1002 – Overall survival according to molecular subtypes and clinical staging in invasive breast carcinoma patients: Kaplan-Meier analysis in a hospital cohort

Abstract

Introduction: Overall survival analysis according to molecular subtypes and clinical staging is essential for predicting
prognostic outcomes in breast cancer. The Kaplan-Meier method estimates the survival function in cohorts with variable follow-up.
Objective: To estimate and compare overall survival of patients with invasive breast carcinoma according to clinical
staging and main molecular subtypes in a private hospital cohort from Central-West Brazil.
Methods: A retrospective cohort study was conducted among 97 patients with confirmed invasive breast carcinoma.
Kaplan-Meier curves were constructed and compared by the log-rank test, stratified by staging (I–II vs. III–IV), triplenegative subtype, hormone receptor status (HR+ vs. HR−), and HER2 status. The mean estimated follow-up was 3.9 years.
Results: Six deaths (6.2%) and 9 recurrences (9.3%) were recorded. Advanced staging (III–IV; n=10) was associated with
significantly worse survival vs. early staging (n=87): death rate 50.0% vs. 1.1% (log-rank p=2.22×10-
¹⁰). Triple-negative subtype (n=15) showed worse survival vs. non-triple-negative (n=82): 26.7% vs. 2.4% deaths (log-rank p=6.32×10-
⁴). Hormone
receptor negativity identified a higher-risk subgroup: 22.7% vs. 1.3% deaths (log-rank p=6.27×10-
⁴). HER2 status showed
no significant difference between groups (log-rank p=0.983).
Conclusion: Advanced staging, triple-negative subtype, and hormone receptor negativity were associated with worse
overall survival. HER2 status did not impact survival differently, possibly reflecting the use of anti-HER2 therapies at the
institution. These findings reinforce the importance of molecular stratification and early diagnosis in breast oncology.
Ethics: Research Ethics Committee Approval (CAAE 76523123.1.0000.5083).