Role of ultraviolet B irradiance and vitamin D in prevention of ovarian cancer
ABSTRACT There is a north-south gradient in age-adjusted mortality rates of ovarian cancer in the United States, with the highest rates in the Northeast and the lowest in the South through Southwest. This suggests that lower levels of solar irradiance might be associated with higher risk of ovarian cancer. Laboratory findings also suggest that low levels of vitamin D metabolites could play a role in the etiology of ovarian cancer.
The association of solar ultraviolet B (UVB) irradiance, stratospheric column ozone, and fertility rates at ages 15 to 19 years with incidence rates of ovarian cancer in 175 countries in 2002 were examined using multiple linear regression in 2006.
Age-adjusted ovarian cancer incidence rates generally were highest in countries located at higher latitudes (R(2)=0.45, p< or =0.01). According to multivariate analysis, UVB irradiance (p< or =0.002) and fertility rates at ages 15 to 19 (p=0.01) were inversely associated with incidence rates, while stratospheric ozone (p< or =0.0008), which reduces transmission of UVB, was positively associated with incidence (R(2)=0.49, p<0.0001).
Solar UVB irradiance was inversely associated with incidence rates of ovarian cancer in this study, adding new evidence to the theory that vitamin D might play a role in the prevention of ovarian cancer. Cohort studies are needed to confirm this possible association.
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ABSTRACT: 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.Nutrients 01/2013; 6(1):163-89. DOI:10.3390/nu6010163 · 3.15 Impact Factor
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ABSTRACT: 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.01/2013; 5(1):181-5. DOI:10.4161/derm.23773
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ABSTRACT: Experimental studies suggest vitamin D inhibits ovarian carcinogenesis. Yet, epidemiologic studies of ovarian cancer risk and lifestyle correlates of vitamin D status, plasma 25-hydroxyvitamin D [25(OH)D], or vitamin D receptor (VDR) variants have been inconsistent.Frontiers in Oncology 10/2014; 4:286. DOI:10.3389/fonc.2014.00286