Breast Radiation Therapy-Related Treatment Outcomes in Patients With or Without Germline Mutations on Multigene Panel Testing.

Authors

Bhavana V Chapman
Diane Liu
Yu Shen
Oluwafikayo O Olamigoke
David S Lakomy
Angelica M Gutierrez Barrera
Shane R Stecklein
Gabriel O Sawakuchi
Scott J Bright
Isabelle Bedrosian
Jennifer K Litton
Benjamin D Smith
Wendy A Woodward
George H Perkins
Karen E Hoffman
Michael C Stauder
Eric A Strom
Banu K Arun
Simona F Shaitelman

Publication Date

2-1-2022

Journal

International Journal of Radiation Oncology, Biology, Physics

Abstract

PURPOSE: Multigene panel testing has increased the detection of germline mutations in patients with breast cancer. The implications of using radiation therapy (RT) to treat patients with pathogenic variant (PV) mutations are not well understood and have been studied mostly in women with only BRCA1 or BRCA2 PVs. We analyzed oncologic outcomes and toxicity after adjuvant RT in a contemporary, diverse cohort of patients with breast cancer who underwent genetic panel testing.

METHODS AND MATERIALS: We retrospectively reviewed the records of 286 women with clinical stage I-III breast cancer diagnosed from 1995 to 2017 who underwent surgery, breast or chest wall RT with or without regional nodal irradiation, multigene panel testing, and evaluation at a large cancer center's genetic screening program. We evaluated rates of overall survival, locoregional recurrence, disease-specific death, and radiation-related toxicities in 3 groups: BRCA1/2 PV carriers, non-BRCA1/2 PV carriers, and patients without PV mutations.

RESULTS: PVs were detected in 25.2% of the cohort (12.6% BRCA1/2 and 12.6% non-BRCA1/2). The most commonly detected non-BRCA1/2 mutated genes were ATM, CHEK2, PALB2, CDH1, TP53, and PTEN. The median follow-up time for the entire cohort was 4.4 years (95% confidence interval, 3.8-4.9 years). No differences were found in overall survival, locoregional recurrence, or disease-specific death between groups (P > .1 for all). Acute and late toxicities were comparable across groups.

CONCLUSION: Oncologic and toxicity outcomes after RT in women with PV germline mutations detected by multigene pane testing are similar to those in patients without detectable mutations, supporting the use of adjuvant RT as a standard of care when indicated.

Keywords

BRCA1 Protein, Breast Neoplasms, Female, Genes, BRCA2, Genetic Predisposition to Disease, Germ-Line Mutation, Humans, Neoplasm Recurrence, Local, Retrospective Studies, Treatment Outcome

DOI

10.1016/j.ijrobp.2021.09.026

PMID

34582940

PMCID

PMC8748284

PubMedCentral® Posted Date

2-1-2023

PubMedCentral® Full Text Version

Author MSS

Published Open-Access

yes