Vitamin D-Race Differences and Breast Cancer

In a case-control study, Song Yao, PhD of Rosewell Park Cancer Institute in Buffalo said that two variants in a gene playing an important role in the metabolism of vitamin D was associated with an increased threat of estrogen-receptor (ER) negative breast cancer in African American women.

Researchers state that same gene variant showed no effects in women of European ancestry.

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American women are expected to have more ER-negative breast cancer risk than European counterparts.. They are also likely to have reduced levels of circulating 25-hydroxyvitamin D. 25-hydroxyvitamin D is a major marker and a metabolite of vitamin D. It is concerned with ER-negative tumors in European women.

Yao et al believed that the racial differences in genetic variation in the pathway of vitamin D and 25-hydroxyvitamin D (25 OHD) might result in observed differences in the characteristics of tumor.

A case-control study was conducted and about 1,771 females were enrolled for the study.

The serum 25OHD levels were measured and tested; relation between variation and risk in three genes was studied: two for vitamin D metabolism (CYP24A1 and CYP27B1) and one for vitamin receptor.

In the study, 928 females had breast cancer. 547 women were African Americans and 381 were from European ancestry.

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Since breast cancer treatment affects levels of vitamin D, the researchers analyzed this crucial aspect in the control group. The African Americans had serum 25OHD levels of 14.0 ng/mL as compared to 21.4 in European women.

The study analysis revealed that 34.3% of African Americans had severe deficiency of vitamin D with low serum 25OHD levels of 10ng/mL while merely 5.9% of European women had severe vitamin D deficiency.

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The experts found a single nucleotide polymorphisms-single base pair alterations-differed by race and ethnicity.

Reference:

Variants in the vitamin D pathway, serum levels of vitamin D, and estrogen receptor negative breast cancer among African-American women: a case-control study; Song Yao et al; Breast Cancer Research 2012

Source-Medindia