Burns EM, et al. - This study investigated the possible association of polymorphisms in the vitamin D receptor (VDR) gene with the development of nonmelanoma skin cancer (NMSC) and the demographic characteristics of the participants. This investigation afforded beneficial revelations especially in regard to early treatment and prevention of NMSC with chemopreventive agents [(for those with the BsmI single-nucleotide polymorphism (SNP)]. NMSC was twice more likely in BsmI SNP carriers than those with no mutation. Furthermore, skin cancer burden may be attenuated via screening for the BsmI SNP, which may emphasize the importance of sun protection and facilitate skin cancer prevention.

Methods

• Researchers performed this case-control study including 100 individuals diagnosed and being treated for basal cell carcinoma or squamous cell carcinoma (cases) and 100 individuals who were receiving treatment of a condition other than skin cancer (controls) at the dermatology clinics at the Kirklin Clinic of the University of Alabama at Birmingham Hospital between January 1, 2012, and December 31, 2014.
• They asked all participants to complete a questionnaire that solicited information on skin, hair, and eye color; skin cancer family history; and sun exposure history, such as tanning ability and number of severe sunburns experienced throughout life.
• They also collected blood samples from all participants for DNA genotyping.
• Thereafter, they assessed polymorphisms in the VDR gene (ApaI, BsmI, and TaqI) to determine the association of polymorphisms with NMSC development and demographic characteristics.
• Using Χ² Analysis, researchers determined if genotype frequencies deviated significantly from Hardy-Weinberg equilibrium.
• Additionally, they used logistic regression to calculate odds ratios (ORs) and associated 95% CIs for the identification of factors related to NMSC diagnosis.
• Notably, they developed a model to predict NMSC diagnoses using known risk factors and, potentially, VDR SNPs.

Results

• This study included overall 97 cases and 100 controls.
• Data showed that, of the 97 cases, 68 (70%) were men and 29 (30%) were women, with a mean (SD) age of 70 (11) years.
• 46 (46%) males and 54 (54%) females constituted the 100 controls, with a mean (SD) age of 63 (9) years.
• All participants self-identified as non-Hispanic white.
• In order to predict the incidence of skin cancer most effectively, a model including age, sex, and skin color was created.
• Researchers determined that the following risk factors significantly increased the odds of an NMSC diagnosis: light skin color (OR, 5.79 [95% CI, 2.79-11.99]), greater number of severe sunburns (OR, 2.59 [95% CI, 1.31-5.10]), light eye color (OR, 2.47 [95% CI, 1.30-4.67]), and less of an ability to tan (OR, 2.35 [95% CI, 1.23-4.48]).
• They also noted that the risk factors of family history of NMSC (OR, 1.66 [95% CI, 0.90-3.07]) and light hair color (OR, 1.17 [95% CI, 0.51-2.71]) did not reach statistical significance.
• Additionally, NMSC was twice more likely in participants with the BsmI SNP than participants with no mutation (OR, 2.04 [95% CI, 1.02-4.08]; P = .045).