by Junsheng Zhang, Ciqiu Yang, Chuqian Lei, Yi Zhang, Fei
Ji, Hongfei Gao, Mei Yang, Liulu Zhang, Jieqing Li, Teng Zhu, Weiping Li,
Xiaosheng Zhuang, Kun Wang
The Breast: Published:
March 31, 2021
Background
Previous studies revealed that patients with early-stage
metaplastic breast cancer (MBC) underwent mastectomy more often than
breast-conserving therapy (BCT) mainly due to the larger tumor size. This study
was performed to compare the survival outcomes following BCT versus mastectomy
for patients with early-stage MBC.
Methods
Surveillance, Epidemiology, and End Results (SEER) database
was used to identify women diagnosed with early-stage MBC (T1-3N0-3M0) between
2001 and 2016, who were treated with either BCT or mastectomy. We assessed
overall survival (OS) and breast cancer-specific survival (BCSS) using the
Kaplan-Meier method and hazard ratios using Cox proportional hazards models.
Results
A total of 2412 MBC patients were identified, 881 (36.5%) of
whom underwent BCT and 1531(63.5%) underwent mastectomy. The median follow-up
time was 73 months. Most of patients had older age (≥50 years old), larger
tumor size, higher American Joint Committee on Cancer (AJCC) stage and hormone
receptor negativity. After adjustment for confounding variables, patients who
underwent BCT had significantly improved OS (5-year OS: 84.3% vs 62.5%; 10-year
OS: 73.0% vs 52.1%; adjusted HR=0.76, 95%CI: 0.59-0.97, p=0.028) and BCSS
(5-year BCSS: 89.1% vs 70.8%; 10-year BCSS: 83.9% vs 67.5%; adjusted HR=0.72,
95%CI: 0.53-0.96, p=0.026) than those who underwent mastectomy, and this
improvement remained significant for all T and N stages of MBC except for N2-3
stage.
Conclusion
BCT conferred improved OS and BCSS compared with mastectomy
for patients with early-stage MBC, and the improvement persisted in almost all
of the subgroups of different T and N stages.
