70P Neoadjuvant chemotherapy in breast cancer in the last 2 decades: Are we improving survival? Retrospective analysis in a single institution

Abstract

A considerable shift from adjuvant chemotherapy (ACT) to neoadjuvant chemotherapy (NACT) has been observed in the last 2 decades. Once equivalence in survival was confirmed, NACT became a standard treatment option for operable and locally advanced disease. The aim of our study was to demonstrate that prognosis of patients treated with NACT has progressively improved in a single institution over the last twenty years. Data were extracted from the prospectively collected Oncology Unit Database. We reviewed patients with biopsy-proven, stage I to III breast cancer, who were diagnosed between February 1997 and June 2019 and treated with neoadjuvant chemotherapy at the University General Hospital of Alicante, Spain. Four period cohorts were assigned: cohort 1 (C1) 1997-2004, cohort 2 (C2) 2005-2009, cohort 3 (C3) 2010-2014 and cohort 4 (C4) 2015-2019. The Kaplan-Meier actuarial method was employed for survival estimations, and the log-rank test for comparison among curves. Values of P <0.05 were considered statistically significant. We identified 563 eligible patients. Median follow-up time for the entire cohort was 5.51 years. Median follow-up times for each cohort were 10.03, 10.70, 6.27 and 3.36 years in C1, C2, C3 and C4, respectively. Significant differences in survival between cohorts were observed, for Invasive disease-free survival (IDFS) (χ2=27.539; p≤0.001) and distant disease-free survival (DDFS) (χ2=19.028; p≤0.001). Cox regression analysis showed lower HR events for IDFS and DDFS in C4 than C3, C2 and C1 respectively.Table: 70PHRP valueIDFS Period CohortC4 (2015-2019)ReferenceC3 (2010-2014)2.24 (1.28, 3.92)0.005C2 (2005-2009)2.93 (1.69, 5.07)≤0.001C1 (1997-2004)3.81 (2.21, 6.58)≤0.001DDFS Period CohortC4 (2015-2019)ReferenceC3 (2010-2014)2.23 (1.23-4.05)0.009C2 (2005-2009)2.53 (1.39-4.59)≤0.001C1 (1997-2004)3.44 (1.92-6.19)≤0.001 Open table in a new tab We demonstrate that prognosis of patients treated with NACT in our institution has improved over the last two decades. This is not only due to new therapies, but also to the learning curve in the selection of patients who can benefit the most from NACT. This improvement is the result of adequate patient management by the multidisciplinary breast cancer committee.