Associations between psoriasis and risk of 33 cancers: a Mendelian randomization study.

BACKGROUND

Several observational studies have reported epidemiologic associations between psoriasis and risk of some cancers, but systematic evidence is lacking. Our aim was to comprehensively estimate the association between psoriasis and the risk of 33 common cancers using systematical Mendelian randomization based on genetic data.

METHOD

Forty-nine independent single-nucleotide polymorphisms (SNPs) significantly associated with psoriasis were extracted as instrumental variables from a large-scale meta-analysis study of genome-wide association study (GWAS) for psoriasis. Outcome GWAS data were obtained from the FinnGen consortium (n = 500,348), UK Biobank (n = 420,531), and other large-scale cancer datasets. The inverse-variance weighted (IVW) was used as the primary method to infer the association between psoriasis and risk of cancer, and finally the results from multiple databases were pooled by meta-analysis.

RESULTS

In the UK Biobank, genetically predicted psoriasis had a suggestive association with colon (OR = 1.055, 95%CI: 1.001-1.113, P = 0.046) and uterine corpus cancer (OR = 0.922, 95%CI: 0.852-0.997, P = 0.042). In the FinnGen consortium, psoriasis had a suggestive association with vulvar cancer (OR = 1.182, 95%CI: 1.023-1.366, P = 0.024), uterine corpus cancer (OR = 0.937, 95%CI: 0.883-0.993, P = 0.028), and prostate cancer (OR = 0.973, 95%CI: 0.948-0.999, P = 0.045). In an additional large-scale cancer dataset, psoriasis also showed a suggestive association with prostate cancer (OR = 0.968, 95%CI:0.942-0.995, P = 0.020). The meta-analysis confirmed the suggestive association of psoriasis with uterine corpus (OR = 0.931, 95% CI: 0.889-0.976, P = 0.003) and prostate cancer (OR = 0.976, 95% CI: 0.955-0.997, P = 0.023). Whereas the effect of psoriasis on colon and vulvar cancer was not in the same direction across different populations. Furthermore, no association between genetically predicted psoriasis and other cancers were observed.

CONCLUSIONS

This comprehensive MR study suggests that psoriasis may be a potential protective factor for uterine corpus cancer in women and prostate cancer in men.