Relationship between cancer mortality/incidence and ambient ultraviolet B irradiance in China

Cancer Incidence Rates in the US in 2016-2020 with Respect to Solar UVB Doses, Diabetes and Obesity Prevalence, Lung Cancer Incidence Rates, and Alcohol Consumption: An Ecological Study

This article reports the results of an ecological study of cancer incidence rates by state in the US for the period 2016-2020. The goals of this study were to determine the extent to which solar UVB doses reduced cancer risk compared to findings reported in 2006 for cancer mortality rates for the periods 1950-1969 and 1970-1794 as well as cancer incidence rates for the period 1998-2002 and to determine which factors were recently associated with cancer risk. The cancer data for non-Hispanic white (European American) men and women were obtained from the Centers for Disease Control and Prevention. Indices were obtained for solar UVB at the surface for July 1992, and alcohol consumption, diabetes, and obesity prevalence near the 2016-2020 period. Lung cancer incidence rates were also used in the analyses as a surrogate for smoking, diet, and air pollution. The cancers for which solar UVB is significantly associated with reduced incidence are bladder, brain (males), breast, corpus uteri, esophageal, gastric, non-Hodgkin's lymphoma, pancreatic, and renal cancer. Lung cancer was significantly associated with colorectal, laryngeal, and renal cancer. Diabetes was also significantly associated with breast, liver, and lung cancer. Obesity prevalence was significantly associated with breast, colorectal, and renal cancer. Alcohol consumption was associated with bladder and esophageal cancer. Thus, diet has become a very important driver of cancer incidence rates. The role of solar UVB in reducing the risk of cancer has been reduced due to people spending less time outdoors, wearing sunscreen that blocks UVB but not UVA radiation, and population increases in terms of overweight and obese individuals, which are associated with lower 25-hydroxyvitamin D concentrations and the generation of systemic inflammation, which is a risk factor for cancer. A dietary approach that would reduce the risk of diabetes, obesity, lung cancer, and, therefore, cancer, would be one based mostly on whole plants and restrictions on red and processed meats and ultraprocessed foods. Solar UVB exposure for a few minutes before applying sunscreen and taking vitamin D supplements would also help reduce the risk of cancer.

Correlation between meteorological factors and vitamin D status under different season

Pregnant women with low vitamin D levels tend to have poor clinical outcomes. Meteorological factors were associated with vitamin D. Here, we aimed to study the current status of 25-Hydroxy vitamin D (25(OH)D) concentrations in pregnant women in Kunshan city and investigate the meteorological factors associated with 25(OH)D levels under different seasons. The correlation between meteorological factors and 25(OH)D levels was estimated by cross-correlation analysis and multivariate logistic regression. A restrictive cubic spline method was used to estimate the non-linear relationship. From 2015 to 2020, a total of 22,090 pregnant women were enrolled in this study. Pregnant women with 25(OH)D concentrations below 50 nmol/l represent 65.85% of the total study population. There is a positive correlation between temperature and 25(OH)D. And there is a protective effect of the higher temperature on vitamin D deficiency. However, in the subgroup analysis, we found that in autumn, high temperatures above 30 °C may lead to a decrease in 25(OH)D levels. This study shows that vitamin D deficiency in pregnant women may widespread in eastern China. There is a potential inverted U-shaped relationship between temperature and 25(OH)D levels, which has implications for understanding of vitamin D changes under different seasons.

Vitamin D and Cancer: An Historical Overview of the Epidemiology and Mechanisms

This is a narrative review of the evidence supporting vitamin D’s anticancer actions. The first section reviews the findings from ecological studies of cancer with respect to indices of solar radiation, which found a reduced risk of incidence and mortality for approximately 23 types of cancer. Meta-analyses of observational studies reported the inverse correlations of serum 25-hydroxyvitamin D [25(OH)D] with the incidence of 12 types of cancer. Case-control studies with a 25(OH)D concentration measured near the time of cancer diagnosis are stronger than nested case-control and cohort studies as long follow-up times reduce the correlations due to changes in 25(OH)D with time. There is no evidence that undiagnosed cancer reduces 25(OH)D concentrations unless the cancer is at a very advanced stage. Meta-analyses of cancer incidence with respect to dietary intake have had limited success due to the low amount of vitamin D in most diets. An analysis of 25(OH)D-cancer incidence rates suggests that achieving 80 ng/mL vs. 10 ng/mL would reduce cancer incidence rates by 70 ± 10%. Clinical trials have provided limited support for the UVB-vitamin D-cancer hypothesis due to poor design and execution. In recent decades, many experimental studies in cultured cells and animal models have described a wide range of anticancer effects of vitamin D compounds. This paper will review studies showing the inhibition of tumor cell proliferation, dedifferentiation, and invasion together with the sensitization to proapoptotic agents. Moreover, 1,25-(OH)₂D₃ and other vitamin D receptor agonists modulate the biology of several types of stromal cells such as fibroblasts, endothelial and immune cells in a way that interferes the apparition of metastases. In sum, the available mechanistic data support the global protective action of vitamin D against several important types of cancer.

A Narrative Review of the Evidence for Variations in Serum 25-Hydroxyvitamin D Concentration Thresholds for Optimal Health

Vitamin D3 has many important health benefits. Unfortunately, these benefits are not widely known among health care personnel and the general public. As a result, most of the world’s population has serum 25-hydroxyvitamin D (25(OH)D) concentrations far below optimal values. This narrative review examines the evidence for the major causes of death including cardiovascular disease, hypertension, cancer, type 2 diabetes mellitus, and COVID-19 with regard to sub-optimal 25(OH)D concentrations. Evidence for the beneficial effects comes from a variety of approaches including ecological and observational studies, studies of mechanisms, and Mendelian randomization studies. Although randomized controlled trials (RCTs) are generally considered the strongest form of evidence for pharmaceutical drugs, the study designs and the conduct of RCTs performed for vitamin D have mostly been flawed for the following reasons: they have been based on vitamin D dose rather than on baseline and achieved 25(OH)D concentrations; they have involved participants with 25(OH)D concentrations above the population mean; they have given low vitamin D doses; and they have permitted other sources of vitamin D. Thus, the strongest evidence generally comes from the other types of studies. The general finding is that optimal 25(OH)D concentrations to support health and wellbeing are above 30 ng/mL (75 nmol/L) for cardiovascular disease and all-cause mortality rate, whereas the thresholds for several other outcomes appear to range up to 40 or 50 ng/mL. The most efficient way to achieve these concentrations is through vitamin D supplementation. Although additional studies are warranted, raising serum 25(OH)D concentrations to optimal concentrations will result in a significant reduction in preventable illness and death.

Role of purinergic system and vitamin D in the anti-cancer immune response

For several years, scientists have recognized that vitamin D plays an important role in mineral and bone homeostasis. It was mostly used to treat osteoporosis and rickets in the past decades. Vitamin D has also been discovered to be modulator of the immune system and may play a role in a variety of diseases, including autoimmune diseases, in recent years. Vitamin D interaction with the vitamin D receptor (VDR), which has transcriptional imparts and is displayed on a variety of cell types, including those of the immune system, appears to be accountable for the immune-modulating effects. The action of tumor cells and vitamin D were the first to be investigated, but the spotlight is now on immunologic and purinergic systems. We conducted a systematic search in Pub Med as well as Google scholar for studies written in English. Vitamin D, cancer, purinergic signaling, and immune response were among the search words. Vitamin D has the potential to be a useful coadjuvant in cancer therapy and the purinergic system may be a potential treatment target to cancer therapy, according to our findings.

Light at night and risk of breast cancer: a systematic review and dose-response meta-analysis

Breast cancer is the most common malignancy in women and the second leading cause of cancer death overall. Besides genetic, reproductive, and hormonal factors involved in disease onset and progression, greater attention has focused recently on the etiologic role of environmental factors, including exposure to artificial lighting such as light-at-night (LAN). We investigated the extent to which LAN, including outdoor and indoor exposure, affects breast cancer risk. We performed a systematic review of epidemiological evidence on the association between LAN exposure and breast cancer risk, using a dose–response meta-analysis to examine the shape of the relation. We retrieved 17 eligible studies through September 13, 2021, including ten cohort and seven case–control studies. In the analysis comparing highest versus lowest LAN exposure, we found a positive association between exposure and disease risk (risk ratio [RR] 1.11, 95% confidence interval-CI 1.07–1.15), with comparable associations in case–control studies (RR 1.14, 95% CI 0.98–1.34) and cohort studies (RR 1.10, 95% CI 1.06–1.15). In stratified analyses, risk was similar for outdoor and indoor LAN exposure, while slightly stronger risks were observed for premenopausal women (premenopausal: RR 1.16, 95% CI 1.04–1.28; postmenopausal: 1.07, 95% CI 1.02–1.13) and for women with estrogen receptor (ER) positive breast cancer (ER + : RR 1.09, 95% CI 1.02–1.17; ER–: RR 1.07, 95% CI 0.92–1.23). The dose–response meta-analysis, performed only in studies investigating outdoor LAN using comparable exposure assessment, showed a linear relation up to 40 nW/cm²/sr after which the curve flattened, especially among premenopausal women. This first assessment of the dose–response relation between LAN and breast cancer supports a positive association in selected subgroups, particularly in premenopausal women.

Low vitamin D exposure and risk of nasopharyngeal carcinoma: Observational and genetic evidence from a multicenter case-control study

BACKGROUND & AIMS

Little is known about the risk of nasopharyngeal carcinoma (NPC) in relation to vitamin D exposure. The aim of this study was to examine the associations of NPC risk with serum level of 25-hydroxyvitamin D (25OHD) and genetic predicted 25OHD, and potential effect modification by several putative risk factors of NPC.

METHODS

Our multicenter case-control study in Hong Kong recruited 815 NPC cases and 1502 frequency-matched (by sex and age) hospital controls from five major regional hospitals, and recruited 299 healthy subjects from blood donation centers (2014-2017). Circulating level of 25-hydroxyvitamin D (25OHD) and genetic predicted 25OHD (rs12785878, rs11234027, rs12794714, rs4588 and rs6013897) were measured by validated enzyme immunoassay and the iPLEX assay on the MassARRAY System, respectively. Data were also collected on demographics, lifestyle factors, ultraviolet radiation exposure, and potential confounders using a computer-assisted, self-administered questionnaire with satisfactory test-retest reliability. Unconditional logistic regression models were used to estimate ORs and 95% CIs.

RESULTS

Despite no significant association of NPC risk with circulating 25OHD and genetic predicted 25OHD, there was evidence for an inverse association in participants with normal body mass index (between 18.5 and 27.5) across categories of 25OHD (P_trend = 0.003), and a positive association in those with low socioeconomic status across categories based on the genetic score (P_trend = 0.005). In addition, risk of NPC diagnosed at an early stage was higher for genetically lower 25OHD level (adjusted OR = 3.09, 95% CI = 1.04-9.21, P_trend = 0.022).

CONCLUSIONS

Findings of this first comprehensive study to investigate the positive association of NPC risk with vitamin D deficiency need to be confirmed and be best interpreted with results of further similar studies. Our findings may inform possible etiological mechanisms of the associations with several putative risk/protective factors of NPC.

Vitamin D as a Potential Therapeutic Option in Cancer Treatment: Is There a Role for Chemoprevention?

BACKGROUND

Vitamin D (Vit D) serves as a precursor to the potent steroid hormone calcitriol, which regulates numerous genes that control homeostasis, epithelial cell differentiation, proliferation, and apoptosis. Low level of Vit D is implicated in the development and progression of several diseases including bone fractures, cardiovascular disease, diabetes mellitus, and cancers. The present review highlights the role of vitamin D in cancer with a particular emphasis on genetic variants related to Vit D metabolism as well as clinical trials of Vit D supplementation as a potential therapeutic option in the treatment of cancer patients.

METHODS

Data were collected following an electronic search in the Web of Science, Medline, PubMed, and Scopus databases by using some keywords such as "cancer", "tumor", "malignancy", "vitamin D", "cholecalciferol" and "calcitriol".

RESULTS

The collected evidence from the studies revealed a consistent and strong association between Vit D status and cancer risk and survival. The associations between Vit D-related genetic variants and cancer survival support the hypothesis that Vit D may affect cancer outcomes. The mechanisms whereby Vit D reduces cancer risk and increases survival are regulation of cellular differentiation, proliferation and apoptosis as well as decreased angiogenesis in tumor microenvironment and inhibition of metastasis.

CONCLUSION

There is a paucity of evidence-based recommendations for the optimal 25(OH)D levels in patients with cancer and the role of Vit D supplementation for primary or secondary prevention of cancer. Well-designed and sufficiently powered randomized clinical trials are necessary to assess the clinical application of Vit D in enhancing the clinical efficacy of standard and adjuvant chemotherapy regimens.

High altitude and cancer: An old controversy

Ecological studies have found that individuals that live at high altitude regions and in places where ultraviolet radiation is maximal, have lower rates of different types of cancer. However, there is evidence that in these same regions, genetic mutations that are prooncogenic, develop, as they are needed to increase human adaptability to hypoxic environments. Debate has arisen between researchers who consider high altitude environments as suitable for human longevity because of its protective effects against malignancies, and scientists that have reported an increased incidence of different type of cancers in these same regions. Evidence is presented that altitude is related to the development of genetic alterations in micro RNAs, p53 protein, lymphocyte activity, decrease in Fas Ligand and other proapoptotic molecules, as well as increase in prometastatic VGEF an HIF. Notwithstanding, higher vitamin D and ultraviolet B levels, and a better metabolic profile, taken together with lower pollution levels hves been related to lower incidence and mortality rates from malignancies in a series of epidemiological studies.

Solar Ultraviolet Radiation and Vitamin D Deficiency on Epstein-Barr Virus Reactivation: Observational and Genetic Evidence From a Nasopharyngeal Carcinoma-Endemic Population

Background

We investigated the relationship of Epstein-Barr virus viral capsid antigen (EBV VCA-IgA) serostatus with ambient and personal ultraviolet radiation (UVR) and vitamin D exposure.

Methods

Using data from a multicenter case-control study, we included 1026 controls subjects in 2014–2017 in Hong Kong, China. Odds ratios (ORs) and 95% confidence intervals (CIs) of the association between UVR exposure and EBV VCA-IgA (seropositivity vs seronegativity) were calculated using unconditional logistic regression models adjusted for potential confounders.

Results

We observed a large increase in seropositivity of EBV VCA-IgA in association with duration of sunlight exposures at both 10 years before recruitment and age 19–30 years (adjusted OR = 3.59, 95% CI = 1.46–8.77; and adjusted OR = 2.44, 95% CI = 1.04–5.73 for ≥8 vs <2 hours/day; P for trend = .005 and .048, respectively). However, no association of EBV VCA-IgA serostatus with other indicators of UVR exposure was found. In addition, both circulating 25-hydroxyvitamin D (25OHD) and genetic predicted 25OHD were not associated with EBV VCA-IgA serostatus.

Conclusions

Our results suggest that personal UVR exposure may be associated with higher risk of EBV reactivation, but we did not find clear evidence of vitamin D exposure (observational or genetic), a molecular mediator of UVR exposure. Further prospective studies in other populations are needed to confirm this finding and to explore the underlying biological mechanisms. Information on photosensitizing agents, and serological markers of EBV, and biomarkers related to systemic immunity and inflammation should be collected and are also highly relevant in future studies.

The role of vitamin D supplementation for primary prevention of cancer: meta-analysis of randomized controlled trials

Background: In the USA cancer is the second leading cause of mortality, as such, primary prevention of cancer is a major public health concern. Vitamin D supplementation has been studied as a primary prevention method for multiple diseases including cardiovascular disease, osteoporosis, diabetes mellitus and cancer. The role of Vitamin D as primary prevention of cancer is still controversial. With fast emergence of large randomized controlled trials (RCTs) in that regards, we aimed to evaluate the efficacy of Vitamin D supplementation as primary prophylaxis for cancer.

Methods: A comprehensive electronic database search was conducted for all RCTs where comparison of Vitamin D supplementation versus placebo for the prevention of any type of disease with at least 3 years of Vitamin D supplementation was used and where cancer incidence or mortality was reported. The primary outcome was cancer-related mortality and cancer incidence. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) using a random-effects model at the longest follow-up.

Results: We included 10 RCTs with 79,055 total patients, mean age of 68.07 years, a female percentage of 78.02% and a minimum follow-up of 4 years and more. Vitamin D was associated with significant reduction of cancer-related mortality compared with placebo (RR 0.87; 95% CI: 0.79–0.96; P = 0.05: I² = 0%). Compared with placebo, Vitamin D was not associated with significant reduction of cancer incidence (RR: 0.96; 95% CI: 0.86–1.07; P = 0.46; I² = 31%).

Conclusion: With inclusion of studies, which did not primarily examine vitamin D for the purpose of preventing cancer or reducing cancer mortality our meta-analysis highlights that the use of vitamin D supplementation for primary prevention of cancer is encouraged as it does possibly decrease cancer-related mortality once cancer is diagnosed; however, it has no role or effect on cancer incidence.

Vitamin D supplementation and total cancer incidence and mortality: a meta-analysis of randomized controlled trials

BACKGROUND

Previous meta-analyses of randomized controlled trials (RCTs) of vitamin D supplementation and total cancer incidence and mortality found inconsistent results, and most included trials administered generally low doses of vitamin D (≤1100 IU/day). We updated the meta-analysis by incorporating recent RCTs that have tested higher doses of vitamin D supplements.

MATERIALS AND METHODS

PubMed and Embase were searched from the inception to November 2018. Summary relative risks (RRs) and 95% confidence intervals (CIs) were estimated using a random-effects model.

RESULTS

For total cancer incidence, 10 trials were included [6537 cases; 3-10 years of follow-up; 54-135 nmol/l of attained levels of circulating 25(OH) vitamin D [25(OH)D] in the intervention group]. The summary RR was 0.98 (95% CI, 0.93-1.03; P = 0.42; I2 = 0%). The results remained null across subgroups tested, including even when attained 25(OH)D levels exceeded 100 nmol/l (RR, 0.95; 95% CI, 0.83-1.09; P = 0.48; I2 = 26%). For total cancer mortality, five trials were included [1591 deaths; 3-10 years of follow-up; 54-135 nmol/l of attained levels of circulating 25(OH)D in the intervention group]. The summary RR was 0.87 (95% CI, 0.79-0.96; P = 0.005; I2 = 0%), which was largely attributable to interventions with daily dosing (as opposed to infrequent bolus dosing). No statistically significant heterogeneity was observed by attained levels of circulating 25(OH)D (Pheterogeneity = 0.83), with RR being 0.88 (95% CI, 0.78-0.98; P = 0.02; I2 = 0%) for ≤100 nmol/l and 0.85 (95% CI, 0.70-1.03; P = 0.11; I2 = 0%) for >100 nmol/l.

CONCLUSIONS

In an updated meta-analysis of RCTs, vitamin D supplementation significantly reduced total cancer mortality but did not reduce total cancer incidence.

Personal ultraviolet Radiation exposure in a cohort of Chinese mother and child pairs: the Chinese families and children study

BACKGROUND

Few studies in China have examined personal ultraviolet radiation (UVR) exposure using polysulfone dosimetry.

METHODS

In this study, 93 mother and adolescent child pairs (N = 186) from two locations in China, one rural (higher latitude) and one urban (lower latitude), completed 3 days of personal UVR dosimetry and a sun/clothing diary, as part of a larger pilot study.

RESULTS

The average daily ambient UVR in each location as measured by dosimetry was 20.24 Minimal Erythemal Doses (MED) in the rural location and 20.53 MED in the urban location. Rural mothers had more average daily time outdoors than urban mothers (5.5 h, compared with 1.5 h, in urban mothers) and a much higher daily average personal UVR exposure (4.50 MED, compared with 0.78 MED in urban mothers). Amongst adolescents, rural males had the highest average daily personal UVR exposure, followed by rural females, urban females and urban males (average 2.16, 1.05, 0.81, and 0.48 MED, respectively).

CONCLUSIONS

Although based on small numbers, our findings show the importance of geographic location, age, work/school responsibilities, and sex of the adolescents in determining personal UVR exposure in China. These results suggest that latitude of residence may not be a good proxy for personal UVR exposure in all circumstances.

The association of gastrointestinal cancers (esophagus, stomach, and colon) with solar ultraviolet radiation in Iran-an ecological study

Iran has variations in the incidence of cancer in its different provinces. Moreover, it is one of the countries with a high incidence of gastrointestinal cancers in the world. The aim of this study was to investigate the relation between the incidence of esophageal, stomach, and colon cancers with ultraviolet radiation. This is an ecological study. The age-standardized incidence of cancer from 2004 to 2008 was obtained from the National Cancer Registry of Iran for all provinces. UV index data was taken from the world weather site. The altitude and latitude of cities were obtained from the National Topography Organization. Demographic variables were taken from the STEPS report of the Ministry of Health. In this study, lung cancer were used as the index of the effects of smoking. Data were analyzed using the SPSS22 software and through linear regression. UV emission levels showed a strong negative correlation with the incidence of esophageal and gastric cancers, in both genders, in all years. However, this correlation was stronger in men. UV radiation showed a significant correlation with colon cancer among both genders as well. There was no relation between altitude and incidence of cancer. Linear regression results showed that with a unit increase in UV, the incidence of gastric and esophagus cancers in males decreases by β = -4.99 and β = - 3.16 significant coefficients, respectively. Cities with higher levels of UV index have a relatively lower incidence of gastrointestinal cancers. Ultraviolet radiation may act as a protective factor against these cancers.

Plasma 25-hydroxyvitamin D concentrations and risk of incident cancer in adults with hypertension: A nested case-control study

BACKGROUND & AIMS

Evidence from epidemiologic studies on the association of circulating 25-hydroxyvitamin D [25(OH)D] concentrations with the incident risk of cancer has been inconsistent. We aimed to investigate the prospective relationship of baseline plasma 25(OH)D concentrations with the risk of cancer, and to examine possible effect modifiers.

METHODS

We employed a nested case-control study design, including 231 patients with incident cancer during a median 4.5 years of follow up, and 231 matched controls from the China Stroke Primary Prevention Trial (CSPPT).

RESULTS

The prevalence of plasma 25(OH)D <15, <20 and <30 ng/mL was 23.6%, 47.4% and 85.5%, respectively. Overall, there was an inverse relation between risk of cancer and plasma 25(OH)D. The Odds ratios (95% CI) for participants in the second (15.1 to <20.6 ng/mL), third (20.6 to <26.4 ng/mL) and fourth quartiles (≥26.4 ng/mL) were 0.45 (95% CI: 0.25-0.80), 0.53 (95% CI: 0.27-1.06) and 0.55 (95% CI: 0.27-1.10), respectively, compared with those in quartile 1. Conversely, low 25(OH)D (<15.1 ng/mL) concentrations were associated with increased risk of cancer (OR, 2.08; 95% CI: 1.20-3.59) compared to higher concentrations. These associations were consistent across subtypes of cancer. Several potential effect modifiers were identified, including plasma vitamin E concentrations and alcohol intake.

CONCLUSIONS

Low plasma 25(OH)D concentrations (<15.1 ng/mL) were associated with increased total cancer risk among Chinese hypertensive adults, compared to higher 25(OH)D concentrations. This finding and the possible effect modifiers warrant additional investigation.

Pathogenic roles of alterations in vitamin D and vitamin D receptor in gastric tumorigenesis

Gastric cancer is currently the second leading cause of cancer-related death worldwide, especially in Japan, Korea and China, and the 5-year survival rate of gastric cancer is less than 30%. Thus, it is important to shed more lights on novel agents to prevent gastric cancer or to improve survival rate of the patients. Vitamin D not only maintains calcium and bone homeostasis, but also mostly inhibits tumor genesis, invasion, and metastasis through activation of vitamin D receptor. Although epidemiological results are not consistent, accumulating evidence from gastric cancer cells, animal models, and clinical trials suggest that vitamin D deficiency may increase the risk and mortality of gastric cancer, but vitamin D supplement might be a safe and economical way to prevent or treat gastric cancer. Here, we reviewed the current studies on vitamin D and its receptor and focused on the pathogenic roles of their alterations in gastric tumorigenesis.

Annual Ambient UVB at Wavelengths that Induce Vitamin D Synthesis is Associated with Reduced Esophageal and Gastric Cancer Risk: A Nested Case-Control Study

Vitamin D has been shown to be beneficial at reducing the risk of cancer; however, studies examining esophageal and gastric cancer have been scarce and findings inconsistent. The UK Biobank cohort was used for this nested case-control study (N = 3732). Primary, incident esophageal and gastric cancer cases diagnosed after recruitment were identified via linkage to National Cancer Registries. Tropospheric Emissions Monitoring Internet Service database was used to calculate ambient annual UVB dose (D-UVB). Conditional logistic regression was used to investigate the relationship between annual ambient D-UVB and risk of esophageal and gastric cancer, and odds ratios (ORs) are reported. In total, 373 esophageal and 249 gastric cancer cases and 3110 age- and gender-matched controls were included in the study. We found a strong inverse association between annual ambient D-UVB and odds of developing esophageal or gastric cancer: Compared to the lowest tertile, OR for the highest tertile was 0.64 (95%CI:0.51-0.79) in adjusted analysis. The association was strengthened when restricted to esophageal cancer (OR = 0.60; 95%CI:0.45-0.80) and esophageal adenocarcinoma cases (OR = 0.48; 95%CI: 0.34-0.68). Similar results were found in unadjusted and stratified analysis. In conclusion, ambient UVB radiation is inversely associated with the development of esophageal and gastric cancer, even in a high-latitude country.

Contribution of sun exposure to the vitamin D dose received by various groups of the Spanish population

Although the harmful effects of excessive exposure to solar ultraviolet (UV) radiation are well known, the recommended dose of UV radiation is beneficial for the synthesis of vitamin D by the skin, in addition to being useful in the treatment of various illnesses and mental problems. Numerous studies have shown that vitamin D performs important functions in the human organism, such as absorbing calcium and phosphorous and contributing to the immune system, among others. Several studies have found that a high percentage of various groups of the Spanish population suffer from vitamin D deficiency, and since very few natural foods contain vitamin D, it was considered important to determine whether groups such as schoolchildren, outdoor workers and athletes, receive enough solar radiation to produce adequate levels of vitamin D in their daily activities. It was found that the amount of vitamin D (in IU) produced by personal effective solar UV doses could exceed the recommended dose of 1000IU/day in spring and summer, while the winter estimate (about 220IU/day) is only one quarter of the recommended dose. These results suggest that most people would not receive the recommended daily vitamin D dose in winter from exposure to solar UV radiation, the main source of vitamin D.

Bayesian age-period-cohort prediction of lung cancer incidence in China

BACKGROUND

  Lung cancer is one of the most common cancers in China. Estimation of future cancer trends is important for cancer control planning. The aim of this study was to examine the trend of lung cancer incidence from 1998 to 2007 and predict the lung cancer burden up to 2020 in China.

MATERIALS AND METHODS

  Lung cancer incidence data were retrieved from the national cancer registration database from 1998 to 2007. Annual population projection for the same period was obtained from the National Statistics Bureau. The Bayesian Age-Period-Cohort Modeling and Prediction package (Institute of Biomedical Engineering, Imperial College, London, UK) was used to describe the trend of lung cancer incidence and to predict the incidence rate and number of cases until the year 2020.

RESULTS

  The crude incidence rates of lung cancer increased from 43.39 per 100 000 in 1998 to 51.25 per 100 000 in 2007. After age standardization, the incidence rates remained stable over the 10-year period. The trends were mainly caused by aging, no obvious period effects and cohort effects were observed. Our projection showed that the age-standardized lung cancer incidence rate would remain steady until 2020. The estimated number of new incident cases was predicted to increase to 693 727 in 2020.

CONCLUSION

  The burden of lung cancer incidence is likely to continue increasing. Effective policies such as smoking cessation and environmental protection are imperative for lung cancer control and prevention.

Ambient ultraviolet radiation exposure and hepatocellular carcinoma incidence in the United States

BACKGROUND

Hepatocellular carcinoma (HCC), the most commonly occurring type of primary liver cancer, has been increasing in incidence worldwide. Vitamin D, acquired from sunlight exposure, diet, and dietary supplements, has been hypothesized to impact hepatocarcinogenesis. However, previous epidemiologic studies examining the associations between dietary and serum vitamin D reported mixed results. The purpose of this study was to examine the association between ambient ultraviolet (UV) radiation exposure and HCC risk in the U.S.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database provided information on HCC cases diagnosed between 2000 and 2014 from 16 population-based cancer registries across the U.S. Ambient UV exposure was estimated by linking the SEER county with a spatiotemporal UV exposure model using a geographic information system. Poisson regression with robust variance estimation was used to calculate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) for the association between ambient UV exposure per interquartile range (IQR) increase (32.4 mW/m2) and HCC risk adjusting for age at diagnosis, sex, race, year of diagnosis, SEER registry, and county-level information on prevalence of health conditions, lifestyle, socioeconomic, and environmental factors.

RESULTS

Higher levels of ambient UV exposure were associated with statistically significant lower HCC risk (n = 56,245 cases; adjusted IRR per IQR increase: 0.83, 95% CI 0.77, 0.90; p < 0.01). A statistically significant inverse association between ambient UV and HCC risk was observed among males (p for interaction = 0.01) and whites (p for interaction = 0.01).

CONCLUSIONS

Higher ambient UV exposure was associated with a decreased risk of HCC in the U.S. UV exposure may be a potential modifiable risk factor for HCC that should be explored in future research.

The role of vitamin D in hepatic metastases from colorectal cancer

Colorectal cancer (CRC) represents a significant health burden worldwide, comprising approximately 10% of annual cancer cases globally. Hepatic metastases are the most common site of CRC metastasis, and are the leading cause of death in CRC patients. There is strong epidemiologic evidence for an inverse association between vitamin D status and risk of CRC; however, the role of vitamin D in the natural history of liver metastases has not yet been investigated. Several researchers have proposed hallmarks of metastases; crucially, metastases can be blocked by interrupting just one rate-limiting step. Vitamin D status has been implicated in each proposed hallmark of metastasis. The aim of this review is to examine the potential role for vitamin D in reducing the development of hepatic metastases from CRC and outline the candidate mechanisms by which vitamin D may mediate these effects. The results of ongoing randomised intervention trials are eagerly awaited to determine whether addressing vitamin D insufficiency in CRC patients could reduce the occurrence of liver metastases, and the consequent morbidity and mortality.

Meta-analysis of the correlation between vitamin D and lung cancer risk and outcomes

In this meta-analysis, we analyzed the association between vitamin D levels and lung carcinoma risk and outcomes. Two authors independently searched the Web of Science, Pubmed, EBSCO and Ovid MEDLINE resources with the key words “vitamin D, lung cancer, solar and latitude” and enrolled 22 studies that satisfied the inclusion criteria. The summary odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using the random (or fixed)-effects model. Potential confounders were carefully adjusted. High vitamin D (or calcium) intake and serum 25(OH)D levels each correlated inversely with lung cancer risk [OR = 0.72 (95% CI: 0.61–0.85, p < 0.001) and OR = 0.89 (95% CI: 0.83–0.97, p < 0.05)]. High circulating 25(OH)D levels also reduced lung cancer mortality with the pooled OR reached 0.39 (95% CI: 0.28–0.54, p < 0.001)]. A positive trend was presented in the relationship between serum 25(OH) D and survival (OR = 1.01, 95% CI: 0.87–1.18, p = 0.87). Subgroup analysis revealed that nonsmokers had higher vitamin D levels, which correlated negatively with lung cancer risk (OR = 0.76, 95% CI: 0.65–0.88, p < 0.01). Moreover, lower sun exposure and high latitude associated with lower vitamin D levels. This meta-analysis shows that high vitamin D (or calcium) intake and serum 25(OH)D levels correlate with lower lung cancer risk and better prognosis. UVB and latitude may play a vital role in lung cancer occurrence and progression, although a direct evidence hasn't been obtained.

Temporal Trends in Satellite-Derived Erythemal UVB and Implications for Ambient Sun Exposure Assessment

Ultraviolet radiation (UVR) has been associated with various health outcomes, including skin cancers, vitamin D insufficiency, and multiple sclerosis. Measurement of UVR has been difficult, traditionally relying on subject recall. We investigated trends in satellite-derived UVB from 1978 to 2014 within the continental United States (US) to inform UVR exposure assessment and determine the potential magnitude of misclassification bias created by ignoring these trends. Monthly UVB data remotely sensed from various NASA satellites were used to investigate changes over time in the United States using linear regression with a harmonic function. Linear regression models for local geographic areas were used to make inferences across the entire study area using a global field significance test. Temporal trends were investigated across all years and separately for each satellite type due to documented differences in UVB estimation. UVB increased from 1978 to 2014 in 48% of local tests. The largest UVB increase was found in Western Nevada (0.145 kJ/m2 per five-year increment), a total 30-year increase of 0.87 kJ/m2. This largest change only represented 17% of total ambient exposure for an average January and 2% of an average July in Western Nevada. The observed trends represent cumulative UVB changes of less than a month, which are not relevant when attempting to estimate human exposure. The observation of small trends should be interpreted with caution due to measurement of satellite parameter inputs (ozone and climatological factors) that may impact derived satellite UVR nearly 20% compared to ground level sources. If the observed trends hold, satellite-derived UVB data may reasonably estimate ambient UVB exposures even for outcomes with long latency phases that predate the satellite record.

Solar ultraviolet doses and vitamin D in a northern mid-latitude

Solar ultraviolet (UV) radiation is one of the most important factors in the development of skin cancer in human, solar erythema and skin aging. Nevertheless, numerous studies have shown the benefits of UV solar radiation in moderate doses, such as the reduction of blood pressure and mental health, treatment of various diseases, and the synthesis of vitamin D in the skin. This paper analyses data from solar ultraviolet erythemal (UVER) irradiance in W/m² measured in a northern mid-latitude as Valencia (Spain) for the period 2003-2010. To estimate effective solar UV radiation in the production of vitamin D (UVD) we used the relationship proposed by McKenzie et al. (2009). It was obtained for one month for each season the minimum exposure time needed around solar noon and at 9 UTC and 15 UTC (Coordinated Universal Time) to obtain the recommended daily dose of 1000IU. Also, it has been calculated time for erythema induction around solar noon for the same months. The median UVER daily dose during the summer months was 4000J/m²day, and 700J/m²day in winter. With regard to UVD, the median UVD daily dose in summer season was 7700J/m²day, and in winter it was 1000J/m²day. Around noon in January it takes more than two hours of solar exposure to obtain the recommended daily dose of vitamin D, whereas the rest of the year range between 7min on July and 31min on October. For the same months around noon, exposure times to produce erythema were obtained, these being of higher value to the previous. The results show that it is difficult to obtain the recommended vitamin D doses in winter in a northern mid-latitude, as the human body is almost entirely covered in this season.

Spatiotemporal exposure modeling of ambient erythemal ultraviolet radiation

BACKGROUND

Ultraviolet B (UV-B) radiation plays a multifaceted role in human health, inducing DNA damage and representing the primary source of vitamin D for most humans; however, current U.S. UV exposure models are limited in spatial, temporal, and/or spectral resolution. Area-to-point (ATP) residual kriging is a geostatistical method that can be used to create a spatiotemporal exposure model by downscaling from an area- to point-level spatial resolution using fine-scale ancillary data.

METHODS

A stratified ATP residual kriging approach was used to predict average July noon-time erythemal UV (UV_Ery) (mW/m²) biennially from 1998 to 2012 by downscaling National Aeronautics and Space Administration (NASA) Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instrument (OMI) gridded remote sensing images to a 1 km spatial resolution. Ancillary data were incorporated in random intercept linear mixed-effects regression models. Modeling was performed separately within nine U.S. regions to satisfy stationarity and account for locally varying associations between UV_Ery and predictors. Cross-validation was used to compare ATP residual kriging models and NASA grids to UV-B Monitoring and Research Program (UVMRP) measurements (gold standard).

RESULTS

Predictors included in the final regional models included surface albedo, aerosol optical depth (AOD), cloud cover, dew point, elevation, latitude, ozone, surface incoming shortwave flux, sulfur dioxide (SO₂), year, and interactions between year and surface albedo, AOD, cloud cover, dew point, elevation, latitude, and SO₂. ATP residual kriging models more accurately estimated UV_Ery at UVMRP monitoring stations on average compared to NASA grids across the contiguous U.S. (average mean absolute error [MAE] for ATP, NASA: 15.8, 20.3; average root mean square error [RMSE]: 21.3, 25.5). ATP residual kriging was associated with positive percent relative improvements in MAE (0.6-31.5%) and RMSE (3.6-29.4%) across all regions compared to NASA grids.

CONCLUSIONS

ATP residual kriging incorporating fine-scale spatial predictors can provide more accurate, high-resolution UV_Ery estimates compared to using NASA grids and can be used in epidemiologic studies examining the health effects of ambient UV.

Markers of Vitamin D Exposure and Esophageal Cancer Risk: A Systematic Review and Meta-analysis

Vitamin D has been associated with reduced risk of many cancers, but evidence for esophageal cancer is mixed. To clarify the role of vitamin D, we performed a systematic review and meta-analysis to evaluate the association of vitamin D exposures and esophageal neoplasia, including adenocarcinoma, squamous cell carcinoma (SCC), Barrett's esophagus, and squamous dysplasia. Ovid MEDLINE, EMBASE, and Web of Science were searched from inception to September 2015. Fifteen publications in relation to circulating 25-hydroxyvitamin D [25(OH)D; n = 3], vitamin D intake (n = 4), UVB exposure (n = 1), and genetic factors (n = 7) were retrieved. Higher [25(OH)D] was associated with increased risk of cancer [adenocarcinoma or SCC, OR = 1.39; 95% confidence interval (CI), 1.04-1.74], with the majority of participants coming from China. No association was observed between vitamin D intake and risk of cancer overall (OR, 1.03; 0.65-1.42); however, a nonsignificantly increased risk for adenocarcinoma (OR, 1.45; 0.65-2.24) and nonsignificantly decreased risk for SCC (OR, 0.80; 0.48-1.12) were observed. One study reported a decreased risk of adenocarcinoma with higher UVB exposure. A decreased risk was found for VDR haplotype rs2238135(G)/rs1989969(T) carriers (OR, 0.45; 0.00-0.91), and a suggestive association was observed for rs2107301. In conclusion, no consistent associations were observed between vitamin D exposures and occurrence of esophageal lesions. Further adequately powered, well-designed studies are needed before conclusions can be made. Cancer Epidemiol Biomarkers Prev; 25(6); 877-86. ©2016 AACR.

Solar radiation and the incidence and mortality of leading invasive cancers in the United States

Invasive cancer risk is inversely related to ultraviolet light exposure. This study explores relationships between cancer and the satellite-derived sunlight energy. We obtained the North America Land Data Assimilation System (NLDAS) daily average sunlight for the continental United States from 1999-2011. US Cancer Statistics age-adjusted-incidence and mortality was also obtained from the Centers for Disease Control and Prevention (CDC). We found that cancer incidence for all invasive cancers and for 11 of 22 leading cancers significantly decreased with increased solar radiation. Cancer mortality for all invasive cancers was not significantly associated with solar radiation, but for 7 of 22 leading cancers, including cancers of the uterus, leukemias, lung, ovary, and urinary bladder, increased solar radiation predicted decreased mortality. With increasing solar radiation, increased incidence and cancer mortality was observed for liver cancer and increased incidence but not mortality was observed for cervical cancer. The current study confirms studies relating UV radiation to the incidence and mortality of a variety of cancer types. We find associations between solar radiation energy and the incidence and mortality of a number of types of cancers.

Serum 25-Hydroxyvitamin D Levels and the Risk of Dysplasia and Esophageal Adenocarcinoma in Patients with Barrett's Esophagus

BACKGROUND

To date, there are no studies reporting an association between vitamin D and Barrett's esophagus (BE), the precursor for esophageal adenocarcinoma (EAC).

AIMS

Our aim was to study the association between serum 25-hydroxyvitamin D (25(OH)D) levels and prevalence and incidence of dysplasia/EAC in BE.

METHODS

Patients from our BE Registry cohort seen between 2000 and 2012 who had serum 25(OH)D levels measured were included. Age, gender, race, BE length, hiatal hernia size, and histological findings were recorded. Patients without high-grade dysplasia (HGD)/EAC at or within 1 year of index biopsy and who had follow-up endoscopies and 25(OH)D levels were studied for incidence of dysplasia/EAC.

RESULTS

Among 429 patients with BE, the mean 25(OH)D level was 72 ± 31.2 nmol/L. Hundred and one (23.6 %) patients had deficiency (<50 nmol/L), 149 (34.7 %) had insufficiency (50-74.9 nmol/L), and 179 (41.7 %) had normal levels of 25(OH)D. There was no association between serum 25(OH)D levels and dysplasia (p = 0.90). In the incidence cohort of 246 patients with median follow-up of 46 months, there were 34 cases of low-grade dysplasia, 12 of HGD, and 5 of EAC. Change in 25(OH)D levels did not impact progression to dysplasia/EAC (every 5 nmol/L increase from baseline, hazard ratio 0.98; p = 0.62).

CONCLUSIONS

Serum 25(OH)D levels were low in 58.3 % of our BE cohort. There was no association between 25(OH)D levels and prevalence or incidence of HGD/EAC in patients with BE. Further long-term studies are needed to study the association between vitamin D status and progression of dysplasia in BE.

The role of geographical ecological studies in identifying diseases linked to UVB exposure and/or vitamin D

Using a variety of approaches, researchers have studied the health effects of solar ultraviolet (UV) radiation exposure and vitamin D. This review compares the contributions from geographical ecological studies with those of observational studies and clinical trials. Health outcomes discussed were based on the author's knowledge and include anaphylaxis/food allergy, atopic dermatitis and eczema, attention deficit hyperactivity disorder, autism, back pain, cancer, dental caries, diabetes mellitus type 1, hypertension, inflammatory bowel disease, lupus, mononucleosis, multiple sclerosis, Parkinson disease, pneumonia, rheumatoid arthritis, and sepsis. Important interactions have taken place between study types; sometimes ecological studies were the first to report an inverse correlation between solar UVB doses and health outcomes such as for cancer, leading to both observational studies and clinical trials. In other cases, ecological studies added to the knowledge base. Many ecological studies include other important risk-modifying factors, thereby minimizing the chance of reporting the wrong link. Laboratory studies of mechanisms generally support the role of vitamin D in the outcomes discussed. Indications exist that for some outcomes, UVB effects may be independent of vitamin D. This paper discusses the concept of the ecological fallacy, noting that it applies to all epidemiological studies.

Knowledge, attitude and practice regarding solar ultraviolet exposure among medical university students in Northeast China

To assess the knowledge, attitudes and practices regarding the health effects of ultraviolet radiation (UVR) and sun exposure among medical university students in Northeast China, 385 subjects were investigated on October 2013 using a self-administered multiple-choice questionnaire. Most of the subjects knew the effects of UVR on skin cancer (95.6%) and sunburn (92.2%), but fewer knew of the eye damage that can result from UVR (27.8% cataract and 3.1% pterygium). Correspondingly, the main purpose of adopting sun protection was considered to be 'preventing sunburn' (55.4%), but 'preventing eye damage' was the least (1.8%). In actual behaviour, the eyes received the least protection as well. Although knowing the effects of UVR on vitamin D synthesis (87.3%), 66.8% of participants never or seldom increased sun exposure. Compared to men, women were more likely to reduce sun exposure (P<0.001). Only a small fraction of subjects (6.6%) thought that tanning was attractive. Considering the response variability to UVR in people with different skin colours, different sun protection programs should be provided. In China, especially in the North, the public should be educated to moderately increase sun exposure to maintain adequate vitamin D status while also protecting against eye damage from UVR.

Review: the impacts of circulating 25-hydroxyvitamin D levels on cancer patient outcomes: a systematic review and meta-analysis

CONTEXT

Circulating levels of 25-hydroxyvitamin D [25(OH)D] may affect the prognosis of cancer patients; however, the epidemiological results are not consistent.

OBJECTIVE

To perform a meta-analysis of all published studies to assess the associations of circulating 25(OH)D levels measured at or near the time of diagnosis and outcomes for cancer patients.

DATA SOURCES

Searches of the PubMed and MEDLINE databases were performed and updated to December 2013.

STUDY SELECTION

Studies reporting an association between circulating 25(OH)D levels at or near the time of diagnosis and outcomes for the patients were included.

DATA EXTRACTION

Data extraction was performed independently by two authors, and conflicts were resolved by a third investigator.

DATA SYNTHESIS

Included in the meta-analysis were 25 studies with 17 332 cases. Significant associations between circulating 25(OH)D levels at or near the time of diagnosis and the outcomes for cancer patients were found. The pooled hazard ratio for the highest vs the lowest quartile of circulating 25(OH)D levels was 0.55 (95% confidence interval [CI] = 0.33-0.91) for overall survival of colorectal cancer patients, 0.63 (95% CI = 0.51-0.77) for breast cancer patients, and 0.48 (95% CI = 0.36-0.64) for lymphoma patients. Higher 25(OH)D levels were significantly associated with reduced cancer-specific mortality for patients with colorectal cancer (P = .005) and lymphoma (P < .001) and improved disease-free survival for patients with breast cancer (P < .001) or lymphoma (P < .05). A 10-nmol/L increment in circulating 25(OH)D levels conferred a hazard ratio of 0.96 (95% CI = 0.95-0.97) for overall survival of the cancer patients.

CONCLUSIONS

The results indicate that cancer patients with higher circulating 25(OH)D levels at or near the time of diagnosis have better outcomes.

Vitamin D status and sun exposure in southeast Asia

Vitamin D deficiency is more common in South Asia and Southeast Asia than is appreciated. Most studies defined 25-hydroxyvitamin D levels [25(OH)D] levels of less than 50 nmol/L (20 ng/mL) as vitamin D deficiency. With this cut-off level, the prevalence of vitamin D deficiency was about 70% or higher in South Asia and varied from 6–70% in Southeast Asia. The determinants for the variation of vitamin D status are skin pigmentation, aging, the sun protection behaviors such as application of a sunscreen, religious, lifestyle and nutritional differences. Advanced age is a known risk factor for vitamin D deficiency. Interestingly, elderly in countries such as Korea and Thailand, had higher 25(OH)D levels when compared with young people. This widespread vitamin D deficiency problem especially in the young generation is an urgent health issue that needs to be remedied.

Vitamin D supplements and cancer incidence and mortality: a meta-analysis

Background:

Observational studies suggest that effects of vitamin D may be stronger for cancer mortality than for incidence. Yet, existing randomised controlled trials (RCTs) of vitamin D supplementation have limited power to examine the relationships as their primary end points are not cancer incidence or mortality.

Methods:

Meta-analyses of RCTs of vitamin D supplementation and total cancer incidence and mortality were conducted.

Results:

Over 2–7 years of duration, vitamin D supplementations had little effect on total cancer incidence (400–1100 IU per day, summary relative risk (RR)=1.00, 95% confidence interval (CI)=0.94–1.06, I²=0% four RCTs with combined 4333 cases), but significantly reduced total cancer mortality (400–833 IU per day, summary RR=0.88, 95% CI=0.78–0.98, I²=0%, three RCTs with combined 1190 deaths).

Conclusions:

Over 2–7 years of duration, the benefit of vitamin D supplementation may be limited to cancer mortality.

Seasonality pattern of breast, colorectal, and prostate cancer is dependent on latitude

Background

The season of diagnosis of several forms of cancer has been observed to impact survival, supporting the hypothesis that vitamin D₃ has a protective role in cancer survival. All previous studies demonstrating this seasonality were performed in European populations residing at latitudes upwards of 50°N. This study investigated whether seasonality of prognosis persists in populations residing in the lower latitudes of the contiguous United States (Latitude 21°N to 48°N).

Material/Methods

The 5-year survival data of 19 204 female breast cancer, 6740 colorectal cancer, and 1644 prostate cancer cases was analyzed.

Results

Female breast cancer patients exhibited improved survival when diagnosed in the summer as compared to the winter at all latitudes (Hazard Ratio [HR]: 0.940, 95%; Confidence Interval [CI]: 0.938 to 0.941, P=0.002). Colorectal cancer and prostate cancer also exhibited a similar seasonal pattern (HR: 0.978, 95% CI: 0.975 to 0.980, P=0.008 and HR: 0.935, 95%, CI 0.929 to 0.943, P=0.006), respectively, when the analysis was restricted to northern regions.

Conclusions

These observations contribute to the mounting evidence that vitamin D₃ may affect the progression of cancer. Data also suggest that vitamin D₃ status at the onset of treatment may synergistically improve the prognosis of several cancer types.

Behavioural cancer risk factors in women diagnosed with primary breast cancer

AIMS

To investigate behavioural risk factors and self-efficacy among women diagnosed with breast cancer.

BACKGROUND

The appearance of new tumours in breast cancer survivors is influenced by risk behaviours. Knowing their prevalence and women's perceived ability to adopt a healthy lifestyle would allow designing educational interventions aimed at modifying these behaviours.

DESIGN

An observational cross-sectional study of women diagnosed with breast cancer.

METHODS

The study was carried out in Asturias (Spain). A total of 2407 breast cancer patients diagnosed between 1998-2008 were selected and 492 women agreed to participate. Self-reported data on risk factors self-efficacy were gathered through a telephone interview based on the European Code against Cancer conducted between February-June 2010.

RESULTS

A total of 16·1% of women in this study were regular smokers, 5% drank alcohol excessively, 49% were overweight, 54% reported a lower level of physical activity than recommended and 7·5% did not use sun protection. The Total Cancer Behavioural Risk indicator was calculated by adding up the results of all modifiable risks contained in the European Code against Cancer, with an average score of 21·6 in a scale from 0-78 points (0 = null cancer risk, 78 = maximum cancer risk). Self-efficacy levels were very high among our participants.

CONCLUSION

The results suggest that there is a need to design programmes to promote a healthy lifestyle among women diagnosed with breast cancer. Nurses have an important role to play in planning and implementing these programmes, using the most efficient educational techniques.

Vitamin D transport proteins megalin and disabled-2 are expressed in prostate and colon epithelial cells and are induced and activated by all-trans-retinoic acid

Megalin and disabled-2 (Dab2) are essential for uptake of the 25-hydroxycholecalciferol (25D3)-vitamin D binding protein (DBP) complex in tissues. In the kidney, this mechanism regulates serum 25D3 levels and production of 1,25-dihydroxycholecalciferol (1,25D3) by CYP27B1 for systemic use. Previously, we showed that mammary epithelial cells expressing CYP27B1 express megalin and Dab2 and internalize DBP by endocytosis, indicating 25D3 was accessible for conversion to 1,25D3 in extra-renal tissues. Moreover, induction of megalin and Dab2 (protein and mRNA abundance) by all-trans-retinoic acid (RA) enhanced DBP uptake. This suggests megalin and Dab2 play a central role in uptake of vitamin D and may predict actions of vitamin D in extra-renal tissues. Here, we characterized megalin and Dab2 expression and uptake of DBP in transformed human prostate and colon epithelial cells. Megalin and Dab2 were expressed in prostate and colon epithelial cells, which was markedly enhanced following treatment with RA. Furthermore, DBP uptake was stimulated by low-dose RA supplementation in LNCaP, PC-3, and Caco-2 cells. Taken together, these are the first studies to our knowledge that have demonstrated modulated expression of megalin and Dab2, as well as an association between increased expression of endocytic proteins with DBP uptake in prostate and colon cells.

Differences in vitamin D nutritional status between newly diagnosed cancer patients from rural or urban settings in Kentucky

Although poor nutritional status and weight loss in cancer patients is known to affect outcomes, little is known about malnutrition differences based on geographic location. We investigated nutritional and inflammatory status of 220 newly diagnosed adults with solid tumors at the University of Kentucky's Markey Cancer Center during December 2008 through October 2011. Chi-square tests were used to determine any associations between suboptimal nutritional levels and rural-urban areas of residence. Out of the 13 lab values collected, the only significant difference between rural and urban participants was found for vitamin D resulting in more rural subjects (67.4%) having a suboptimal vitamin D status as compared to those residing in urban areas (53.3%, P = 0.04). Controlling for baseline demographics including age, race, sex, body mass index, nutritional status, and type of cancer, logistic regression analyses concluded those in rural areas had nearly a twofold increase in the odds of having a suboptimal vitamin D level compared to those in urban areas (odd's ratio = 1.97; 95% confidence interval = 1.04, 3.74). Further investigation into the rural-urban differences in vitamin D needs to be investigated in order to improve outcomes during cancer treatment.

1,25-dihydroxyvitamin D in the pathogenesis of Barrett's esophagus and esophageal adenocarcinoma

The incidence of reflux-related esophageal disease - Barrett's esophagus and esophageal adenocarcinoma - is rising, and the prognosis remains poor. Evidence exists that 1,25-dihydroxyvitamin D may augment the course of colon, breast and prostate cancer but little knowledge exists regarding its impact on disease of the esophagus. Important immune cells involved in reflux-related esophageal disease include CD4(+) T cells, macrophages and dendritic cells, and key signaling pathways include Wnt, Hedgehog, NFκ-B and IL-6-JAK-STAT. There is an inter-relationship between these entities and 1,25-dihydroxyvitamin D, which has been described in animal models and some human tissue. Despite this, there is an incomplete understanding of how the immune cell population and signaling pathways contribute to the course and prognosis of Barrett's esophagus and esophageal adenocarcinoma. More investigation with a focus on the clinical outcomes of patients with Barrett's esophagus and esophageal adenocarcinoma and the immune cell population and cell signaling activity in the diseased esophagus is necessary to determine the immunomodulatory role of 1,25-dihydroxyvitamin D in the pathogenesis of esophageal diseases.

Does sunlight exposure improve survival in patients with non-small cell lung cancer?

BACKGROUND

Some epidemiological studies reported that sunlight exposure and highvitamin D levels may decrease the morbidity and mortality related to cancer. We aimed to evaluate whether sunlight exposure has an impact on survival in patients with non small cell lung cancer.

MATERIALS AND METHODS

A total of 546 patients with NSCLC from two different regions (Kayseri and Adana) differing according to sunlight exposure were analysed retrospectively.

RESULTS

The median overall survival (OS) rates were 11. 6 (CI: 9.50-13.6) and 15.6 months (CI: 12.4-18.8) for Kayseri and Adana, respectively, in all patients (p=0.880).

CONCLUSIONS

There were no differences between groups in terms of OS. While there is strong evidence regarding inverse relationship between cancer incidence and sunlight exposure, it is still controversial whether sunlight exposure is a good prognostic factor for survival in patients with lung cancer.

The relationship between ambient ultraviolet radiation (UVR) and objectively measured personal UVR exposure dose is modified by season and latitude

Despite the widespread use of ambient ultraviolet radiation (UVR) as a proxy measure of personal exposure to UVR, the relationship between the two is not well-defined.

A multicountry ecological study of cancer incidence rates in 2008 with respect to various risk-modifying factors

Observational and ecological studies are generally used to determine the presence of effect of cancer risk-modifying factors. Researchers generally agree that environmental factors such as smoking, alcohol consumption, poor diet, lack of physical activity, and low serum 25-hdyroxyvitamin D levels are important cancer risk factors. This ecological study used age-adjusted incidence rates for 21 cancers for 157 countries (87 with high-quality data) in 2008 with respect to dietary supply and other factors, including per capita gross domestic product, life expectancy, lung cancer incidence rate (an index for smoking), and latitude (an index for solar ultraviolet-B doses). The factors found to correlate strongly with multiple types of cancer were lung cancer (direct correlation with 12 types of cancer), energy derived from animal products (direct correlation with 12 types of cancer, inverse with two), latitude (direct correlation with six types, inverse correlation with three), and per capita gross national product (five types). Life expectancy and sweeteners directly correlated with three cancers, animal fat with two, and alcohol with one. Consumption of animal products correlated with cancer incidence with a lag time of 15–25 years. Types of cancer which correlated strongly with animal product consumption, tended to correlate weakly with latitude; this occurred for 11 cancers for the entire set of countries. Regression results were somewhat different for the 87 high-quality country data set and the 157-country set. Single-country ecological studies have inversely correlated nearly all of these cancers with solar ultraviolet-B doses. These results can provide guidance for prevention of cancer.

The Inverse Relationship between 25-Hydroxyvitamin D and Cancer Survival: Discussion of Causation

Cancer mortality rates vary inversely with geographic latitude and solar ultraviolet-B doses. This relationship may be due to an inhibitory role of vitamin D on cancer development. The relationship between vitamin D and cancer appears to be stronger for studies of cancer mortality than incidence. Because cancer mortality reflects both cancer incidence and survival, the difference may be due to effects of vitamin D on cancer survival. Here we review analytic epidemiologic studies investigating the relation between vitamin D, measured by circulating levels of 25-hydroxyvitamin D (25-OHD), and cancer survival. A relationship between low 25-OHD levels and poor survival is shown by most of the reviewed studies. This relationship is likely to be causal when viewed in light of most criteria for assessing causality (temporality, strength, exposure-response, biological plausibility and consistency). A serum level of 25-OHD around 50 nmol/L appears to be a threshold level. Conversely, there are several mechanisms whereby cancer could lower serum levels of 25-OHD. The severity of disease at the time of diagnosis and time of serum sampling are key factors to clarify the temporal aspect of these relationships. Evidence that vitamin D supplementation could retard the disease process or prolong survival time would be key evidence, but is difficult to generate. However, recent clinical trial results in prostate cancer support a role for vitamin D in this regard.

Molecular link between vitamin D and cancer prevention

The metabolite of vitamin D, 1α,25-dihydroxyvitamin D₃ (also known as calcitriol), is a biologically active molecule required to maintain the physiological functions of several target tissues in the human body from conception to adulthood. Its molecular mode of action ranges from immediate nongenomic responses to longer term mechanisms that exert persistent genomic effects. The genomic mechanisms of vitamin D action rely on cross talk between 1α,25-dihydroxyvitamin D₃ signaling pathways and that of other growth factors or hormones that collectively regulate cell proliferation, differentiation and cell survival. In vitro and in vivo studies demonstrate a role for vitamin D (calcitriol) in modulating cellular growth and development. Vitamin D (calcitriol) acts as an antiproliferative agent in many tissues and significantly slows malignant cellular growth. Moreover, epidemiological studies have suggested that ultraviolet-B exposure can help reduce cancer risk and prevalence, indicating a potential role for vitamin D as a feasible agent to prevent cancer incidence and recurrence. With the preventive potential of this biologically active agent, we suggest that countries where cancer is on the rise--yet where sunlight and, hence, vitamin D may be easily acquired--adopt awareness, education and implementation strategies to increase supplementation with vitamin D in all age groups as a preventive measure to reduce cancer risk and prevalence.

Prevalence of asthma symptoms in schoolchildren, and climate in west European countries: an ecologic study

The aim of the present study was to estimate the associations between the prevalence of asthma symptoms in schoolchildren and meteorological variables in west European countries that participated in the International Study of Asthma and Allergies in Children (ISAAC), Phase III 1997-2003. An ecologic study was carried out. The prevalence of asthma was obtained from this study from 48 centers in 14 countries, and meteorological variables from those stations closest to ISAAC centers, together with other socioeconomic and health care variables. Multilevel mixed-effects linear regression models were used. For schoolchildren aged 6-7 years, the prevalence rate of asthma decreased with an increase in mean annual sunshine hours, showed a positive association with rainy weather, and warm temperature, and a negative one with relative humidity and physician density (PD). Current wheeze prevalence was stronger in autumn/winter seasons and decreased with increasing PD. Severe current wheeze decreased with PD. For schoolchildren aged 13-14 years, the prevalence rates of asthma and current wheeze increased with rainy weather, and these rates decreased with increased PD. Current wheeze, as measured by a video questionnaire, was inversely associated with sunny weather, and nurse density. Severe current wheeze prevalence was stronger during autumn/winter seasons, decreased with PD, and indoor chlorinated public swimming pool density, and increased with rainy weather. Meteorological factors, including sunny and rainy weather, and PD may have some effect on the prevalence rates of asthma symptoms in children from west European countries.

The association of ultraviolet radiation-B (305 nm), season of diagnosis, and latitude on the survival outcome of prostate cancer in the high UV environment of Australia

BACKGROUND

Positive associations between sun exposure and cancer survival have been observed in regions of high latitudes, where ambient solar ultraviolet (SUV) radiation is generally low.

PURPOSE

We examined the effects of ambient ultraviolet-B radiation (UVB) at time of diagnosis, season of diagnosis and latitude of residence on survival outcome from prostate cancer.

METHOD

Regression models for relative survival were used to estimate relative excess risks (RER) of death after diagnosis of prostate cancer from cancer registries in Eastern Australia (Queensland, New South Wales, Victoria and Tasmania).

RESULTS

Relative excess risks was increased with diagnosis in summer (RER = 1.20; 95 % CI 1.14-1.26) relative to winter, high ambient UVB at the time of diagnosis (>60 mW/m(2); RER = 1.10; 95 % CI 1.05-1.15) relative to low SUV (<30 mW/m(2)), and with residence in high latitudes (35°S-43°S; RER = 1.20; 95 % CI 1.14-1.26) relative to low latitudes (9°S-29.9°S). RER was highest for summer diagnosis in all three latitude bands, after adjusting for age, follow-up period, and socioeconomic status.

CONCLUSION

The contradictory outcome from season and latitude suggests that their use as surrogates for UV warrants validation. Our data suggest that high ambient solar ultraviolet radiation at the time of diagnosis of prostate cancer increases the risk of dying from this cancer.

Prospective study of ultraviolet radiation exposure and mortality risk in the United States

Geographic variations in mortality rate in the United States could be due to several hypothesized factors, one of which is exposure to solar ultraviolet radiation (UVR). Limited evidence from previous prospective studies has been inconclusive. The association between ambient residential UVR exposure and total and cause-specific mortality risks in a regionally diverse cohort (346,615 white, non-Hispanic subjects, 50-71 years of age, in the National Institutes of Health (NIH)-AARP Diet and Health Study) was assessed, with accounting for individual-level confounders. UVR exposure (averaged for 1978-1993 and 1996-2005) from NASA's Total Ozone Mapping Spectrometer was linked to the US Census Bureau 2000 census tract of participants' baseline residence. Multivariate-adjusted Cox proportional-hazards models were used to estimate hazard ratios and 95% confidence intervals. Over 12 years, UVR exposure was associated with total deaths (n = 41,425; hazard ratio for highest vs. lowest quartiles (HRQ4 vs. Q1) = 1.06, 95% confidence interval (CI): 1.03, 1.09; Ptrend < 0.001) and with deaths (all Ptrend < 0.05) due to cancer (HRQ4 vs. Q1 = 1.06, 95% CI: 1.02, 1.11), cardiovascular disease (HRQ4 vs. Q1 = 1.06, 95% CI: 1.00, 1.12), respiratory disease (HRQ4 vs. Q1 = 1.37, 95% CI: 1.21, 1.55), and stroke (HRQ4 vs. Q1 = 1.16, 95% CI: 1.01, 1.33) but not with deaths due to injury, diabetes, or infectious disease. These results suggest that UVR exposure might not be beneficial for longevity.

Relationship between cancer survival and ambient ultraviolet B irradiance in China

BACKGROUND

Ecological studies in predominantly European populations have reported higher cancer survival in areas of higher solar ultraviolet (UV) B irradiation, perhaps due to a cancer protective effect of vitamin D synthesized photochemically in the skin. Such studies have not been done in developing countries, perhaps because of lack of cancer registries that can do outcome follow-up. One minus the mortality-to-incidence ratio (1-MIR), however, can be used as a measure of survival, and MIR as a measure of fatality, in developing country cancer registries. We analyzed the association between ambient solar UVB and MIR in China.

METHODS

National cancer registration data in 32 counties of China in 2004-2005 were used to estimate MIR by age, sex, and area. The accuracy of 1-MIR as a measure of survival was assessed in the Cixian County cancer registry. Contemporary satellite measurements of cloud-adjusted ambient UVB intensity at 305 nm were taken from an NASA database and spatial Kriging methods used to estimate the average daily irradiance in each county. We estimated mortality hazard ratios (HRs) per 10 mW/m(2) of UVB for all cancers together, and the ten commonest cancer types by fitting a generalized linear model assuming mortality had a binomial distribution conditional on the sum of mortality and incidence, adjusted for sex, age, and location.

RESULTS

The 5-year survival proportions for the main cancer types were in good agreement with 1-MIR in Cixian County. MIR ratios for all cancers combined were inversely associated with ambient UVB in men (HR = 0.96, 95% CI 0.93-0.99) and women (HR = 0.91, 95% CI 0.88-0.94) and in urban (HR = 0.95, 95% CI 0.94-0.96) and rural areas (HR = 0.90, 95% CI 0.87-0.93). Similar inverse associations were present for cancers of esophagus, stomach, and bladder in both sexes together and breast cancer in women. They were present in urban residents for all major cancers except liver cancer, bladder cancer, and breast cancer in women. For rural residents, most HRs were <1.0 but, with the exception of breast cancer, their upper 95% confidence bounds were >1.0.

CONCLUSION

Ambient UVB was significantly inversely associated with MIR for all cancers together and four of ten cancer types. Solar UVB may increase survival from some cancers in China.

Vitamin D and the epidemiology of upper gastrointestinal cancers: a critical analysis of the current evidence

Prospective analyses have yet to uncover a consistent relationship between vitamin D status and incidence and mortality of rarer cancers including esophageal and upper gastrointestinal cancers. We searched PubMed for literature about the epidemiology of upper gastrointestinal cancers and vitamin D published over the last decade and then summarized and critiqued the results of these studies in this review. The search yielded nine relevant studies. Overall, no consistent relationship was reported between serum vitamin D levels or a surrogate and upper gastrointestinal cancers. Four studies reported negative correlations between vitamin D status and upper gastrointestinal cancer, three reported positive correlations, one reported no correlation, and one reported both positive and negative correlations. No relationship has been established on the basis of epidemiologic data, but studies examining sun exposure consistently report an inverse association with esophageal cancer. The current literature is limited by the methods used to assess vitamin D status, lack of specific data for the types of upper gastrointestinal cancer, and failure to establish a temporal relationship between vitamin D status assessment and presentation of upper gastrointestinal cancer. It is possible that the lack of a consistent relationship is a consequence of inaccurate and imprecise assessment of vitamin D status.

Association of carcinogenic polycyclic aromatic hydrocarbon emissions and smoking with lung cancer mortality rates on a global scale

The objective of this research was to investigate the relationship between lung cancer mortality rates, carcinogenic polycyclic aromatic hydrocarbon (PAH) emissions, and smoking on a global scale, as well as for different socioeconomic country groups. The estimated lung cancer deaths per 100,000 people (ED100000) and age standardized lung cancer death rate per 100,000 people (ASDR100000) in 2004 were regressed on PAH emissions in benzo[a]pyrene equivalence (BaPeq), smoking prevalence, cigarette price, gross domestic product per capita, percentage of people with diabetes, and average body mass index using simple and multiple linear regression for 136 countries. Using stepwise multiple linear regression, a statistically significant positive linear relationship was found between loge(ED100000) and loge(BaPeq) emissions for high (p-value <0.01) and for the combination of upper-middle and high (p-value <0.05) socioeconomic country groups. A similar relationship was found between loge(ASDR100000) and loge(BaPeq) emissions for the combination of upper-middle and high (p-value <0.01) socioeconomic country groups. Conversely, for loge(ED100000) and loge(ASDR100000), smoking prevalence was the only significant independent variable in the low socioeconomic country group (p-value <0.001). These results suggest that reducing BaPeq emissions in the U.S., Canada, Australia, France, Germany, Brazil, South Africa, Poland, Mexico, and Malaysia could reduce ED100000, while reducing smoking prevalence in Democratic People's Republic of Korea, Nepal, Mongolia, Cambodia, and Bangladesh could significantly reduce the ED100000 and ASDR100000.