Relationship Between Level of Serum 25-Hydroxyvitamin D and Risk of Squamous Cell Carcinoma in an Iranian Population

Exposome and Skin. Part 2. The Influential Role of the Exposome, Beyond UVR, in Actinic Keratosis, Bowen's Disease and Squamous Cell Carcinoma: A Proposal

Actinic keratosis (AK) is the main risk factor for the development of cutaneous invasive squamous cell carcinoma (SCC). It represents the first sign of severe chronic ultraviolet radiation exposure, which has a clear significant effect. Nevertheless, the skin is exposed to many other exposome factors which should be thoroughly considered. Our aim was to assess the impact of exposome factors other than ultraviolet radiation (UVR) on the etiopathology of AK and Bowen's disease (BD) and progression of AK to SCC and to design tailored prevention strategies. We performed an exhaustive literature search in September 2021 through PubMed on the impact of exposome factors other than UVR on AK, BD and SCC. We conducted several parallel searches combining terms of the following topics: AK, BD, SCC and microbiome, hormones, nutrition, alcohol, tobacco, viral infections, chemical contaminants and air pollution. Notably, skin microbiome studies have shown how Staphylococcus aureus infections are associated with AK and AK-to-SCC progression by the production of chronic inflammation. Nutritional studies have demonstrated how a caloric restriction in fat intake, oral nicotinamide and moderate consumption of wine significantly reduce the number of premalignant keratoses and SCC. Regarding lifestyle factors, both alcohol and smoking are associated with the development of SCC in a dose-dependent manner. Relevant environmental factors are viral infections and chemical contaminants. Human papillomavirus infections induce deregulation of cellular proliferation and are associated with AK, BD and SCC. In addition to outdoor jobs, occupations such as industrial processing and farming also increase the risk of developing keratoses and SCC. The exposome of AK will undoubtedly help the understanding of its etiopathology and possible progression to SCC and will serve as a basis to design tailored prevention strategies.

Vitamin D and the Risk of Non-Melanoma Skin Cancer: A Systematic Literature Review and Meta-Analysis on Behalf of the Italian Melanoma Intergroup

Simple Summary

Vitamin D has been extensively studied in relation to cancer risk at several body sites, but its relationship with non-melanoma skin cancer (NMSC), the most frequent malignancy in humans, is still unclear. Here, we performed a systematic literature search and meta-analysis of published studies and did not find convincing evidence that a causal association exists between vitamin D intake (from foods and supplements), vitamin D blood concentration, or polymorphisms of the genes coding for the vitamin D receptor and binding protein, and NMSC risk.

Abstract

We aimed to provide a comprehensive overview of the link between vitamin D and non-melanoma skin cancer (NMSC). For this purpose, we conducted a systematic literature review (updated to 3 February 2021) and meta-analysis of the studies reporting on the association between vitamin D intake (from diet and supplements) and blood concentration, polymorphisms of the vitamin D receptor (VDR) and vitamin D binding protein (VDBP) genes, and the risk of NMSC. Random effects meta-analysis models were fitted to merge study-specific risk estimates into summary relative risk (SRR) and corresponding 95% confidence intervals (CI). Twenty-four studies altogether were included. There was a suggestive association between increasing serum/plasma vitamin D concentration and NMSC risk (SRR for highest vs. lowest concentration 1.67, 95%CI 0.61–4.56), although with large heterogeneity across studies (I² = 91%). NMSC risk was associated with highest vitamin D intake in observational studies but not in clinical trials. Finally, there was no significant association between any polymorphism of the VDR and VDBP genes and NMSC risk. In conclusion, no strong relationship between vitamin D metabolism and NMSC risk appears to exist according to our systematic review and meta-analysis, although some findings are worthy of further investigation.

Serum 25-Hydroxyvitamin D and Subsequent Cancer Incidence and Mortality: A Population-Based Retrospective Cohort Study

OBJECTIVE

To determine the relationship between 25-hydroxyvitamin D (25[OH]D) values and subsequent cancer incidence and mortality.

PATIENTS AND METHODS

We identified all adult patients living in Olmsted County, Minnesota, between January 1, 2005, and December 31, 2011, who had at least 1 25(OH)D measurement and no prior diagnosis of cancer. Cancer outcomes were retrieved starting 30 days after 25(OH)D measurement and until patients' final clinical visit as an Olmsted County resident; December 31, 2014; or death. Cox proportional hazards regression was used to analyze data.

RESULTS

A total of 8700 individuals had a 25(OH)D measurement and no history of cancer, with a mean ± SD 25(OH)D value of 29.7±12.8 ng/mL (to convert to nmol/L, multiply by 2.496). The mean ± SD age was 51.5±16.4 years, and most were women (78.1%; n=6796) and White (85.7%; n=7460). A total of 761 individuals developed cancer (skin cancer, n=360; nonskin cancer, n=401) during a median follow-up of 4.6 (interquartile range, 3.4-6.1) years. Compared with participants with 25(OH)D values of 20 to 50 ng/mL (reference group), those with 25(OH)D values less than 12 ng/mL had a greater nonskin cancer incidence (hazard ratio [HR], 1.56; 95% CI, 1.03 to 2.36; P=.04) after adjustment. There was no association between 25(OH)D values and total cancer or skin cancer incidence. Compared with individuals from the reference group, 25(OH)D levels less than 12 ng/mL (HR, 2.35; 95% CI, 1.01 to 5.48; P=.047) and 12 to 19 ng/mL (HR, 2.10; 95% CI, 1.05 to 4.22; P=.04) were associated with increased cancer mortality.

CONCLUSION

Low 25(OH)D levels were associated with increased risk for incident nonskin cancer and cancer-related mortality.