Non-Invasive Buccal Swab Gene Testing for Skin Cancer Risk
May 2019 | Volume 18 | Issue 5 | Original Article | 448 | Copyright © May 2019
Lauren Moy MD,a Alexis B. Lyons MD,b William Fox MS,c Marcie A. Glicksman PhD,d Ronald Moy MD,b Rebecca Tung MDa
aLoyola University Medical Center, Division of Dermatology, Maywood, IL bDepartment of Dermatology, Henry Ford Hospital, Detroit, MI cGeorgia Institute of Technology, Department of Computer Science, Atlanta, GA dOrig3n Labs, Boston, MA
Background: Studies have identified numerous genetic polymorphisms associated with increased risk of melanoma and non-melanoma skin cancer (NMSC). In this pilot study, we aimed to examine whether previously identified melanoma and non-melanoma associated single nucleotide polymorphisms (SNPs) which were found to be associated with cutaneous malignancy were also present in a relatively heterogeneous population with a history of skin cancer versus an age and environmental matched controls. The undertaking of this project serves to further the current understanding of the genetic profile for those at higher risk for developing skin cancer. Methods: Nineteen NMSC patients and their age-matched and environmental controls underwent genotyping of 7 previously discovered SNPs associated with melanoma and NMSC. Results: In a random, heterogeneous population in Southern California, SNP’s Chr1, PAD16, PIGU, TDG had a similar association with NMSC previously reported in prior studies. Due to small trial size, no conclusions or observable associations could be drawn from the SNPs MC1R, TP53, and XRCC1. Conclusion: This data supports that 4 of the 7 SNP’s studied had similar associations and could potentially be predictive tool of NMSC risk in this patient population. The remaining three SNP’s did not have a definitive association with malignancy. Larger studies are needed to further elucidate the specific roles of these SNPs collectively and ultimately to develop a genetic profile for those patients at increased risk of developing skin cancer.
J Drugs Dermatol. 2019;18(5):448-453.
It is well known ultraviolet (UV) light and DNA damage can lead to skin cancer. This occurs when epidermal keratinocytes are exposed to UV radiation, forming dimers and oxygen radicals that alter the structure of nucleotides. When these defects are not repaired, DNA replication is altered leading to mutations in p53 and PTCH tumor suppressor gene1 and ultimately tumor development.2 Major DNA repair defects can give rise to cancer-prone phenotypes. This phenomenon is illustrated in xeroderma pigmentosum, a disease with mutated repair genes that predispose patients to extreme UV sensitivity and 2,000-fold risk of NMSC and other malignancies.3 However, aside from rare syndromes, the variants in DNA repair genes for the general population and the association with cancer risk is not yet well understood. Recent advances in genomics and technology have linked genetic polymorphisms to skin properties by examining single nucleotide polymorphisms (SNPs). Such knowledge could assist in predicting a patient’s potential for manifesting signs of cutaneous aging and malignancy and for establishing cancer risk stratification of both melanoma and NMSCs based on an individual’s genetics.4The incidence of NMSC is rising and is a health concern especially in fair-skinned populations.5 NMSC is the most common cancer and has been strongly linked to UV exposure, immunosuppression, radiation, and arsenic exposure.6 The two major types of NMSC are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). Although these are usually localized, there is an increased risk for development of other non-cutaneous malignancies such as salivary gland, lip, mouth and pharynx, and non-Hodgkin lymphoma.7 It is not known why this association exists. Because of this positive correlation for multiple malignancies, it is possible the precursor NMSC could be a marker of phenotypes that have a predisposition for cancer in general. Several commercial proprietary kits (such as ORIG3N, Boston, MA or Blueprintgenetics, San Francisco, CA) are currently on the market, which advertise the ability to provide a patient with a skin cancer risk profile. These tests are based on research findings that reported individual SNPs and genes related to skin cancer risk. However, to our knowledge, there is no current study in the literature that examines the prevalence of an extended set of identified SNPs within the skin cancer