Breast Conservation Surgery and Mastectomy have Similar Locoregional Recurrence Following Neoadjuvant Chemotherapy

Abstract

Neoadjuvant chemotherapy (NAC) increases rates of successful breast-conserving surgery (BCS) in patients with breast cancer. However, some studies suggest that BCS after NAC may confer an increased risk of locoregional recurrence (LRR). We assessed LRR rates and locoregional recurrence-free survival (LRFS) in patients enrolled on I-SPY2 (NCT01042379), a prospective NAC trial for patients with clinical stage II to III, molecularly high-risk breast cancer. Cox proportional hazards models were used to evaluate associations between surgical procedure (BCS vs mastectomy) and LRFS adjusted for age, tumor receptor subtype, clinical T category, clinical nodal status, and residual cancer burden (RCB). In 1462 patients, surgical procedure was not associated with LRR or LRFS on either univariate or multivariate analysis. The unadjusted incidence of LRR was 5.4% after BCS and 7.0% after mastectomy, at a median follow-up time of 3.5 years. The strongest predictor of LRR was RCB class, with each increasing RCB class having a significantly higher hazard ratio for LRR compared with RCB 0 on multivariate analysis. Triple-negative receptor subtype was also associated with an increased risk of LRR (hazard ratio: 2.91, 95% CI: 1.8–4.6, P < 0.0001), regardless of the type of operation. In this large multi-institutional prospective trial of patients completing NAC, we found no increased risk of LRR or differences in LRFS after BCS compared with mastectomy. Tumor receptor subtype and extent of residual disease after NAC were significantly associated with recurrence. These data demonstrate that BCS can be an excellent surgical option after NAC for appropriately selected patients.

De-Escalation Surgery in cT3-4 Breast Cancer Patients after Neoadjuvant Therapy: Predictors of Breast Conservation and Comparison of Long-Term Oncological Outcomes with Mastectomy

“…Additionally, Werutsky et al [ 41 ] conducted a pooled analysis of 10,075 primary patients with BC treated with NAT, revealing 5-year loco-regional recurrence rates of 7.8% in the BCS group and 11.3% in those undergoing mastectomy. In the I-SPY2 trial, a prospective, randomized study, Mukhtar et al [ 42 ] evaluated the relationship between NAT response, assessed via the residual cancer burden (RCB) method, and loco-regional recurrence in 1462 patients with BC who received surgical treatment (BCS or mastectomy) from 2010 to 2021. With a median follow-up of 3.5 years, loco-regional recurrences were observed in 5.4% of BCS patients and 7.0% of mastectomy patients ( p = 0.18).…”

Breast-conserving surgery is not associated with increased local recurrence in patients with early-stage node-negative triple-negative breast cancer treated with neoadjuvant chemotherapy

“…Recently, a retrospective report from the I-SPY2 trial was published [ 37 ]. The authors analyzed the locoregional outcome of 1462 patients according to the type of surgery.…”

Breast surgery after neoadjuvant systemic therapy

“…The 4-year LR-free survival was 96.2% (95% CI: 94.5–97.9%) for the entire cohort, with no difference between the BCS-eligible patients, BCS-ineligible patients who downstaged and chose BCS, and those who downstaged and chose mastectomy (4-year LR-free survival 98.1% vs. 93.7% vs. 97.3%, respectively, P=0.17), supporting the oncologic safety of BCS in patients who downstage with NAC. More recently, the authors of the I-SPY2 prospective multicenter adaptive randomized NAC trial reported locoregional recurrence rates and LR-free survival between BCS and mastectomy patients enrolled on trial ( 31 ). Overall, 1,462 patients with clinical stage II–III molecularly high-risk breast cancer who had NAC followed by surgery between 2010 and 2021 were included in the analysis, with 43% undergoing BCS and 57% undergoing mastectomy per physician and patient preference.…”