Effectiveness of radiotherapy after breast-conserving surgery in older patients with T1-2N0 breast cancer

Journal article (2019)

Authors

Anna Z. de Boer Leiden University Medical Center
E. Bastiaannet Leiden University Medical Center
Nienke A. de Glas Leiden University Medical Center
P.J. Marang-van de Mheen Leiden University Medical Center
Olaf M. Dekkers Leiden University Medical Center
Sabine Siesling University of Twente, Netherlands Comprehensive Cancer Organisation (IKNL)
Linda de Munck Netherlands Comprehensive Cancer Organisation (IKNL)
Kelly M. de Ligt Netherlands Comprehensive Cancer Organisation (IKNL), University of Twente
Johanneke E.A. Portielje Leiden University Medical Center
Gerrit Jan Liefers Leiden University Medical Center
Affiliation
External organisation
Breast cancer Older patients Breast-conserving treatment Locoregional recurrence
More Info
expand_more

Published Date

2019

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Affiliation

External organisation

Abstract

Purpose: In the Netherlands, radiotherapy after breast-conserving surgery (BCS) is omitted in up to 30% of patients aged ≥ 75 years. Although omission of radiotherapy is considered an option for older women treated with endocrine treatment, the majority of these patients do not receive systemic treatment following Dutch treatment guidelines. Therefore, the aim of this study was to evaluate the effect of omission of radiotherapy on locoregional recurrence risk in this patient population. Methods: Patients aged ≥ 75 years undergone BCS for T1-2N0 breast cancer diagnosed between 2003 and 2009 were selected from the Netherlands Cancer Registry. To minimize confounding by indication, hospital variation was used to assess the impact of radiotherapy-use on locoregional recurrence risk using cox proportional hazards regression. Hazards ratios with 95% confidence interval (CI) were estimated. Results: Overall, 2390 patients were included. Of the patients with hormone receptor-positive breast cancer, 39.3% received endocrine treatment. Five-year incidences of locoregional recurrence were 1.9%, 2.8%, and 3.0% in patients treated at hospitals with higher (average radiotherapy-use 96.0%), moderate (88.0%), and lower radiotherapy-use (72.2%) respectively, and nine-year incidences were 2.2%, 3.1%, and 3.2% respectively. Adjusted hazard ratios were 1.46 (95% CI 0.77–2.78) and 1.50 (95% CI 0.79–2.85) for patients treated at hospitals with moderate and lower radiotherapy-use, compared to patient treated at hospitals with higher radiotherapy-use. Conclusions: Despite endocrine treatment in only 39.3%, locoregional recurrence risk was low, even in patients treated at hospitals with lower radiotherapy-use. This provides reasonable grounds to consider omission of radiotherapy in patients aged ≥ 75 years with T1-2N0 breast cancer.