Malignancy development risk in psoriatic arthritis patients undergoing treatment: A systematic review and meta-analysis

Background: Psoriatic arthritis (PsA) is a chronic and seronegative inflammatory arthritis occurring in patients with psoriasis. The current knowledge about the risk of malignancy associated with psoriatic arthritis (PsA) patients undergoing therapy is controversial. We focused on the relationship between malignancy and therapy and undertook a meta-analysis to address this issue. Methods: A systematic literature search of the PubMed, EMBASE, and Web of Science databases was performed to identify relevant studies and trials. Statistical analysis was conducted using STATA 11.2 software. Results: Nine cohort studies were included, corresponding to a total of 43,115 PsA patients undergoing therapy. A significant positive association between therapy and increased risk for overall malignancy was found relative to the general population as the reference group (pooled RR, 1.29; 95% CI: 1.04–1.60). High heterogeneity was found (I ² = 71.37%). Subgroup analysis reported that PsA patients treated with conventional synthetic disease modifying antirheumatic drugs (csDMARDs) presented increased cancer risk (pooled RR, 1.75; 95% CI: 1.40–2.18) but patients treated with biological disease modifying antirheumatic drugs (bDMARDs) did not (pooled RR, 0.957; 95% CI: 0.80–1.14). Compared to controls, patients with PsA undergoing treatment specifically are at increased risk for non-melanoma skin cancers (pooled RR, 2.46; 95% CI: 1.84–3.28). Conclusions: This study allowed the estimation of cancer risk in PsA patients during therapy. Large-scale longitudinal studies will be essential to draw firm conclusions regarding PsA-associated risk for treatment-induced malignancy.