Breast cancer is a global problem, with many new cases recorded annually with a significant number of deaths, although prevention plays an important role in the benefits thanks to the Early Detection of cancer. An important factor related to breast cancer survival is the time in which the diagnosis is made. The objective of the study is to determine the risk factors associated with breast cancer in two ISSSTE units. Epidemiological study of cases and controls, analytical, observational, cross-sectional, retrospective, carried out in women with and without breast cancer who attended the Clinic Hospital ISSSTE Coatzacoalcos and the Clinic Hospital ISSSTE Ciudad de México in the years 2021 and first semester of 2022. To calculate the sample size, the Schelesselman tables were used. Data were analyzed and descriptive statistics were used and the odds ratio was calculated. 50 cases and 30 controls with a mean of 52.29 years of age with a deviation of ± 9.83 for the cases and 42.81 (DE ±11.01) for the controls were studied. The age in the patients with breast cancer yielded an odds ratio (OR) equal to 5.75 (95% CI), a hereditary family history of breast cancer in 88% of cases, and the oldest age at first pregnancy was 34 years. Lifestyle with sedentary lifestyle and with BMI of obesity in 70% of both cases and controls. Only 52% of the patients with breast cancer breastfed and in the controls 43.33% breastfed. The results suggest that age and lifestyle can influence the evolution of cancer as well as family history, but in this case 88% of patients in the cases did not have a family history of cancer against the control cases that all had a history of cancer. Relatives of cancer and do not have the disease.