Survival outcomes and clinicopathological factors analysis of breast cancer patients. A single-institution cohort from 2012 to 2020 in a Mexican population.

Abstract

e13104 Background: In Mexico, The Instituto Mexicano del Seguro Social (IMSS) is a tripartite contribution which provides care to more than 74 million beneficiaries, which represents more than 50% of the general population of the country. Although Mexican breast cancer statistics have been reported, it is imperative to know the updated statistics on the epidemiology in our Institution. The aim of this study is to describe the survival outcomes and the clinical-pathological characteristics of patients with breast cancer. Methods: Records of breast cancer patients treated at the Oncology Hospital from Centro Medico Nacional Siglo XXI of IMSS, from January 2012 to December 2020 were included. We analyzed clinical and demographic characteristics of the population, as well as survival outcomes at 5-years. Results: A cohort of 5,264 patients was included. Median follow up was 54.9 months. Forty-three percent (n = 2,274) were diagnosed in early-stage breast cancer (I–IIA), 43.1% (n = 2,269) in stages IIB-III, and 7% (n = 383) in stage IV. The most common immunophenotype was hormone receptor (HR) positive, HER2-negative (70.8%, n = 3,726). HER2-positive represents 19.3% (n = 1011), among HR-positive were 12.4% (n = 650) and HR-negative, 6.9% (n = 361). 527 patients (10.1%) were triple negative. At 5-years, disease-free survival was 74.9% (95% CI, 73.5 to 76.3) and overall survival was 90.4% (95% CI, 89.4 to 91.3). High histologic grade (HR 1.51; 95% CI, 1.33 to 1.7; p < 0.001) and lymphovascular invasion (HR 1.84; 95% CI, 1.62 to 2.1; p < 0.001) were associated with higher risk of recurrence. Adjuvant chemotherapy was significantly associated to a 42% reduction in the risk of recurrence, HR 0.58 (95% CI, 0.49 to 0.69; p < 0.0001), and 54% in the risk of death, HR 0.46 (95% CI, 0.33 to 0.63; p < 0.0001) in stage III. Lobular histology was also associated with worse survival, HR 1.41 (95% CI, 1.069 to 1.859; p = 0.015). Conclusions: An update of breast cancer Mexican patients treated at IMSS is presented. We highlight the impact of adjuvant treatment and pathological risk factors for recurrence and death. This work can contribute to evaluate areas for improvement in management and outcomes in our population.