Relationship between body mass index and cholesterol levels with histopathological grading of breast cancer

A retrospective study in tumour characteristics and clinical outcomes of overweight and obese women with breast cancer

INTRODUCTION

Obesity and breast cancer are two major pathologies closely associated with increasing incidence and mortality rates, especially amongst women. The association between both diseases have been thoroughly discussed but much is still to uncover.

AIM

The aim of this study is to analyse tumour characteristics and clinical outcomes of overweight and obese women to disclosure potential associations and better understand the impact of obesity in breast cancer.

MATERIALS AND METHODS

Clinicopathological information of 2246 women were extracted from the institutional database of comprehensive cancer centre in Portugal diagnosed between 2012 and 2016. Women were stratified according to body mass index as normal, overweight, and obese. Patients' demographic information and tumour features (age, family history, topographic localization, laterality, histological type, and receptor status) were taken as independent variables and overall survival, tumour stage, differentiation grade and bilaterality were considered clinical outcomes.

RESULTS

The main results reveal that overweight and obesity are predominantly associated with worse outcomes in breast cancer patients. Obese patients present larger (p-value: 0.002; OR 1.422; 95% CI 1.134-1.783) and more poorly differentiated tumours (p-value: 0.002; OR 1.480; 95% CI 1.154-1.898) and tend to have lower overall survival although without statistical significance (p-value: 0.117; OR 1.309; 95% CI 0.934-1.833). Overweighted women are more likely to have bilateral breast cancer (p-value: 0.017; OR 3.076; 95% CI 1.225-7.722) than obese women. The results also reveal that overweight women present less distant metastasis (p-value: 0.024; OR 0.525; 95%CI 0.299-0.920). Topographic localization and laterality did not achieve statistical significance.

Adipose tissue-to-breast cancer crosstalk: Comprehensive insights

The review focuses on mechanistic evidence for the link between obesity and breast cancer. According to the IARC study, there is sufficient evidence that obesity is closely related to a variety of cancers. Among them, breast cancer is particularly disturbed by adipose tissue due to the unique histological structure of the breast. The review introduces the relationship between obesity and breast cancer from two aspects, including factors that promote tumorigenesis or metastasis. We summarize alterations in adipokines and metabolic pathways that contribute to breast cancer development. Breast cancer metastasis is closely related to obesity-induced pro-inflammatory microenvironment, adipose stem cells, and miRNAs. Based on the mechanism by which obesity causes breast cancer, we list possible therapeutic directions, including reducing the risk of breast cancer and inhibiting the progression of breast cancer. We also discussed the risk of autologous breast remodeling and fat transplantation. Finally, the causes of the obesity paradox and the function of enhancing immunity are discussed. Evaluating the balance between obesity-induced inflammation and enhanced immunity warrants further study.