Introduction: Triple-negative breast cancer (TNBC) is notably an aggressive breast cancer (BC) subtype, leading to early relapse and poor prognosis. Effects of adjuvant chemotherapy among early-stage TNBC (pT1N0M0) patients remain unclear in different populations. Objectives: Our study aimed to determine the impact of adjuvant chemotherapy on overall survival (OS) and progression-free survival (PFS) within the specific subset of Peruvian pT1N0M0 TNBC patients (pT1a/b vs. pT1c). Methods: We retrospectively analyzed 2007 TNBC cases diagnosed between 2000-2014 at the Instituto Nacional de Enfermedades Neoplásicas (Lima, Peru). We included only non-metastatic TNBC cases and classified them as pT1N0M0 after surgery. TNBC patients who underwent neoadjuvant chemotherapy were excluded. We describe our population according to the tumor size from the residue disease (pT1a/b vs. pT1c). We used the...

Introduction: Triple-negative breast cancer (TNBC) is a heterogeneous disease associated with a poor prognosis. Delaying in time to start adjuvant chemotherapy (TTC) has been related to an increased risk of distant recurrence-free survival (DRFS). We aimed to develop a prognostic model to estimate the effects of delayed TTC among TNBC risk subgroups. Materials and methods: We analyzed 687 TNBC patients who received adjuvant chemotherapy at the Instituto Nacional de Enfermedades Neoplasicas (Lima, Peru). Database was randomly divided to create a discovery set (n=344) and a validation set (n=343). Univariate and multivariate Cox regression models were performed to identify prognostic factors for DRFS. Risk stratification was implemented through two models developed based on proportional hazard ratios from significant clinicopathological characteristics. Subpopulation treatment effect patte...

Purpose: In Peru, breast cancer (BC) stands as the most predominant malignancy neoplasm among women. Trastuzumab has marked a significant milestone in the management of this disease. It has been shown to improve prognosis in human epidermal growth factor receptor 2 (HER2)-expressing female patients, but its repercussions and efficacy are yet to be analyzed in a context with limited resources. Methods: The study population is made of woman patients aged 18 years and older diagnosed with HER2-positive BC at Instituto Nacional de Enfermedades Neoplásicas (INEN, Lima, Peru) during 2019-2021 and treated with at least one dose of subcutaneous trastuzumab. We reviewed medical records to register treatment characteristics, adverse events (AEs), disease progression, and survival status. We considered a median follow-up time of 36 and 45 months for progression and survival status. Results: The ma...