The presence of psoriasis is associated with an increased risk for cancer and cancer-related mortality, study research in JAMA Dermatology reports.
The study was a systematic review and meta-analysis of cohort and case-control studies that reported estimates of the risk for cancer or cancer-related mortality in association with psoriasis. In the review and subsequent analysis, researchers examined data from 58 unique studies and compared the risk for cancer and cancer-related mortality in patients with psoriasis and those without psoriasis.
In 9 studies, the presence of severe psoriasis was associated with an increased risk for cancer (relative risk [RR], 1.22; 95% CI, 1.08-1.39). In 7 studies, all severities of psoriasis were associated with an increased cancer incidence (RR, 1.18; 95% CI, 1.06-1.31).
Psoriasis was also associated with site-specific cancers, such as colon cancer (RR, 1.18; 95% CI, 1.03-1.35), colorectal cancer (RR, 1.34; 95% CI, 1.06-1.70), kidney cancer (RR, 1.58; 95% CI, 1.11-2.24), laryngeal cancer (RR, 1.79; 95% CI, 1.06-3.01), liver cancer (RR, 1.83; 95% CI, 1.28-2.61), lymphoma (RR, 1.40; 95% CI, 1.24-1.57), non-Hodgkin lymphoma (RR, 1.28; 95% CI, 1.15-1.43), keratinocyte cancers (RR, 1.71; 95% CI, 1.08-2.71), esophageal cancer (RR, 2.05; 95% CI, 1.04-4.07), oral cavity cancer (RR, 2.80; 95% CI, 1.99-3.93), and pancreatic cancer (RR, 1.41; 95% CI, 1.16-1.73).
The risk for overall cancer mortality was highest in severe psoriasis (RR, 1.22; 95% CI, 1.08-1.38), based on data from 4 studies. Severe psoriasis was associated with higher mortality rates in liver cancer (RR, 1.43; 95% CI, 1.09-1.88), esophageal cancer (RR, 2.53; 95% CI, 1.87-3.41), and pancreatic cancer (RR, 1.31; 95% CI, 1.02-1.69). The investigators reported very high heterogeneity of estimates across studies. There was noticeable risk attenuation in studies adjusting for smoking, alcohol consumption, and obesity estimates.
Limitations of this analysis included the high heterogeneity between studies as well as the variation in psoriasis severity classifications among analyzed studies.
Increased inflammation in psoriasis represents a likely contributor to the increased risk for cancer. The study researchers concluded that additional research is needed to understand “specific lifestyle factors, treatments, and the inflammatory processes that contribute to psoriasis” and “the underlying mechanisms for the apparent increased cancer risk.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Trafford AM, Parisi R, Kontopantelis E, Griffiths CEM, Ashcroft DM. Association of psoriasis with the risk of developing or dying of cancer: A systematic review and meta-analysis [published online October 16, 2019]. JAMA Dermatol. doi: 10.1001/jamadermatol.2019.3056