Type 2 Diabetes Mellitus and Clinicopathological Tumor Characteristics in Women Diagnosed with Breast Cancer: A Systematic Review and Meta-Analysis

Impact of Breast Cancer on Cardiometabolic Health in Spanish Women ≥50 Years with Pre-Existing Type 2 Diabetes Mellitus

During breast cancer (BC), cardiometabolic disorders can worsen prognosis, particularly in women with type 2 diabetes mellitus (T2DM). This study aimed to determine the impact of BC diagnosis on cardiometabolic parameters and the incidence of complication in women over 50 years of age (90% aged ≥ 65 years) with pre-existing T2DM. Using primary care registries from Asturias (Spain), a total of 106 women diagnosed with T2DM followed by BC were selected and matched with women with T2DM (n = 212) in a cohort study. Indicators of cardiometabolic health and microvascular complications associated with T2DM were collected. Women were monitored from two years prior to five years after BC diagnosis. Conditional logistic regressions were used to compare the adjusted odds of staying below each indicator's threshold. During follow-up, women with T2DM+BC had a higher risk of fasting blood glucose ≥126 mg/dL (adjusted odds ratio [aOR] = 1.83; 95% confidence interval [CI95%]: 1.01-3.32) and glycosylated hemoglobin (Hb1Ac) ≥ 48 mmol/mol or 6.5% (aOR: 2.44; IC95%: 1.21-4.91). There was no difference between the groups regarding the incidence of microvascular complications. BC incidence negatively impacted the glycemic control of Spanish women with pre-existing T2DM measured by basal blood glucose and HbA1c, but not cardiometabolic health indicators or T2DM complications.

Metformin Alters Tumor Immune Microenvironment, Improving the Outcomes of Breast Cancer Patients With Type 2 Diabetes Mellitus

This study investigated the clinical effect of metformin on breast cancer patients with preexisting type 2 diabetes mellitus (T2DM). We analyzed 177 patients with T2DM who underwent breast cancer surgery and assessed tumor-associated macrophages (TAMs) and tumor-infiltrating lymphocytes (TILs) in patients who underwent tumor resection with or without metformin treatment using multiplex immunohistochemistry (IHC). Patients who received metformin either pre- or postoperatively exhibited reduced distant organ recurrence and improved postoperative recurrence-free survival compared to those of patients who did not. Additionally, in a subgroup of 40 patients receiving preoperative systemic therapy, metformin treatment was associated with increased rates of pathological complete response. IHC analysis revealed significantly lower levels of cluster of differentiation (CD) 68(+) CD163(+) M2-type TAMs (p < 0.01) but higher CD3(+) and CD8(+) TIL densities in the metformin-treated group compared with the same parameters in those without metformin treatment, with a significant difference in the CD8(+)/CD3(+) TIL ratio (p < 0.01). Despite the constraints posed by our small sample size, our findings suggest a potential role for metformin in modulating the immunological microenvironment, which may contribute to improved outcomes in diabetes patients with breast cancer.

Antidiabetic Drugs in Breast Cancer Patients

Diabetes is one of the leading chronic conditions worldwide, and breast cancer is the most prevalent cancer in women worldwide. The linkage between diabetes and its ability to increase the risk of breast cancer should always be analyzed in patients. This review focuses on the impact of antihyperglycemic therapy in breast cancer patients. Patients with diabetes have a higher risk of developing cancer than the general population. Moreover, diabetes patients have a higher incidence and mortality of breast cancer. In this review, we describe the influence of antidiabetic drugs from insulin and metformin to the current and emerging therapies, incretins and SGLT-2 inhibitors, on breast cancer prognosis. We also emphasize the role of obesity and the metastasis process in breast cancer patients who are treated with antidiabetic drugs.

Diabetes and incidence of breast cancer and its molecular subtypes: A systematic review and meta-analysis

Diabetes mellitus (DM) has been proposed to be positively associated with breast cancer (BCa) risk due to shared risk factors, metabolic dysfunction, and the use of antidiabetic medications. We conducted a systematic review and meta-analysis to evaluate the association between DM and BCa risk. We searched PubMed, Embase, and Web of Science for cohort and case-control studies assessing the association between DM and BCa published before 10 December 2021. Two reviewers independently screened the studies for inclusion, abstracted article data, and rated study quality. Random effects models were used to estimate summary risk ratios (RRs) and 95% confidence intervals (CIs). From 8396 articles identified in the initial search, 70 independent studies were included in the meta-analysis. DM was associated with an overall increased risk of BCa (RR = 1.20, 95% CI: 1.11-1.29). The 24 case-control studies demonstrated a stronger association (RR = 1.26, 95% CI: 1.13-1.40) than the 46 cohort studies (RR = 1.15, 95% CI: 1.05-1.27). Studies reporting risk by menopausal status found that postmenopausal women had an elevated risk of developing BCa (RR = 1.12, 95% CI: 1.07-1.17). No association between DM and BCa risk was observed among premenopausal women (RR = 0.95, 95% CI: 0.85-1.05). In addition, DM was associated with significantly increased risks of oestrogen receptor (ER)+ (RR = 1.09, 95% CI: 1.00-1.20), ER- (RR = 1.16, 95% CI: 1.04-1.30), and triple negative BCa (RR = 1.41, 95% CI: 1.01-1.96). The association estimate for human epidermal growth factor 2-positive BCa was also positive (RR = 1.21, 95% CI: 0.52-2.82), but the CI was wide and crossed the null. Our meta-analysis confirms a modest positive association between DM and BCa risk. In addition, our results suggest that the association between DM and BCa may be modified by menopausal status, and that DM may be differentially associated with BCa subtypes defined by receptor status. Additional studies are warranted to investigate the mechanisms underlying these associations and any influence of DM on BCa receptor expression.

Updates on Triple-Negative Breast Cancer in Type 2 Diabetes Mellitus Patients: From Risk Factors to Diagnosis, Biomarkers and Therapy

Triple-negative breast cancer (TNBC) is usually the most malignant and aggressive mammary epithelial tumor characterized by the lack of expression for estrogen receptors and progesterone receptors, and the absence of epidermal growth factor receptor (HER)2 amplification. Corresponding to 15-20% of all breast cancers and well-known by its poor clinical outcome, this negative receptor expression deprives TNBC from targeted therapy and makes its management therapeutically challenging. Type 2 diabetes mellitus (T2DM) is the most common ageing metabolic disorder due to insulin deficiency or resistance resulting in hyperglycemia, hyperinsulinemia, and hyperlipidemia. Due to metabolic and hormonal imbalances, there are many interplays between both chronic disorders leading to increased risk of breast cancer, especially TNBC, diagnosed in T2DM patients. The purpose of this review is to provide up-to-date information related to epidemiology and clinicopathological features, risk factors, diagnosis, biomarkers, and current therapy/clinical trials for TNBC patients with T2DM compared to non-diabetic counterparts. Thus, in-depth investigation of the diabetic complications on TNBC onset, development, and progression and the discovery of biomarkers would improve TNBC management through early diagnosis, tailoring therapy for a better outcome of T2DM patients diagnosed with TNBC.

Association of diabetes and breast cancer characteristics at diagnosis

PURPOSE

This study aims to examine the association of diabetes and breast cancer characteristics at diagnosis in Aotearoa/New Zealand.

METHODS

Patients diagnosed with invasive breast cancer between 2005 and 2020 were identified from the National Breast Cancer Register. Logistic regression modeling was used to estimate the adjusted odds ratio (OR) of having stage III-IV cancer and the OR of having stage IV cancer for women with diabetes compared to those without diabetes. The adjusted OR of having screen-detected breast cancers for patients aged 45-69 years with diabetes compared to patients without diabetes was estimated.

RESULTS

26,968 women were diagnosed with breast cancer, with 3,137 (11.6%) patients having diabetes at the time of cancer diagnosis. The probability of co-occurrence of diabetes and breast cancer increased with time. Māori, Pacific and Asian women were more likely to have diabetes than European/Others. The probability of having diabetes also increased with age. For patients with diabetes, the probability of being diagnosed with stage III-IV cancer and stage IV cancer was higher than for patients without diabetes (OR 1.14, 95% CI 1.03-1.27; and 1.17, 95% CI 1.00-1.38). Women aged 45-69 years with diabetes were more likely to have screen-detected cancer than those without diabetes (OR 1.13, 95% CI 1.02-1.26).

CONCLUSIONS

The co-occurrence of diabetes and breast cancer is becoming more common. Overall there is a small but significant adverse impact of having advanced disease for women with diabetes that is found at the time of breast cancer diagnosis, and this may contribute to other inequities that occur in the treatment pathway that may impact on patient outcomes.

Diet Quality Influences the Occurrence of Food Aversions in Women Undergoing Adjuvant Chemotherapy for Breast Cancer

Food aversions in women undergoing adjuvant chemotherapy for breast cancer may be linked to oxidative stress and gastrointestinal consequences underlying it, and diet possibly plays a role in this association. This follow-up study included 73 women with breast cancer treated in Florianopolis City, Brazil. Dietary antioxidant capacity-DaC (mmol/d), diet quality-Brazilian Healthy Eating Index Revised (BHEI-R score), and oxidative stress biomarkers were accessed before the treatment, and women were asked if they developed food aversions during adjuvant chemotherapy. Red meat was the main aversion-causing food reported (37.9%, n = 9). There was no difference in DaC, BHEI-R score, or oxidative stress biomarkers between women with no food aversion occurrence and those showing food aversions. A logistic regression adjusted model showed that women exhibiting higher BHEI-R scores were 1.08 times more likely to not develop food aversions during adjuvant chemotherapy (p = 0.041). In summary, this innovative investigation showed that diet quality before adjuvant chemotherapy may influence the non-occurrence of food aversion. Considering this, the result opens new areas for early nutritional interventions, focusing on reducing the occurrence of food aversions and consequently benefiting women with breast cancer by having better outcomes in oncologic treatment.

Type 2 Diabetes Mellitus Promotes the Differentiation of Adipose Tissue-derived Mesenchymal Stem Cells into Cancer-associated Fibroblasts, Induced by Breast Cancer Cells

Triple Negative Breast Cancer (TNBC) is a highly aggressive and invasive type of breast cancer. In addition, type 2 diabetes mellitus (T2DM) is recognized as a risk factor for cancer metastasis, which is associated with mortality in patients with breast cancer. Cancer-associated fibroblasts (CAFs) generated from adipose tissue-derived mesenchymal stem cells (AT-MSCs) play a vital role in the progression of TNBC. However, to date, whether T2DM affects the ability of AT-MSCs to differentiate into CAFs is still unclear. In the present study, we found that in coculture with TNBC cells (BCCs) under hypoxic conditions, AT-MSCs derived from T2DM donors (dAT-MSCs) were facilitated to differentiate into CAFs, which showed fibroblastic morphology, and the induced expression of fibroblastic markers, such as FAP, FSP and vimentin. This was involved in the higher expression of TGFRand the phosphorylation of Smad2/3. Furthermore, T2DM affected the fate and functions of CAFs derived from dAT-MSCs. While CAFs derived from AT-MSCs of healthy donors (AT-CATs) exhibited the markers of inflammatory CAFs, those derived from dAT-MSCs (dAT-CAFs) showed the markers of myofibroblastic CAFs. Of note, in comparison to AT-CAFs, dAT-CAFs showed a higher ability to induce the proliferation and in vivo metastasis of BCCs, which was involved in the activation of the TGF-Smad2/3 signaling pathway. Collectively, our study suggests that T2DM contributes to metastasis of BCCs by inducing the myofibroblastic CAFs differentiation of dAT-MSCs. In addition, targeting the TGF-Smad2/3 signaling pathway in dAT-MSCs may be useful in cancer therapy for TNBC patients with T2DM.