Survival implications of non-organized breast cancer screening in a Brazilian tertiary women’s health center: a retrospective cohort study of 1517 patients

Breast cancer (BC) is the most prevalent malignancy among Brazilian women. Advanced-stage diagnosis remains frequent, largely due to limited access to screening and treatment. Despite national recommendations for organised screening, implementation remains opportunistic. This study compared prognostic outcomes between clinically detected and opportunistically screened breast cancers and estimated Years of Life Lost (YLL) and Years of Disease-Free Life Lost (YDFL) to quantify the impact of clinical stage on survival and disease-free survival expectancy. A retrospective cohort of 1,517 women with unilateral, invasive, non-metastatic BC who underwent surgery at a tertiary public hospital in Brazil between 2012 and 2016 was analysed. Patients were classified as symptomatic (diagnosed based on clinical signs and symptoms) or asymptomatic (diagnosed through screening). Clinicopathological features, treatments, and outcomes were compared using the Chi-square, Fisher’s exact, and Kruskal–Wallis tests. Survival was analysed using Kaplan–Meier estimates and Cox regression models. YLL and YDFL were derived from Weibull survival models, using stage I patients as the reference. Most patients (69.5%) were symptomatic at diagnosis, with palpable tumours in 94.3%. Compared with asymptomatic cases, symptomatic women were younger and presented with more advanced stages, and aggressive tumours. They more frequently underwent mastectomy and neoadjuvant chemotherapy ( p < 0.001). Both YLL and YDFL increased progressively with advancing clinical stage, reaching over 15 years in stage III. The predominance of advanced-stage diagnoses may reflect limitations in the current implementation of opportunistic screening, although this interpretation should be considered in light of potential screening-related biases. Advanced disease was associated with substantial loss of lifetime and disease-free years, reinforcing the prognostic value of early-stage detection.