Increased Prevalence of Cancer in Adult Patients With Psoriasis in the United States: A Claims Based Analysis.

Background: Psoriasis (Ps) is a chronic inflammatory immune-mediated skin disease that has been identified as a risk factor for various conditions including neoplasms. Objective: To compare prevalence of cancer between Ps and Ps-free patients. Methods: Adult patients continuously enrolled for >= 12 months (>= 1 month in 2014) were selected from a large United States (US) claims database (Q1:2010-Q4:2014) and classified as Ps patients (>= 2 Ps diagnoses; International Classification of Diseases 9th Revision, [ICD-9] code: 696.1x) and Ps-free patients (no Ps diagnosis). Patients were exactly matched (1:1) based on age, gender, state of residence, and insurance plan type. Prevalence of cancer was compared between cohorts over patients' last 12 months of continuous healthcare plan enrollment using logistic-regression models. Results: A total of 179,066 pairs of Ps and Ps-free patients were selected. Median age was 54.0 years, 51.7% were females. Prevalence of cancer was higher among Ps patients for any type of neoplasms (OR [95% confidence interval (CI)]=1.86 [1.83; 1.891), malignant neoplasms (OR [95% CI]=1.53 [1.49;1.57]), as well as malignant skin neoplasms (OR [95% CI]=1.87 [1.79;1.95]), lymphatic and hematopoietic tissues (OR [95% CI]=1.70 [1.57;1.84]), genital (OR [95% CI]=1.33 [1.26;1.41]), breast (OR [95% CI]=1.32 [1.24;1.401), digestive organs and peritoneum (OR [95% CI]=1.24 [1.13;1.35]), urinary organs (OR [95% CI]=1.49 [1.36;1.64]), respiratory and intrathoracic organs (OR [95% CI]=1.30 [1.17;1.44]), and metastatic cancer (OR [95% CI]=1.14 [1.06;1.24]), all P < 0.01. Limitations: Impact of Ps severity could not be assessed. Conclusion: Ps patients had a higher prevalence of cancer than Ps-free patients.