Does response to neo-adjuvant chemotherapy impact breast reconstruction?

Neo-adjuvant chemotherapy (NAC) is administered in breast cancer treatment for downstaging of disease. Here, we determined the impact of response to NAC on breast reconstruction uptake. A prospective NAC and mastectomy database with or without reconstruction were reviewed with IRB approval. Univariable analyses were conducted using Kruskal-Wallis or Fisher's exact tests. Multivariable logistic regression was used to adjust for potential confounders. We identified 271 patients with unilateral breast cancer receiving NAC and either unilateral or bilateral mastectomy from 9/2013 to 5/2016. Seventy patients (25.8%) had a pCR to NAC. One hundred and seventy-five patients (64.6%) had immediate reconstruction (IR), and 96 had no IR. On univariable analysis, younger age (P < .001), lower T-stage at presentation (P < .001), bilateral versus unilateral mastectomy (P<.001) and HR-negative tumor subtype (P = .006) were significantly associated with higher IR rates. On multivariable analysis, pCR (P = .792) and tumor subtype (P = 0.061) were not significantly associated with IR; T-stage was significantly associated with IR (P < .001), such that patients with T4 tumors at presentation had lower odds of IR (OR 0.10, 95% CI 0.02-0.50), even when accounting for response to NAC. One hundred and seventy-three patients (63.8%) received adjuvant radiation therapy; this was associated with lower IR frequency (P = .048) but was not associated with reconstruction type (tissue expander versus autologous, P = 1.0) among 175 patients who had IR. In patients who have mastectomy after NAC, IR is influenced by age, T-stage at presentation, and choice of bilateral mastectomy, but not by response to NAC. A subset of patients who are young, with earlier T-stage and pCR, is more likely to proceed with bilateral mastectomy.