Inverse association between dietary vitamin D and risk of cutaneous melanoma in a northern Italy population

Malignant Melanoma: An Overview, New Perspectives, and Vitamin D Signaling

Melanoma, originating through malignant transformation of melanin-producing melanocytes, is a formidable malignancy, characterized by local invasiveness, recurrence, early metastasis, resistance to therapy, and a high mortality rate. This review discusses etiologic and risk factors for melanoma, diagnostic and prognostic tools, including recent advances in molecular biology, omics, and bioinformatics, and provides an overview of its therapy. Since the incidence of melanoma is rising and mortality remains unacceptably high, we discuss its inherent properties, including melanogenesis, that make this disease resilient to treatment and propose to use AI to solve the above complex and multidimensional problems. We provide an overview on vitamin D and its anticancerogenic properties, and report recent advances in this field that can provide solutions for the prevention and/or therapy of melanoma. Experimental papers and clinicopathological studies on the role of vitamin D status and signaling pathways initiated by its active metabolites in melanoma prognosis and therapy are reviewed. We conclude that vitamin D signaling, defined by specific nuclear receptors and selective activation by specific vitamin D hydroxyderivatives, can provide a benefit for new or existing therapeutic approaches. We propose to target vitamin D signaling with the use of computational biology and AI tools to provide a solution to the melanoma problem.

Circulating vitamin D concentration and risk of 14 cancers: a bidirectional Mendelian randomization study

BACKGROUND

Observational studies have revealed relationships between circulating vitamin D concentrations and the risk of different types of cancer, although the potential causal relationship remains controversial. This study aims to investigate the presence of a causal relationship between circulating vitamin D concentrations and the risk of different types of cancer.

METHODS

Summary statistics from corresponding genome-wide association studies (GWASs) were used to investigate the causal relationship between circulating vitamin D concentrations and the risk of 14 cancers. A two-sample Mendelian randomization (MR) analysis using inverse-variance weighting (IVW) as the primary method was performed. Additionally, the results were verified using four other methods, including MR-Egger, weighted median, weighted mode, and simple mode. Multiple sensitivity analyses were conducted to ensure the robustness of our MR findings.

RESULTS

The MR analysis showed no causal relationship between circulating vitamin D concentrations and most types of cancer, except for a causal relationship with melanoma skin cancer (MSC) (odds ratio [OR]IVW = 1.003, 95% confidence intervals [CI] 1.001-1.005, P = 0.004). Conversely, reverse MR revealed a causal relationship between circulating vitamin D concentration and colorectal cancer (ORIVW = 0.398, 95% CI 0.195-0.813, P = 0.01; ORweighted median = 0.352, 95% CI 0.135-0.917, P = 0.03).

CONCLUSIONS

Our findings provide support for a causal relationship between circulating vitamin D concentration and risk of MSC. Additionally, we found a causal relationship between circulating vitamin D concentration and risk of colorectal cancer in reverse-MR analysis. This evidence indicate that vitamin D is of great significance in the prevention and treatment of MSC and the prognosis of colorectal cancer.

Systemic Photoprotection in Melanoma and Non-Melanoma Skin Cancer

Non-melanoma skin cancers (NMSCs), which include basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and actinic keratosis (AK), are the most common cancer diseases in the Caucasian race. If diagnosed late and improperly treated, BCC and SCC can become locally advanced and metastasize. Malignant melanoma (MM) is less frequent but more lethal than NMSC. Given the individual and social burdens of skin cancers, performing an adequate prevention is needed. Ultraviolet (UV) ray exposure is one of the main risk factors for skin cancer. Thus, the first-choice prevention strategy is represented by photoprotection that can be both topical and systemic. The latter consists of the oral administration of molecules which protect human skin against the damaging effects of UV rays, acting through antioxidant, anti-inflammatory, or immunomodulator mechanisms. Although several compounds are commonly used for photoprotection, only a few molecules have demonstrated their effectiveness in clinical trials and have been included in international guidelines for NMSC prevention (i.e., nicotinamide and retinoids). Moreover, none of them have been demonstrated as able to prevent MM. Clinical and preclinical data regarding the most common compounds used for systemic photoprotection are reported in this review, with a focus on the main mechanisms involved in their photoprotective properties.

Neutrophil Gelatinase-Associated Lipocalin as Potential Predictive Biomarker of Melanoma and Non-Melanoma Skin Cancers in Psoriatic Patients: A Pilot Study

Background: Studies have demonstrated a higher risk of nonmelanoma skin cancers (NMSC) and a modestly increased melanoma risk in patients with psoriasis. To date, no biomarkers predictive of evolution have been identified yet. Methods: The aim of this prospective case-control study was to investigate the potential role of neutrophil gelatinase-associated lipocalin (NGAL) as a predictive biomarker of skin cancers in psoriatic patients. Patients with a diagnosis of psoriasis were enrolled, as well as healthy subjects and patients with skin cancers as controls. Plasma protein expression of NGAL, metalloproteinases (MMP)-2, and MMP-9 was performed by an enzyme-linked immunosorbent assay (ELISA). In all the patients who developed skin cancer at follow-up, NGAL, MMP-2, and MMP-9 serum levels were dosed again. Results: Plasma NGAL levels were significantly higher in psoriatic patients with NMSC than without (182.3 ± 36.6 ng/mL vs. 139.9 ± 39.3 ng/mL) (p < 0.001). Plasma NGAL levels were significantly higher (p < 0.00001) in patients with psoriasis and NMSC than in patients with skin tumors without psoriasis (182.3 vs. 122.9). Patients with psoriasis who developed NMSC at follow-up showed increased plasma MMP-9 levels. Conclusion: NGAL seems to play a role in the pathogenesis of NMSC but not melanoma in patients with psoriasis.

To identify the association between dietary vitamin D intake and serum levels and risk or prognostic factors for melanoma-systematic review and meta-analysis

OBJECTIVE

To evaluate the association of serum vitamin D levels and dietary intake with melanoma risk and prognostic factors.

METHODS

Two independent investigators systematically searched PubMed, Embase and ISI Web of Knowledge (Thomson Scientific Technical Support, New York) databases for eligible studies published between January 1992 and September 2020 using the following combinations of search terms: (vitamin D, or 25-hydroxyvitamin D) AND (melanoma, malignant melanoma, cutaneous melanoma, or cutaneous malignant melanoma). Articles not written in English but with English titles and abstracts were also checked. We obtained the full text of all potentially eligible articles, and reference lists of all studies retrieved at the first stage were also checked to identify other eligible papers. Review articles not reporting original data were excluded, but their reference lists were inspected.

RESULTS

Six studies including 212 723 cases reported the association between dietary intake of 25(OH) D serum levels and melanoma risk. The total relative risk for the comparison between the highest and lowest quantiles of the distribution of vitamin D intake was 1.10 (95% CI 0.96 to 1.26) with I ²=56%. Another six studies including 12 297 cases evaluated the association between serum vitamin D levels and melanoma risk. The total relative risk for the comparison of serum vitamin D levels between the highest and lowest quantiles was 1.12 (95% CI 0.53 to 2.35) with I ²=91%. Four studies with 2105 cases investigated the association between serum 25(OH)D (nmol/L) and Breslow thickness, three of which found an inverse association between serum 25(OH)D (nmol/L) and melanoma thickness.

CONCLUSIONS

Vitamin D intake and serum 25(OH)D levels were not closely related with melanoma risk, but an inverse association between serum 25(OH)D levels with melanoma thickness was discovered. As the positive correlation between melanoma thickness and melanoma mortality has been recognised, hence it is concluded that a moderate dietary vitamin D supplement to avoid the serum 25(OH)D deficient might be beneficial to the long-term survival of patients with melanoma.

Nutritional Interventions for Patients with Melanoma: From Prevention to Therapy-An Update

Melanoma is an aggressive skin cancer, whose incidence rates have increased over the past few decades. Risk factors for melanoma are both intrinsic (genetic and familiar predisposition) and extrinsic (environment, including sun exposure, and lifestyle). The recent advent of targeted and immune-based therapies has revolutionized the treatment of melanoma, and research is focusing on strategies to optimize them. Obesity is an established risk factor for several cancer types, but its possible role in the etiology of melanoma is controversial. Body mass index, body surface area, and height have been related to the risk for cutaneous melanoma, although an 'obesity paradox' has been described too. Increasing evidence suggests the role of nutritional factors in the prevention and management of melanoma. Several studies have demonstrated the impact of dietary attitudes, specific foods, and nutrients both on the risk for melanoma and on the progression of the disease, via the effects on the oncological treatments. The aim of this narrative review was to summarize the main literature results regarding the preventive and therapeutic role of nutritional schemes, specific foods, and nutrients on melanoma incidence and progression.

Nutrition and melanoma prevention

There has been considerable research in recent years on dietary factors and/or nutritional elements that might impact melanoma risk. A wide variety of dietary compounds have been studied, but only a selected group will be discussed in this review. Many have promising in vitro evidence supporting their potential, and some have been associated with decreased melanoma risk in epidemiologic studies; however, data from randomized controlled trials in humans are lacking. Future studies may be able to clarify the potential role of dietary components in melanoma risk reduction.

Sodium and Potassium Content of Foods Consumed in an Italian Population and the Impact of Adherence to a Mediterranean Diet on Their Intake

High sodium and low potassium intakes are associated with increased levels of blood pressure and risk of cardiovascular diseases. Assessment of habitual dietary habits are helpful to evaluate their intake and adherence to healthy dietary recommendations. In this study, we determined sodium and potassium food-specific content and intake in a Northern Italy community, focusing on the role and contribution of adherence to Mediterranean diet patterns. We collected a total of 908 food samples and measured sodium and potassium content using inductively coupled plasma mass spectrometry. Using a validated semi-quantitative food frequency questionnaire, we assessed habitual dietary intake of 719 adult individuals of the Emilia-Romagna region. We then estimated sodium and potassium daily intake for each food based on their relative contribution to the overall diet, and their link to Mediterranean diet patterns. The estimated mean sodium intake was 2.15 g/day, while potassium mean intake was 3.37 g/day. The foods contributing most to sodium intake were cereals (33.2%), meat products (24.5%, especially processed meat), and dairy products (13.6%), and for potassium they were meat (17.1%, especially red and white meat), fresh fruits (15.7%), and vegetables (15.1%). Adherence to a Mediterranean diet had little influence on sodium intake, whereas potassium intake was greatly increased in subjects with higher scores, resulting in a lower sodium/potassium ratio. Although we may have underestimated dietary sodium intake by not including discretionary salt use and there may be some degree of exposure misclassification as a result of changes in food sodium content and dietary habits over time, our study provides an overview of the contribution of a wide range of foods to the sodium and potassium intake in a Northern Italy community and of the impact of a Mediterranean diet on intake. The mean sodium intake was above the dietary recommendations for adults of 1.5-2 g/day, whilst potassium intake was only slightly lower than the recommended 3.5 g/day. Our findings suggest that higher adherence to Mediterranean diet patterns has limited effect on restricting sodium intake, but may facilitate a higher potassium intake, thereby aiding the achievement of healthy dietary recommendations.

25-Hydroxyvitamin D status, vitamin D intake, and skin cancer risk: a systematic review and dose-response meta-analysis of prospective studies

Sun exposure is a major environmental risk factor for skin cancers and is also an important source of vitamin D. However, while experimental evidence suggests that vitamin D may have a protective effect on skin cancer risk, epidemiologic studies investigating the influence of 25-hydroxyvitamin D (25(OH)D) level and/or vitamin D intake on skin cancer risk are conflicting. A systematic review and dose–response meta-analyses of prospective studies was conducted to clarify these associations. Relevant studies were identified by searching the PubMed database up to 30th August 2019. Random effects dose–response meta-analyses were used to estimate summary relative risks (SRRs) and 95% confidence intervals (CIs). Overall, thirteen prospective studies were included. Circulating level of 25(OH)D was associated with higher risks of melanoma (SRR (95% CI) per 30 nmol = 1.42 (1.17–1.72)) and keratinocyte cancer (KC) (SRR (95% CI) per 30 nmol/L = 1.30 (1.13–1.49)). The SRR (95% CI) per 30 nmol/L increase in 25(OH) D level was 1.41 (1.19–1.67), and 1.57 (0.64–3.86), for basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), respectively. However, while we found that vitamin D intake (from diet, supplemental and total) was not associated with risks of melanoma and SCC, vitamin D intake was associated with slightly increased BCC risk, albeit with no heterogeneity across skin cancer type. This meta-analysis suggests positive associations between circulating 25(OH)D level and risk of melanoma and KC, however, this finding is most likely confounded by sun exposure. We found no associations between vitamin D intake skin cancers, except positive associations with BCC risk.

The association between serum vitamin D level and risk and prognosis of melanoma: a systematic review and meta-analysis

BACKGROUND

Vitamin D has antineoplastic effects, but the synthesis of vitamin D requires ultraviolet radiation, a known risk factor for melanoma.

OBJECTIVE

To investigate the correlations between serum vitamin D levels and risk and prognosis of melanoma.

METHODS

A systematic review and meta-analysis were conducted. Online databases were searched on 31 Oct 2018.

RESULTS

Twenty-five studies with a total of 11166 patients with melanoma were included. There was no significant difference in serum vitamin D levels between patients with melanoma and controls [standardized mean difference (SMD), -0.185; 95% confidence interval (CI), -0.533 to 0.162]. However, the prevalence of vitamin D deficiency was significantly higher in patients with melanoma than that in controls (odds ratio, 2.115; 95% CI, 1.151-3.885). In terms of prognosis, serum vitamin D levels were significantly higher in melanoma patients with lower Breslow thickness (≦1 vs. >1 mm: SMD, 0.243; 95% CI, 0.160-0.327). Moreover, melanoma patients with lower vitamin D levels had a significantly higher mortality rate (hazard ratio, 1.558; 95% CI, 1.258-1.931).

CONCLUSIONS

Vitamin D deficiency is associated with higher Breslow thickness and mortality in melanoma patients.

Dietary cadmium intake and risk of cutaneous melanoma: An Italian population-based case-control study

INTRODUCTION

Exposure to the heavy metal cadmium has been associated with many adverse health effects, such as atherosclerosis, diabetes, and cancer, possibly melanoma. In non-occupationally exposed individuals, food intake is a major source of cadmium exposure, after smoking. We aimed to assess the risk of melanoma in relation to dietary cadmium intake.

METHODS

Using a population-based case-control study design, we recruited 380 incident cases of newly-diagnosed cutaneous melanoma and 719 matched controls in the Emilia-Romagna Region, Northern Italy in the years 2005-2006. We evaluated dietary intake using a semi-quantitative food frequency questionnaire. We used conditional logistic regression to compute odds ratios (ORs) and 95% confidence intervals (CIs) for melanoma according to quintiles of dietary cadmium intake, adjusting for several potential confounders, and we modeled the association non-parametrically, using restricted cubic splines.

RESULTS

Median energy-adjusted intake of cadmium was 6.11 μg/day (interquartile range 5.38-6.91) among cases and 5.97 μg/day (5.15-6.79) among controls. For each 1 μg/day-increase in cadmium intake, the OR for melanoma was 1.11 (95% CI 1.00-1.24). Melanoma risk generally increased with increasing quintile of cadmium exposure, with ORs of 1.55 (95% CI 0.99-2.42), 1.54 (95% CI 0.99-2-40), 1.75 (95% CI 1.12-2.75), and 1.65 (95% CI 1.05-2.61) for the second through fifth quintiles, compared with the lowest quintile. Sex-stratified analysis showed ORs per 1 μg/day-increase in cadmium intake of 1.10 (95% CI 0.93-1-29) among men and 1.15 (95% CI 0.99-1.33) among women. Using spline regression analysis, we observed a generally linear increase in melanoma risk up to 6 μg/day of cadmium intake, after which the risk appeared to plateau.

CONCLUSIONS

We observed a positive non-linear association between dietary cadmium intake and risk of cutaneous melanoma in a Northern Italy population. However, further studies are needed to elucidate this association, due to concerns about exposure misclassification, unmeasured confounding, and the limited and conflicting evidence from epidemiological findings.

Amyotrophic lateral sclerosis incidence following exposure to inorganic selenium in drinking water: A long-term follow-up

Some studies have reported an association between overexposure to selenium and risk of amyotrophic lateral sclerosis (ALS), a rare degenerative disease of motor neurons. From 1986 through 2015, we followed a cohort in Northern Italy that had been inadvertently consuming tap water with unusually high concentrations of inorganic hexavalent selenium from 1974 to 1985. We had previously documented an excess incidence of ALS in this cohort during 1986-1994. Here, we report extended follow-up of the cohort for an additional 21 years, encompassing 50,100 person-years of the exposed cohort and 2,233,963 person-years of the unexposed municipal cohort. We identified 7 and 112 incident ALS cases in the exposed and unexposed cohorts, respectively, yielding crude incidence rates of 14 and 5 cases per 100,000 person-years. A Poisson regression analysis, adjusting for age, sex and calendar year, produced an overall incidence rate ratio (IRR) for ALS of 2.8 (95% confidence interval (CI) 1.3, 6), with a substantially stronger IRR in 1986-1994 (8.2, 95% CI 2.7, 24.7) than in 1995-2015 (1.5, 95% CI 0.5, 4.7), and among women (5.1, 95% CI 1.8, 14.3) than men (1.7, 95% CI 0.5, 5.4). Overall, these results indicate an association between high exposure to inorganic selenium, a recognized neurotoxicant, and ALS incidence, with declining rates after cessation of exposure and stronger effects among women.

Food and Beverage Consumption and Melanoma Risk: A Population-Based Case-Control Study in Northern Italy

It has been suggested that diet may influence the risk of melanoma, but few studies are available on this topic. We assessed the relation between food consumption and the risk of cutaneous melanoma in a Northern Italy population. We carried out a population-based case-control study involving 380 cases of melanoma and 719 age- and sex-matched controls. Dietary habits were established through a self-administered semi-quantitative food frequency questionnaire. We computed the odds ratios (ORs) of melanoma and the corresponding 95% confidence intervals (CIs) according to tertiles of daily intake of each food item, using multiple logistic regression models adjusted for major confounding factors. We observed an indication of a positive association between melanoma risk and consumption of cereals and cereal products (OR = 1.32; 95% CI 0.89-1.96, higher vs. lowest tertile), sweets (OR = 1.22; 95% CI 0.84-1.76), chocolate, candy bars. etc., (OR = 1.51; 95% CI 1.09-2.09) and cabbages (OR = 1.51; 95% CI 1.09-2.09). Conversely, an inverse association with disease risk was found for the intake of legumes (OR = 0.77; 95% CI 0.52-1.13), olive oil (OR = 0.77; 95% CI 0.51-1.16), eggs (OR = 0.58; 95% CI 0.41-0.82), and onion and garlic (OR = 0.80; 95% CI 0.52-1.14). No relationship was observed with beverage consumption. Our results suggest potentially adverse effects on melanoma risk of foods characterized by high contents of refined flours and sugars, while suggesting a protective role for eggs and two key components of the Mediterranean diet, legumes and olive oil. These associations warrant further investigation and, if confirmed, they might have important public health implications for the reduction of melanoma incidence through dietary modification.

Is there a causal relationship between vitamin D and melanoma risk? A Mendelian randomization study

BACKGROUND

Several preclinical studies have identified the antiproliferative effects of 25-hydroxyvitamin D [25(OH)D; vitamin D]. Ultraviolet radiation (UVR) is essential for vitamin D synthesis yet increases the risk of melanoma. Observational studies on the association of vitamin D levels with melanoma risk have reported inconclusive results, and are difficult to interpret owing to the potential confounding from the dual role of UVR.

OBJECTIVES

To determine whether there is a causal association between genetically predicted 25(OH)D concentrations and melanoma using a Mendelian randomization (MR) approach.

METHODS

We performed MR using summary data from a large genome-wide association study (GWAS) meta-analysis of melanoma risk, consisting of 12 874 cases and 23 203 controls. Five single nucleotide polymorphisms associated with 25(OH)D concentration - rs12785878, rs10741657, rs2282679, rs6013897 and rs116970203 - were selected as instrumental variables. An inverse variance weighted method was used to access the evidence for causality. MR results from the melanoma meta-analysis were combined with results from an MR study based on a melanoma risk GWAS using UK Biobank data.

RESULTS

A 20 nmol L^-1 decrease in 25(OH)D was not associated with melanoma risk [odds ratio (OR) 1·06, 95% confidence interval (CI) 0·95-1·19]. Results from the UK Biobank were concordant with this, with meta-analysis of our and UK Biobank-derived MR causal estimates showing no association (OR 1·02, 95% CI 0·92-1·13 for a 20 nmol L^-1 decrease).

CONCLUSIONS

The results suggest that vitamin D levels may not be causally associated with the risk of melanoma. What's already known about this topic? Antitumour activity of vitamin D has been identified in preclinical studies. Observational studies link vitamin D deficiency with an increased risk of a range of cancers. There is a growing public interest for vitamin D supplementation. Observational studies of melanoma are fraught with difficulties because while higher ultraviolet radiation levels increase vitamin D levels, such exposure is also associated with increased melanoma risk. Results from observational studies are inconclusive regarding the effect of vitamin D on melanoma risk. What does this study add? Using Mendelian randomization, an approach to causal inference, which is analogous to a natural randomized controlled trial, we found no causal association between vitamin D levels and melanoma.

Aluminum and tin: Food contamination and dietary intake in an Italian population

Aluminum and tin are ubiquitous in the environment. In normal biological systems, however, they are present only in trace amounts and have no recognized biological functions in humans. High exposure to these metals can result in adverse health effects such as neurodegenerative diseases. In non-occupationally exposed subjects, diet is the primary source of exposure. In this study, we aimed at estimating dietary aluminum and tin intake in an Italian adult population. We measured aluminum and tin concentrations through inductively-coupled plasma mass spectrometry in 908 food samples. We also estimated dietary intake of these two metals, by using a validated semi-quantitative food-frequency questionnaire administered to 719 subjects (319 men and 400 women) recruited from the general population of the Emilia Romagna region, Northern Italy. We found the highest aluminum levels in legumes, sweets, and cereals, while the highest tin levels were in sweets, meat and seafood. The estimated median daily dietary intake of aluminum was 4.1 mg/day (Interquartile range - IQR: 3.3-5.2), with a major contribution from beverages (28.6%), cereals (16.9%), and leafy vegetables (15.2%). As for tin, we estimated a median intake of 66.8 μg/day (IQR: 46.7-93.7), with a major contribution from vegetables (mainly tomatoes) (24.9%), fruit (15.5%), aged cheese (12.2%), and processed meat (10.4%). This study provides an updated estimate of the dietary intake of aluminum and tin in a Northern-Italy adult population, based on data from a validated food-frequency questionnaire. The intake determined for this population does not exceed the established thresholds of tolerable intake.

Dietary intake of cadmium, chromium, copper, manganese, selenium and zinc in a Northern Italy community

This study provides the dietary intakes of six trace elements (cadmium, chromium, copper, manganese, selenium and zinc), generally characterized by both nutritional and toxicological features depending on their exposure. Being diet the most relevant source of exposure to trace elements in non-professionally exposed subjects, we measured content of these trace elements in foods composing the typical Italian diet using inductively coupled plasma-mass spectrometry, and assessing dietary habits using a validated semi-quantitative food frequency questionnaire we eventually estimated dietary daily intake of trace elements in a Northern Italian community. In the 890 analyzed food samples, the main contributors to cadmium intake are cereals, vegetables and sweets, while cereals, beverages and vegetable are to primary source of manganese. The primary contributors for copper are cereals, fresh fruits and vegetables, while for chromium are beverages, cereals and meat. The main source of selenium intake are cereals and meat, followed by fish, seafood and milk and dairy products, while of zinc intake are meat, cereals, milk and dairy products. In our Italian population sample, the estimated median (interquartile range) dietary daily intakes are 5.00 (3.17-7.65), 56.70 (36.08-86.70) and 66.53 (40.04-101.32) μg/day for cadmium, chromium and selenium, and corresponding figures are 0.98 (0.61-1.49), 2.34 (1.46-3.52) and 8.50 (5.21-12.48) mg/day for copper, manganese and zinc. The estimated intakes are generally within the average intake reported in other European populations, and in such cases well above the daily dietary intakes recommended by national international agencies, avoiding the risk of excess or deficiency. The present estimated intake data can be used to examine a specific trace element of interest and would afford enhanced health protection from those trace elements characterized by both nutritional and toxicological effects.

An Epidemiological Review of Diet and Cutaneous Malignant Melanoma

Incidence of cutaneous malignant melanoma has continued to rise despite public efforts to promote sun protection behaviors among populations at risk. However, dietary factors may also affect the development of melanoma. In the past few decades, findings from epidemiologic and experimental research have linked consumption of several foods and other nutrients to the risk of melanoma. Caffeine has been associated with a lower risk of melanoma, and citrus fruits and alcohol with increased risk. Associations between polyunsaturated fatty acid, niacin/nicotinamide, folate, and vitamin D with melanoma remain controversial. Diet likely influences melanoma development through several potential mechanisms, such as enhancing UV-induced apoptosis and increasing photosensitivity. We conducted a narrative review to summarize recent epidemiologic studies of diet and melanoma based on published literature. Given the high prevalence of the food items and nutrients covered in this review and the decades-long rising melanoma incidence worldwide, the associations we discuss may have important public health implications in terms of reducing melanoma incidence through dietary modification. Cancer Epidemiol Biomarkers Prev; 27(10); 1115-22. ©2018 AACR.

Intake of arsenic and mercury from fish and seafood in a Northern Italy community

Regular consumption of fish is generally recommended by authorities because fish is an important source of essential nutrients. However, the presence of potentially toxic contaminants in fish has raised many concerns about the food's safety for human health. In the present study, we used a validated semi-quantitative food frequency questionnaire to assess the dietary habits of a representative sample of 719 individuals (319 males and 400 females) aged 18-87 years residing in Northern Italy. We estimated weekly dietary intakes of Arsenic (As) and Mercury (Hg), and we compared them with safety standards set by the European Food Safety Authority. In this population, fish was the main contributor to As and Hg intake. The highest levels of As were in sardine, sole/flounder and cephalopods, and of Hg in the biggest, predatory fish. About the other foods, cereals were the second contributor to the intake of these elements, especially rice for As and bread for Hg, and high levels of As and Hg were also found in mushrooms, coffee and wine. Average weekly intake of both contaminants was below recommended safety limits.

A Case-Control Study of the Risk of Cutaneous Melanoma Associated with Three Selenium Exposure Indicators

Aims and background

A direct association between exposure to the metalloid selenium and risk of cutaneous melanoma has been suggested by some observational and experimental cohort studies, whereas other studies have yielded inconsistent results. Since some of the inconsistencies may be due to exposure misclassification arising from the use of exposure indicators that do not adequately reflect body tissue selenium content or the levels of the biologically relevant species of this metalloid, we examined this issue using multiple indicators of exposure.

Methods

We analyzed the relation of selenium exposure with risk of cutaneous melanoma using two different biomarkers, plasma and toenail selenium concentration, and estimated dietary selenium intake in a population-based case-control series (54 cases, 56 controls) from an Italian community.

Results

In unmatched and matched logistic regression models as well as nonparametric generalized additive models, higher plasma selenium levels were strongly associated with excess disease risk. In contrast, toenail and dietary selenium exhibited little relation with melanoma risk. The pattern of correlation among indicators of exposure differed by disease status, with dietary intake associated with plasma selenium levels in patients but not in controls.

Conclusions

Our data showed that different selenium exposure indicators can yield different inferences about melanoma risk. Although the series was small, our results are consistent with a positive association between circulating levels of selenium and melanoma risk. Further investigation of the exposure classification performance of various selenium biomarkers and of metabolic patterns of the metalloid and of its speciation are needed to help elucidate the relation between selenium exposure and human health.

Mechanisms and prevention of UV-induced melanoma

Melanoma is the deadliest form of skin cancer and its incidence is rising, creating a costly and significant clinical problem. Exposure to ultraviolet (UV) radiation, namely UVA (315-400 nm) and UVB (280-315 nm), is a major risk factor for melanoma development. Cumulative UV radiation exposure from sunlight or tanning beds contributes to UV-induced DNA damage, oxidative stress, and inflammation in the skin. A number of factors, including hair color, skin type, genetic background, location, and history of tanning, determine the skin's response to UV radiation. In melanocytes, dysregulation of this UV radiation response can lead to melanoma. Given the complex origins of melanoma, it is difficult to develop curative therapies and universally effective preventative strategies. Here, we describe and discuss the mechanisms of UV-induced skin damage responsible for inducing melanomagenesis, and explore options for therapeutic and preventative interventions.

Vitamin D status and risk for malignant cutaneous melanoma: recent advances

Cutaneous malignant melanoma, whose incidence is increasing steadily worldwide, is the result of complex interactions between individual genetic factors and environmental risk factors. Ultraviolet radiation represents the most important environmental risk factor for the development of skin cancers, including melanoma. Sun exposure and early sunburn during childhood are the principal causes of cutaneous melanoma insurgence in adults, with double the risk relative to a nonexposed population. Consequently, ultraviolet protection has long been recognized as an important measure to prevent such a malignancy. Biological and epidemiological data suggest that vitamin D status could affect the risk of cancer and play a role in cancer prevention by exerting antiproliferative effects. Solar radiations are critical for vitamin D synthesis in humans; however, uncontrolled and intensive sun exposure is dangerous to skin health and may contribute toward the development of cutaneous malignant melanoma. An optimum balance between sun protection and exposure is thus advocated. Additional research is required to confirm the preventive role of vitamin D in melanoma incidence or a positive influence on patient outcome.

Glycaemic index, glycaemic load and risk of cutaneous melanoma in a population-based, case-control study

Glycaemic index (GI) and glycaemic load (GL) are indicators of dietary carbohydrate quantity and quality and have been associated with increased risk of certain cancers and type 2 diabetes. Insulin resistance has been associated with increased melanoma risk. However, GI and GL have not been investigated for melanoma. We present the first study to examine the possible association of GI and GL with melanoma risk. We carried out a population-based, case-control study involving 380 incident cases of cutaneous melanoma and 719 age- and sex-matched controls in a northern Italian region. Dietary GI and GL were computed for each subject using data from a self-administered, semi-quantitative food frequency questionnaire. We computed the odds ratio (OR) for melanoma according to quintiles of distribution of GL and GL among controls. A direct association between melanoma risk and GL emerged in females (OR 2·38; 95 % CI 1·25, 4·52 for the highest v. the lowest quintile of GL score, P for trend 0·070) but not in males. The association in females persisted in the multivariable analysis after adjusting for several potential confounders. There was no evidence of an association between GI and melanoma risk. GL might be associated with melanoma risk in females.

25-OH Vitamin D and Interleukin-8: Emerging Biomarkers in Cutaneous Melanoma Development and Progression

BACKGROUND

There are several circulatory biomarkers that are involved in forecasting the clinical outcome of cutaneous melanoma. Serum/plasma vitamin D status is one of the markers intensively studied in this type of cutaneous cancer. The combination of validated serum biomarkers (like LDH) with new biomarkers such as IL-8, angiogenic factor, and vitamin D is still at the dawn of research. Hence, we are aiming to establish the predictive power of inflammatory biomarkers, such as IL-8, and metabolic ones, such as vitamin D. These candidate biomarkers are intended to aid classical biomarkers, such as LDH, in the prognosis of cutaneous melanoma.

METHODS

Serum vitamin D and IL-8 were quantified in melanoma patients and in matching healthy controls.

RESULTS

Median serum vitamin D concentrations were significantly lower (p = 0.003) in melanoma patients as compared to healthy control subjects, while around 65% of the investigated patients have proven a severe circulatory deficiency of this vitamin. IL-8 was found increased (p = 0.001) in melanoma patients as compared to controls.

CONCLUSION

Upregulation of proangiogenic factors associated with vitamin D deficiency can prove to be potent future biomarkers candidates, enhancing the predictive power of classical LDH.

Association Between Prediagnostic Serum 25-Hydroxyvitamin D Concentration and Glioma

There are no previous studies of the association between prediagnostic serum vitamin D concentration and glioma. Vitamin D has immunosuppressive properties; as does glioma. It was, therefore, our hypothesis that elevated vitamin D concentration would increase glioma risk. We conducted a nested case-control study using specimens from the Janus Serum Bank cohort in Norway. Blood donors who were subsequently diagnosed with glioma (n = 592), between 1974 and 2007, were matched to donors without glioma (n = 1112) on date and age at blood collection and sex. We measured 25-hydroxyvitamin D [25(OH)D], an indicator of vitamin D availability, using liquid chromatography coupled with mass spectrometry. Seasonally adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated for each control quintile of 25(OH)D using conditional logistic regression. Among men diagnosed with high grade glioma >56, we found a negative trend (P = .04). Men diagnosed ≤ 56 showed a borderline positive trend (P = .08). High levels (>66 nmol/L) of 25(OH)D in men >56 were inversely related to high grade glioma from ≥2 yr before diagnosis (OR = 0.59; 95% CI = 0.38, 0.91) to ≥15 yr before diagnosis (OR = 0.61; 95% CI = 0.38,0.96). Our findings are consistent long before glioma diagnosis and are therefore unlikely to reflect preclinical disease.

Melanoma risk perception and prevention behavior among African-Americans: the minority melanoma paradox

Introduction

Melanoma is the most deadly type of skin cancer with 75% of all skin cancer deaths within the US attributed to it. Risk factors for melanoma include ultraviolet exposure, genetic predisposition, and phenotypic characteristics (eg, fair skin and blond hair). Whites have a 27-fold higher incidence of melanoma than African-Americans (AA), but the 5-year survival is 17.8% lower for AA than Whites. It is reported continuously that AA have more advanced melanomas at diagnosis, and overall lower survival rates. This minority melanoma paradox is not well understood or studied.

Objective

To explore further, the possible explanations for the difference in melanoma severity and survival in AA within the US.

Methods

Qualitative review of the literature.

Results

Lack of minority-targeted public education campaigns, low self-risk perception, low self-skin examinations, intrinsic virulence, vitamin D differences, and physician mistrust may play a role in the melanoma survival disparity among AA.

Conclusion

Increases in public awareness of melanoma risk among AA through physician and media-guided education, higher index of suspicion among individuals and physicians, and policy changes can help to improve early detection and close the melanoma disparity gap in the future.

Systematic review of studies investigating the association between dietary habits and cutaneous malignant melanoma

OBJECTIVE

Several papers have dealt with diet as a risk factor for cutaneous malignant melanoma (CMM). This study aimed to synthesize available data on the topic.

STUDY DESIGN

A systematic review of observational studies assessing the association between dietary habits and CMM was performed.

METHODS

Electronic databases were used to identify eligible articles. Quality was assessed through the Newcastle-Ottawa scale. Case-control and cohort studies evaluating the intake of food/nutrients through the assessment of dietary habits and the occurrence of CMM were considered eligible. Data comparing the highest and lowest levels of consumption were collected from single studies and described qualitatively as data combination was not possible. Results were reported as percentages on the basis of relative risks and odds ratios.

RESULTS

Eighteen studies reported in 21 articles were selected. Cohort studies showed better quality than case-control studies. Most articles did not detect any significant association between food/nutrient intake and CMM, except for limited evidence of a protective role associated with fish, vegetables and fruit. Risk reduction was shown to be 35-37%, 40-57% and 34-46%, respectively, in studies reporting significant results. Similarly, few articles showed protective roles of beta-carotene and vitamins A, C, D and E, with risk reduction of 64%, 37-43%, 41%, 15-39% and 50-66%, respectively.

CONCLUSION

A trend towards reduced risk of CMM associated with higher intake of fish, vegetables and fruit, as well as beta-carotene and vitamins A, C, D and E, has been shown but further research is needed to provide decisive data.

Diet Quality and Risk of Melanoma in an Italian Population

BACKGROUND

Some results from laboratory and epidemiologic studies suggest that diet may influence the risk of melanoma, but convincing evidence for a role of single nutrients or food items is lacking. Diet quality, which considers the combined effect of multiple food items, may be superior for examining this relation.

OBJECTIVE

We sought to assess whether diet quality, evaluated with the use of 4 different dietary indexes, is associated with melanoma risk.

METHODS

In this population-based case-control study, we analyzed the relation between 4 diet quality indexes, the Healthy Eating Index 2010 (HEI-2010), Dietary Approaches to Stop Hypertension (DASH) index, Greek Mediterranean Index (GMI), and Italian Mediterranean Index (IMI), and melanoma risk in a northern Italian community, with the use of data from 380 cases and 719 matched controls who completed a semiquantitative food frequency questionnaire.

RESULTS

In the overall sample, we found an inverse association between disease risk and the HEI-2010 and DASH index, but not the Mediterranean indexes, adjusting for potential confounders (skin phototype, body mass index, energy intake, sunburn history, skin sun reaction, and education). However, in sex stratified analyses, the association appeared only in women (P-trend: 0.10 and 0.04 for the HEI-2010 and DASH index, respectively). The inverse relations were stronger in women younger than age 50 y than in older women, for whom the GMI and IMI scores also showed an inverse association with disease risk (P-trend: 0.05 and 0.02, respectively).

CONCLUSIONS

These results suggest that diet quality may play a role in cutaneous melanoma etiology among women.

Vitamins and Melanoma

A tremendous amount of information was published over the past decades in relation to the role of vitamins in various neoplastic diseases. In particular, several studies showed an inverse relationship between selected vitamins intake and cancer risk. In this review we will focus on the role played by vitamins in melanoma with particular regard to vitamin A, D, K, E and C. Given that vitamin supplementation is easy, convenient, and readily accepted by patients, in the future the use of vitamins in chemoprevention and therapy of melanoma could be encouraged if supported by pre-clinical and clinical evidence.

Differences in clinicopathological features and distribution of risk factors in Italian melanoma patients

BACKGROUND

No studies are available in the literature on the distribution of different melanoma features and risk factors in the Italian geographical areas.

OBJECTIVE

To identify the differences in clinical-pathological features of melanoma, the distribution of risk factors and sun exposure in various Italian macro-areas.

METHODS

Multicentric-observational study involving 1,472 melanoma cases (713 north, 345 centre, 414 south) from 26 referral centres belonging to the Italian Multidisciplinary Group for Melanoma.

RESULTS

Melanoma patients in northern regions are younger, with thinner melanoma, multiple primaries, lower-intermediate phototype and higher counts of naevi with respect to southern patients; detection of a primary was mostly connected with a physician examination, while relatives were more involved in the south. Northern patients reported a more frequent use of sunbeds and occurrence of sunburns before melanoma despite sunscreen use and a lower sun exposure during the central hours of the day.

CONCLUSIONS

The understanding of differences in risk factors distribution could represent the basis for tailored prevention programmes.

Toenail selenium and risk of type 2 diabetes: the ORDET cohort study

Epidemiologic studies, particularly randomized controlled trials, have shown a direct relation between dietary and environmental exposure to the metalloid selenium and risk of type 2 diabetes. We investigated the association between baseline toenail selenium levels and diabetes occurrence in a case-control study nested in ORDET, a population-based female cohort in Northern Italy. After a median follow-up of 16 years, we identified 226 cases of type 2 diabetes cases and 395 age-matched control women with available toenail samples at baseline. The multivariate odds ratios of diabetes in increasing a priori defined categories of toenail selenium exposure were 1.09 (95% confidence interval 0.61, 1.96), 0.71 (0.38, 1.34) and 1.14 (0.46, 2.80) compared with the lowest category. The results were not substantially altered when quartile distribution of toenail selenium in controls was used to define exposure categories. Spline regression analysis did not show homogeneous risk trends. Overall, we did not find an association between toenail selenium and subsequent development of diabetes. Since the diabetogenic activity of selenium is strongly supported by experimental studies and some observational investigations, our null results might be explained by the limitations of overall selenium toenail content to assess environmental exposure to selenium species of etiologic relevance in the study population.

Diet in dermatology: Part II. Melanoma, chronic urticaria, and psoriasis

The roles of dietary factors in aggravating, preventing, or treating skin diseases are common questions encountered in dermatology practice. Part II of this two-part series reviews dietary modifications that can potentially be utilized in the management of melanoma, chronic urticaria, and psoriasis patients. Specifically, we examine the effect of alcohol consumption and supplementation with vitamins D and E, polyunsaturated fatty acids, selenium, green tea, resveratrol, and lycopene on melanoma risk. The relationships between chronic urticaria symptoms and dietary pseudoallergens, gluten, and vitamin D are analyzed. We explore weight loss, reduced alcohol consumption, and gluten avoidance as means of reducing psoriasis-associated morbidity, as well as the possible utility of supplementation with polyunsaturated fatty acids, folic acid, vitamin D, and antioxidants. With proper knowledge of the role of diet in these cutaneous disease processes, dermatologists can better answer patient inquiries and consider implementation of dietary modifications as adjuncts to other treatments and preventative measures.

Review of natural compounds for potential skin cancer treatment

Most anti-cancer drugs are derived from natural resources such as marine, microbial and botanical sources. Cutaneous malignant melanoma is the most aggressive form of skin cancer, with a high mortality rate. Various treatments for malignant melanoma are available, but due to the development of multi-drug resistance, current or emerging chemotherapies have a relatively low success rates. This emphasizes the importance of discovering new compounds that are both safe and effective against melanoma. In vitro testing of melanoma cell lines and murine melanoma models offers the opportunity for identifying mechanisms of action of plant derived compounds and extracts. Common anti-melanoma effects of natural compounds include potentiating apoptosis, inhibiting cell proliferation and inhibiting metastasis. There are different mechanisms and pathways responsible for anti-melanoma actions of medicinal compounds such as promotion of caspase activity, inhibition of angiogenesis and inhibition of the effects of tumor promoting proteins such as PI3-K, Bcl-2, STAT3 and MMPs. This review thus aims at providing an overview of anti-cancer compounds, derived from natural sources, that are currently used in cancer chemotherapies, or that have been reported to show anti-melanoma, or anti-skin cancer activities. Phytochemicals that are discussed in this review include flavonoids, carotenoids, terpenoids, vitamins, sulforaphane, some polyphenols and crude plant extracts.

Vitamin D and melanoma and non-melanoma skin cancer risk and prognosis: a comprehensive review and meta-analysis

Vitamin D is formed mainly in the skin upon exposure to sunlight and can as well be taken orally with food or through supplements. While sun exposure is a known risk factor for skin cancer development, vitamin D exerts anti-proliferative and pro-apoptotic effects on melanocytes and keratinocytes in vitro. To clarify the role of vitamin D in skin carcinogenesis, we performed a review of the literature and meta-analysis to evaluate the association of vitamin D serum levels and dietary intake with cutaneous melanoma (CM) and non-melanoma skin cancer (NMSC) risk and melanoma prognostic factors. Twenty papers were included for an overall 1420 CM and 2317 NMSC. The summary relative risks (SRRs) from random effects models for the association of highest versus lowest vitamin D serum levels was 1.46 (95% confidence interval (CI) 0.60-3.53) and 1.64 (95% CI 1.02-2.65) for CM and NMSC, respectively. The SRR for the highest versus lowest quintile of vitamin D intake was 0.86 (95% CI 0.63-1.13) for CM and 1.03 (95% CI 0.95-1.13) for NMSC. Data were suggestive of an inverse association between vitamin D blood levels and CM thickness at diagnosis. Further research is needed to investigate the effect of vitamin D on skin cancer risk in populations with different exposure to sunlight and dietary habits, and to evaluate whether vitamin D supplementation is effective in improving CM survival.

Vitamin D in cutaneous carcinogenesis: part II

The role of vitamin D in health maintenance and disease prevention in fields ranging from bone metabolism to cancer is currently under intensive investigation. A number of epidemiologic studies have suggested that vitamin D may have a protective effect on cancer risk and cancer-associated mortality. With regard to skin cancer, epidemiologic and laboratory studies suggest that vitamin D and its metabolites may have a similar risk reducing effect. Potential mechanisms of action include inhibition of the hedgehog signaling pathway and upregulation of nucleotide excision repair enzymes. The key factor complicating the association between vitamin D and skin cancer is ultraviolet B radiation. The same spectrum of ultraviolet B radiation that catalyzes the production of vitamin D in the skin also causes DNA damage that can lead to epidermal malignancies. Part II of this continuing medical education article will summarize the literature on vitamin D and skin cancer to identify evidence-based optimal serum levels of vitamin D and to recommend ways of achieving those levels while minimizing the risk of skin cancer.

Vitamin D and melanoma incidence and mortality

The role of vitamin D (25-OH-D, or 25-hydroxyvitamin D) and its potential confounders in relationship to melanoma risk and mortality is discussed. The paradox that ultraviolet radiation (UVR) exposure is the major environmental risk factor for melanoma etiology as well as a major source of vitamin D might be explained by viewing vitamin D levels as the result of a healthy lifestyle rather than a cause of health.

A case-control study of the risk of cutaneous melanoma associated with three selenium exposure indicators

AIMS AND BACKGROUND

A direct association between exposure to the metalloid selenium and risk of cutaneous melanoma has been suggested by some observational and experimental cohort studies, whereas other studies have yielded inconsistent results. Since some of the inconsistencies may be due to exposure misclassification arising from the use of exposure indicators that do not adequately reflect body tissue selenium content or the levels of the biologically relevant species of this metalloid, we examined this issue using multiple indicators of exposure.

METHODS

We analyzed the relation of selenium exposure with risk of cutaneous melanoma using two different biomarkers, plasma and toenail selenium concentration, and estimated dietary selenium intake in a population-based case-control series (54 cases, 56 controls) from an Italian community.

RESULTS

In unmatched and matched logistic regression models as well as nonparametric generalized additive models, higher plasma selenium levels were strongly associated with excess disease risk. In contrast, toenail and dietary selenium exhibited little relation with melanoma risk. The pattern of correlation among indicators of exposure differed by disease status, with dietary intake associated with plasma selenium levels in patients but not in controls.

CONCLUSIONS

Our data showed that different selenium exposure indicators can yield different inferences about melanoma risk. Although the series was small, our results are consistent with a positive association between circulating levels of selenium and melanoma risk. Further investigation of the exposure classification performance of various selenium biomarkers and of metabolic patterns of the metalloid and of its speciation are needed to help elucidate the relation between selenium exposure and human health.

Pre-diagnostic circulating vitamin D and risk of melanoma in men

PURPOSE

Various studies have examined the association between serum vitamin D levels and different cancers; however, this is the first prospective study of this association with melanoma risk. The aim of this study is to investigate the association between serum vitamin D [25(OH)D] levels and melanoma in a cohort of older, middle-aged Finnish male smokers.

METHODS

We conducted a nested case-control study within the Alpha-Tocopherol Beta-Carotene Cancer Prevention (ATBC) Study. From the ATBC cohort, 368 subjects were chosen for our study; 92 participants that developed melanoma and 276 matched control subjects. At study baseline, lifestyle questionnaires and blood samples were collected. Serum 25(OH)D was modeled as three sets of categorical variables: clinically-defined categories, season-specific quartiles and season-adjusted residual quartiles. Conditional logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (95% CIs) to estimate the association between circulating vitamin D and melanoma risk.

RESULTS

Overall no association of serum 25(OH)D and melanoma risk was observed. A decreased risk of developing melanoma was observed in the middle categories compared to the lowest category, albeit not significant.

CONCLUSION

Results indicate no association between serum 25(OH)D levels and melanoma. Additional studies, including possibly consortium efforts, are needed to investigate the association between serum 25(OH)D levels and risk of melanoma in larger, more diverse study populations.