Diabetes mellitus and risk of breast cancer: a large-scale, prospective, population-based study

Association of Life's Essential 8 cardiovascular health with breast cancer incidence and mortality according to genetic susceptibility of breast cancer: a prospective cohort study

BACKGROUND

Accumulating evidence suggests that cardiovascular diseases and breast cancer share a number of common risk factors, however, evidence on the association between cardiovascular health (CVH) and breast cancer is limited. The present study aimed to assess the association of CVH, defined by Life's Essential 8 (LE8) and genetic risk with breast cancer incidence and mortality among premenopausal and postmenopausal women.

METHODS

We used data from the UK Biobank and conducted the multivariate Cox proportional-hazards models to examine associations of LE8 score and genetic risk with breast cancer incidence and mortality. Date on LE8 score was collected between 2006 and 2010 and composed of eight components, including behavioral metrics (diet, tobacco or nicotine exposure, physical activity, and sleep health), and biological metrics (body mass index, blood lipids, blood glucose, and blood pressure). The polygenic risk score (PRS) was calculated as the sum of effect sizes of individual genetic variants multiplied by the allele dosage.

RESULTS

A total of 150,566 premenopausal and postmenopausal women were included. Compared to postmenopausal women with low LE8 score, those with high LE8 score were associated with 22% lower risk of breast cancer incidence (HR: 0.78, 95% CI: 0.70-0.87) and 43% lower risk of breast cancer mortality (HR: 0.57, 95% CI: 0.36-0.90). By contrast, we did not observe the significant association among premenopausal women. Further analyses stratified by PRS categories showed that high LE8 score was associated with 28% and 71% decreased risk of breast cancer incidence (HR: 0.72, 95% CI: 0.60-0.87) and mortality (HR: 0.29, 95% CI: 0.10-0.83) compared to low LE8 score among high genetic risk groups, but no significant associations were found among low genetic risk groups. Furthermore, compared with postmenopausal women with high LE8 score and low genetic risk, those with low LE8 score and high genetic risk were associated with increased risk of breast cancer incidence (HR: 6.26, 95% CI: 4.43-8.84).

CONCLUSIONS

The present study suggests that better CVH is a protective factor for both breast cancer incidence and mortality among postmenopausal women. Moreover, the risk of developing breast cancer caused by high genetic susceptibility could be largely offset by better CVH.

Associations between Diabetes Mellitus and Selected Cancers

Cancer is one of the major causes of mortality and is the second leading cause of death. Diabetes mellitus is a serious and growing problem worldwide, and its prevalence continues to grow; it is the 12th leading cause of death. An association between diabetes mellitus and cancer has been suggested for more than 100 years. Diabetes is a common disease diagnosed among patients with cancer, and evidence indicates that approximately 8-18% of patients with cancer have diabetes, with investigations suggesting an association between diabetes and some particular cancers, increasing the risk for developing cancers such as pancreatic, liver, colon, breast, stomach, and a few others. Breast and colorectal cancers have increased from 20% to 30% and there is a 97% increased risk of intrahepatic cholangiocarcinoma or endometrial cancer. On the other hand, a number of cancers and cancer therapies increase the risk of diabetes mellitus. Complications due to diabetes in patients with cancer may influence the choice of cancer therapy. Unfortunately, the mechanisms of the associations between diabetes mellitus and cancer are still unknown. The aim of this review is to summarize the association of diabetes mellitus with selected cancers and update the evidence on the underlying mechanisms of this association.

Risk factors of diabetes and cancer-specific mortalities in patients with infiltrating ductal carcinoma of the breast: a population-based study

BACKGROUND AND AIMS

Breast cancer is considered one of the most common neoplasms worldwide. Diabetes (DM) increases mortality among postmenopausal patients with breast cancer. Our study aims to identify the risk factors of DM-specific mortality and infiltrating ductal carcinoma (IDC) mortality in patients with IDC of the breast.

MATERIALS AND METHODS

Data of IDC patients were obtained from the Surveillance, Epidemiology, and End Results database from 1975 to 2016. Independent variables included age, race, marital status, the primary site of IDC, breast subtype, the disease stage, grade, chemotherapy, radiation, and surgery. Kaplan-Meier, Cox and Binary regression tests were used to analyze the data using SPSS software.

RESULTS

A total of 673 533 IDC patients were analyzed. Of them, 4224 died due to DM and 116 822 died due to IDC. Factors that increase the risk of overall, IDC-specific, and DM-specific mortalities include older age, black race, widowed, uninsured, regional and distant stages, grade II and III, and no treatment with chemotherapy or radiotherapy or surgery. Additionally, the IDC mortality increased with separated status, all primary sites, all breast subtypes, and stage IV.

CONCLUSION

In patients with IDC, controlling DM besides cancer is recommended to reduce the mortality risk. Old, black, widowed, uninsured, regional and distant stages, grade II and III, and no treatment are common risk factors for DM- and IDC-mortality.

Molecular Effect of Variants in Toll-like Receptor 4 Gene in Saudi Patients with Type 2 Diabetes Mellitus

Single-nucleotide polymorphisms (SNPs) in the Toll-like receptor 4 (TLR4) gene have been documented in type 2 diabetes mellitus (T2DM) and other diseases in the Saudi population. We investigated the relationship between rs11536889, rs4986790, and rs4986791 SNPs in the TLR4 gene and T2DM in the Saudi population; 105 patients with T2DM and 105 healthy controls were analyzed. The TLR4 gene was amplified through PCR, followed by restriction fragment length polymorphism analysis for rs4986791 and Sanger sequencing for rs11536889 and rs4986790 SNPs. The clinical and biochemical characteristics were associated with T2DM (p < 0.05). The rs11536889, rs4986790, and rs4986791 SNPs in control subjects followed the Hardy-Weinberg equilibrium (p > 0.05). Alleles were associated with rs11536889, rs4986791, heterozygous codominant, and dominant models (p < 0.05). However, the rs4986790 SNP was not associated with T2DM (p > 0.05). Logistic regression analysis showed that high-density lipoprotein cholesterol (HDLc) levels were associated with T2DM (p < 0.001). Analysis of variance showed that waist (p = 0.0005) and hip circumferences (p = 0.002) in rs4986790 and rs4986791 SNPs, in SBP (p = 0.001), DBP (p = 0.002), and HDLc levels (p = 0.003), were associated with T2DM subjects. T2DM was also associated with the haplotype (p < 0.001) but not with linkage disequilibrium. The gene-gene interaction was associated with the three SNPs studied in patients with T2DM according to the generalized multifactor dimensionality reduction model (p < 0.0001). Dendrogram and graphical depletion analysis revealed a moderate association in patients with T2DM. The results suggest that rs11536889 and rs4986790 SNPs are genotypically and allelically associated with T2DM in Saudi patients. Future functional studies are recommended to validate the genetic roles of these SNPs in the pathogenesis and progression of diseases.