Solar radiation, vitamin D and survival rate of colon cancer in Norway

Is Season of Diagnosis a Predictor of Cancer Survival? Results from the Zurich Cancer Registry

In Switzerland, there is a large seasonal variation in sunlight, and vitamin D deficiency is relatively common during winter. The season of diagnosis may be linked to cancer survival via vitamin D status. Using data from the Cancer Registry of Zurich, Zug, Schaffhausen, and Schwyz with more than 171,000 cancer cases registered since 1980, we examined the association of the season of diagnosis with survival for cancers including prostate (ICD10 code C61; International Categorization of Diseases, version 10), breast (C50), colorectal (C18-21), lung (C34), melanoma (C43), and all sites combined. Cox proportional hazards regression models were used to assess the differences in the all-cause mortality by the season of the diagnosis. Winter was used as the reference season. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated for all the cancers combined (excluding nonmelanoma skin cancer) and for prostate (in men), breast (in women), colorectal, lung cancer, and melanomas, separately. A diagnosis in summer and/or autumn was associated with improved survival in all the sites combined for both sexes (men: HR 0.97 [95% CI 0.96-0.99]; women: HR 0.97 [95% CI 0.94-0.99]) and in colorectal (HR 0.91 [95% CI 0.84-0.99]), melanoma (HR 0.81 [95% CI 0.65-1.00]), and breast cancer (HR 0.91 [95% CI 0.94-0.99]) in women. Our study results suggest that a cancer diagnosis in summer and/or autumn is associated with a better prognosis. The improved seasonal survival coincides with the seasonal variation of sun-induced vitamin D, and vitamin D may play a protective and beneficial role in cancer survival.

High level of circulating vitamin D during neoadjuvant therapy may lower risk of metastatic progression in high-risk rectal cancer

BACKGROUND

Following curative-intent neoadjuvant therapy in locally advanced rectal cancer, metastatic progression is still dominant. We investigated if patients' circulating 25-hydroxyvitamin D [25(OH)D] levels were associated with outcome.

METHODS

Serum 25(OH)D concentration was assessed by liquid chromatography-mass spectrometry in samples collected from 84 patients at baseline, completion of the neoadjuvant therapy, and treatment evaluation before surgery, and analyzed with respect to season, disease presentation, and treatment effects.

RESULTS

In the cohort of patients residing at latitude 58-62°N, baseline 25(OH)D differed significantly over the seasons, with highest measures (mean of 71.2 ± 5.6 nmol/L) in summer and lowest (48.7 ± 4.5 nmol/L) in spring, and changed over the three-month neoadjuvant period till response evaluation solely owing to season. The patient subgroup with slightly reduced performance status, anemia, and T4 disease that did not respond to the neoadjuvant therapy (ypT4 cases), had significantly lower baseline 25(OH)D (below 50 nmol/L) than T4 cases with response (ypT0-3) and T2-3 cases (above 60 nmol/L). Compared to the T4 patients with levels above 50 nmol/L, regarded as sufficient for a healthy bone status, those presenting levels below had significantly heightened risk of disease progression (mainly metastasis) and death, with hazard ratio of 3 and 17, respectively, on adjustment for age, sex, body mass index, and season.

CONCLUSION

Rectal cancer T4 cases had high risk of metastatic progression and death if circulating 25(OH)D levels were insufficient but obtained short-term and long-term outcome to neoadjuvant treatment no worse than patients with T2-3 disease when 25(OH)D was sufficient.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00278694 ; registration date: 16 January 2006, retrospective to enrollment of the first 10 patients of the current report.

Geographic distribution of the incidence of colorectal cancer in Iran: a population-based study

OBJECTIVES

Colorectal cancer (CRC) is the third most common cancer and the fourth most common cause of cancer death in the world. The aim of this study was to investigate the provincial distribution of the incidence of CRC across Iran.

METHODS

This epidemiologic study used data from the National Cancer Registry of Iran and the Center for Disease Control and Prevention of the Ministry of Health and Medical Education of Iran. The average annual age-standardized rate (ASR) for the incidence of CRC was calculated for each province.

RESULTS

We found that adenocarcinoma (not otherwise specified) was the most common histological subtype of CRC in males and females, accounting for 81.91 and 81.95% of CRC cases, respectively. Signet ring cell carcinoma was the least prevalent subtype of CRC in males and females and accounted for 1.5 and 0.94% of CRC cases, respectively. In patients aged 45 years or older, there was a steady upward trend in the incidence of CRC, and the highest ASR of CRC incidence among both males and females was in the age group of 80-84 years, with an ASR of 144.69 per 100,000 person-years for males and 119.18 per 100,000 person-years for females. The highest incidence rates of CRC in Iran were found in the central, northern, and western provinces. Provinces in the southeast of Iran had the lowest incidence rates of CRC.

CONCLUSIONS

Wide geographical variation was found in the incidence of CRC across the 31 provinces of Iran. These variations must be considered for prevention and control programs for CRC, as well as for resource allocation purposes.

Plasma 25-Hydroxyvitamin D3 Levels in Colorectal Cancer Patients and Associations with Physical Activity

Physical activity (PA) and vitamin D are thought to affect colorectal cancer prognosis. The present study investigates associations between 25(OH)D₃ and PA in prospectively followed colorectal cancer patients in the ColoCare study. At 6, 12, and 24 mo after surgery, patients donated a blood sample, wore an accelerometer for 10 consecutive days, and completed a PA questionnaire. Plasma 25-hydroxyvitamin D₃ (25(OH)D₃) levels were measured by high-performance liquid chromatography. We tested associations using partial correlations and multivariate linear regression analysis, adjusted for season, age, and body mass index. A total of 137 assessments of 25(OH)D₃ levels and PA were conducted (58 at 6 mo, 51 at 12 mo, and 28 at 24 mo). More than 60% of the patients were vitamin D-deficient (25(OH)D₃ ≤20 ng/ml), independent of study time point. At 6-mo follow-up, accelerometry-based vigorous and moderate-to-vigorous PAs were positively associated with 25(OH)D₃ levels (P = 0.04; P = 0.006,). PA together with season was a significant predictor of elevated 25(OH)D₃ levels. Our results suggest that the majority of colorectal cancer patients may suffer from vitamin D deficiency. Engaging in PA may be an effective approach to increase their 25(OH)D₃ levels.

Vitamin D, PTH, and calcium in relation to survival following prostate cancer

PURPOSE

Epidemiological studies suggest that low levels of vitamin D constitute a risk factor for prostate cancer. However, the results are conflicting, perhaps because prostate cancer is a very heterogeneous disease. More recent studies have focused on cancer progression and mortality. Vitamin D is closely related to both calcium metabolism and parathyroid hormone (PTH) levels, and all three factors have been implicated in prostate cancer.

METHODS

We examined the associations between pre-diagnostic serum levels of vitamin D (25OHD), PTH, and calcium and mortality among 943 participants within the Malmö Diet and Cancer Study, who were diagnosed with prostate cancer. The mean time from diagnosis until the end of followup was 9.1 years (SD 4.5), and the mean time from inclusion until end of follow-up was 16.6 years (SD 4.9). The analytes were divided into quartiles, and the risk of death from prostate cancer was analyzed using Cox proportional hazard analysis, yielding hazards ratios (HR) with 95 % confidence intervals. The models were adjusted for season and year of inclusion, age at baseline, age at diagnosis, body mass index (BMI), and tumor characteristics (TNM and Gleason score).

RESULTS

We observed a trend toward a lower prostate-specific mortality with 25OHD >85 nmol/L in the unadjusted analysis. This became statistically significantly in the third quartile of 25OHD (85-102 nmol/L) compared to the first (<68 nmol/L), HR 0.54 (0.34-0.85) when adjusting for age, time of inclusion, and BMI. The association was further strengthened when adjusted for age at diagnosis, Gleason score, and TNM classification with a HR in Q3 0.36 (0.22-0.60). p for trend was 0.03. Regarding calcium, there was a significantly lower HR for the second quartile (2.35-2.39 mmol/L) compared to the first (≤2.34 mmol/L) with a HR of 0.54 (0.32-0.86) in the unadjusted analysis. However, this association disappeared when adjusting for tumor characteristics. There were no associations between levels of PTH and prostate cancer mortality.

CONCLUSION

This study shows that levels of pre-diagnostic vitamin D above 85 nmol/L may improve survival in men with prostate cancer.

The relationship between circulating 25-hydroxyvitamin D and survival in newly diagnosed advanced non-small-cell lung cancer

BACKGROUND

Serum 25-hydroxyvitamin D [25(OH)D], the major circulating form of vitamin D used for evaluating the vitamin D status of patients, has been associated with survival in a variety of cancers with conflicting evidence. We aimed to investigate this association in newly diagnosed advanced non-small-cell lung cancer (NSCLC) patients.

METHODS

This was a consecutive cohort of 359 newly diagnosed stages III-IV NSCLC patients who underwent a baseline serum 25(OH)D evaluation prior to receiving any treatment at our institution between January 2008 and December 2010. We used the vitamin D categories of "deficient (<20 ng/ml)" and "not deficient (> = 20 ng/ml)". Cox regression was used to evaluate the prognostic significance of serum 25(OH)D after adjusting for relevant confounders.

RESULTS

Mean age at diagnosis was 57.4 years. Of the 359 patients, 151 (42.1 %) were deficient in vitamin D at the time of diagnosis. The median survival in deficient and not deficient cohorts was 11.7 and 12.8 months respectively (p = 0.06). Season of diagnosis, performance status, smoking status and hospital location significantly predicted vitamin D status. On univariate Cox analysis, gender, stage of disease, hospital location, histologic subtype, subjective global assessment (SGA), performance status, smoking status, body mass index and serum albumin were significantly associated with survival (p <0.05 for all). On multivariate Cox analysis, six variables demonstrated statistically significant associations with survival: stage of disease, hospital location, histologic subtype, SGA, smoking status and serum albumin (p <0.05 for all). Serum vitamin D, which was borderline significant in univariate analysis, lost its significance in multivariate analysis.

CONCLUSIONS

We found season of diagnosis, performance status and smoking history to be predictive of vitamin D status. Consistent with previously published research in advanced NSCLC, we did not find any significant association between pre-treatment serum 25(OH)D and survival in our patients.

The association between pre-treatment serum 25-hydroxyvitamin D and survival in newly diagnosed stage IV prostate cancer

Background/Aims

Emerging evidence in the literature suggests a positive association between serum 25-hydroxyvitamin D [25(OH)D], a standard indicator of vitamin D status, and survival in certain types of cancer. We investigated this relationship in newly diagnosed stage IV prostate cancer patients.

Methods

A consecutive cohort of 125 newly diagnosed stage IV prostate cancer patients underwent a baseline serum 25(OH)D evaluation prior to receiving any treatment at our institution between January 2008 and December 2011. We used the vitamin D categories of “deficient (<20 ng/ml)”, “insufficient (20 to 32 ng/ml)”, and “sufficient (>32 ng/ml)”. Cox regression was used to evaluate the prognostic significance of serum 25(OH)D after adjusting for relevant confounders.

Results

Mean age at diagnosis was 60 years. Of the 125 patients, 32 (25.6%) were deficient, 49 (39.2%) were insufficient and 44 (35.2%) were sufficient in vitamin D at the time of diagnosis. The median survival in deficient, insufficient and sufficient cohorts was 47.8, 44.0 and 52.6 months respectively (p = 0.60). On univariate analysis, four variables demonstrated a statistically significant association with survival: nutritional status, bone metastasis, corrected serum calcium and serum albumin (p<0.05 for all). On multivariate analysis, five variables demonstrated statistically significant associations with survival: hospital location, age, bone metastasis, serum albumin and corrected serum calcium (p<0.05 for all). Serum vitamin D status was not significant on either univariate or multivariate analysis.

Conclusion

Contrary to previously published research, we found no significant association between pre-treatment serum 25(OH)D and survival in newly diagnosed stage IV prostate cancer patients. The lack of a significant association between serum vitamin D and survival in our study could perhaps be due to the fact that the disease was far too advanced in our patients for vitamin D levels to have any impact on prognosis.

Recurrence season impacts the survival of epithelial ovarian cancer patients

BACKGROUND

Several studies indicated that the diagnosis season affects the prognosis of some cancers, such as examples in the prostate, colon and breast This retrospective study aimed to investigate whether the diagnosis and recurrent season impacts the prognosis of epithelial ovarian cancer patients.

METHODS

From January 2005 to August 2010, 161 epithelial ovarian cancer patients were analyzed and followed up until August 2013. Kaplan- Meier survival curves and the log-rank test were used to make the survival analysis. Multivariate analysis was conducted to identify independent prognostic factors.

RESULTS

The prognostic factors of overall survival in epithelial ovarian cancer patients included age, clinical stage, pathological type, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles. Moreover, clinical stage, histological grade, residual disease after primary surgery, recurrent season and adjuvant chemotherapy cycles also impacted the progression-free survival of epithelial ovarian cancer patients. The diagnosis season did not have a significantly relationship with the survival of operable epithelial ovarian cancer patients. Median overall survival of patients with recurrent month from April to November was 47 months, which was longer (P < 0.001) than that of patients with recurrence month from December to March (19 months). Median progression-free survival of patients with recurrence month from April to November and December to March was 20 and 8 months, respectively (P < 0.001).

CONCLUSION

The recurrence season impacts the survival of epithelial ovarian cancer patients. However, the diagnosed season does not appear to exert a significant influence.

Vitamin D levels in patients with breast cancer: importance of dressing style

BACKGROUND

Vitamin D deficiency is a potentially modifiable risk factor that may be targeted for breast cancer (BC) prevention. It may also be related to prognosis after diagnosis and treatment. The aim of our study was to determine the prevalence of vitamin D deficiency as measured by serum 25-hydroxy vitamin D (25-OHD) levels in patients with BC and to evaluate its correlations with life-style and treatments.

MATERIALS AND METHODS

This study included 186 patients with stage 0-III BC treated in our breast center between 2010-2013. The correlation between serum baseline 25-OHD levels and supplement usage, age, menopausal status, diabetes mellitus, usage of bisphosphonates, body-mass index (BMI), season, dressing style, administration of systemic treatments and radiotherapy were investigated. The distribution of serum 25-OHD levels was categorized as deficient (<10ng/ ml), insufficient (10-24 ng/ml), and sufficient (25-80 ng/ml).

RESULTS

The median age of the patients was 51 years (range: 27-79 years) and 70% of them had deficient/insufficient 25-OHD levels. On univariate analysis, vitamin D deficiency/insufficiency was more common in patients with none or low dose vitamin D supplementation at the baseline, high BMI (≥25), no bisphosphonate usage, and a conservative dressing style. On multivariate analysis, none or low dose vitamin D supplementation, and decreased sun-exposure due to a conservative dressing style were found as independent factors increasing risk of vitamin D deficiency/insufficiency 28.7 (p=0.002) and 13.4 (p=0.003) fold, respectively.

CONCLUSIONS

The prevalence of serum 25-OHD deficiency/insufficiency is high in our BC survivors. Vitamin D status should be routinely evaluated for all women, especially those with a conservative dressing style, as part of regular preventive care, and they should take supplemental vitamin D.

Plasma vitamin D concentration influences survival outcome after a diagnosis of colorectal cancer

PURPOSE

We investigated whether the plasma level of 25-hydroxyvitamin D (25-OHD) after a diagnosis of colorectal cancer (CRC) influences survival outcome.

PATIENTS AND METHODS

We prospectively studied 1,598 patients with stage I to III CRC. We sought association between plasma 25-OHD and stage-specific survival and tested for interaction between 25-OHD level and variation at the vitamin D receptor (VDR) gene locus. Blood was sampled postoperatively, and plasma was assayed for 25-OHD by liquid chromatography-tandem mass spectrometry. VDR polymorphisms (rs1544410, rs10735810, rs7975232, rs11568820) were genotyped, and haplotypes were inferred by using BEAGLE software. We tested for association between survival and 25-OHD, VDR genotype/haplotype, and after applying a VDR genotype-25-OHD interaction term. We conducted Kaplan-Meier survival analysis and used Cox proportional hazards models to estimate adjusted hazard ratios (HRs).

RESULTS

We found strong associations between plasma 25-OHD concentration and CRC-specific (P = .008) and all-cause mortality (P = .003). Adjusted HRs were 0.68 (95% CI, 0.50 to 0.90) and 0.70 (95% CI, 0.55 to 0.89), respectively (highest v lowest 25-OHD tertile), particularly in stage II disease (HR, 0.44; P = .004 for CRC-specific mortality). We detected gene-environment interactions between 25-OHD concentration and rs11568820 genotype for CRC-specific (P = .008) and all-cause (P = .022) mortality, number of protective alleles (P = .004 and P = .018, respectively), and GAGC haplotype at the VDR locus for all-cause mortality (P = .008).

CONCLUSION

In patients with stage I to III CRC, postoperative plasma vitamin D is associated with clinically important differences in survival outcome, higher levels being associated with better outcome. We observed interactions between 25-OHD level and VDR genotype, suggesting a causal relationship between vitamin D and survival. The influence of vitamin D supplementation on CRC outcome will require further investigation.

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.

Relationship between sun exposure and kidney cancer: preliminary experience with the evaluation of recreational UV exposure

INTRODUCTION

Recent findings reported an inverse relationship between solar ultraviolet-B (UV-B) exposure and mortality from various types of cancers, including renal cancer.

METHODS

We reviewed the literature concerning the relationship between sun exposure and incidence of kidney cancer. We performed a case-control study, evaluating recreational sun exposure in 50 kidney cancer patients and 50 controls.A questionnaire concerning sun exposure habits during childhood, adult life and in the previous 2 years was filled in by every patient. The questionnaire focused on: hours/day spent in the sun during summer; hours/day spent sunbathing (considering as well which kind of UV protection was used); sunburns; holidays in tropical countries.

RESULTS

We found and analyzed few articles concerning the relationship between kidney cancer and sunlight exposure. The two cohorts of patients we evaluated were homogeneous for age, phototype, origin and living area.We found no statistically significant differences between sun exposure in patients affected by kidney cancer and controls, both during childhood and adult life; no differences were found in the use of sunscreens either.

CONCLUSIONS

Recreational sunlight exposure does not differ in our cohorts of patients and controls; studies on greater cohorts are needed to evaluate the effect of recreational sun exposure in the development of kidney cancer.

How I treat vitamin d deficiency

Vitamin D plays an important role in the homeostasis of a variety of organ systems, but its role in prevention of cancer and recurrence-along with necessary blood levels-has yet to be defined.

Is season a prognostic factor in breast cancer?

BACKGROUND

Some studies have indicated an inverse relationship between cancer risk and sunlight exposure. Others have reported that the prognosis of some cancers such as prostate, colon, ovarian and non melanoma skin cancer, were affected by the season in which the cancer was diagnosed. In our study, we evaluated whether season is prognostic in Turkish patients with breast cancer.

MATERIALS AND METHODS

A total of 517 patients from Kayseri Training and Research Hospital were analysed retrospectively. Patients were divided into 4 groups according to season of cancer diagnosis: winter, spring, summer and autumn. The prognostic factors for disease free survival and overall survival were investigated.

RESULTS

No significant differences were found among groups regarding prognostic factors overall. Only estrogen receptor status and lymphovascular invasion were independent prognostic factors (p=0.001 and p=0.001 respectively). We found significantly differences for mean disease free survival among groups (p=0.019). Winter group had better mean DFS while summer group had worse DFS. Mean overall survival was similar in the four groups (p=0.637).

CONCLUSIONS

The season is not an independent predictive factor. However, due to interaction with other factors, we think that the season of cancer diagnosis is important for cancer prognosis.

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 status in healthy Romanian caregivers and risk of respiratory infections

OBJECTIVES

To investigate the vitamin D status during winter of a healthy population of hospital employees and to assess the correlation between vitamin D status and risk of infections in the upper respiratory tract.

DESIGN

One hundred and ten healthy volunteers answered a questionnaire on their solar exposure habits and vitamin D intake and delivered one blood sample for quantification of vitamin D level (serum 25-hydroxyvitamin D (25(OH)D) concentration) during December 2007-January 2008. At the end of the winter we screened for the occurrence of respiratory infections and sought associations with vitamin D status.

SETTING

Bucharest, Romania, 45°N.

SUBJECTS

One hundred and ten healthy hospital employees.

RESULTS

Eighty per cent of participants were vitamin D deficient (25(OH)D level below 50 nmol/l). The main determinant of serum 25(OH)D was sun exposure during the summer previous to the study (P = 0·02 in multivariate analysis). Intake of vitamin D, BMI and age played no significant role for the level of 25(OH)D. Overall we found a non-significant negative correlation between 25(OH)D level and new cases of infection (Spearman correlation coefficient of -0·12, P = 0·2).

CONCLUSIONS

Vitamin D status is alarmingly poor in active, relatively young women residing in Romania. If our results are reproduced by other investigations, action to improve vitamin D status at the population level is necessary. We were not able to show a statistically significant relationship between vitamin D status and infection risk in our material.

Differences in vitamin D status may account for unexplained disparities in cancer survival rates between African and white Americans

Considerable disparities in cancer survival rates exist between African Americans (AAs) and white Americans (WAs). Various factors such as differences in socioeconomic status (SES), cancer stage at time of diagnosis, and treatment—which this analysis considers primary explanatory factors—have accounted for many of these differences. An additional factor not usually considered is vitamin D. Previous studies have inversely correlated higher solar ultraviolet-B (UVB) doses and serum 25-hydroxyvitamin D (25(OH)D) concentrations with incidence and/or mortality rates for about 20 types of cancer and improved survival rates for eight types of cancer. Because of darker skin pigmentation, AAs have 40% lower serum 25(OH)D concentrations than WAs. This study reviews the literature on disparities in cancer survival between AAs and WAs. The journal literature indicates that there are disparities for 13 types of cancer after consideration of SES, stage at diagnosis and treatment: bladder, breast, colon, endometrial, lung, ovarian, pancreatic, prostate, rectal, testicular, and vaginal cancer; Hodgkin lymphoma and melanoma. Solar UVB doses and/or serum 25(OH)D concentrations have been reported inversely correlated with incidence and/or mortality rates for all of these cancers. This finding suggests that future studies should consider serum 25(OH)D concentrations in addressing cancer survival disparities through both measurements of serum 25(OH)D concentrations and increasing serum 25(OH)D concentrations of those diagnosed with cancer, leading to improved survival rates and reduced disparities.

Vitamin D, sun, sunbeds and health

Objective

To review the health effects of solar radiation, sunbeds and vitamin D.

Design

The literature was searched in the electronic database MEDLINE to indentify published data between 1981 and 2011. Studies were included if they reported relative risk for cutaneous malignant melanoma (CMM) associated with sunbed use, vitamin D and UV effects on human health.

Setting

Data from different time periods for populations at different latitudes.

Subjects

Persons of different ages and ethnic groups.

Results

UV from sun and sunbeds is the main vitamin D source. Young people with white or pigmented skin in northern Europe have a low vitamin D status. A number of health benefits from sufficient levels of vitamin D have been identified. However, UV exposure has been suspected of causing skin cancer, notably CMM, and authorities warn against it.

Conclusions

The overall health benefit of an improved vitamin D status may be more important than the possibly increased CMM risk resulting from carefully increasing UV exposure. Important scientific facts behind this judgement are given.

Availability of vitamin D photoconversion weighted UV radiation in southern South America

Ultraviolet radiation (UVR) plays a key role in several biological functions, including human health. Skin exposure to UVR is the main factor in vitamin D photoconversion. There is also evidence relating low levels of vitamin D with certain internal cancers, mainly colon, breast and prostate, as well as other diseases. Several epidemiological studies have shown an inverse relationship between the above-mentioned diseases and latitude, in accordance with the ultraviolet radiation latitudinal gradient. The aim of this study is to determine whether UV irradiance levels in the southern South America are sufficient to produce suitable levels of vitamin D year around. For this purpose, vitamin D photoconversion weighted-irradiance was analyzed between S.S. de Jujuy (24.17°S, 65.02°W) and Ushuaia (54° 50'S, 68° 18'W). In addition to irradiance, skin type and area of body exposed to sunlight are critical factors in vitamin D epidemiology. Due to a broad ethnic variability, it was assumed that the skin type in this region varies between II and V (from the most to the less sensitive). All sites except South Patagonia indicate that skin II under any condition of body area exposure and skin V when exposing head, hands, arms and legs, would produce suitable levels of vitamin D year round (except for some days in winter at North Patagonian sites). At South Patagonian sites, minimum healthy levels of vitamin D year round can be reached only by the more sensitive skin II type, if exposing head, hands, arms and legs, which is not a realistic scenario during winter. At these southern latitudes, healthy vitamin D levels would not be obtained between mid May and beginning of August if exposing only the head. Skin V with head exposure is the most critical situation; with the exception of the tropics, sun exposure would not produce suitable levels of vitamin D around winter, during a time period that varies with latitude. Analyzing the best exposure time during the day in order to obtain a suitable level of vitamin D without risk of sunburn, it was concluded that noon is best during winter, as determined previously. For skin type II when exposing head, exposure period in winter varies between 30 and 130 min, according to latitude, except for South Patagonian sites. During summer, noon seems to be a good time of day for short periods of exposure, while during leisure times, longer periods of exposure without risk of sunburn are possible at mid-morning and mid-afternoon. At 3 h from noon, solar zenith angles are almost the same for sites between the tropics and North Patagonia, and at 4 h from noon, for all sites. Then, in these cases, the necessary exposure periods varied slightly between sites, only due to meteorological differences.

Influenza, solar radiation and vitamin D

The annual death numbers of influenza and pneumonia in Norway were studied for the time period 1980-2000. No direct relationships were found with the variations of the annual UVB fluences, probably due to the fact that these variations did not exceed 30%. However, there was a very pronounced seasonal variation of both influenza deaths and pneumonia deaths, the vast majority occurring during the winter. Vitamin D levels were also estimated from several publications. The data support the hypothesis that a high vitamin D level, as that found in the summer, acts in a protective manner with respect to influenza as well as pneumonia. The findings are discussed and compared with data from tropical and subtropical areas.

[The role of vitamin D in the prevention and the additional therapy of cancers]

The active metabolite of vitamin D apart from a crucial role in maintaining mineral homeostasis and skeletal functions, has antiproliferative, apoptosis and differentiation inducing as well as immunomodulatory effects in cancer. It is well known that with increasing sunshine exposure the incidence of breast, prostate and colorectal cancer is decreasing. A number of in vitro and in vivo experiments documented the effects of vitamin D in the inhibition of the tumorigenesis. In studying the role of vitamin D in cancer, it is imperative to examine the potential pathways that control local tissue levels of vitamin D. The enzyme 24-hydroxylase converts the active vitamin D to inactive metabolite. Extra-renal production of this enzyme is observed and has been increasingly recognized as present in cancer cells. This enzyme is rate limiting for the amount of local vitamin D in cancer tissues and elevated expression is associated with an adverse prognosis. 24-hydroxylase may be a predictive marker of vitamin D efficacy in patients with cancer as an adjunctive therapy. There are many vitamin D analogs with no pronounced hypercalcemizing effects. Some analogs are in phase 1 and 2 clinical test, and they might have a role in the therapy of several types of cancer. At present our main task is to make an effort to decrease the vitamin D deficiency in Hungary. Speer G. The D-day. The role of vitamin D in the prevention and the additional therapy of cancers.

Vitamin D status in patients with stage IV colorectal cancer: findings from Intergroup trial N9741

PURPOSE

Previous studies have suggested that higher plasma 25-hydroxyvitamin D(3) [25(OH)D] levels are associated with decreased colorectal cancer risk and improved survival, but the prevalence of vitamin D deficiency in advanced colorectal cancer and its influence on outcomes are unknown.

PATIENTS AND METHODS

We prospectively measured plasma 25(OH)D levels in 515 patients with stage IV colorectal cancer participating in a randomized trial of chemotherapy. Vitamin D deficiency was defined as 25(OH)D lower than 20 ng/mL, insufficiency as 20 to 29 ng/mL, and sufficiency as ≥ 30 ng/mL. We examined the association between baseline 25(OH)D level and selected patient characteristics. Cox proportional hazards models were used to calculate hazard ratios (HR) for death, disease progression, and tumor response, adjusted for prognostic factors.

RESULTS

Among 515 eligible patients, 50% of the study population was vitamin D deficient, and 82% were vitamin D insufficient. Plasma 25(OH)D levels were lower in black patients compared to white patients and patients of other race (median, 10.7 v 21.1 v 19.3 ng/mL, respectively; P < .001), and females compared to males (median, 18.3 v 21.7 ng/mL, respectively; P = .0005). Baseline plasma 25(OH)D levels were not associated with patient outcome, although given the distribution of plasma levels in this cohort, statistical power for survival analyses were limited.

CONCLUSION

Vitamin D deficiency is highly prevalent among patients with stage IV colorectal cancer receiving first-line chemotherapy, particularly in black and female patients.

Vitamin D insufficiency in Aboriginal Australians

OBJECTIVE

To investigate the adequacy of vitamin D status in a South Australian Aboriginal population, and to examine the relationship between serum 25-hydroxyvitamin D (25-OHD) levels and biochemical variables of calcium and bone mineral homeostasis, as well as other factors which may influence vitamin D synthesis, storage and metabolism.

DESIGN, SETTING AND PARTICIPANTS

A single-visit, observational study of 58 adults from two Aboriginal community-controlled health services in Adelaide and Yalata, South Australia. Participants were recruited between May 2008 and December 2009.

MAIN OUTCOME MEASURES

Serum levels of 25-OHD, parathyroid hormone (PTH), fasting glucose and fasting C-terminal telopeptides of type I collagen (β-CTx).

RESULTS

Serum 25-OHD levels showed clear seasonal variation, being higher in summer (P < 0.001). The overall mean level was 56.8 nmol/L (SD, 22.1), which is below the recommended target level of 60 nmol/L. Serum 25-OHD levels correlated significantly with β-CTx (P = 0.03), but not with age, body mass index (BMI), PTH levels or levels of fasting glucose. A significant association was found between BMI and PTH levels (P = 0.001). A significant inverse association between serum 25-OHD levels and BMI, observed in other studies, was not found in our study.

CONCLUSIONS

Vitamin D insufficiency is highly prevalent in this population of adult Aboriginal Australians, with low mean values found in all seasons other than summer.

Sunlight robbery: a critique of public health policy on vitamin D in the UK

The British Isles have a very cloudy climate and as a result receive fewer hours of clear sunlight than most other industrial regions. The majority of people in these islands have low blood levels of vitamin D [25(OH)D] all year round. Few food products are fortified with vitamin D in the UK and the government does not recommend any vitamin D supplement for most adults in the UK. Diseases associated with vitamin D insufficiency such as cancer, heart disease, diabetes (types 1 and 2) and multiple sclerosis are more frequent in the UK, and particularly in Scotland, than in many other European countries and some, such as multiple sclerosis and diabetes (types 1 and 2), are increasing in incidence. Present knowledge suggests that the risk of some chronic diseases could be reduced if vitamin D intake or sun exposure of the population were increased. Yet policy and public health recommendations of the UK government and its agencies (e.g. the Health Protection Agency, the Food Standards Agency) and of Cancer Research UK have failed to take full account of established and putative benefits of vitamin D and/or sunshine. The epidemic of chronic disease in the UK, which is associated with and caused at least in part by vitamin D insufficiency, has not been adequately recognized by these agencies, and too often measures taken by them have been misguided, inappropriate or ineffective.

The seasonality of pandemic and non-pandemic influenzas: the roles of solar radiation and vitamin D

OBJECTIVES

Seasonal variations in ultraviolet B (UVB) radiation cause seasonal variations in vitamin D status. This may influence immune responses and play a role in the seasonality of influenza.

METHODS

Pandemic and non-pandemic influenzas in Sweden, Norway, the USA, Singapore, and Japan were studied. Weekly/monthly influenza incidence and death rates were evaluated in view of monthly UVB fluences.

RESULTS

Non-pandemic influenzas mostly occur in the winter season in temperate regions. UVB calculations show that at high latitudes very little, if any, vitamin D is produced in the skin during the winter. Even at 26°N (Okinawa) there is about four times more UVB during the summer than during the winter. In tropical regions there are two minor peaks in vitamin D photosynthesis, and practically no seasonality of influenza. Pandemics may start with a wave in an arbitrary season, while secondary waves often occur the following winter. Thus, it appears that a low vitamin D status may play a significant role in most influenzas.

CONCLUSIONS

In temperate latitudes even pandemic influenzas often show a clear seasonality. The data support the hypothesis that high fluences of UVB radiation (vitamin D level), as occur in the summer, act in a protective manner with respect to influenza.

Epidemiology of vitamin D and colorectal cancer: casual or causal link?

INTRODUCTION

Since Garland and Garland hypothesized that better vitamin D status lowered risk of colorectal cancer in 1980, the relation between vitamin D status and colorectal cancer risk has been investigated in epidemiologic studies. These studies are reviewed.

MATERIALS AND METHODS

Various approaches have been used to estimate vitamin D status, including direct measures of circulating 25(OH)vitamin D levels, surrogates or determinants of vitamin D (including region of residence, intake, and sun exposure estimates, or a combination of these). These measures of vitamin D status have been studied in relation to colorectal adenoma, cancer incidence and mortality.

RESULTS

In general, all lines of inquiry from observational studies indicate that an association between better vitamin D status and lower colorectal cancer risk exists. While most of the studies have examined vitamin D status in relation to risk of cancer, some evidence suggests that vitamin D may be additionally important for colorectal cancer progression and mortality.

DISCUSSION

Although confounding factors cannot be entirely excluded, the consistency of the association using various approaches to measure vitamin D, for diverse endpoints and in diverse populations shows high consistency and is suggestive of a causal association. Thus, improving vitamin D status could be potentially beneficial against colorectal cancer incidence and mortality.

The relationship between ultraviolet radiation exposure and vitamin D status

This paper reviews the main factors influencing the synthesis of vitamin D, with particular focus on ultraviolet radiation exposure. On the global level, the main source of vitamin D is the sun. The effect of solar radiation on vitamin D synthesis depends to some extent on the initial vitamin D levels. At moderate to high latitudes, diet becomes an increasingly important source of vitamin D due to decreased solar intensity and cold temperatures, which discourage skin exposure. During the mid-winter season, these factors result in decreased solar radiation exposure, hindering extensively the synthesis of vitamin D in these populations.

Seasonal variations of cancer incidence and prognosis

The overall death rates are highest in the winter season in many countries at high latitudes. In some but not all countries, this is also true for more specific diseases such as cancer, cardiovascular diseases and influenza. For internal cancers we find no consistent, significant seasonal variation, neither of incidence nor of death rates. On the other hand, we find a significant seasonal variation of cancer prognosis with season of diagnosis in Norway. Best prognosis is found for summer and autumn diagnosis; i.e., for the seasons of the best status of vitamin D in the population. There were no corresponding seasonal variations, neither of the rates of diagnosis, nor of the rates of death which could explain the variations of prognosis. The most likely reason for this variation is that the vitamin D status in Norway is significantly better in summer and autumn than in winter and spring. Earlier, seasonal variations have been explained by circannual variations of certain hormones, but the data are not consistent.

Epidemiology of vitamin D in health and disease

Results from ecological, case-control and cohort studies have shown that vitamin D reduces the risk of bone fracture, falls, autoimmune diseases, type 2 diabetes, CVD and cancer. However, there is still epidemic vitamin D insufficiency especially among individuals living at high latitudes or with dark skin. Serum levels of 25-hydroxyvitamin D (25(OH)D) are considered the best biomarker of vitamin D nutritional status. Appropriate sunshine exposure or oral supplementation is necessary to maintain sufficient vitamin D status, which is generally accepted as serum 25(OH)D>75 nmol/l. Immunoassays, especially RIA, have been primarily used to measure serum 25(OH)D while liquid chromatography-MS (LC-MS) is considered the 'gold standard'. There is significant disparity among the immunoassays, and all immunoassays have considerable bias compared with LC-MS methods. Because of the variations among the results from these different assays, it is necessary that assay-specific reference ranges be established or standardisation of the assays take place. The present review focuses on ecological, case-control, and cohort studies that investigated the role of vitamin D in health and disease. In addition, analytical techniques used in laboratory evaluation of vitamin D nutritional status are also critically reviewed. The majority of the literature included in the present review is selected from that searchable in PubMed up to the end of September 2008.

Season of tumor surgery in relation to deaths among brain tumor patients: does sunlight and month of surgery play a role in brain tumor deaths?

The objective of this study is to investigate the effect at the season of the time of surgery on the survival of brain tumor patients. The population studied consisted of 101 patients (39 males and 62 females), gathered from a geographically large area in northern Finland (from 64 degrees N to 70 degrees N), aged between 20 and 82 years, with a solitary primary brain tumor treated surgically at the Oulu Clinic for Neurosurgery, Oulu University Hospital. The distribution of tumor surgery dates and mean hours of sunshine hours was analyzed by bimonthly periods. When comparing the proportion of deceased patients of all patients operated in each bimonthly period, a significant bimonthly peak in deaths was found in patients operated during the period of February to March (ratio 1.7, 95% CI 1.1-2.3). More than half of the patients who died during the peak period had grade III-IV gliomas. In 40% of the cases, the surgery time of deceased brain tumor patients occurred in the bimonthly period following the four darkest months of the year with the lowest amount of sunshine in northern Finland. The relation of low vitamin D level in the etiology and course of the disease as well as in treatment settings deserves further study.

Vitamin D for cancer prevention: global perspective

PURPOSE

Higher serum levels of the main circulating form of vitamin D, 25-hydroxyvitamin D (25(OH)D), are associated with substantially lower incidence rates of colon, breast, ovarian, renal, pancreatic, aggressive prostate and other cancers.

METHODS

Epidemiological findings combined with newly discovered mechanisms suggest a new model of cancer etiology that accounts for these actions of 25(OH)D and calcium. Its seven phases are disjunction, initiation, natural selection, overgrowth, metastasis, involution, and transition (abbreviated DINOMIT). Vitamin D metabolites prevent disjunction of cells and are beneficial in other phases.

RESULTS/CONCLUSIONS

It is projected that raising the minimum year-around serum 25(OH)D level to 40 to 60 ng/mL (100-150 nmol/L) would prevent approximately 58,000 new cases of breast cancer and 49,000 new cases of colorectal cancer each year, and three fourths of deaths from these diseases in the United States and Canada, based on observational studies combined with a randomized trial. Such intakes also are expected to reduce case-fatality rates of patients who have breast, colorectal, or prostate cancer by half. There are no unreasonable risks from intake of 2000 IU per day of vitamin D(3), or from a population serum 25(OH)D level of 40 to 60 ng/mL. The time has arrived for nationally coordinated action to substantially increase intake of vitamin D and calcium.

Cutaneous vitamin D synthesis versus skin cancer development: The Janus faces of solar UV-radiation

In scientific and public communities, there is an ongoing discussion how to balance between positive and negative effects of solar UV-exposure. On the one hand, solar UV-radiation represents the most important environmental risk factor for the development of non-melanoma skin cancer. Consequently, UV protection is an important measure to prevent these malignancies, especially in risk groups. Otherwise, approximately 90% of all vitamin D needed by the human body has to be formed in the skin through the action of UV-radiation. This dilemma represents a serious problem, for an association of vitamin D-deficiency and multiple independent diseases including various types of cancer, bone diseases, autoimmune diseases, infectious diseases, cardiovascular diseases and hypertension has now been reported in a large number of investigative and epidemiologic studies. As a consequence, it has been assumed that for the general population in the US, Europe and other countries, the net effects of solar UV B-radiation on human health are beneficial at or near current levels. We and others have shown that strict sun protection causes vitamin D-deficiency/insufficiency and that detection and treatment of vitamin D-deficiency in sun deprived risk groups is of high importance. Although further work is necessary to define an adequate vitamin D-status and adequate guidelines for solar and artificial UV-exposure, it is at present mandatory that public health campaigns and sun protection recommendations to prevent skin cancer consider these facts. In this review, we analyze the present literature to help developing well-balanced recommendations on sun protection that ensure an adequate vitamin D-status. These recommendations will hopefully protect us against adverse effects of UV protection without significantly increasing the risk to develop UV-induced skin cancer.

Ecological studies of ultraviolet B, vitamin D and cancer since 2000

PURPOSE

The purpose of this review is to summarize ecological studies of solar ultraviolet B (UVB), vitamin D and cancer since 2000.

METHODS

The journal literature is surveyed and summarized.

RESULTS

The ecological approach has been the primary tool used during the past two decades to extend the applicability of the UVB-vitamin D-cancer theory to include at least 18 types of cancer. Many of these studies were conducted in the United States, which has the advantages of availability of reliable age-standardized cancer incidence and mortality rate data for geographic areas at various spatial resolutions, and an asymmetric solar UVB dose pattern, with higher UVB irradiance in the west and lower in the east, at any particular latitude. In addition, indices for other cancer risk-modifying factors are readily available including those for smoking, alcohol consumption, ethnic background, urban/rural residence, socioeconomic status, air pollution, and in limited fashion, diet. The ecological approach has also been used to identify latitudinal variations in cancer mortality rates in Australia, China, Japan, and Spain, and in multicountry studies. It has been used to investigate the relative roles of solar UVB and dietary factors on a global scale. The ecological approach has also been applied to cancer survival. Studies in Norway and England found that individuals diagnosed with cancer in summer or fall, when serum 25-hydroxyvitamin D levels are highest, had a milder clinical course and longer survival than those diagnosed in winter or spring.

CONCLUSION

These findings provide strong evidence that vitamin D status plays an important role in controlling the outcome of cancer. Support for the UVB-vitamin D-cancer theory is now scientifically strong enough to warrant use of vitamin D in cancer prevention, and as a component of treatment. More research studies would help to explore whether there are benefits beyond the substantial effects that have been observed.

Seasonal variation of 1,25-dihydroxyvitamin D and its association with body mass index and age

Under most normal conditions the serum level of 1,25-dihydroxyvitamin D is constant throughout the year, due to tight biochemical regulation. In contrast to this, the level of 25-hydroxyvitamin D is variable through the year, being largest in late summer, due to photosynthesis in the skin. The vitamin D status is usually assessed by measuring the level of the latter vitamin D derivative, rather than that of the presumably most active derivative 1,25(OH)2 vitamin D.We here show that for persons with a high body mass index (BMI) there is a significant seasonal variation, not only of 25(OH) vitamin D, but also of 1,25(OH)2 vitamin D. The variation seems to be largest for those with the poorest vitamin D status. Furthermore, there seems to be a correlation between the levels of the two vitamin D metabolites, indicating that the regulation of 1,25(OH)2 vitamin D is not always tight, notably in persons with high BMI.

Season of diagnosis and prognosis in breast and prostate cancer

BACKGROUND

Patients with breast or prostate cancer diagnosed during the summer season have been observed to have better survival. The extent to which this is due to biological and/or health care system related factors is unclear.

METHODS

Using the Swedish Cancer Register and clinical databases, we analyzed overall survival by month of diagnosis among the incident cases of breast (n = 89,630) cancer and prostate (n = 72,375) cancer diagnosed from 1960 to 2004. We retrieved data on tumor stage from 1976 for breast cancer and 1997 for prostate cancer. Cox proportional hazards models were used to calculate relative risk of survival by the season of diagnosis.

RESULTS

There was a higher hazard ratio of death in men and women diagnosed with cancer in the summer with a relative hazard of 1.20 (95% confidence interval 1.15-1.25) for July for prostate cancer and 1.14 (95% confidence interval 1.09-1.19) for August for breast cancer when compared to being diagnosed in January. This difference coincided with a lower mean number of cases diagnosed per day, and a higher proportion of advanced cases diagnosed in the summer. This pattern of presentation was stronger in the later years.

CONCLUSION

The difference in stage distribution explains the seasonal variation in prognosis seen in this study. The variation may be because of structure of the health care system and a strong tradition of vacationing from mid June to mid August. Thus, the health care infrastructure and the late presentation of symptomatic disease may influence cancer survival studied by season of diagnosis substantially.

Circulating 25-hydroxyvitamin d levels and survival in patients with colorectal cancer

PURPOSE

Higher plasma 25-hydroxyvitamin D(3) (25(OH)D) levels are associated with a decreased incidence of colorectal cancer, but the influence of plasma 25(OH)D on the outcome of patients with established colorectal cancer is unknown.

PATIENTS AND METHODS

We prospectively examined the association between prediagnosis 25(OH)D levels and mortality among 304 participants in the Nurses' Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS) who were diagnosed with colorectal cancer from 1991 to 2002. Participants diagnosed within 2 years of blood collection were excluded. Patients were observed until death, June 2005 (NHS), or January 2005 (HPFS), whichever came first. The primary end point was overall mortality. Cox proportional hazards models were used to calculate hazard ratios (HR) adjusted for other risk factors for cancer survival.

RESULTS

Higher plasma 25(OH)D levels were associated with a significant reduction in overall mortality (P for trend = .02). Compared with the lowest quartile, participants in the highest quartile had an adjusted HR of 0.52 (95% CI, 0.29 to 0.94) for overall mortality. A trend toward improved colorectal cancer-specific mortality was also seen (HR = 0.61; 95% CI, 0.31 to 1.19). The results remained unchanged after excluding patients diagnosed within 5 years of blood collection (P for trend = .04); the multivariate HR for overall mortality comparing extreme quartiles was 0.45 (95% CI, 0.19 to 1.09).

CONCLUSION

Among patients with colorectal cancer, higher prediagnosis plasma 25(OH)D levels were associated with a significant improvement in overall survival. Further study of the vitamin D pathway and its influence on colorectal carcinogenesis and cancer progression is warranted.