Locoregional Recurrence After Neoadjuvant Versus Adjuvant Chemotherapy

Locoregional Recurrence After Neoadjuvant Versus Adjuvant Chemotherapy Based on Tumor Subtypes in Patients With Early-stage Breast Cancer: A Multi-institutional Retrospective Cohort Study

Neoadjuvant chemotherapy (NACT) for early-stage breast cancer is associated with an increased risk of locoregional recurrence (LRR). However, few studies have conducted subgroup analyses of patients with various molecular subtypes, which are one of the determinant factors for treatments. The aim of the study is to investigate whether the risk of LRR after NACT varies across tumor subtypes. The investigators retrospectively reviewed the medical records of female breast cancer patients who underwent breast-conserving surgery at three institutions between January 1, 2004, and Dec 31, 2018.

Inclusion Criteria:

• Patients who underwent breast-conserving surgery for invasive breast cancer between 2004 and 2018

Exclusion Criteria:

• Total mastectomy
• No pre- or postoperative chemotherapy
• No radiation therapy
• Bilateral breast cancer
• Male breast cancer patients
• Secondary breast cancer
• Metachronous or synchronous cancers