Impact of Detection Mode in a Large Cohort of Women Taking Part in a Breast Screening Program

Objective: The aim of this study was to evaluate the existing survival rate and clinical-pathological differences among patients with breast cancer detected by mammographic screening. Materials and Methods: This multicenter cohort study examined 1,248 patients who took part in a national screening program for the early detection of breast cancer over an eight-year period. Results: Of the two patient subgroups (interval and screening), we found significant differences in the distribution of prognostic factors, with interval cases presenting at a lower mean age (p = 0.002), with higher percentages of human epidermal growth factor receptor 2 (HER-2) or triple negative and lower percentages of luminal A or luminal B carcinomas (p = 0.001), advanced stages (p<0.001), lower hormone receptor expression (p<0.001), poorer differentiation (p<0.001) and lower survival (p<0.001). Among the screening group, patients with tumors detected during the first screening round had a significantly lower mean age (p<0.001), a lower frequency of comorbidities (p = 0.038) and a lower tendency (p<0.1) to be diagnosed as triple negative breast carcinomas than incident cases. Conclusion: Our results highlight that breast tumors detected during the first screening round are frequently characterized by a more benign phenotype than the rest of the screening subgroups, which could be of help when stratifying the risk of death and selecting the best treatment option for each patient.