Demetrius Albanes

MD

National Cancer Institute

Senior Investigator

PLCO (Learn more about this study)

PLCO-1626

Jul 22, 2024

Associations between vitamin D-related genotypes and prostate and colorectal cancer risk and survival by race/ethnicity in PLCO

Black men in the US and elsewhere experience higher rates of prostate cancer incidence and mortality compared with White men and those of other races/ethnicities. Similarly, Black men and women experience higher colorectal cancer rates. Vitamin D biochemical status 1) is known to be lower among Black men and women owing to the influence of increased skin pigmentation leading to decreased UVB-stimulated production of 25(OH)-vitamin D in the skin, 2) is associated with risk of prostate and colorectal cancer, 3) is strongly influenced by a few genes and their related polymorphic variants, including those related to vitamin D transport, biosynthesis, and metabolism, and 4) the prevalence of variant alleles in the GC gene encoding the vitamin D-binding protein (DBP) differ in Black versus non-Black individuals. This study will examine vitamin D-related genotypes (including GC, DHCR7, CYP2R1, and CYP24A1), available from the PLCO genome-wide scan, in relation to prostate cancer risk (in men) and colorectal cancer risk (in men and women) by race/ethnicity in order to determine whether higher or lower risks/rates exist for individuals with specific genotypes.

1. To determine whether, relative to White men and men of other races/ethnicities, increased prostate cancer risk among Black men exists for specific vitamin D-related genotypes, including GC, DHCR7, CYP2R1, and CYP24A1.

2. To determine whether, relative to White men and men of other races/ethnicities, decreased prostate cancer survival among Black men exists for specific vitamin D-related genotypes, including GC, DHCR7, CYP2R1, and CYP24A1.

3. To determine whether, relative to White men and women and those of other races/ethnicities, decreased colorectal cancer risk among Black men and women exists for specific vitamin D-related genotypes, including GC, DHCR7, CYP2R1, and CYP24A1.

4. To determine whether, relative to White men and women and those of other races/ethnicities, decreased colorectal cancer survival among Black men and women exists for specific vitamin D-related genotypes, including GC, DHCR7, CYP2R1, and CYP24A1.