Association of high-sensitivity C-reactive protein and odds of breast cancer by molecular subtype: analysis of the MEND study

Effect of Probiotics in Breast Cancer: A Systematic Review and Meta-Analysis

Probiotics may have the potential to protect against breast cancer, partly through systemic immunomodulatory action and active impact upon intestinal microbiota. Given a few clinical studies on their curative role, we conducted a systematic review of the potential effects of probiotics in breast cancer patients and survivors of breast cancer, aiming to support further clinical studies. A literature search was performed using PubMed, Embase, and the CENTRAL databases from inception through to March 2022. A total of eight randomized clinical trials were identified from thirteen articles published between 2004 and 2022. We evaluated quality-of-life measures, observed bacterial species and diversity indices, probiotic-related metabolites, inflammatory biomarkers, and other responses in breast cancer patients and survivors. Results were synthesized qualitatively and quantitatively using random-effects meta-analysis. Different probiotics supplements utilized included Lactobacillus species alone (Lacto), with or without estriol; probiotic combinations of Lactobacillus with Bifidobacterium (ProLB), with or without prebiotic fructooligosaccharides (FOS); ProLB plus Streptococcus and FOS (ProLBS + FOS); and ProLB plus Enterococcus (ProLBE). We found that use of ProLBS with FOS in breast cancer patients and use of ProLBE in survivors of breast cancer show potential benefits in countering obesity and dyslipidemia. ProLBS with FOS use decreases pro-inflammatory TNF-α in breast cancer survivors and improves quality of life in those with breast-cancer-associated lymphedema. Supplementing probiotics capsules (10⁹ CFU) with a prebiotic and using an intake duration of 10 weeks could provide a better approach than probiotics alone.

The association between the inflammatory potential of diet and the risk of histopathological and molecular subtypes of breast cancer in northwestern Iran: Results from the Breast Cancer Risk and Lifestyle study

BACKGROUND

This study explored the association between diet-associated inflammation and the risk of different molecular subtypes of breast cancer (BrCA) in a large, population-based case-control study conducted in northwestern Iran.

METHODS

The study consisted of 1007 women with histopathologically confirmed BrCA and 1004 controls admitted to hospitals in Tabriz, northwestern Iran, for nonneoplastic conditions. Dietary Inflammatory Index scores and energy-adjusted Dietary Inflammatory Index (E-DII) scores, with and without supplements, were computed on the basis of dietary intake collected using a validated 136-item food frequency questionnaire.

RESULTS

Women with the highest E-DII scores (quartile 4) versus those with the lowest E-DII scores (quartile 1) showed a significantly increased BrCA risk (odds ratio for quartile 4 vs quartile 1 [OR_Q4vsQ1 ], 1.87; 95% confidence interval [CI], 1.42-2.47), particularly for lobular carcinoma (OR_Q4vsQ1 , 3.07; 95% CI, 1.34-7.02). Findings were similar for premenopausal women diagnosed with luminal A BrCA (OR_Q4vsQ1 , 2.71; 95% CI, 1.74-4.22) or luminal B BrCA (OR_Q4vsQ1 , 2.86; 95% CI, 1.39-5.89). Women consuming the most proinflammatory diets were 3 times more likely to have triple-negative BrCA (OR_Q4vsQ1 , 3.00; 95% CI, 1.002-8.96) while compared to luminal A BrCA. The BrCA risk for women consuming diets in the highest half of E-DII scores (E-DII > 0) was 59% greater than the risk for those in the lowest half (95% CI, 1.29-1.97). Also, higher E-DII scores that took into account supplements were associated with larger tumor sizes (T3 > 5 cm; P < .05).

CONCLUSIONS

A proinflammatory diet, as indicated by higher E-DII scores, appears to increase the risk of BrCA in Iranian women. Large increases in risk were seen in invasive molecular subtypes of BrCA. Anti-inflammatory diets are suggested to prevent the risk of overall BrCA and more aggressive forms of BrCA in particular.

Metabolic Syndrome and Risk of Breast Cancer by Molecular Subtype: Analysis of the MEND Study

Metabolic syndrome is a cluster of biological irregularities that is a known risk factor for cardiovascular disease, stroke, and diabetes. In a case-control study of 555 West African women, we observed that metabolic syndrome was strongly associated with breast cancer and the aggressive triple-negative molecular subtype, highlighting a need for clinical and lifestyle interventions targeting metabolic syndrome to reduce breast cancer risk in this population.

The Role of Chronic Inflammation in the Development of Breast Cancer

Chronic inflammation contributes to the malignant transformation of several malignancies and is an important component of breast cancer. The role of chronic inflammation in the initiation and development of breast cancer from normal breast tissue, however, is unclear and needs to be clarified. A review of the literature was conducted to define the chronic inflammatory processes in normal breast tissue at risk for breast cancer and in breast cancer, including the role of lymphocyte and macrophage infiltrates, chronic active adipocytes and fibroblasts, and processes that may promote chronic inflammation including the microbiome and factors related to genomic abnormalities and cellular injury. The findings indicate that in healthy normal breast tissue there is systemic evidence to suggest inflammatory changes are present and associated with breast cancer risk, and adipocytes and crown-like structures in normal breast tissue may be associated with chronic inflammatory changes. The microbiome, genomic abnormalities, and cellular changes are present in healthy normal breast tissue, with the potential to elicit inflammatory changes, while infiltrating lymphocytes are uncommon in these tissues. Chronic inflammatory changes occur prominently in breast cancer tissues, with important contributions from tumor-infiltrating lymphocytes and tumor-associated macrophages, cancer-associated adipocytes and crown-like structures, and cancer-associated fibroblasts, while the microbiome and DNA damage may serve to promote inflammatory events. Together, these findings suggest that chronic inflammation may play a role in influencing the initiation, development and conduct of breast cancer, although several chronic inflammatory processes in breast tissue may occur later in breast carcinogenesis.