Adjuvant radiotherapy alone, an effective treatment option for early-stage low- risk breast cancer in women over 50: results from a population based cohort study using a Canadian provincial database

IF 5.3 1区医学 Q1 ONCOLOGY

Radiotherapy and Oncology Pub Date : 2025-09-29 DOI:10.1016/j.radonc.2025.111175

Kurian Joseph , Ayoola Ademola , Julia Zebak , Armaan Singh , Hanxiao Zuo , Heather Warkentin , Aswin Abraham , Zsolt Gabos , Keith Tankel , Susan Chafe , Karen King

{"title":"Adjuvant radiotherapy alone, an effective treatment option for early-stage low- risk breast cancer in women over 50: results from a population based cohort study using a Canadian provincial database","authors":"Kurian Joseph , Ayoola Ademola , Julia Zebak , Armaan Singh , Hanxiao Zuo , Heather Warkentin , Aswin Abraham , Zsolt Gabos , Keith Tankel , Susan Chafe , Karen King","doi":"10.1016/j.radonc.2025.111175","DOIUrl":null,"url":null,"abstract":"<div><h3>Purpose</h3><div>Breast conserving surgery (BCS) is the primary treatment for early-stage breast cancer(EBC). Typically, adjuvant endocrine therapy (ET) and radiation therapy (RT) are standard treatments offered for EBC. However, non-compliance and toxicity remain as issues with HT and many patients choose adjuvant RT alone. The benefit of adjuvant RT alone in women with low-risk EBC remains unclear. It is hypothesized that adjuvant RT-alone can improve outcomes in low-risk EBC patients, similar to ET alone or RT + ET combination.</div></div><div><h3>Methods</h3><div>This population-based study identified women aged 50–80 with T1, N0, Estrogen receptor positive (ER + ve), human epidermal growth receptor-2 negative(Her-2/neu-ve) EBC treated with BCS, followed by adjuvant treatments (RT-alone, ET-alone, or RT + ET combination) from 2010 to 2015. Primary outcomes were recurrence free survival (RFS), overall survival (OS), and breast cancer specific survival (BCSS).</div></div><div><h3>Results</h3><div>2810 patients were identified. Median follow-up was 73 months(Interquartile <span><math><mrow><mfenced><mrow><msub><mi>Q</mi><mn>1</mn></msub><mo>,</mo><mspace></mspace><mspace></mspace><msub><mi>Q</mi><mn>3</mn></msub></mrow></mfenced><mrow><mo>:</mo><mspace></mspace><mn>55.0</mn><mo>,</mo><mspace></mspace><mn>91.6</mn><mo>)</mo></mrow></mrow></math></span>. Adjuvant treatments were: BCS only 216 (8 %), RT alone 803 (29 %), ET alone 274 (10 %), and RT + ET combination 1517 (54 %). 398 patients (22.2 %) completed 5-years of ET. Compared to BCS alone, there was no statistically significant difference between treatment groups for RFS and BCSS. There were significant difference among the treatment groups for OS compared to BCS alone: Hazard ratio (HR) 0.66 (95 % confidence interval (CI): 0.45 – 0.97) for RT alone, 0.55 (95 % CI: 0.35 – 0.87) for ET alone, and 0.48 (95 % CI: 0.33 – 0.70) for RT + ET combination. Determinants of OS were age, tumor grade, comorbidities, and adjuvant therapy.</div></div><div><h3>Conclusions</h3><div>Our population-based cohort study showed that there was no statistically significant difference in RFS and BCSS among various adjuvant treatments versus BCS alone. However, RT alone, ET alone and RT + ET combination resulted in a statistically significant improvement in OS compared to BCS alone. Our findings support RT alone can be a viable alternative to ET + RT combination for women over 50 with low-risk EBC. Ongoing studies like EUROPA, REaCT trial and EPOPE will provide more insight into the role of RT alone as a definite treatment option.</div></div>","PeriodicalId":21041,"journal":{"name":"Radiotherapy and Oncology","volume":"213 ","pages":"Article 111175"},"PeriodicalIF":5.3000,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Radiotherapy and Oncology","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167814025051795","RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ONCOLOGY","Score":null,"Total":0}

引用次数: 0

Abstract

Purpose

Breast conserving surgery (BCS) is the primary treatment for early-stage breast cancer(EBC). Typically, adjuvant endocrine therapy (ET) and radiation therapy (RT) are standard treatments offered for EBC. However, non-compliance and toxicity remain as issues with HT and many patients choose adjuvant RT alone. The benefit of adjuvant RT alone in women with low-risk EBC remains unclear. It is hypothesized that adjuvant RT-alone can improve outcomes in low-risk EBC patients, similar to ET alone or RT + ET combination.

Methods

This population-based study identified women aged 50–80 with T1, N0, Estrogen receptor positive (ER + ve), human epidermal growth receptor-2 negative(Her-2/neu-ve) EBC treated with BCS, followed by adjuvant treatments (RT-alone, ET-alone, or RT + ET combination) from 2010 to 2015. Primary outcomes were recurrence free survival (RFS), overall survival (OS), and breast cancer specific survival (BCSS).

Results

2810 patients were identified. Median follow-up was 73 months(Interquartile

(Q_{1}, Q_{3}) : 55.0, 91.6)

. Adjuvant treatments were: BCS only 216 (8 %), RT alone 803 (29 %), ET alone 274 (10 %), and RT + ET combination 1517 (54 %). 398 patients (22.2 %) completed 5-years of ET. Compared to BCS alone, there was no statistically significant difference between treatment groups for RFS and BCSS. There were significant difference among the treatment groups for OS compared to BCS alone: Hazard ratio (HR) 0.66 (95 % confidence interval (CI): 0.45 – 0.97) for RT alone, 0.55 (95 % CI: 0.35 – 0.87) for ET alone, and 0.48 (95 % CI: 0.33 – 0.70) for RT + ET combination. Determinants of OS were age, tumor grade, comorbidities, and adjuvant therapy.

Conclusions

Our population-based cohort study showed that there was no statistically significant difference in RFS and BCSS among various adjuvant treatments versus BCS alone. However, RT alone, ET alone and RT + ET combination resulted in a statistically significant improvement in OS compared to BCS alone. Our findings support RT alone can be a viable alternative to ET + RT combination for women over 50 with low-risk EBC. Ongoing studies like EUROPA, REaCT trial and EPOPE will provide more insight into the role of RT alone as a definite treatment option.

查看原文本刊更多论文

单独辅助放疗是50岁以上妇女早期低风险乳腺癌的有效治疗选择：来自加拿大省级数据库的基于人群的队列研究结果。

目的：保乳手术是早期乳腺癌（EBC）的主要治疗方法。通常，辅助内分泌治疗（ET）和放射治疗（RT）是EBC的标准治疗方法。然而，不顺应性和毒性仍然是HT的问题，许多患者选择单独辅助RT。对于低风险EBC患者，单纯辅助放疗的益处尚不清楚。假设辅助RT单独可以改善低风险EBC患者的预后，类似于ET单独或RT + ET联合。方法：这项基于人群的研究确定了年龄在50-80岁的女性，她们在2010年至2015年期间接受BCS治疗，T1, N0，雌激素受体阳性（ER + ve），人表皮生长受体2阴性（Her-2/ new -ve） EBC，随后接受辅助治疗（RT单独，ET单独或RT + ET联合）。主要结局是无复发生存期（RFS）、总生存期（OS）和乳腺癌特异性生存期（BCSS）。结果：共发现2810例患者。中位随访时间为73 个月（四分位数Q1，Q3:55.0,91.6）。辅助治疗：BCS仅216例（8 %），RT单独803例（29 %），ET单独274例（10 %），RT + ET联合1517例（54 %）。398例患者（22.2% %）完成了5年的ET治疗。与单独使用BCS相比，RFS和BCSS治疗组之间无统计学差异。治疗组间OS与单独BCS相比有显著差异：单独RT的风险比（HR）为0.66(95 %可信区间（CI）： 0.45 - 0.97)，单独ET的风险比（HR）为0.55(95 % CI: 0.35 - 0.87)， RT + ET联合的风险比（HR）为0.48(95 % CI: 0.33 - 0.70)， OS的决定因素为年龄、肿瘤分级、合并症和辅助治疗。结论：我们基于人群的队列研究显示，各种辅助治疗与单独使用BCS相比，RFS和BCSS没有统计学差异。然而，与单独BCS相比，单独RT，单独ET和RT + ET联合治疗的OS改善具有统计学意义。我们的研究结果支持，对于50岁以上的低风险EBC女性，单独RT可以替代单独ET或ET + RT联合治疗。正在进行的研究，如EUROPA， REaCT试验和EPOPE，将提供更多关于单独放疗作为明确治疗选择的作用。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Radiotherapy and Oncology 医学-核医学

CiteScore

10.30

自引率

10.50%

发文量

2445

审稿时长

45 days

期刊介绍： Radiotherapy and Oncology publishes papers describing original research as well as review articles. It covers areas of interest relating to radiation oncology. This includes: clinical radiotherapy, combined modality treatment, translational studies, epidemiological outcomes, imaging, dosimetry, and radiation therapy planning, experimental work in radiobiology, chemobiology, hyperthermia and tumour biology, as well as data science in radiation oncology and physics aspects relevant to oncology.Papers on more general aspects of interest to the radiation oncologist including chemotherapy, surgery and immunology are also published.