidence intervals (CI).

RESULTS:

From 3860 citations, 10 prospective studies met eligibility criteria. Omission of RT alone was evaluated in 7 RCTs (n = 4604) and one PCS (n = 667); omission of ET alone was assessed in 1 PCS (n = 271); and omission of either ET or RT was compared to ET plus RT in 1 RCT (n = 495). Adjuvant RT compared to no RT reduced 5- and 10-year in-breast tumor recurrence [5-year: RR 0.16, 95 %CI 0.09-0.27 l 10-year: 0.28, 95 %CI 0.16-0.5], but had no effect on survival [5-year: RR 0.94, 95 %CI 0.77-1.15; 10-year: 1.01, 95 %CI 0.9-1.12].

CONCLUSION:

The current body of evidence suggests that RT can be omitted in older patients with lower-risk disease. However, more trials on the omission of ET are required to better inform treatment decisions.

• Authors: Marie-France Savard, Mark Clemons, Brian Hutton, Meshari Jemaan Alzahrani, Jean-Michel Caudrelier, Lisa Vandermeer, Michelle Liu, Deanna Saunders, Marta Sienkiewicz, Carol Stober, Katherine Cole, Risa Shorr, Angel Arnaout, Lynn Chang
• Journal: Cancer treatment reviews (Cancer Treat Rev) Vol. 99 Pg. 102254 (Sep 2021) ISSN: 1532-1967 [Electronic] Netherlands
• PMID: 34242928 (Publication Type: Journal Article, Meta-Analysis, Systematic Review)
• Copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.

Chemical References

• Antineoplastic Agents, Hormonal
• Receptors, Estrogen

Topics

• Age Factors
• Antineoplastic Agents, Hormonal
• Breast Neoplasms (metabolism, surgery, therapy)
• Chemotherapy, Adjuvant
• Clinical Trials, Phase III as Topic
• Female
• Humans
• Mastectomy, Segmental (methods)
• Radiotherapy, Adjuvant
• Randomized Controlled Trials as Topic
• Receptors, Estrogen (metabolism)
• Risk Factors