Does HER2 status influence locoregional failure rates in breast cancer patients treated with mastectomy for pT1–2pN0 disease?

Abstract

Background: The impact of HER2 overexpression on the locoregional control of breast cancer is controversial.Patients and methods: Data on 906 women diagnosed with pT1–2pN0 breast cancer from 1986 to 1992 with known HER2 status and treated with a modified radical mastectomy without adjuvant radiotherapy or adjuvant trastuzumab were analyzed with respect to local relapse-free survival (LRFS), regional relapse-free survival (RRFS) and distant relapse-free survival (DRFS). Log-rank statistics were used to compare 10-year Kaplan–Meier curves of LRFS, RRFS and DRFS in HER2+ and HER2- patients.Results: Median follow-up was 12.8 years. HER2+ patients had a worse DRFS (P=0.028) but there was no statistically significant difference in LRFS or RRFS between HER2+ and HER2- patients (P=0.32 and 0.24 for LRFS and RRFS, respectively). Ten-year LRFS estimates among HER2+ patients was 91.3% and 86.9% for HER2- patients. Ten-year RRFS estimates for HER2+ and HER2- patients were 88.0% and 93.0%, respectively.Conclusion: HER2 overexpression was not associated with higher local or regional recurrence risk in subjects with pT1–2pN0 breast cancer following mastectomy and nodal dissection after a median follow-up of >12 years.