Vitamin D as a Potential Preventive Agent For Young Women's Breast Cancer

Altered liver metabolism post-wean abolishes efficacy of vitamin D for breast cancer prevention in a mouse model

Young women have increased risk of vitamin D deficiency, which may increase breast cancer incidence. Here, we assessed the anti-cancer efficacy of vitamin D in mouse models of young-onset breast cancer. In never-pregnant mice, vitamin D supplementation increased serum 25(OH)D and hepatic 1,25(OH)2D3, reduced tumor size, and associated with anti-tumor immunity. These anti-tumor effects were not replicated in a mouse model of postpartum breast cancer, where hepatic metabolism of vitamin D was suppressed post-wean, which resulted in deficient serum 25(OH)D and reduced hepatic 1,25(OH)2D3. Treatment with active 1,25(OH)2D3 induced hypercalcemia exclusively in post-wean mice, highlighting metabolic imbalance post-wean. RNAseq revealed suppressed CYP450 expression postpartum. In sum, we provide evidence that vitamin D anti-tumor activity is mediated through immunomodulatory mechanisms and is ineffective in the post-wean window due to altered hepatic metabolism. These findings have implications for suppressed xenobiotic metabolism in postpartum women beyond vitamin D.

Interdisciplinary Integrative Oncology Group-Based Program: Evaluation of Long-Term Effects on Resilience and Use of Complementary and Alternative Medicine in Patients With Cancer

BACKGROUND

Cancer often causes reduced resilience, quality of life (QoL) and poorer overall well-being. To mitigate these problems, complementary and alternative medicine (CAM) is widely used among patients with cancer. This study aimed to evaluate the long-term effects of an interdisciplinary integrative oncology group-based program (IO-GP) on the resilience and use of CAM in patients with cancer.

METHODS

This was a prospective, observational, single-center study. Resilience (RS-13), CAM usage (I-CAM-G), QoL (SF-12) and health-related lifestyle factor (nutrition, smoking, alcohol consumption and physical exercise) data were collected for 70 patients who participated in a 10-week IO-GP between January 2019 and June 2022 due to cancer. The IO-GP is offered at the setting of a university hospital and is open to adult patients with cancer. It contains elements from mind-body medicine and positive psychology, as well as recommendations on healthy diet, exercise and CAM approaches. Patients who completed the IO-GP at least 12 months prior (1-4.5 years ago) were included in this study. Statistical analysis included descriptive analysis and parametric and nonparametric tests to identify significant differences (P < .05).

RESULTS

Resilience increased significantly ≥12 months after participation in the IO-GP (n = 44, P = .006, F = 8.274) and had a medium effect size (r = .410). The time since the IO-GP was completed ("12-24 months," "24-36 months," and ">36 months") showed no statistically significant interaction with changes in resilience (P = .226, F = 1.544). The most frequently used CAM modalities within the past 12 months were vitamins/minerals (85.7%), relaxation techniques (54.3%), herbs and plant medicine (41.1%), yoga (41.4%) and meditation (41.4%). The IO-GP was the most common source informing study participants about relaxation techniques (n = 24, 64.9%), meditation (n = 21, 72.4%) and taking vitamin D (n = 16, 40.0%). Significantly greater levels of resilience were found in those practicing meditation (P = .010, d = -.642) or visualization (P = .003, d = -.805) compared to non-practitioners.

CONCLUSION

IO-GPs have the potential to empower patients with cancer to continue using CAM practices-especially from mind-body medicine-even 1 to 4.5 years after completing the program. Additionally, resilience levels increased. These findings provide notable insight into the long-term effects of integrative oncology interventions on resilience and the use of CAM, especially in patients with breast cancer.

Local production of active vitamin D3 metabolites in breast cancer cells by CYP24A1 and CYP27B1

The role of vitamin D3 and its metabolites in cancer and especially as a treatment option has been widely disputed. Clinicians noting low serum 25-hydroxyvitamin D3 [25(OH)D3] levels in their patients, recommend vitamin D3 supplementation as a method of reducing the risk of cancer; however, data supporting this are inconsistent. These studies rely on systemic 25(OH)D3 as an indicator of hormone status, but 25(OH)D3 is further metabolized in the kidney and other tissues under regulation by several factors. This study examined if breast cancer cells also possess the ability to metabolize 25(OH)D3, and if so, whether the resulting metabolites are secreted locally; if this ability reflects ERα66 status; and if they possess vitamin D receptors (VDR). To address this question, estrogen receptor alpha (ERα) positive (MCF-7) and ERα negative (HCC38 and MDA-MB-231) breast cancer cell lines were examined for expression of ERα66, ERα36, CYP24A1, CYP27B1, and VDR as well as for local production of 24,25-dihydroxyvitamin D3 [24,25(OH)2D3] and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] after treatment with 25(OH)D3. The results showed that independent of ER status, breast cancer cells express the enzymes CYP24A1 and CYP27B1, which are responsible for converting 25(OH)D3 into its dihydroxylated forms. Moreover, these metabolites are produced at levels comparable to the levels observed in blood. They are positive for VDR, indicating that they can respond to 1α,25(OH)2D3, which can upregulate CYP24A1. These findings suggest that vitamin D metabolites may contribute to the tumorigenicity of breast cancer via autocrine and/or paracrine mechanisms.

Vitamin D Receptor Expression Is Significantly Decreased in Bone Metastases Compared to Matched Primary Breast Cancer Tumours

There is ample evidence today that vitamin D signalling via the vitamin D receptor (VDR) plays a pivotal role in cancer growth and metastasis. The aim of this study was to analyse VDR expression of primary breast cancer and corresponding bone metastases tissue samples. Collectively, 15 sample pairs and 11 samples of patients that did not develop metastases were analysed histologically for VDR expression (n = 41). Overall, VDR expression was significantly lower in bone metastases compared to primary tumour samples (p < .0001). Downregulation of the VDR in breast cancer cells may define a critical turning point in oncogenesis that accelerates cancer cell dissemination and metastases.

Vitamin D Levels in Newly Diagnosed Breast Cancer Patients according to Tumor Sub-Types

Vitamin D is an important regulator of bone health. In addition, as a ligand for a nuclear receptor expressed in breast cancer cells, vitamin D exerts neoplasia modulating effects in breast cancer. However, despite extensive investigations, associations of vitamin D levels with breast cancer patient characteristics and disease sub-types are conflicting. A retrospective review of medical records of consecutive breast cancer patients treated and followed in a single cancer center was undertaken. All patients with 25-hydroxyvitamin D (25-OHD, the circulating form of vitamin D) measurements available within 3 months of their diagnosis and before the start of any systemic treatment were included. Characteristics of patients and tumors with sufficient levels of 25-OHD were compared with those of patients with 25-OHD insufficiency. Two hundred ninety-two patients were included in the study. Almost two-thirds of the patients were 25-OHD insufficient, defined as having 25-OHD levels below 75 nmol/L. Compared with the group of patients who were 25-OHD sufficient, patients with 25-OHD insufficiency were younger and more often obese. Tumors of patients with 25-OHD insufficiency were more often ductal, of higher grade, and ER negative. 25-OHD insufficiency is prevalent in breast cancer patients and even more prevalent in younger and obese patients. 25-OHD insufficiency is associated with cancers that have aggressive characteristics, including higher grade and ER negativity.

Vitamin D Deficiency in Women with Breast Cancer: A Correlation with Osteoporosis? A Machine Learning Approach with Multiple Factor Analysis

Breast cancer (BC) is the most frequent malignant tumor in women in Europe and North America, and the use of aromatase inhibitors (AIs) is recommended in women affected by estrogen receptor-positive BCs. AIs, by inhibiting the enzyme that converts androgens into estrogen, cause a decrement in bone mineral density (BMD), with a consequent increased risk of fragility fractures. This study aimed to evaluate the role of vitamin D3 deficiency in women with breast cancer and its correlation with osteoporosis and BMD modifications. This observational cross-sectional study collected the following data regarding bone health: osteoporosis and osteopenia diagnosis, lumbar spine (LS) and femoral neck bone mineral density (BMD), serum levels of 25-hydroxyvitamin D3 (25(OH)D3), calcium and parathyroid hormone. The study included 54 women with BC, mean age 67.3 ± 8.16 years. Given a significantly low correlation with the LS BMD value (r2 = 0.30, p = 0.025), we assessed the role of vitamin D3 via multiple factor analysis and found that BMD and vitamin D3 contributed to the arrangement of clusters, reported as vectors, providing similar trajectories of influence to the construction of the machine learning model. Thus, in a cohort of women with BC undergoing Ais, we identified a very low prevalence (5.6%) of patients with adequate bone health and a normal vitamin D3 status. According to our cluster model, we may conclude that the assessment and management of bone health and vitamin D3 status are crucial in BC survivors.

Vitamin D May Protect against Breast Cancer through the Regulation of Long Noncoding RNAs by VDR Signaling

Dietary vitamin D3 has attracted wide interest as a natural compound for breast cancer prevention and therapy, supported by in vitro and animal studies. The exact mechanism of such action of vitamin D3 is unknown and may include several independent or partly dependent pathways. The active metabolite of vitamin D3, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D, calcitriol), binds to the vitamin D receptor (VDR) and induces its translocation to the nucleus, where it transactivates a myriad of genes. Vitamin D3 is involved in the maintenance of a normal epigenetic profile whose disturbance may contribute to breast cancer. In general, the protective effect of vitamin D3 against breast cancer is underlined by inhibition of proliferation and migration, stimulation of differentiation and apoptosis, and inhibition of epithelial/mesenchymal transition in breast cells. Vitamin D3 may also inhibit the transformation of normal mammary progenitors into breast cancer stem cells that initiate and sustain the growth of breast tumors. As long noncoding RNAs (lncRNAs) play an important role in breast cancer pathogenesis, and the specific mechanisms underlying this role are poorly understood, we provided several arguments that vitamin D3/VDR may induce protective effects in breast cancer through modulation of lncRNAs that are important for breast cancer pathogenesis. The main lncRNAs candidates to mediate the protective effect of vitamin D3 in breast cancer are lncBCAS1-4_1, AFAP1 antisense RNA 1 (AFAP1-AS1), metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), long intergenic non-protein-coding RNA 511 (LINC00511), LINC00346, small nucleolar RNA host gene 6 (SNHG6), and SNHG16, but there is a rationale to explore several other lncRNAs.