Biologic Therapy and Malignancy Risk in Psoriasis: A Retrospective Cohort Study

The long-term impact of biologic therapy on malignancy risk in patients with psoriasis remains unclear. Given the chronic nature of psoriasis and the increasing use of biologics, understanding their long-term safety profile is crucial. This study aimed to compare the incidence of malignancy between patients receiving continuous biologic therapy and those treated with topical monotherapy. We retrospectively analyzed 446 patients with psoriasis treated at a single center between May 2010 and March 2023 (biologic therapy: n = 226; topical monotherapy: n = 220). Malignancy incidence was estimated using the Kaplan-Meier method. Multivariable Cox proportional hazards regression with propensity score adjustment was employed to control for confounding variables. Subgroup analysis was performed within the biologic-treated cohort to identify additional malignancy risk factors. Malignancies occurred in 11.2% (50/446) of patients, with rates of 4.4% (10/226) in the biologic therapy group and 18.2% (40/220) in the topical therapy group (p < 0.0001). Kaplan-Meier analysis demonstrated a significantly lower cumulative incidence of malignancy in the biologic group (p = 0.0035, log-rank test). Cox regression confirmed that biologic therapy was associated with a significantly reduced malignancy risk (hazard ratio [HR]: 0.316; 95% confidence interval [CI]: 0.119-0.841; p = 0.0211). Notably, subgroup analysis using Cox regression within the biologic-treated cohort revealed that family history of malignancy was significantly associated with an increased risk of malignancy (HR: 9.01; 95% CI: 1.69-4.87; p < 0.05). In conclusion, biologic therapy was associated with a significantly lower risk of malignancy in patients with psoriasis compared to topical monotherapy. Furthermore, family history of malignancy may represent an independent risk factor for malignancy among biologic-treated patients. These findings underscore the importance of individualized cancer risk assessment when selecting treatment strategies and highlight the need for further prospective studies.