Prevalence and influence of overweight and obesity on clinical and epidemiological profile of breast cancer patients in the North of Mato Grosso, Brazil: a retrospective cross-sectional study

Obesity is one of the main preventable risk factors in post-menopausal breast cancer. This retrospective cross-sectional study aimed to demonstrate the clinical and epidemiological profile of breast cancer patients diagnosed in the period from 2013 to 2018 in the North of Mato Grosso, Brazil and to verify the prevalence and influence of overweight and obesity in these patients. Data were collected from patient’s medical records who were diagnosed with breast carcinoma in the Department of Oncology of Santo Antônio’s Hospital, in Sinop-MT. 196 patients were included. 99.5% were women. The majority were married, ≥50 years old (57.7%) and overweight or obese. In the overweight and obesity group the percentage of patients with invasive breast carcinoma were significantly higher when compared with eutrophic group (p=0.03). In all groups the profile of estrogen and progesterone receptors positive and HER-2 negative were more prevalent, however, the frequency of triple negative profile was higher in the overweight (7.1%) and obesity (6.3%) group when compared with control (4.3%) group, as well as the presence of hypertension and diabetes. In conclusion, it was observed a high prevalence of overweight and obesity in breast cancer patients, which contributed to modify the histological type of breast cancer (high prevalence of invasive and lobular carcinomas), increase the frequency of patients in stages 3 and 4, the percentage of triple negative profile and the frequency of other comorbidities, as hypertension and diabetes. Furthermore, metformin, an antidiabetic drug, seems to be contributing to reduce tumor development and improve the clinical profile and prognosis in diabetic breast cancer patients.