Cancer Management and Research (Jul 2019)

Comparison of long-term results between radiotherapy after breast-conserving surgery and postmastectomy radiotherapy in stage T1-2N1M0 breast cancer

  • Lan XW,
  • Wen G,
  • He Z,
  • Huang JH,
  • Zou XB,
  • Lin X,
  • Tan YT,
  • Huang XB

Journal volume & issue
Vol. Volume 11
pp. 6477 – 6487

Abstract

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Xiao-Wen Lan,1,2,* Ge Wen,3,* Zhen He,4 Jiang-Hua Huang,1,2 Xue-Bin Zou,5 Xiao Lin,1,6 Yu-Ting Tan,1,6 Xiao-Bo Huang1–2,61Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, People’s Republic of China; 2Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, People’s Republic of China; 3Department of Radiation Oncology, The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou 510150, People’s Republic of China; 4Department of Oncology, The First Affiliation Hospital of Guangdong Pharmaceutical University, Guangzhou 510062, People’s Republic of China; 5Department of Ultrasound, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangdong 510060, People’s Republic of China; 6Department of Breast Tumor Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou 510120, People’s Republic of China*These authors contributed equally to this workPurpose: Postoperative radiotherapy (RT) can improve survival for T1-2N1 breast cancer. However, there exists a concern whether BCS plus RT has the same or a superior therapeutic effect as that of mastectomy. In this study, we aimed to compare the long-term results between RT after BCS and postmastectomy RT in stage T1-2N1M0 breast cancer.Patients and Methods: Totally 1816 pathological stage T1-2N1M0 breast cancer patients were analyzed. The propensity score matching (PSM) method was used to select 196 pairs of patients between BCS and mastectomy receiving postoperative RT. Five-year locoregional relapse (LRR), locoregional relapse-free survival (LRFS), distant metastasis (DM), distant metastasis-free survival (DMFS), disease-free survival (DFS), breast cancer-specific survival (BCSS) were analyzed as endpoints.Results: In the whole group, significant differences were observed in all endpoints (P<0.05) between the no-RT and RT groups. For patients receiving mastectomy, DM, DMFS, DFS and BCSS rates had no differences between the two groups. For patients without RT in the multivariable analysis, the molecular subtype was associated with each endpoint (P<0.05). Age, primary tumor site, tumor size, and LVI status were significantly associated with DM. The analysis of 196 pairs of patients selected by PSM showed that BCS plus RT resulted in a significantly lower 5-year DM rate (P=0.015) and superior survival in terms of the 5-year DMFS (P=0.046), DFS (P=0.049) and BCSS (P=0.024) compared with mastectomy.Conclusions: Postoperative radiotherapy remarkably improved survival in T1-2N1M0 breast cancer but not in the mastectomy subgroup, except for LRR and LRFS. Patients with BCS plus RT had better survival compared with those with postmastectomy radiation in terms of DM, DMFS, DFS and BCSS.Keywords: breast cancer, stage T1-2N1M0, radiotherapy, breast-conserving surgery, mastectomy

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