Purpose: The Instituto Mexicano del Seguro Social is a tripartite contribution providing care to more than 74 million beneficiaries, representing more than 50% of the country's general population. This study aims to describe the survival outcomes and clinicopathologic characteristics of patients with breast cancer at our Center.
Methods: A retrospective cohort of patients with breast cancer treated between January 2012 and December 2020 was conducted. Survival outcomes were assessed using the Kaplan-Meier method. Univariate and multivariate analyses were performed using a Cox proportional hazards model.
Results: There were 5,264 patients included with a median follow-up of 54.9 months. Forty-three percent (n = 2,274) were diagnosed in stage I-IIA, 43.1% (n = 2,269) in stage IIB-III, and 7% (n = 383) in stage IV. At 5 years, disease-free survival was 74.9% (95% CI, 73.5 to 76.3) and overall survival (OS) 90.4% (95% CI, 89.4 to 91.3). For stage IV, it was 22.7% (95% CI, 17.3 to 28.5). High histologic grade (hazard ratio, 1.51 [95% CI, 1.34 to 1.7]; P < .001) and lymphovascular invasion (LVI; hazard ratio, 1.85 [95% CI, 1.62 to 2.1]; P < .001) were associated with a higher risk of recurrence.
Conclusion: Histologic grade and LVI should be considered in the decision to treat with adjuvant chemotherapy in sites where genomic signatures are not available. Our OS data are comparable with other Mexican series; however, it is lower in stage IV. Much remains to be done at the national level, mainly regarding access to additional therapies for each breast cancer subtype. This work contributes to the evaluation of areas for improvement in outcomes in our population.