Body mass index (BMI) and breast cancer: impact on tumor histopatologic features, cancer subtypes and recurrence rate in pre and postmenopausal women

Abstract

The study aims to analyze the association between body mass index (BMI) at time of diagnosis, breast cancer histopathologic features (tumor size, nuclear grade, estrogen and progesterone receptor (ER and PgR) and HER-2/neu expression, histological subtypes, Ki-67 index, lymphatic/vascular invasion, axillary nodes involvement) and incidence of different subtypes defined using hormone receptors and HER2/neu expression, according to menopausal status; to evaluate the impact of BMI on disease free survival (DFS) at multivariate analysis. A total of 2148 patients (592 premenopausal, 1556 postmenopausal) were classified into subgroups according to BMI distribution. High BMI was significantly associated with larger size tumor both in pre (p = 0.01) and postmenopausal women (p = 0.00). Obese premenopausal women showed worse histopathologic features (more metastatic axillary lymphnodes, p = 0.017 and presence of vascular invasion, p = 0.006) compared to under/normal weight group. Postmenopausal patients with BMI > 25 developed more frequently ER/PgR positive cancers (87% versus 75%, p 0.017), while no association was found in premenopausal women. We could not found any statistically significant correlation between breast cancer subtypes (luminal A, B, HER-2 and basal-like) and BMI both in pre and postmenopause. Higher BMI was significantly associated with a shorter DR-FS in postmenopausal women but the independent prognostic role of obesity was not confirmed in our analysis.

Correlation between obesity and prognostic/predictive parameters with emphasis on the importance of lymph node metastases in patients with invasive breast carcinoma

“…Different studies have revealed that OW and OB are associated with larger tumor diameters [16,28,29]. In our study, OB and OW were also associated with tumors with a diameter of 21-50 mm (p = 0.7, OR = 1.26, 1.48).…”

“…Accord- ing to the literature, OB and OW are associated with a higher rate of axillary metastatic lymph nodes and higher lymph node ratio [29,25,28]. However, no other studies evaluating the relationship between obesity and LNR and/or ECE (the presence of ECE and the size of ECE) have been previously published to the best of our knowledge.…”

Obesity as an independent risk factor for decreased survival in node-positive high-risk breast cancer

“…Obese women with breast cancer are typically diagnosed late in life, have large primary tumors and a high number of lymph node metastases [15][16][17]. Thus, the advanced or potentially more aggressive disease of women with a high BMI at diagnosis might contribute to the worse prognosis found in obese breast cancer patients.…”

Obesity and breast cancer: role of inflammation and aromatase

“…BMI is routinely used to quantify adiposity. In the case of breast cancer, a BMI of 30 kg/m 2 carries with it a twofold increased risk compared with a 'normal' BMI of 24-25, and the risk continues to increase with increased obesity (Biglia et al 2012, Garrisi et al 2012, Kamineni et al 2012. Breast cancer risk increases with ageing and the relationship with BMI appears to apply primarily to postmenopausal women.…”