Genetic Link Between Inflammatory Bowel Disease and Skin Cancer?
Posted: Tuesday, June 16, 2020
Gene mutations, such as IFIH1, PTPN22, and IL2RA, increase the risk of inflammatory bowel disease. They also may increase the risk for development of non-melanoma skin cancer, in a manner independent of thiopurine usage. This finding, reported by Kelly Cushing, MD, of the University of Michigan, and colleagues, was presented as part of the 2020 virtual Digestive Disease Week (DDW; Abstract Mo1120) and published in the journal of Gastroenterology.
Researchers performed a phenome-wide association study using publically available genotype-phenotype data from the Roslin Gene Atlas. A total of 39 published fine-mapped inflammatory bowel disease susceptibility variants were chosen for evaluation. Patients with non-melanoma skin cancer were identified from this data set. Heatmaps were created to find significant associations between the allele variants and the development of skin cancer. Associations were then validated using the UK biobank data set.
A cluster of small nucleotide polymorphisms were found to be correlated with melanoma and other skin cancers. The highest risk mutation was observed with s2476601 (PTPN22 [W620R]), followed by mutations in rs35667974 (IFIH1 [I923V]), rs2188962, rs61839660 (IL2RA), rs34536443 (TYK2 [P1104A]), and rs3812565. Expanding this phenome-wide association study to be more specific in each neoplasm category showed this cluster of small nucleotide polymorphisms was actually specific for non-melanoma skin cancer.
Individual-level data from the UK biobank identified 11,109 cases of non-melanoma skin cancer along with 398,252 controls. This data set showed a significant association between non-melanoma skin cancer and thiopurine use (odds ratio = 3.2), male gender, and age. Multivariate analysis revealed a genetic association between non-melanoma skin cancer and rs35667974 (odds ratio = 1.14), rs2476601 (odds ratio = 1.09), rs61839660 (odds ratio = 1.06), rs3812565 (odds ratio = 1.05), and rs2188962 (odds ratio = 1.03), which was independent of thiopurine use, age, or gender.
Disclosure: For a full list of author disclosures, visit gastrojournal.org.