A delay between surgery and adjuvant chemotherapy (CT) has been associated with worse outcome in early breast cancer (BC), but little is known about timing-related consequences in the neoadjuvant setting. Aim of this study is to investigate the impact of the interval between the end of neoadjuvant CT and surgery (CTTS).
This retrospective study analyzed a series of 469 consecutive BC patients (pts) receiving neoadjuvant CT at the Department of Oncology of Udine (n = 222) and of the Istituto Nazionale Tumori of Milan (n = 247), between 2004 and 2015. CTTS was defined as the time between the last CT administration and surgery. Prognostic impact was investigated through Cox regression.
Luminal-like subtype was the most frequent (53.69%) followed by HER2-positive (29.26%) and triple negative BC (17.05%). Median follow-up was 55.07 months (mo). Estimated overall survival (OS) at 24 and 60 mo was 96.4% and 88.2%, respectively. Estimated relapse free survival (RFS) at 24 and 60 mo was 83.6% and 65.8%. Median CTTS was 1.08 mo (25%-75% range: 0.89 - 1.2 mo). Among the total population no statistically significant differences were observed in terms of OS and RFS between CTTS > 1 vs =20% were associated with worse RFS (HR 2.09, 95%CI 1.31-3.33; HR 2.77, 95%CI 1.30-5.91, respectively); on the other hand, a pathological complete response was associated with better RFS (HR 0.23, 95%CI 0.09-0.56). In terms of OS, grading and Ki67 were marginally significant. Subgroup analysis for CTTS showed no statistically significant differences when stratification for the main clinico-pathological features was applied. Notably, a trend for interaction in the nodal status stratification was observed.
This study explored the impact on RFS and OS of the interval between the end of neaodjuvant CT and surgery. Notwithstanding the exploratory purpose, the results suggest that an interval superior to 1 month was not significantly detrimental in terms of both RFS and OS.
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All authors have declared no conflicts of interest.