Purpose

To determine whether a higher serum 25-hydroxyvitamin D [25(OH)D] concentration at diagnosis is associated with longer survival of colorectal cancer patients.

Methods

A meta-analysis was performed of studies of the relationship between 25(OH)D and mortality of patients with colorectal cancer. A random-effects model was used to calculate a pooled hazards ratio. Homogeneity was evaluated through a DerSimonian-Laird test.

Results

Higher serum concentrations of 25(OH)D were associated with lower mortality in patients with colorectal cancer. Patients in the highest quintile of 25(OH)D had 37% lower mortality from colorectal cancer compared to those in the lowest quintile of 25(OH)D (pooled odds ratio=0.63, p<0.0001). Dose-response curves showed lower hazard ratios for mortality with higher serum 25(OH)D through at least 40ng/ml. There were no exceptions.

Conclusions

Higher serum 25(OH)D was associated with lower mortality of patients with colorectal cancer. These results suggest that colorectal cancer patients with deficient levels of serum 25(OH)D should have their levels restored to a normal range (30-80ng/ml). This could be done with regular testing of serum 25(OH)D to be confident that an adequate serum level is being maintained. Additional studies would be worthwhile to evaluate confounding or the possibility of reverse causation.

Background

Vitamin D has been identified as a potential protective factor in the development of colorectal cancer (CRC). We expect to see a stronger association of ultraviolet B (UVB) exposure and CRC crude rates with increasing age since chronic vitamin D deficiency leads to sustained molecular changes that increase cancer risk. The DINOMIT (disjunction, initiation, natural selection, overgrowth, metastasis, involution, and transition) model postulates various stages of cancer development due to vitamin D deficiency and the associated latency period. The purpose of this study is to examine this age-dependent inverse relationship globally.

Methods

In this ecological study, a series of linear and polynomial regression tests were performed between country-specific UVB estimates adjusted for cloud cover and crude incidence rates of CRC for different age groups. Multiple linear regression was used to investigate the association between crude incidence rates of colorectal cancer and UVB estimate adjusting for urbanization, skin pigmentation, smoking, animal consumption, per capita GDP, and life expectancy. Statistical analysis was followed by geospatial visualization by producing choropleth maps.

Results

The inverse relationship between UVB exposure and CRC crude rates was stronger in older age groups at the country level. Quadratic curve fitting was preferred, and these models were statistically significant for all age groups. The inverse association between crude incidence rates of CRC and UVB exposure was statistically significant for age groups above 45 years, after controlling for covariates.

Conclusion

The age-dependent inverse association between UVB exposure and incidence of colorectal cancer exhibits a greater effect size among older age groups in global analyses. Studying the effect of chronic vitamin D deficiency on colorectal cancer etiology will help in understanding the necessity for population-wide screening programs for vitamin D deficiency, especially in regions with inadequate UVB exposure. Further studies are required to assess the need for adequate public health programs such as selective supplementation and food fortification.

Background

Controversy exists regarding whether vitamin D deficiency could influence the etiology of pancreatic cancer. Several cohort studies have found that high serum 25-hydroxyvitamin D [25(OH)D] concentrations are associated with low risk of pancreatic cancer, while others have not.

Hypothesis

Low ultraviolet B irradiance is associated with high incidence of pancreatic cancer.

Methods

Age-standardized pancreatic cancer incidence rates were obtained from GLOBOCAN in 2008. The association between cloud-adjusted UVB irradiance and age-standardized incidence rates of pancreatic cancer was analyzed using regression.

Results

Overall, the lower the cloud-adjusted UVB irradiance, the higher the incidence rate of pancreatic cancer. Residents of countries with low UVB irradiance had approximately 6 times the incidence rates as those in countries with high UVB irradiance (p<0.0001 for males and p<0.0001 for females). This association persisted after adjustment for traditional risk factors of pancreatic cancer (p=0.0182 for males and p=0.0029 for females).

Conclusions

There was an inverse association of cloud-adjusted UVB irradiance with incidence of pancreatic cancer that persisted after adjustment. This result is consistent with an inverse association of overall vitamin D deficiency in countries with lower UVB irradiance with risk of pancreatic cancer. Further research on the role of 25(OH)D in reduction of pancreatic cancer in individuals would be desirable to expand the limited avenues available for prevention of this highly fatal disease. This article is part of a Special Issue entitled '17th Vitamin D Workshop'.

There are 52,380 cases of leukemia and 24,090 deaths from it in the US annually. Its causes are unknown and no preventive strategies have been implemented. We hypothesized that leukemia is due mainly to vitamin D deficiency, which is due mainly to low solar ultraviolet B (UVB) irradiance. To test this hypothesis, we estimated age-standardized cloud-cover-adjusted winter UVB irradiance using cloud cover data from the International Satellite Cloud Climatology Project, latitudes of population centroids, and standard astronomical calculations. Incidence rates for 172 countries, available from the International Agency for Cancer Research, were plotted according to cloud-adjusted UVB irradiance. We used multiple regression to account for national differences in elevation and average life expectancy. Leukemia incidence rates were inversely associated with cloud-adjusted UVB irradiance in males (p ≤ 0.01) and females (p ≤ 0.01) in both hemispheres. There were few departures from the trend line, which was parabolic when plotted with the equator at the center of the display, northern hemisphere countries on the right side and southern hemisphere countries on the left. The bivariate association displayed by the polynomial trend line indicated that populations at higher latitudes had at least two times the risk of leukemia compared to equatorial populations. The association persisted in males (p ≤ 0.05) and females (p ≤ 0.01) after controlling for elevation and life expectancy. Incidence rates of leukemia were inversely associated with solar UVB irradiance. It is plausible that the association is due to vitamin D deficiency. This would be consistent with laboratory studies and a previous epidemiological study. Consideration should be given to prudent use of vitamin D for prevention of leukemia.

The purpose of this study is to examine the relationship between ultraviolet B and global incidence of colorectal cancer, while controlling for relevant covariates. Linear regression was used to assess the relationship between latitude and incidence rates of colon cancer in 173 countries. Multiple linear regression was employed to investigate the relationship between ultraviolet B dose and colorectal cancer rates while controlling for per capita intake of energy from animal sources, per capita health expenditure, pigmentation, and life expectancy. Data on all variables were available for 139 countries. Incidence of colon cancer was highest in countries distant from the equator (R(2) = 0.50, p < 0.0001). UV B dose (p < 0.0001) was independently, inversely associated with incidence rates of colorectal cancer after controlling for intake of energy from animal sources, per capita health expenditure, pigmentation, and life expectancy (R(2) for overall model = 0.76, p < 0.0001). Consistent with previous research, UVB was inversely associated with incidence of colon cancer. Further research on vitamin D and prevention of colon cancer in individuals should be conducted, including studies of higher serum 25-hydroxyvitamin D concentrations than have been studied to date.

Background

The purpose of this study was to determine whether an inverse association exists between latitude, solar ultraviolet B (UVB) irradiance, and incidence rates of multiple myeloma.Methods Associations of latitude and UVB irradiance with age-standardized incidence rates of multiple myeloma were analyzed for 175 countries while controlling for sex-specific obesity prevalence, cigarette consumption, and alcohol consumption using multiple linear regression.Results Incidence rates of multiple myeloma were greater at higher latitudes (R(2) for latitude for males=0.31, p<0.0001; females R(2)=0.27, p<0.0001). In regression models for males (R(2)=0.62, p<0.0001) and females (R(2)=0.51, p<0.0001), UVB irradiance was independently inversely associated with incidence rates.Conclusions Age-adjusted incidence rates of multiple myeloma were higher in countries with lower solar UVB irradiance. Further investigation is warranted in individuals of the association of prediagnostic serum 25(OH)D with risk.

Introduction

Sex hormones have been implicated in the etiology of a number of diseases. To better understand disease etiology and the mechanisms of disease-risk factor associations, this analysis aimed to investigate the associations of anthropometric, sociodemographic and behavioural factors with a range of circulating sex hormones and sex hormone-binding globulin.

Methods

Statistical analyses of individual participant data from 12,330 male controls aged 25-85 years from 25 studies involved in the Endogenous Hormones Nutritional Biomarkers and Prostate Cancer Collaborative Group. Analysis of variance was used to estimate geometric means adjusted for study and relevant covariates.

Results

Older age was associated with higher concentrations of sex hormone-binding globulin and dihydrotestosterone and lower concentrations of dehydroepiandrosterone sulfate, free testosterone, androstenedione, androstanediol glucuronide and free estradiol. Higher body mass index was associated with higher concentrations of free estradiol, androstanediol glucuronide, estradiol and estrone and lower concentrations of dihydrotestosterone, testosterone, sex hormone-binding globulin, free testosterone, androstenedione and dehydroepiandrosterone sulfate. Taller height was associated with lower concentrations of androstenedione, testosterone, free testosterone and sex hormone-binding globulin and higher concentrations of androstanediol glucuronide. Current smoking was associated with higher concentrations of androstenedione, sex hormone-binding globulin and testosterone. Alcohol consumption was associated with higher concentrations of dehydroepiandrosterone sulfate, androstenedione and androstanediol glucuronide. East Asians had lower concentrations of androstanediol glucuronide and African Americans had higher concentrations of estrogens. Education and marital status were modestly associated with a small number of hormones.

Conclusion

Circulating sex hormones in men are strongly associated with age and body mass index, and to a lesser extent with smoking status and alcohol consumption.