Circulating 25-hydroxyvitamin D and survival in women with ovarian cancer

Screening by Q Exactive liquid chromatography/tandem mass spectrometry identified Choline, 25-hydroxyvitamin D2, and SM(d18:0/16:1(9Z) (OH)) as biomarkers for high-grade serous ovarian cancer

High-grade serous ovarian cancer (HGSOC) has a high death rate and poor prognosis. The main causes of poor prognosis are asymptomatic early disease, no effective screening method at present, and advanced disease. Changes in cellular metabolism are characteristic of cancer, and plasma metabolome analysis can be used to identify biomarkers. In this study, we used Q Exactive liquid chromatography tandem mass spectrometry (LC-MS/MS, QE) to compare the differentiation between plasma samples (22 HGSOC samples and 22 normal samples). In total, we detected 124 metabolites, and an orthogonal partial least-squares-discriminant analysis (OPLS-DA) model was useful to distinguish HGSOC patients from healthy controls. Choline, 25-hydroxyvitamin D2, and sphingomyelin (d18:0/16:1(9Z) (OH))/SM(d18:0/16:1(9Z) (OH)) showed significantly differential plasma levels in HGSOC patients under the conditions of variable importance in projection (VIP) > 1, p < 0.05 using Student's t-test, and fold change (FC)  ≥ 1.5 or ≤ 0.667. Metabolic pathway analysis can provide valuable information to enhance the understanding of the underlying pathophysiology of HGSOC. In conclusion, the Q Exactive LC/MS/MS method validation-based plasma metabolomics approach may have potential as a convenient screening method for HGSOC and may be a method to monitor tumor recurrence in patients with HGSOC after surgery SIGNIFICANCE: High-grade serous ovarian cancer (HGSOC) has a high death rate and poor prognosis. The main causes of poor prognosis are asymptomatic early disease, no effective screening method at present, and advanced disease. Changes in cellular metabolism are characteristic of cancer, and plasma metabolome analysis can be used to identify biomarkers. In this study, we used Q Exactive liquid chromatography tandem mass spectrometry (LC-MS/MS, QE) to compare the differentiation between plasma samples (20 HGSOC samples and 20 normal samples). In total, we detected 124 metabolites, and an orthogonal partial least-squares-discriminant analysis (OPLS-DA) model was useful to distinguish HGSOC patients from healthy controls. Choline, 25-hydroxyvitamin D2, and sphingomyelin (d18:0/16:1(9Z) (OH))/SM(d18:0/16:1(9Z) (OH)) showed significantly differential plasma levels in HGSOC patients under the conditions of variable importance in projection (VIP) > 1, p < 0.05 using Student's t-test, and fold change (FC) ≥ 1.5 or ≤ 0.667. Metabolic pathway analysis can provide valuable information to enhance the understanding of the underlying pathophysiology of HGSOC. In conclusion, the Q Exactive LC/MS/MS method validation-based plasma metabolomics approach may have potential as a convenient screening method for HGSOC and may be a method to monitor tumor recurrence in patients with HGSOC after surgery.

Insight into vitamin D3 action within the ovary-Basic and clinical aspects

Vitamin D3 is a fat-soluble secosteroid predominantly synthesized in the skin or delivered with a diet. Nevertheless, recently it is considered more as a hormone than a vitamin due to its pleiotropic function within the organism ensured by widely distributed vitamin D receptors and metabolic enzymes. Besides the main role in calcium and phosphorus homeostasis, vitamin D3 was shown to regulate many cellular and metabolic processes in normal and cancerous tissues within the immune system, the cardiovascular system, the respiratory system and the endocrine system. The ovary is an important extraskeletal tissue of vitamin D3 action and local metabolism, indicating its role in the regulation of ovarian functions upon physiological and pathological conditions. This chapter reviews firstly the updated information about vitamin D3 metabolism and triggered intracellular pathways. Furthermore, the basic information about ovarian physiology and several aspects of vitamin D3 effects within the ovary are presented. Finally, the special attention is paid into possible mechanism of vitamin D3 action within ovarian pathologies such as premature ovarian failure, polycystic ovary syndrome, and ovarian cancer, considering its clinical application as alternative therapy.

Cancer Prevention and Treatment Based on Lifestyles

Cancer morbidity and mortality incidence are rapidly increasing over the period of time. Cancer prevention, alongside innovative therapies and earlier detection, is considered a key strategy for reducing the overall cancer burden. Substantial evidence indicates a clear correlation between lifestyle factors and changes in nutrient metabolism. Approximately 5-10% of all cancer cases are attributed to genetic factors, whereas 90-95% are due to environmental and lifestyle factors, suggesting that lifestyle interventions have significant prospects for preventing various cancers. Healthy lifestyle changes, in particular healthy diets, physical activity, staying at a healthy weight, reduction or elimination of tobacco/alcohol consumption, and avoiding exposure to radiation and other carcinogens, are significant factors to be considered to tackle the challenges associated with cancer in modern society. This chapter aims to provide lifestyle intervention strategies to improve cancer prevention and risk reduction while promoting the health of cancer patients. The therapeutic role of some dietary regimens and supplements, as well as complementary and alternative health approaches, in cancer treatment is also discussed.

Vitamin D status during and after treatment and ovarian cancer survival

PURPOSE

Five-year relative survival for ovarian cancer remains below 50%. Strategies to improve outcomes are needed. Higher serum 25-hydroxyvitamin D [25(OH)D] concentrations [measure of vitamin D status] at and before diagnosis have been associated with longer survival in cancer patients; however, data for ovarian cancer are limited. We aimed to determine if 25(OH)D concentrations during and after primary treatment were associated with ovarian cancer-specific survival.

METHODS

We used data from a nationwide prospective cohort study of women with ovarian cancer. Among 886 participants treated with chemotherapy, 700 (79%) had a blood sample collected during (n = 591) and/or after (n = 458) primary treatment. These were tested for 25(OH)D. Clinical and survival data were abstracted from medical records. We used multivariable Cox proportional hazards regression to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between 25(OH)D and ovarian cancer-specific survival.

RESULTS

Mean 25(OH)D concentrations were lower during than after primary treatment (82 and 91 nmol/L, respectively); only 14% and 8% had concentrations below 50 nmol/L during and after primary treatment, respectively. There was no association between 25(OH)D and ovarian cancer-specific survival during five years of follow-up [HR 1.10 (95% CI: 0.76, 1.61) and 0.95 (0.54, 1.68) for the highest vs. lowest quintile during and after treatment, respectively].

CONCLUSIONS

We did not observe any association between serum 25(OH)D concentration and ovarian cancer-specific survival. Our results suggest that, in the absence of vitamin D deficiency, vitamin D supplementation to improve ovarian cancer survival is not warranted.

Vitamin D and docosahexaenoic acid inhibit proliferation of the ovarian cancer cell line OVCAR4

BACKGROUND

Ovarian cancer is one of the deadliest cancers in women. Improved preventative, diagnostic, and therapeutic strategies are needed. Certain dietary patterns and nutrients such as vitamin D and omega-3 fatty acids are associated with reduced cancer risk, but their effects on ovarian cancer remain to be fully elucidated, and their combined effects have not been explored.

AIM

To determine the individual and combined effects of the active vitamin D metabolite, calcitriol, and the omega-3 fatty acid, docosahexaenoic acid, on cell growth, and the abundance of the vitamin D receptor (VDR), proteins that modulate cell cycle progression, and apoptotic markers.

METHODS

OVCAR4 cells, a model of ovarian cancer, were treated with calcitriol, and docosahexaenoic acid, either alone or in combination. Effects on cell growth were determined by the sulforhodamine B assay. Changes in VDR, the cell cycle promotor c-Myc, the cell cycle inhibitor p27 and cleaved PARP, were determined by Western blotting.

RESULTS

While OVCAR4 cell growth was inhibited by individual treatment with either calcitriol or docosahexaenoic acid, the combined treatment revealed enhanced growth inhibition as compared to either treatment alone. Furthermore, long-term treatment (12 days) yielded stronger growth inhibition at lower concentrations as compared to short-term treatments (3 days). Accompanying this growth inhibition was a decrease in c-Myc, and an increase in p27.

CONCLUSIONS

The observed reduction in cell growth mediated by calcitriol and docosahexaenoic acid highlights the need for further research utilizing these nutrients, alone and especially in combination, to support ovarian cancer prevention and treatment.

Association of serum 25-hydroxyvitamin D levels with all-cause and cause-specific mortality among postmenopausal females: results from NHANES

BACKGROUND

Vitamin D deficiency is common among the population, but its relationship with mortality of postmenopausal females is unclear. The aim of this study is to explore the association between serum 25-Hydroxyvitamin D (25(OH)D) and all-cause and cause-specific mortality among postmenopausal women in the United States.

METHODS

6812 participants of postmenopausal females from the National Health and Nutrition Examination Survey (2001-2018) were included in this study. The mortality status of the follow-up was ascertained by linkage to National Death Index (NDI) records through 31 December 2019. We used cox proportional hazards models to estimate the association of serum 25(OH)D concentrations and mortality of postmenopausal females.

RESULTS

The mean level of serum 25(OH)D was 72.57 ± 29.93 nmol/L, and 65.34% had insufficient vitamin D. In postmenopausal females, low serum 25(OH)D concentrations were significantly associated with higher levels of glycohemoglobin, glucose, and lower levels of HDL. During follow-up, 1448 all-cause deaths occurred, including 393 cardiovascular disease (CVD)-related deaths and 263 cancer deaths. After multivariate adjustment, higher serum 25(OH)D levels were significantly related with lower all-cause and CVD mortality. In addition, serum 25(OH)D presented a L-shaped relationship with all-cause mortality, while appeared a U-shaped with CVD mortality, and the cut-off value is 73.89 nmol/L and 46.75 nmol/L respectively.

CONCLUSIONS

Low serum 25(OH)D levels are associated with the higher risk of all-cause and CVD mortality in postmenopausal females. These findings provide new ideas and targets for the health management of postmenopausal women.

Integrative Medicine for Ovarian Cancer

PURPOSE OF REVIEW

Integrative oncology (IO) services provide a wide range of complementary medicine therapies, many of which can augment the beneficial effects of conventional supportive and palliative care for patients with ovarian cancer. This study aims to assess the current state of integrative oncology research in ovarian cancer care.

RECENT FINDINGS

We review the clinical research both supporting the effectiveness of leading IO modalities in ovarian cancer care as well as addressing potential safety-related concerns. There is growing amount of clinical research supporting the use of IO and implementation of integrative gynecological oncology models of care within the conventional supportive cancer care setting. Additional research is still needed in order to create clinical guidelines for IO interventions for the treatment of female patients with ovarian cancer. These guidelines need to address both effectiveness and safety-related issues, providing oncology healthcare professionals with indications for which these patients can be referred to the IO treatment program.

Association between Serum Biomarkers with Postoperative Complications and Delay of Adjuvant Chemotherapy Initiation in Ovarian Cancer Patients Undergoing Primary Cytoreductive Surgery: A Pilot Study

This study sought to describe and relate the factors associated with complications and delays in adjuvant chemotherapy in patients with ovarian cancer treated with primary cytoreductive surgery. Serum from patients diagnosed with ovarian cancer scheduled for primary cytoreductive surgery were analyzed for prealbumin, 25-OH Vitamin D, intracellular adhesion molecule 1 (ICAM-1), interleukin 6 (IL-6), interleukin 8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), monocyte chemoattractant protein 2 (MCP-2), macrophage derived chemokine (MDC). Postoperative complications were identified using common terminology criteria for adverse events 4.0 and 30 day after surgery. Delays in adjuvant chemotherapy were defined as >1 week interval between surgery and initiation. Patients with postoperative complications (39.6%) were significantly older, had lower serum prealbumin levels, and higher serum IL-6 and IL-8 than those without. Univariate logistic regression found that age (OR: 1.12, 95%CI: 1.00-1.35) and IL-6 (OR: 1.02, 95%CI: 0.99-1.05) were associated with postoperative complications, whereas age remained significant after multivariate analysis (OR:1.14, 95%CI: 1.00-1.29). Patients with delays in chemotherapy exhibited greater BMI and lower 25-OH Vitamin D than those without. Multivariate analysis found that increasing levels of 25-OH Vitamin D were associated with a lower risk of delayed chemotherapy initiation after controlling for age, body mass index, and tumor grade (OR: 0.93, 95%CI:0.87-0.99). This work suggests that in addition to age being predictive of postoperative complications, serum 25-OH Vitamin D may a provide insight into a patient's risk for postsurgical delays in chemotherapy initiation. These findings should, however, be confirmed in a larger study including robust survival analysis.

The Effect of Vitamin D and Its Analogs in Ovarian Cancer

Ovarian cancer is one of the deadliest cancers in women, due to its heterogeneity and usually late diagnosis. The current first-line therapies of debulking surgery and intensive chemotherapy cause debilitating side effects. Therefore, there is an unmet medical need to find new and effective therapies with fewer side effects, or adjuvant therapies, which could reduce the necessary doses of chemotherapeutics. Vitamin D is one of the main regulators of serum calcium and phosphorus homeostasis, but it has also anticancer effects. It induces differentiation and apoptosis, reduces proliferation and metastatic potential of cancer cells. However, doses that would be effective against cancer cause hypercalcemia. For this reason, synthetic and less calcemic analogs have been developed and tested in terms of their anticancer effect. The anticancer role of vitamin D is best understood in colorectal, breast, and prostate cancer and much less research has been done in ovarian cancer. In this review, we thus summarize the studies on the role of vitamin D and its analogs in vitro and in vivo in ovarian cancer models.

Zinc, ω-3 polyunsaturated fatty acids and vitamin D: An essential combination for prevention and treatment of cancers

Zinc, ω-3 polyunsaturated fatty acids (PUFAs) and vitamin D are essential nutrients for health, maturation and general wellbeing. Extensive literature searches have revealed the widespread similarity in molecular biological properties of zinc, ω-3 PUFAs and vitamin D, and their similar anti-cancer properties, even though they have different modes of action. These three nutrients are separately essential for good health, especially in the aged. Zinc, ω-3 PUFAs and vitamin D are inexpensive and safe as they are fundamentally natural and have the properties of correcting and inhibiting undesirable actions without disturbing the normal functions of cells or their extracellular environment. This review of the anticancer properties of zinc, ω-3 PUFAs and vitamin D is made in the context of the hallmarks of cancer. The anticancer properties of zinc, ω-3 PUFAs and vitamin D can therefore be used beneficially through combined treatment or supplementation. It is proposed that sufficiency of zinc, ω-3 PUFAs and vitamin D is a necessary requirement during chemotherapy treatment and that clinical trials can have questionable integrity if this sufficiency is not checked and maintained during efficacy trials.

Association among Vitamin D, Retinoic Acid-Related Orphan Receptors, and Vitamin D Hydroxyderivatives in Ovarian Cancer

Vitamin D and its derivatives, acting via the vitamin D receptor (VDR) and retinoic acid-related orphan receptors γ and α (RORγ and RORα), show anticancer properties. Since pathological conditions are characterized by disturbances in the expression of these receptors, in this study, we investigated their expression in ovarian cancers (OCs), as well as explored the phenotypic effects of vitamin D hydroxyderivatives and RORγ/α agonists on OC cells. The VDR and RORγ showed both a nuclear and a cytoplasmic location, and their expression levels were found to be reduced in the primary and metastatic OCs in comparison to normal ovarian epithelium, as well as correlated to the tumor grade. This reduction in VDR and RORγ expression correlated with a shorter overall disease-free survival. VDR, RORγ, and RORα were also detected in SKOV-3 and OVCAR-3 cell lines with increased expression in the latter line. 20-Hydroxy-lumisterol3 (20(OH)L3) and synthetic RORα/RORγ agonist SR1078 inhibited proliferation only in the OVCAR-3 line, while 20-hydroxyvitamin-D3 (20(OH)D3) only inhibited SKOV-3 cell proliferation. 1,25(OH)2D3, 20(OH)L3, and SR1078, but not 20(OH)D3, inhibited spheroid formation in SKOV-3 cells. In summary, decreases in VDR, RORγ, and RORα expression correlated with an unfavorable outcome for OC, and compounds targeting these receptors had a context-dependent anti-tumor activity in vitro. We conclude that VDR and RORγ expression can be used in the diagnosis and prognosis of OC and suggest their ligands as potential candidates for OC therapy.

Serum vitamin D deficiency and risk of epithelial ovarian cancer in Lagos, Nigeria

The studies that have evaluated the association between vitamin D and risk of ovarian cancer have reported inconsistent findings. Many of these studies were carried out in regions with relatively low sunshine all year round unlike in Africa. This study was aimed to determine the relationship between vitamin D deficiency and epithelial ovarian cancer (EOC) amongst women in Lagos, Nigeria. We conducted a case–control study involving women with histologically confirmed EOC (case group) and an equal number of healthy women without cancer (control group) treated at the gynaecological oncology units of two public tertiary hospitals in Lagos, Nigeria, between 1 August, 2016 and 31 May, 2017. Relevant information was obtained from the participants using a structured interviewer-administered questionnaire, and then, venous blood samples were collected and analysed for serum 25-hydroxyvitamin D levels using the CALBIOTECH® 25(OH) vitamin D ELISA kit. The descriptive statistics were conducted for all relevant data, and the multivariable analysis using binary logistic regression model was performed to examine the association between vitamin D deficiency and EOC after adjusting for all possible confounders. The mean age of the participants was 50.6 ± 11.1 years. There was no statistically significant association between serum vitamin D deficiency and EOC (p = 0.09). However, 10 mmol/L change in circulating vitamin D levels was associated with EOC amongst the study participants (adjusted odds ratio 0.96; 95% confidence interval 0.93–0.99; p = 0.04), but following adjustment for potential confounders in a multivariable analysis, there was no statistically significant relationship observed with EOC (adjusted odds ratio 0.99; 95% confidence interval 0.97–1.00; p = 0.06). In addition, there was no evidence of an interaction effect between these confounders and change in circulating 25(OH)D levels in relation to the risk of EOC. The study revealed no statistically significant association between the circulating levels of vitamin D and the risk of EOC. A better assessment of sun exposure in the future as well as better dietary compositional data may help to clarify whether the association between vitamin D and EOC actually exists. Therefore, the future large prospective longitudinal studies are recommended to further examine this relationship and then evaluate the possible need for vitamin D supplementation in women with an increased risk of EOC in Nigeria.

Association between vitamin D/calcium intake and 25-hydroxyvitamin D and risk of ovarian cancer: a dose-response relationship meta-analysis

BACKGROUND

The association between vitamin D/calcium and risk of ovarian cancer is still a debatable point. The aim of our study was to systematically investigate the association between vitamin D/calcium, and the risk of ovarian cancer and estimate their dose-response association quantitatively.

METHODS

PubMed, EMBASE, and Web of Science databases were searched to identify relevant observational studies. Two investigators screened citations and extracted data independently. Data were extracted and the association between vitamin D/calcium and ovarian cancer risk was estimated by calculating pooled relative risks (RRs). Subgroup analyses, publication bias estimation, and dose-response analyses were carried out as well.

RESULTS

In total, 21 articles involving 980,008 participants were included in our present study. No significant association was observed between total vitamin D intake and ovarian cancer risk (RR: 1.02; 95% CI, 0.89-1.16, p = 0.81). Further subgroup analysis suggested that neither dietary vitamin D intake (RR: 0.80; 95% CI, 0.62-1.03, p = 0.09) nor supplementary vitamin D intake (RR: 0.98; 95% CI, 0.85-1.13, p = 0.80) was associated with the risk of ovarian cancer. As for calcium, total calcium intake was found to be statistically inversely associated with ovarian cancer risk in case-control studies (RR: 0.73; 95% CI, 0.63-0.86, p < 0.001) but not in cohort studies (RR: 1.05; 95% CI, 0.90-1.24, p = 0.52). Besides, supplementation with calcium plus vitamin D was not effective for the prevention of ovarian cancer (p = 0.98). Of note, dose-response analysis based on cohort studies suggested a potential inverse U-shape relationship between calcium intake (including total calcium and dietary calcium) and ovarian cancer risk, which indicated that low dose of calcium intake might reduce ovarian cancer risk while high dose of calcium intake might not.

CONCLUSIONS

Taken together, vitamin D could not decrease the risk of ovarian cancer. The role of calcium intake was not proven for reducing ovarian cancer risk. Besides, no evidence showed combinative use of calcium and vitamin D have additional benefits for ovarian cancer prevention.

1α,25(OH)2D3 Radiosensitizes Cancer Cells by Activating the NADPH/ROS Pathway

The radioresistance of tumors affect the outcome of radiotherapy. Accumulating data suggest that 1α,25(OH)₂D₃ is a potential anti-oncogenic molecule in various cancers. In the present study, we investigated the radiosensitive effects and underlying mechanisms of 1α,25(OH)₂D₃ in vitro and in vivo. We found that 1α,25(OH)₂D₃ enhanced the radiosensitivity of lung cancer and ovarian cancer cells by promoting the NADPH oxidase-ROS-apoptosis axis. Compared to the group that only received radiation, the survival fraction and self-renewal capacity of cancer cells treated with a combination of 1α,25(OH)₂D₃ and radiation were decreased. Both apoptosis and ROS were significantly increased in the combination group compared with the radiation only group. Moreover, N-acetyl-L-cysteine, a scavenger of intracellular ROS, reversed the apoptosis and ROS induced by 1α,25(OH)₂D₃, indicating that 1α,25(OH)₂D₃ enhanced the radiosensitivity of cancer cells in vitro by promoting ROS-induced apoptosis. Moreover, our results demonstrated that 1α,25(OH)₂D₃ promoted the ROS level via activating NADPH oxidase complexes, NOX4, p22^phox, and p47^phox. In addition, knockdown of the vitamin D receptor (VDR) abolished the radiosensitization of 1α,25(OH)₂D₃, which confirmed that 1α,25(OH)₂D₃ radiosensitized tumor cells that depend on VDR. Similarly, our study also evidenced that vitamin D₃ enhanced the radiosensitivity of cancer cells in vivo and extended the overall survival of mice with tumors. In summary, these results demonstrate that 1α,25(OH)₂D₃ enhances the radiosensitivity depending on VDR and activates the NADPH oxidase-ROS-apoptosis axis. Our findings suggest that 1α,25(OH)₂D₃ in combination with radiation enhances lung and ovarian cell radiosensitivity, potentially providing a novel combination therapeutic strategy.

Role of vitamin D3 in selected malignant neoplasms

Vitamin D₃ is a fat-soluble essential nutrient that affects multiple biologic functions in the organism through calcitriol and the vitamin D₃ receptor. This review article focuses on the results of studies on the relationship between the level of vitamin D₃ and cancer incidence or mortality, but also on the anticancer properties of vitamin D₃ that support its significant role in the prevention, clinical course, and overall survival rates of selected cancers (colorectal, prostate, breast, ovarian, endometrial, bladder, and malignant melanoma). The mechanisms of vitamin D₃ action involve, among others, polymorphism of vitamin D₃ receptor, cell cycle, caspases, and cancer stem cells. The level of vitamin D₃ has been also demonstrated to serve as a biomarker in some cancers, and high levels of vitamin D₃ can be conducive to successful cancer therapy.

Cytoplasmic VDR expression as an independent risk factor for ovarian cancer

The vitamin D receptor (VDR), primarily known as a crucial mediator of calcium homeostasis and metabolism, has been shown to play a significant role in various cancer entities. Previous studies have focused on vitamin D and its receptor in gynecological cancers, noting that the receptor is upregulated in epithelial ovarian cancer (EOC). The aim of this study is to analyze the prognostic impact of VDR and its functional significance in ovarian cancer. Through immunohistochemistry, VDR staining was examined in 156 ovarian cancer samples. Evaluation of VDR staining was conducted in the nucleus and the cytoplasm using the semi-quantitative immunoreactive score, and the scores were classified into high- and low-level expressions. Expression levels were correlated with clinical and pathological parameters as well as with overall survival to assess for prognostic impact. Differences in cytoplasmic VDR expression were identified between the histological subtypes (p = 0.001). Serous, clear cell, and endometrioid subtypes showed the highest staining, while the mucinous subtype showed the lowest. Cytoplasmic VDR correlated with higher FIGO stage (p = 0.013; Cc = 0.203), positive lymph node status (p = 0.023; Cc = 0.236), high-grade serous histology (p = 0.000; Cc = 0.298) and grading from the distinct histological subtypes (p = 0.006; Cc = − 0.225). Nuclear VDR did not correlate with clinicopathological data. High cytoplasmic expression of VDR was associated with impaired overall survival (HR 2.218, 32.5 months vs. median not reached; p < 0.001) and was confirmed as a statistically independent prognostic factor in the Cox regression multivariate analysis. Additional knowledge of VDR as a biomarker and its interactions within the mitogen-activated protein kinase (MAPK) signaling pathway could potentially improve the prognosis of therapeutic approaches for specific subgroups in EOC.

Vitamin D and Cancer Survival: Does Vitamin D Supplementation Improve the Survival of Patients with Cancer?

PURPOSE OF REVIEW

Clinical evidence suggesting the beneficial effects of vitamin D on survival of patients with cancer has been accumulating. Recent articles were thoroughly reviewed to determine if there is enough evidence to conclude that vitamin D supplementation improves survival of patients with cancer.

RECENT FINDINGS

Meta-analyses of observational studies showed that higher blood 25-hydroxyvitamin D levels in patients with cancer at a variety of sites were associated with lower cancer-specific and overall mortalities. Moreover, meta-analyses of randomized clinical trials (RCTs) also suggested that vitamin D supplementation improved the survival of patients with cancer. However, each RCT used in these meta-analyses, as well as very recent RCTs, e.g., the SUNSHINE and the AMATERASU trial, did not show statistical significance in the primary results. For now, compelling evidence that vitamin D supplementation effectively improves survival of patients with cancer is lacking. Thus, confirmatory RCTs are still obligatory for the future.

Vitamin D Exposure and Ovarian Cancer Risk and Prognosis

Given the poor prognosis of ovarian cancer and limited population-level strategies for early detection and long-term treatment success, knowledge of modifiable risk factors for prevention and improved prognosis is important. Vitamin D has received wide scientific interest in cancer research as having the potential to be one such factor. We carried out a systematic narrative review of the literature on vitamin D and ovarian cancer risk and survival. We included 17 case-control and cohort studies on ovarian cancer incidence. Five analyses were of sun exposure, among which three reported an inverse association. Of 11 analyses of dietary vitamin D, two reported an inverse association. Among five studies of 25(OH)D levels, an inverse association was reported in two. Across all studies the findings were inconsistent, but some recent studies have suggested that vitamin D exposure at earlier ages may be important. Only three studies examining vitamin D exposure in relation to survival among ovarian cancer survivors were identified and the findings were inconsistent. The evidence to date supports a null influence of vitamin D on both ovarian cancer risk and survival. Future research should ensure that exposure assessment captures vitamin D exposure from all sources and for the etiologically or prognostically pertinent period.

Vitamin D and Ovarian Cancer: Systematic Review of the Literature with a Focus on Molecular Mechanisms

Vitamin D is a lipid soluble vitamin involved primarily in calcium metabolism. Epidemiologic evidence indicates that lower circulating vitamin D levels are associated with a higher risk of ovarian cancer and that vitamin D supplementation is associated with decreased cancer mortality. A vast amount of research exists on the possible molecular mechanisms through which vitamin D affects cancer cell proliferation, cancer progression, angiogenesis, and inflammation. We conducted a systematic review of the literature on the effects of vitamin D on ovarian cancer cell.

The Effects of the Dietary and Nutrient Intake on Gynecologic Cancers

The contribution of diet to cancer risk has been considered to be higher in advanced countries than in developing countries. In this paper, I review the current issues (a review of the relevant literature), and the effects of the dietary and nutrient intake on three types of gynecologic cancer (cervical, endometrial and ovarian cancers). In cervical cancer, the most important roles of diet/nutrition in relation to cancer are prophylaxis and countermeasures against human papillomavirus (HPV) infection. The main preventive and reductive factors of cervical cancer are antioxidants, such as vitamin A, C, D and E, carotenoids, vegetables and fruits. These antioxidants may have different abilities to intervene in the natural history of diseases associated with HPV infection. For endometrial cancer, the increase in peripheral estrogens as a result of the aromatization of androgens to estrogens in adipose tissue in obese women and insulin resistance are risk factors. Thus, we must mainly take care to avoid the continuous intake of fat energy and sugar. In ovarian cancer, the etiology has not been fully understood. To the best of our knowledge, the long-term consumption of pro-inflammatory foods, including saturated fat, carbohydrates and animal proteins is a risk factor. The intake of acrylamide is also a risk factor for both endometrial and ovarian cancer. Most papers have been epidemiological studies. Thus, further research using in vitro and in vivo approaches is needed to clarify the effects of the dietary and nutrient intake in detail.

Biologic Mechanisms Linked to Prognosis in Ovarian Cancer that May Be Affected by Aging

The increase of both life expectancy of the Western industrialized population and cancer incidence with aging is expected to result in a rapid expansion of the elderly cancer population, including patients with epithelial ovarian cancer (EOC). Although the survival of patients with EOC has generally improved over the past three decades, this progress has yet to provide benefits for elderly patients. Compared with young age, advanced age has been reported as an adverse prognostic factor influencing EOC. However, contradicting results have been obtained, and the mechanisms underlying this observation are poorly defined. Few papers have been published on the underlying biological mechanisms that might explain this prognosis trend. We provide an extensive review of mechanisms that have been linked to EOC prognosis and/or aging in the published literature and might underlie this relationship in humans.

Vitamin D and health in the Mediterranean countries

Vitamin D, traditionally well known for its role in maintaining optimal health through its contribution to calcium metabolism and skeletal health, has received increased attention over the past two decades, with considerable focus being placed on its nonskeletal benefits. This paper is a narrative review of the nonskeletal health benefits of vitamin D, of particular interest to inhabitants of Mediterranean countries, namely, autism, cancer, cardiovascular disease, chronic obstructive pulmonary disease, dental caries, diabetes mellitus, erectile dysfunction, hypertension, metabolic syndrome, respiratory tract infections, all-cause mortality, and pregnancy and birth outcomes, because of the relatively high incidence and/or prevalence of these disorders in this region. Currently, the best evidence is coming out of observational studies related to serum 25-hydroxyvitamin D [25(OH)D] concentrations. Vitamin D clinical trials have generally been poorly designed and conducted, usually being based on vitamin D dose rather than 25(OH)D concentration. The optimal 25(OH)D concentration is above 75 nmol/l (30 ng/ml), with even better health outcomes in the range of 100-150 nmol/l. Achieving these concentrations with vitamin D₃ supplements will require 1000-4000 IU/day of vitamin D₃. Sensible sun exposure should also be encouraged. Countries should also consider fortifying grain and dairy products with vitamin D₃.

Pre-diagnostic 25-hydroxyvitamin D levels and survival in cancer patients

PURPOSE

Our main aim was to explore whether pre-diagnostic circulating levels of 25-hydroxyvitamin D (25(OH)D) among older individuals with cancer were associated with overall and cancer-specific survival after diagnosis.

DESIGN

We used data from the Reykjavik-AGES Study on participants (n = 4,619) without cancer at entry, when blood samples were taken for 25(OH)D standardized measurements. The association with cancer risk, all-cause- and cancer-specific mortality was assessed among those later diagnosed with cancer, comparing four 25(OH)D categories, using 50-69.9 nmol/L as the reference category.

RESULTS

Cancer was diagnosed in 919 participants on average 8.3 years after blood draw. No association was observed between the reference group and other 25(OH)D groups and total cancer incidence. Mean age at diagnosis was 80.9 (± 5.7) years. Of those diagnosed, 552 died during follow-up, 67% from cancer. Low pre-diagnostic levels of 25(OH)D < 30 nmol/L were significantly associated with increased total mortality (HR: 1.39, 95% CI 1.03, 1.88) and non-significantly with cancer-specific mortality (HR: 1.33, 95% CI 0.93, 1.90). Among patients surviving more than 2 years after diagnosis, higher pre-diagnostic 25(OH)D levels (≥ 70 nmol/L) were associated with lower risk of overall (HR: 0.68, 95% CI 0.46, 0.99) and cancer-specific mortality (HR: 0.47, 95% CI 0.26, 0.99).

CONCLUSIONS

Among elderly cancer patients, low pre-diagnostic serum 25(OH)D levels (< 30 nmol/L) were associated with increased overall mortality.

The role of vitamin D in ovarian cancer: epidemiology, molecular mechanism and prevention

Vitamin D is a fat-soluble prohormone best known for its role in maintaining calcium homeostasis. Large numbers of epidemiological studies have shown that vitamin D plays an important role in cancer prevention by regulating cellular proliferation and metabolism. Studies of the cellular mechanism of vitamin D in ovarian cancer strongly suggest that it exhibits protective and antitumorigenic activities through genomic and nongenomic signal transduction pathways. These results indicate that vitamin D deficiency results in an increase in the risk of developing ovarian cancer and that vitamin supplements may potentially be an efficient way of preventing cancer. Consequently, this review describes the epidemiology, molecular mechanism and evidence linking vitamin D deficiency to ovarian cancer.

Circulating Vitamin D and Overall Survival in Breast Cancer Patients: A Dose-Response Meta-Analysis of Cohort Studies

Studies have shown that vitamin D could have a role in breast cancer survival; however, the evidence of the relationship between patients' vitamin D levels and their survival has been inconsistent. This meta-analysis explores possible dose-response relationships between vitamin D levels and overall survival by allowing for differences in vitamin D levels among populations of the various studies. Studies relating vitamin D (25-OH-D [25-hydroxyvitamin D]) levels in breast cancer patients with their survival were identified by searching PubMed and Embase. A pooled HR (hazard ratio) comparing the highest with the lowest category of circulating 25-OH-D levels were synthesized using the Mantel-Haenszel method under a fixed-effects model. A two-stage fixed-effects dose-response model including both linear (a log-linear dose-response regression) and nonlinear (a restricted cubic spline regression) models were used to further explore possible dose-response relationships. Six studies with a total number of 5984 patients were identified. A pooled HR comparing the highest with the lowest category of circulating 25-OH-D levels under a fixed-effects model was 0.67 (95% confidence interval = 0.56-0.79, P < .001). Utilizing a dose-response meta-analysis, the pooled HR for overall survival in breast cancer patients was 0.994 (per 1 nmol/L), Pfor linear trend < .001. At or above a 23.3 nmol/L threshold, for a 10 nmol/L, 20 nmol/L, or 25 nmol/L increment in circulating 25-OH-D levels, the risk of breast cancer overall mortality decreased by 6%, 12%, and 14%, respectively. There was no significant nonlinearity in the relationship between overall survival and circulating 25-OH-D levels. Our findings suggest that there is a highly significant linear dose-response relationship between circulating 25-OH-D levels and overall survival in patients with breast cancer. However, better designed prospective cohort studies and clinical trials are needed to further confirm these findings.

Vitamin D and VDR in Gynecological Cancers-A Systematic Review

In recent years, a vast amount of studies have centered on the role of vitamin D in the pathogenesis of certain types of cancers such as breast, colorectal and lung cancer. Increasing evidence suggests that vitamin D and its receptor play a crucial role in the development of gynecological cancers. In this review, we systematically analyzed the effect of vitamin D and the vitamin D receptor on endometrial, ovarian, cervical, vulvar and vaginal cancer. Our literature research shows that vitamin D levels and vitamin-D-related pathways affect the risk of gynecological cancers. Numerous ecological studies give evidence on the inverse relationship between UVB exposure and gynecological cancer risk. However, epidemiologic research is still inconclusive for endometrial and ovarian cancer and insufficient for rarer types of gynecological cancers. The vitamin D receptor (VDR) is upregulated in all gynecological cancers, indicating its influence on cancer etiology. The VDR polymorphism FokI (rs2228570) seems to increase the risk of ovarian cancer. Other nuclear receptors, such as the RXR, also influence gynecological cancers. Although there is limited knowledge on the role of the VDR/RXR on the survival of endometrial, cervical, vulvar or vaginal cancer patients, some studies showed that both receptors influence survival. Therefore, we suggest that further studies should focus on the vitamin D- and its hetero dimer receptor RXR in gynecological cancers.

Inflammation Modifies the Association of Obesity with Circulating 25-Hydroxyvitamin D Levels in Cancer Survivors

OBJECTIVE

Obesity, inflammation, and circulating 25-hydroxyvitamin D (25-OHD) have distinct roles in cancer prognosis. The interplay of these factors was investigated by evaluating the associations of body mass index (BMI) with circulating 25-OHD levels in cancer survivors and determining whether associations were modified by inflammation, defined by C-reactive protein (CRP) levels.

METHODS

Data on cancer survivors were aggregated from the US National Health and Nutrition Examination Survey (2001-2010). Multivariable linear regression models were used to evaluate the associations of BMI with circulating 25-OHD. Analyses were stratified by CRP levels: low < 1.0 mg/L, moderate 1.0-3.0 mg/L, and high > 3.0-9.9 mg/L.

RESULTS

Among 1,305 cancer survivors (mean age = 60.8 years, mean BMI = 28.0 kg/m2 ), circulating 25-OHD levels were 8.74 nmol/L lower (95% CI: 4.71 to 12.77) in cancer survivors with BMI ≥ 30.0 kg/m2 compared with those with BMI < 25.0 kg/m2 . This association was, however, limited to those with moderate CRP (-9.90 nmol/L, 95% CI: -16.45 to -3.36) and high CRP (-11.61 nmol/L, 95% CI: -18.71 to -5.05), but not among those with low CRP levels (-5.31 nmol/L, 95% CI:-12.66 to 2.04).

CONCLUSIONS

A greater understanding of the interplay between 25-OHD and inflammation in cancer survivors with obesity should allow for targeted secondary prevention and help improve prognosis in these patients.

Leisure-time physical activity and circulating 25-hydroxyvitamin D levels in cancer survivors: a cross-sectional analysis using data from the US National Health and Nutrition Examination Survey

OBJECTIVES

Circulating 25-hydroxyvitamin D (25-OHD) is associated with improved cancer prognosis in some studies, yet it may be a surrogate marker for physical activity. We investigated the associations of leisure-time physical activity (LTPA) with circulating 25-OHD levels in cancer survivors, and determined whether associations differ by indoor and outdoor activity.

DESIGN

Cross-sectional study.

SETTING

The US National Health and Nutrition Examination Survey (NHANES).

PARTICIPANTS

Cancer survivors with available data on demographic information, measures of adiposity, smoking history, self-reported LTPA and circulating 25-OHD levels in five waves of NHANES (2001-2010).

MAIN OUTCOMES MEASURES

Circulating 25-OHD levels.

RESULTS

Multivariable linear regression and logistic regression models were used to evaluate the associations of self-reported LTPA with 25-OHD, adjusting for potential confounders. Due to the differences in LTPA measure, the analyses were conducted separately for 2001-2006 and 2007-2010 data. We further estimated associations by indoor and outdoor activity in the 2001-2006 data. There were 1530 cancer survivors (mean age=60.5 years, mean body mass index=28.6 kg/m2). The prevalent cancer sites were breast (19.3%), prostate (18.8%), cervix (10.4%) and colon (8.6%). Compared with inactive cancer survivors, being physically active was associated with higher circulating 25-OHD levels (8.07 nmol/L, 95% CI 4.63 to 11.52) for 2001-2006 data. In the mutually adjusted model, higher outdoor activity (5.83 nmol/L, 95% CI 1.64 to 10.01), but not indoor activity (2.93 nmol/L, 95% CI -1.80 to 7.66), was associated with statistically significantly higher 25-OHD levels. The interaction between indoor and outdoor activities was, however, not significant (p=0.29). The only statistically significant association seen in the 2007-2010 data was among obese cancer survivors.

CONCLUSION

Physical activity, particularly outdoor activity, is associated with higher 25-OHD levels in cancer survivors. In view of the possible beneficial effects of vitamin D on cancer prognosis, engaging in outdoor physical activity could provide clinically meaningful increases in 25-OHD levels among cancer survivors.

The impact of vitamin D pathway genetic variation and circulating 25-hydroxyvitamin D on cancer outcome: systematic review and meta-analysis

BACKGROUND

Vitamin D has been linked with improved cancer outcome. This systematic review and meta-analysis investigates the relationship between cancer outcomes and both vitamin D-related genetic variation and circulating 25-hydroxyvitamin D (25OHD) concentration.

METHODS

A systematic review and meta-analysis of papers until November 2016 on PubMed, EMBASE and Web of Science pertaining to association between circulating vitamin D level, functionally relevant vitamin D receptor genetic variants and variants within vitamin D pathway genes and cancer survival or disease progression was performed.

RESULTS

A total of 44 165 cases from 64 studies were included in meta-analyses. Higher 25OHD was associated with better overall survival (hazard ratio (HR=0.74, 95% CI: 0.66-0.82) and progression-free survival (HR=0.84, 95% CI: 0.77-0.91). The rs1544410 (BsmI) variant was associated with overall survival (HR=1.40, 95% CI: 1.05-1.75) and rs7975232 (ApaI) with progression-free survival (HR=1.29, 95% CI: 1.02-1.56). The rs2228570 (FokI) variant was associated with overall survival in lung cancer patients (HR=1.29, 95% CI: 1.0-1.57), with a suggestive association across all cancers (HR=1.26, 95% CI: 0.96-1.56).

CONCLUSIONS

Higher 25OHD concentration is associated with better cancer outcome, and the observed association of functional variants in vitamin D pathway genes with outcome supports a causal link. This analysis provides powerful background rationale to instigate clinical trials to investigate the potential beneficial effect of vitamin D in the context of stratification by genotype.

The role of vitamin D and VDR in carcinogenesis: Through epidemiology and basic sciences

In the last two decades vitamin D (VD) research has demonstrated new extraskeletal actions of this pre-hormone, suggesting a protective role of this secosteroid in the onset, progression and prognosis of several chronic noncommunicable diseases, such as cardiovascular disease, diabetes mellitus or cancer. Regarding carcinogenesis, both preclinical and epidemiological evidence available show oncoprotective actions of VD and its receptor, the VDR. However, in late neoplastic stages the VD system (VDS) seems to be less functional, which appears to be due to an epigenetic silencing of the system. In preclinical experimental studies, VD presents oncoprotective actions through modulation of inflammation, cell proliferation, cell differentiation, angiogenesis, invasive and metastatic potential, apoptosis, miRNA expression regulation and modulation of the Hedgehog signalling pathway. Moreover, epidemiological evidence points towards an oncoprotective role of vitamin D and VDR in colorectal cancer. This association is more controversial with breast, ovarian and prostate cancers, although with a few adverse effects. Nonetheless, we should consider other factors to determine the benefit of increased serum concentration of VD. Much of the epidemiological evidence is still inconclusive, and we will have to wait for new, better-designed ongoing RCTs and their results to discern the real effect of vitamin D in cancer risk reduction and therapy. The objective of this literature review is to offer an up-to-date analysis of the role of the VD and VDR, in the onset, progression and prognosis of all types of cancer. We further discuss the available literature and suggest new hypotheses and future challenges in the field of VD research.

Association of vitamin D levels and risk of ovarian cancer: a Mendelian randomization study

BACKGROUND

In vitro and observational epidemiological studies suggest that vitamin D may play a role in cancer prevention. However, the relationship between vitamin D and ovarian cancer is uncertain, with observational studies generating conflicting findings. A potential limitation of observational studies is inadequate control of confounding. To overcome this problem, we used Mendelian randomization (MR) to evaluate the association between single nucleotide polymorphisms (SNPs) associated with circulating 25-hydroxyvitamin D [25(OH)D] concentration and risk of ovarian cancer.

METHODS

We employed SNPs with well-established associations with 25(OH)D concentration as instrumental variables for MR: rs7944926 (DHCR7), rs12794714 (CYP2R1) and rs2282679 (GC). We included 31 719 women of European ancestry (10 065 cases, 21 654 controls) from the Ovarian Cancer Association Consortium, who were genotyped using customized Illumina Infinium iSelect (iCOGS) arrays. A two-sample (summary data) MR approach was used and analyses were performed separately for all ovarian cancer (10 065 cases) and for high-grade serous ovarian cancer (4121 cases).

RESULTS

The odds ratio for epithelial ovarian cancer risk (10 065 cases) estimated by combining the individual SNP associations using inverse variance weighting was 1.27 (95% confidence interval: 1.06 to 1.51) per 20 nmol/L decrease in 25(OH)D concentration. The estimated odds ratio for high-grade serous epithelial ovarian cancer (4121 cases) was 1.54 (1.19, 2.01).

CONCLUSIONS

Genetically lowered 25-hydroxyvitamin D concentrations were associated with higher ovarian cancer susceptibility in Europeans. These findings suggest that increasing plasma vitamin D levels may reduce risk of ovarian cancer.

Vitamin D postpones the progression of epithelial ovarian cancer induced by 7, 12-dimethylbenz [a] anthracene both in vitro and in vivo

Purpose

Ovarian cancer is the most lethal malignancy of the female reproductive system, and the prevention and treatment of ovarian carcinoma are still far from optimal. Epidemiological studies reported that ovarian cancer risk was inversely associated with low level of 25-hydroxy vitamin D [25(OH)]. Therefore, this study focuses on exploring the chemoprevention of vitamin D on epithelial ovarian cancer induced by 7, 12-dimethylbenz [a] anthracene (DMBA).

Methods

The mouse ovarian surface epithelial cells were isolated from estrus mice by mild trypsinization and maintained in completed culture medium by repeated passaging. The malignant transformation of mouse ovarian surface epithelial cells was induced by DMBA in vitro. DMBA was directly injected into the bursa of mouse ovary to produce optimized in vivo ovarian cancer model.

Results

The results indicate that 1α,25 dihydroxyvitamin D3 may delay malignant transformation of mouse ovarian surface epithelial cells induced by DMBA and significantly decreased the colony formation rate from 18.4% to 3.2% (P<0.05). There was a negative correlation between incidence of DMBA-induced tumor and 25-hydroxy vitamin D level (R²=0.978, P<0.05). Vitamin D3 can delay the progression of ovarian cancer induced by DMBA, and the administration of vitamin D3 during the whole process worked more effectively than the administration only during tumor initiation or promotion. Moreover, we found the vitamin D3 increased the expression of E-cadherin and vitamin D receptor while it decreased the expression of β-catenin.

Conclusion

We succeeded in establishment of epithelial ovarian cancer models both in vitro and in vivo. The DMBA-implanted model in mice yields high incidence and specificity of epithelial derived tumors. We also found that vitamin D delays the progression of ovarian cancer. However, spontaneous epithelial ovarian carcinoma models are still to be explored for testing the preventive effects of vitamin D on epithelial ovarian cancer.