Abstract
PURPOSE: Mammographic screening is effective in reducing breast cancer mortality, but the impact of screening on triple-negative breast cancers (TNBCs) outcomes remains debated. This study aims to determine if screen detection is an independent prognostic factor for TNBCs and to analyse the radiological and pathological differences between screen-detected and symptomatic TNBCs. METHODS: This retrospective cohort study analysed 353 histologically confirmed TNBC cases diagnosed between 2013 and 2020 at a single institution in Turin, Italy. Cases were categorized into screen-detected and symptomatic groups based on initial presentation. Clinical, radiological and pathological characteristics as well as disease-free survival (DFS) and overall survival (OS) were compared between groups. Statistical analyses included Kaplan-Meier survival curves and Cox proportional hazard models, adjusting for several clinical and biological variables. RESULTS: 50.1% of cases were screen-detected and 49.9% were symptomatic. Screen-detected cases were more commonly smaller (T1 or T2) (96.6%) than symptomatic cases (75%) (p < 0.001). Also, compared to symptomatic tumours, screen-detected ones were more often node negative (62.4% vs. 48%, p = 0.007) and diagnosed at a lower stage (85.4% vs. 63.8%, p < 0.001), with better DFS and OS. Detection method was not an independent prognostic factor, while stage at diagnosis, vascular invasion, histologic type and tumour-infiltrating lymphocytes (TILS) were more significant predictors of prognosis. Radiological and biological features were similar between the two groups. CONCLUSIONS: TNBCs correlate with favourable pathological features and improved survival outcomes in univariate analyses, but these benefits diminish when accounting for traditional prognostic factors. Hence, the better prognosis observed among screen-detected cases is more likely due to stage shift rather than tumour biology.