Increased Prevalence of Cancer in Adult Patients With Psoriasis in the United States: A Claims Based Analysis
February 2018 | Volume 17 | Issue 2 | Original Article | 180 | Copyright © February 2018
Alexandra B. Kimball MD MPH,a Murali Sundaram PhD,b Martin Cloutier MSc,c Marjolaine Gauthier-Loiselle PhD,c Patrick Gagnon-Sanschagrin, MSc,c Annie Guérin MSc,c and Arijit Ganguli PhDd
aHarvard Medical School, Boston, MA bPrevious employee of AbbVie Inc., North Chicago, IL cAnalysis Group, Inc., Montreal, Quebec, Canada dGlobal Health Economics and Outcomes Research, AbbVie Inc., North Chicago, IL
Abstract
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; 1.89]), 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;1.40]), 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 less than 0.01.
LIMITATIONS: Impact of Ps severity could not be assessed.
CONCLUSION: Ps patients had a higher prevalence of cancer than Ps-free patients.
J Drugs Dermatol. 2018;17(2):180-186.
INTRODUCTION
Psoriasis (Ps) is a chronic autoimmune disease manifesting itself as red, thick, and flaky skin patches that can occur anywhere on the body and that can become painful and itchy.1 In the United States (US), it is estimated to affect approximately 7 million people.2 In addition to skin manifestations, Ps has been associated with numerous comorbid conditions, including cardiovascular disease, diabetes, hypertension, hyperlipidemia, obesity, psoriatic arthritis, and depressive disorders.1,3 The comorbidity burden appears to increase with disease severity and is likely to contribute to the negative impact that Ps has on the patients’ quality of life, which has been shown to be comparable to that of diabetes, cancer, and heart disease.4,5A growing body of evidence is also pointing to a link between psoriasis and neoplastic disease,3,6,7 further aggravating the comorbidity burden of Ps. The state of chronic inflammation underlying Ps, in fact, is believed to be associated with carcinogenesis.8 Indeed, while a well-regulated inflammatory response can have anti-tumorigenic effects and contribute to cancer suppression, persistent chronic inflammation has been linked to epigenetic changes and alterations of key pathways regulating cellular homeostasis, resulting in pro-tumorigenic effects and cancer progression.9 Since pro-inflammatory cytokines such as interleukins and tumor necrosis factors are both key players in the pathogenesis of Ps and mediators of inflammation-induced cancer,9,10 it is not surprising that, over the past two decades, numerous studies have reported a higher prevalence of several types of cancer among Ps patients compared to the general population, including respiratory tract cancer, upper aerodigestive tract cancer, urinary tract cancer, non-melanoma skin cancer (squamous cell carcinoma and basal cell carcinoma), Hodgkin’s and non- Hodgkin’s lymphoma as well as liver, kidney, lung, colon, and breast cancer.3,6,7,11-14 However, most existing studies focused on particular types of cancer or did not comprehensively report results stratified by specific cancer. Most importantly, since many studies were conducted on a limited sample size, statistical power to detect
