Low dose TamOxifen and LifestylE changes for bReast cANcer prevention (TOLERANT study): Study protocol of a randomized phase II biomarker trial in women at increased risk for breast cancer.

BACKGROUND: Breast Cancer (BC) prevention strategies range from lifestyle changes such as increasing physical activity and reducing body weight to preventive drugs like tamoxifen, known to reduce BC incidence in high-risk women. Sex Hormone Binding Globulin (SHBG) is related to BC risk due to its ability to bind circulating estradiol at high affinity and to regulate estradiol action. A study protocol is presented based on the assessment of the effect of different interventions such as tamoxifen at 10 mg every other day (LDT), intermittent caloric restriction (ICR) two days per week, lifestyle intervention (LI, step counter use) and their combination on the modulation of SHBG and several other biomarkers associated to BC. METHODS: A randomized phase II biomarker study will be conducted in 4 Italian centers. Unaffected women aged between 18 and 70 years, carriers of a germline pathogenetic variant (BRCA1, BRCA2, PALB2, or other moderate penetrance genes), or with a >5% BC risk at 10 years (according to the Tyrer-Cuzick or the Breast Cancer Surveillance Consortium Risk models) or with a previous diagnosis of intraepithelial neoplasia will be eligible. A total of 200 participants will be randomized to one of the four arms: LDT; LDT + ICR; LI; LI + ICR. Interventions will span six months, with baseline and follow-up clinic visits and interim phone calls. DISCUSSION: The aim of the study is to verify whether LDT increases circulating SHBG more than LI with or without ICR after 6 months. Secondary objectives include assessing HOMA-index, inflammatory markers, adiponectin/leptin ratio, quality of life (QoL), safety, toxicity, mammographic density, and changes in microbiome composition across groups. The study's innovation lies in its inclusion of diverse BC risk categories and combination of pharmaceutical and behavioral interventions, potentially enhancing intervention efficacy while balancing tamoxifen's side effects on QoL, especially menopausal symptoms. TRIAL REGISTRATION: EuCT number:2023-503994-39-00; Clinical trials.gov NCT06033092.

Vitamin D Supplementation and Adherence to World Cancer Research Fund (WCRF) Diet Recommendations for Colorectal Cancer Prevention: A Nested Prospective Cohort Study of a Phase II Randomized Trial.

Vitamin D and a healthy diet, based on World Cancer Research Fund (WCRF) recommendations, are considered key elements for colorectal cancer (CRC) prevention. In a CRC case-control study, we observed that CRC cases were often significantly Vitamin D deficient while subjects following WCRF recommendations significantly decreased their risk of developing CRC. We conducted a randomized phase-II trial (EudraCT number-2015-000467-14) where 74 CRC patients showed differences in response to Vitamin D supplementation, 2000 IU in average per day, according to gender and microbiota. The aim of this nested study is to correlate Vitamin D (supplementation, serum level and receptor polymorphisms), circulating biomarkers, and events (polyp/adenoma, CRC relapse and other cancers) in concomitant to WCRF recommendation adherence. Vitamin D supplementation did not modulate circulating biomarkers or follow-up events. FokI and TaqI VDR were associated with 25-hydroxyvitamin D (25OHD) levels. Patients following the WCRF recommendations had significantly lower leptin, significantly lower IL-6 (only in females), and significantly lower risk of events (HR = 0.41, 95%CI: 0.18-0.92; p = 0.03; median follow-up 2.6 years). Interestingly, no WCRF adherents had significantly more events if they were in the placebo (p < 0.0001), whereas no influence of WCRF was observed in the Vitamin D arm. While one-year Vitamin D supplementation might be too short to show significant preventive activity, a healthy diet and lifestyle should be the first step for preventive programs.

Colorectal cancer, Vitamin D and microbiota: A double-blind Phase II randomized trial (ColoViD) in colorectal cancer patients.

BACKGROUND: Several studies suggest a role of gut microbiota in colorectal cancer (CRC) initiation and progression. Vitamin D (vitD) blood levels are also inversely correlated with CRC risk and prognosis. However, these factors' interplay remains unknown. METHODS: 74 CRC patients after standard treatment were randomized to 1-year 2000 IU/day vitD or placebo.  Baseline and post-treatment fecal microbiota for shotgun metagenomics sequencing was collected. Coda-lasso and Principal Component Analysis were used to select and summarize treatment-associated taxa and pathways. Associations between vitD and taxa/pathways were investigated with logistic regression. Mediation analysis was performed to study if treatment-associated taxa mediated the effect of supplementation on 25(OH)D levels. Cox proportional-hazards model was used for disease-free survival (DFS). RESULTS: 60 patients were analyzed. Change in alpha diversity (Shannon: p = 0.77; Simpson: p = 0.63) and post-treatment beta diversity (p = 0.70) were comparable between arms. Post-treatment abundances of 63 taxa and 32 pathways differed between arms. The 63 taxa also mediated the effect of supplementation on 25(OH)D (p = 0.02). There were sex differences in vitD levels, microbiota and pathways. Pathways of essential amino acids' biosynthesis were more abundant in supplemented women. Fusobacterium nucleatum presence at baseline was associated with worse DFS (p = 0.02). Those achieving vitD sufficiency (25(OH)D≥30 ng/ml) had lower post-treatment abundances (p = 0.05). Women were more likely to have F. nucleatum post-treatment (p = 0.02). CONCLUSIONS: VitD supplementation may contribute shaping the gut microbiota and the microbiota may partially mediate the effect of supplementation on 25(OH)D. The observed sex-specific differences highlight the necessity of including sex/gender as a variable in microbiome studies.

Alternative dosing of exemestane in postmenopausal women with ER-positive breast cancer. Design and methods of a randomized presurgical trial.

INTRODUCTION: Aromatase inhibitors are effective in lowering breast cancer incidence among postmenopausal women, but adverse events represent a barrier to their acceptability and adherence as a preventive treatment. This study aims to assess whether lowering exemestane schedule may retain biological activity while improving tolerability in breast cancer patients. METHODS/DESIGN: We are conducting a, pre-surgical, non-inferiority phase IIb study in postmenopausal women with newly diagnosed estrogen receptor-positive breast cancer. Participants are randomized to receive either exemestane 25 mg/day or 25 mg/three times-week or once a week for 4 to 6 weeks prior to surgery. The primary endpoint is the percentage change of serum estradiol concentration between baseline and surgery comparing the three arms. Sample size of 180 women was calculated assuming a 6% non-inferiority of the percent change of estradiol in the lower dose arms compared with the 80% decrease predicted in the full dose arm, with 80% power and using a one-sided 5% significance level and a two-sample t-test. Main secondary outcomes are: safety; change in Ki-67 in cancer and adjacent pre-cancer tissue, circulating sex hormones, adipokines, lipid profile, insulin and glucose changes, in correlation with drug and metabolites concentrations. RESULTS AND DISCUSSION: The present paper is focused on methodology and operational aspects of the study. A total of 180 participants have ben enrolled. The trial is still blinded, and the analyses are ongoing. Despite the short term duration, results may have relevant implications for clinical management of women at increased risk of developing a ER positive breast cancer.

Association of Vitamin D Receptor and Vitamin D-Binding Protein Polymorphisms with Familial Breast Cancer Prognosis in a Mono-Institutional Cohort.

Low 25-hydroxyvitamin D (25OHD) has been associated with an increased cancer incidence and poorer prognosis. Single nucleotide polymorphisms (SNPs) of vitamin D receptor (VDR) and vitamin D binding protein (GC gene) may interfere with vitamin D activity. This study assesses the role of VDR and GC SNPs on breast cancer (BC) recurrence and survival in a cohort of patients with a family history of breast cancer, without the pathogenic variant for BRCA1 and BRCA2. A consecutive series of patients who underwent genetic testing were genotyped for VDR and GC genes. Specifically, ApaI, FokI, TaqI, BsmI and rs2282679, rs4588, rs7041 SNPs were determined. A total of 368 wild type (WT) patients with BC were analyzed for VDR and GC SNPs. The GC rs2282679 minor allele was significantly associated with luminal subtype of the primary tumor compared to Her2+/TN breast cancer (p = 0.007). Multivariate Cox models showed that BmsI and TaqI are significantly associated with BC outcome. Patients with the major alleles showed more than 30% lower hazard of relapse (BsmI p = 0.02 and TaqI p = 0.03). Our study supports the evidence for a pivotal role of 25OHD metabolism in BC. GC SNPs may influence the hormone tumor responsiveness and VDR may affect tumor prognosis.