Comprehensive diagnosis of advanced-stage breast cancer: exploring detection methods, molecular subtypes, and demographic influences - A cross-sectional study.

Background: Brazil faces notable Breast Cancer (BC) mortality despite lower incidence rates versus developed countries. Despite guidelines from medical societies, Brazilian public policy recommends biennial mammographic screening for women aged 50 to 69. This study investigates sociodemographic and clinical factors related to BC detection methods and clinical stage at diagnosis.

Methods: The authors conducted a cross-sectional study at a São Paulo tertiary hospital. Patients were divided into 'symptomatic' and 'mammographic' detection groups. Bivariate analyses by detection method and clinical stage compared groups' profiles in terms of sociodemographic and clinical characteristics. Poisson regression analyses assessed sociodemographic and molecular subtypes´ influence on "mammographic detection" prevalence and "advanced-stage BC", reporting prevalence ratios and 95 % Confidence Intervals.

Results: The authors studied 1,536 BC patients admitted from January 2016 to December 2017. The "mammographic detection" group had a higher proportion of patients aged 50‒69 years (62.9 % vs. 44.1 %), white race (63.3 % vs. 51.6 %), Catholic religion (58.2 % vs. 51.1 %), and Luminal A subtype (25.2 % vs. 13.2 %) compared to the "symptomatic detection" group. Patients with early-stage disease were more likely to have higher education levels (8.1 % vs. 5.5 %) and be married (39.8 % vs. 46.6 %) compared to those with advanced-stage. Molecular subtypes were significantly associated with the detection method and stage. The prevalence of advanced-stage disease in "mammographic" (n=313) and "symptomatic" (n=1191) groups was 18.5 % and 55 %, respectively . Mammographic detection significantly reduced advanced-stage BC prevalence (PR = 0.40, 95 % CI 0.31‒0.51).

Conclusion: Mammographic detection reduces advanced-stage breast cancer prevalence in Brazil, emphasizing the importance of regular screenings, especially among at-risk sociodemographic groups. Enhancing mammographic screening accessibility, lowering the starting age to 40, and extending coverage to include annual mammograms can significantly lower breast cancer mortality in Brazil, benefiting public health and patient outcomes.