Molecular subtypes of breast cancer - predicting clinical benefits of radiotherapy after breast-conserving surgery - a propensity-score-matched cohort study

Q: What question does the study address about radiotherapy after breast-conserving surgery?

It examines whether molecular subtypes of breast cancer predict differences in the clinical benefits of radiotherapy after breast-conserving surgery, using a population-based cohort approach.

Q: How were patients compared between receiving radiotherapy and not receiving radiotherapy?

Patients were matched using propensity scores to balance confounding variables between those with and without radiotherapy within each molecular subtype.

Q: Which outcomes were evaluated in the study?

Local recurrence, regional recurrence, distant metastasis, disease-free survival, and overall survival were assessed across molecular subtypes after post-BCS radiotherapy.

Sep 24, 2026

Upload by Anna Hans

Molecular expression-based breast cancer subtypes are used to estimate outcomes, yet evidence remains limited on how subtypes affect radiotherapy (RT) efficacy after breast-conserving surgery (BCS), especially in population-level settings. This propensity-score-matched cohort study evaluated whether molecular subtype stratification influences post-BCS RT outcomes and which specific clinical benefits emerge. Using matched comparisons of RT vs no-RT within luminal and non-luminal subtypes, it quantified effects on recurrence, metastasis, and survival endpoints.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

Abstract

Background

Methods

Results

Conclusion

Introduction

Hung et al. Breast Cancer Research (2023) 25:149 [https://doi.org/10.1186/s13058-023-01747-9](https://doi.org/10.1186/s13058-023-01747-9) Breast Cancer Research RESEARCH Open Access Molecular subtypes of breast cancer predicting clinical benefits of radiotherapy after breast-conserving surgery: a propensity-score-matched cohort study Shih‑Kai Hung 1,2†, Hsuan‑Ju Yang1†, Moon‑Sing Lee 1,2, Dai‑Wei Liu2,3, Liang‑Cheng Chen1,2,4, Chia‑Hui Chew 1, Chun‑Hung Lin2,5, Cheng‑Hung Lee2,5, Szu‑Chin Li2,6, Chung‑Lin Hong6, Chih‑Chia Yu7, Ben‑Hui Yu1, Feng‑Chun Hsu 1, Wen‑Yen Chiou 1,2* and Hon‑Yi Lin 1,2,8* Abstract Background Based on the molecular expression of cancer cells, molecular subtypes of breast cancer have been applied to classify patients for predicting clinical outcomes and prognosis. However, further evidence is needed regarding the influence of molecular subtypes on the efficacy of radiotherapy (RT) after breast‑conserving surgery (BCS), particularly in a population‑based context. Hence, the present study employed a propensity‑score‑matched cohort design to investigate the potential role of molecular subtypes in stratifying patient outcomes for post‑BCS RT and to identify the specific clinical benefits that may emerge. Methods From 2006 to 2019, the present study included 59,502 breast cancer patients who underwent BCS from the Taiwan National Health Insurance Research Database. Propensity scores were utilized to match confound‑ ing variables between patients with and without RT within each subtype of breast cancer, namely luminal A, lumi‑ nal B/HER2‑negative, luminal B/HER2‑positive, basal‑like, and HER2‑enriched ones. Several clinical outcomes were assessed, in terms of local recurrence (LR), regional recurrence (RR), distant metastasis (DM), disease‑free survival (DFS), and overall survival (OS) . Results After post‑BCS RT, patients with luminal A and luminal B/HER2‑positive breast cancers exhibited a decrease in LR (adjusted hazard ratio [aHR] = 0 . 18, p < 0. 0001; and, 0 . 24, p = 0 . 0049, respectively) . Furthermore, reduced RRand improved DFS were observed in patients with luminal A (aHR = 0 . 15, p = 0 . 0004; and 0 . 29, p < 0. 0001), luminal B/ HER2‑negative (aHR = 0 . 06, p = 0 . 0093; and, 0 .46, p = 0 . 028), and luminal B/HER2‑positive (aHR = 0 . 14, p = 0 . 01; and, 0 . 38, p < 0. 0001) breast cancers. Notably, OS benefits were found in patients with luminal A (aHR = 0 . 62, p = 0 . 002), luminal B/HER2‑negative (aHR = 0 . 30, p < 0. 0001), basal‑like (aHR = 0 .40, p < 0. 0001), and HER2‑enriched (aHR = 0 . 50, p = 0 . 03), but not luminal B/HER2‑positive diseases. Remarkably, when considering DM, luminal A patients who received RT demonstrated a lower cumulative incidence of DM than those without RT (p = 0 . 02) . †Shih‑Kai Hung and Hsuan‑Ju Yang authors contribute equally. *Correspondence: Wen‑Yen Chiou [cwyncku@gmail.com](cwyncku@gmail.com)[ ](cwyncku@gmail.com)Hon‑Yi Lin [doc31221@gmail.com](doc31221@gmail.com) Full list of author information is available at the end of the article © The Author(s) 2023. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit [http://creativecommons.org/licenses/by/4.0/](http://creativecommons.org/license

FAQs

What question does the study address about radiotherapy after breast-conserving surgery?

It examines whether molecular subtypes of breast cancer predict differences in the clinical benefits of radiotherapy after breast-conserving surgery, using a population-based cohort approach.

How were patients compared between receiving radiotherapy and not receiving radiotherapy?

Patients were matched using propensity scores to balance confounding variables between those with and without radiotherapy within each molecular subtype.

Which outcomes were evaluated in the study?

Local recurrence, regional recurrence, distant metastasis, disease-free survival, and overall survival were assessed across molecular subtypes after post-BCS radiotherapy.

Sep 24, 2026

Upload by Anna Hans