Background: There are limited comparable data on rates of malignancies and hospitalized infectious events (HIEs) in psoriasis (PsO) patients (pts) and among PsO pts on specific treatments (txs).
Objectives: We assessed the incidence of malignancies and HIEs in a general population (GP), a PsO population (pop’n), and PsO pop’ns prescribed specific txs within a large US health-insured pop’n.
Methods: Using an administrative claims database, we identified a GP (N = 18,094,518) and a cohort of PsO (ICD-9 code 696.1) pts aged ‡18 years between 1/1/06 and 12/31/06 followed through 12/31/09 to assess incidence of malignancies (lymphoma, non-melanoma skin cancer (NMSC), all cancers excluding NMSC) and HIEs. PsO pts prescribed the following txs for ‡1 dose after diagnosis (dx) were exposed to that tx: non-biologic (NB) systemics (methotrexate, cyclosporine), phototherapy (PUVA, UVB), other TNF blockers (adalimumab, infliximab), and etanercept. Follow-up ended at first dx of an outcome event, loss to follow-up, or completion of 3 years of follow-up. For HIEs, follow-up also ended 30 days after tx discontinuation or switch. Age- and sex-standardized incidence rates and 95% confidence limits were calculated.
Results: Among 40,987 PsO pts, 11% were prescribed NB, 6.2% other TNF blockers, 15% etanercept, and 11% phototherapy. Some pts were prescribed more than one tx. For all cancers, lymphoma, and NMSC, the incidence rates per 10,000 person-years for the PsO cohort were significantly elevated compared to the GP (all cancers: 114 (95% CI: 107–121) vs. 95 (95% CI: 95.0–95.6); lymphoma: 9.4 (95% CI: 7.4–11.4) vs. 5.8 (95% CI: 5.8–5.9); NMSC: 129 (95% CI: 121–136) vs. 78 (95% CI: 77.7– 78.3)]. For the four tx groups, small differences were shown in incidence of all cancers and lymphoma from the GP but NMSC rates were higher in each. HIE rates were higher in the three systemic tx PsO groups relative to the phototherapy group.
Conclusions: Incidence rates of malignancies are elevated in PsO pts compared to the GP. Rates of malignancies and HIEs vary by tx, suggesting that risks from both tx and the underlying disease must be taken into account to understand tx-related risks.
