Post-mastectomy radiotherapy benefits subgroups of breast cancer patients with T1-2 tumor and 1-3 axillary lymph node(s) metastasis

Yu-Li Su; Shan-Hsuan Li; Yen-Yang Chen; Hui-Chun Chen; Yen Tang; Cheng-Hua Huang; Fong-Fu Chou; Shih-Chung Wu; Kun-Ming Rau

doi:10.2478/raon-2013-0085

Post-mastectomy radiotherapy benefits subgroups of breast cancer patients with T1-2 tumor and 1-3 axillary lymph node(s) metastasis

Radiol Oncol. 2014 Jul 10;48(3):314-22. doi: 10.2478/raon-2013-0085. eCollection 2014 Sep.

Authors

Yu-Li Su¹, Shan-Hsuan Li², Yen-Yang Chen¹, Hui-Chun Chen³, Yen Tang⁴, Cheng-Hua Huang¹, Fong-Fu Chou⁵, Shih-Chung Wu⁶, Kun-Ming Rau⁷

Affiliations

¹ Division of Hematology-Oncology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
² Division of Hematology-Oncology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan ; Chang Gung University, College of Medicine, Taoyuan, Taiwan.
³ Department of Radiation Oncology, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
⁴ Division of Hematology-Oncology, Department of Internal Medicine, E-Da Hospital, Kaohsiung, Taiwan.
⁵ Chang Gung University, College of Medicine, Taoyuan, Taiwan ; Department of General Surgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
⁶ Department of General Surgery, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.
⁷ Division of Hematology-Oncology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan ; Chang Gung University, College of Medicine, Taoyuan, Taiwan ; Cancer Center, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan.

Abstract

Background: To determine the role of postmastectomy radiotherapy (PMRT) in breast cancer patients with T1-2 and N1 disease.

Patients and methods: A total of 207 postmastectomy women were enrolled. The 5-year Kaplan-Meier estimates of locoregional recurrence rate (LRR), distant recurrence rate (DRR) and overall survival (OS) were analyzed by different tumor characteristics. Multivariate analyses were performed using Cox proportional hazards modeling.

Results: With median follow-up 59.5 months, the 5-year LRR, DRR and OS were 9.1%, 20.3% and 84.4%, respectively. On univariate analysis, age < 40 years old (p = 0.003) and Her-2/neu over-expression (p = 0.016) were associated with higher LRR, whereas presence of LVI significantly predicted higher DRR (p = 0.026). Negative estrogen status (p = 0.033), Her-2/neu overexpression (p = 0.001) and LVI (p = 0.01) were significantly correlated with worse OS. PMRT didn't prove to reduce 5-year LRR (p = 0.107), as well as 5-year OS (p = 0.918). In subgroup analysis, PMRT showed significant benefits of improvement LRR and OS in patients with positive LVI.

Conclusions: For patients with T1-2 and N1 stage breast cancer, PMRT can decrease locoregional recurrence and increase overall survival only in patients with lymphovascular invasion.

Keywords: breast cancer; locoregional recurrence; lymphovascular invasion; overall survival; postmastectomy radiotherapy.