J Cancer 2019; 10(25):6225-6232. doi:10.7150/jca.35204

Research Paper

Effects of Postoperative Radiotherapy in Early Breast Cancer Patients Older than 75 Years: A Propensity-Matched Analysis

Linghui Zhou1,2*, Pengtao Yang2*, Yi Zheng1*, Tian Tian1,2, Cong Dai1, Meng Wang2, Shuai Lin2, Yujiao Deng1,2, Qian Hao1,2, Zhen Zhai1,2, Hongtao Li3✉, Zhijun Dai1✉

1. Department of Breast Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China.
2. Department of Oncology, The 2nd Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, Shaanxi, China.
3. Department of Breast Head and Neck surgery, The 3rd Affiliated Teaching Hospital of Xinjiang Medical University (Affiliated Tumor Hospital), Urumqi 830000, Xinjiang, China.
* LH Z, PT Y and Y Z contributed equally to this work.

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Citation:
Zhou L, Yang P, Zheng Y, Tian T, Dai C, Wang M, Lin S, Deng Y, Hao Q, Zhai Z, Li H, Dai Z. Effects of Postoperative Radiotherapy in Early Breast Cancer Patients Older than 75 Years: A Propensity-Matched Analysis. J Cancer 2019; 10(25):6225-6232. doi:10.7150/jca.35204. Available from http://www.jcancer.org/v10p6225.htm

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Abstract

Background: Currently, there is still some controversy regarding whether early breast cancer patients with a tumor size of ≤5 cm and 1-3 positive lymph nodes should undergo postoperative radiotherapy (PRT).

Materials and Methods: We obtained data from the Surveillance, Epidemiology, and End Results (SEER) 18 database. Then, we conducted propensity score matching (PSM), according to the radiotherapy record. The Kaplan-Meier and Cox regression analysis were conducted to explore prognostic factors in breast cancer.

Results: A total of 6,777 patients aged 75+ years old were eligible and 2,361 patients were included after PSM. We found PRT could improve patient overall survival (OS) (P = 0.01, hazard ratio [HR] = 0.88, 95% confidence interval [CI], 0.80-0.97). Subgroup analysis revealed PRT could improve OS in patients with hormone receptor positive (HR+) (P = 0.001, HR = 0.84, 95% CI, 0.76 - 0.94) or white patients (P =0.004, HR = 0.86, 95% CI, 0.77 - 0.95).

Conclusions: PRT may benefit for elderly women with early breast cancer, especially in HR+ patients or white patients. These findings may inform future optimized options whether elderly female patients with early breast cancer should undergo postoperative radiotherapy.

Keywords: postoperative radiotherapy, early breast cancer, seer database, propensity score matching, prognosis