Psoriasis Associated With Increased Risk of Cancer and Mortality

Patients with psoriasis have an increased risk of cancer and cancer-related mortality, according to a study published in JAMA Dermatology.

Researchers conducted a systematic review and meta-analysis of observational studies from MEDLINE, Embase, MEDLINE in Process, Cochrane Central Register, Web of Science, and LILACS through November 2017. They included cohort and case-control studies that provided estimates of the risk of cancer incidence or cancer mortality associated with psoriasis.

A total of 58 studies were included, with quality varying for the incidence and the mortality studies.

Psoriasis is associated with these cancer types …

Severe psoriasis (relative risk [RR] = 1.22; 95% CI, 1.08-1.39) and all severities of psoriasis (RR=1.18; 95% CI, 1.06-1.31) were associated with an overall increased risk of cancer. These associations were observed among the following cancer types:

• 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 cancer (RR=2.80; 95% CI, 1.99-3.93)
• Pancreatic cancer (RR=1.41; 95% CI, 1.16-1.73)

Overall cancer mortality risk was higher in patients with severe psoriasis (RR=1.22; 95% CI, 1.08-1.38). The following cancers were associated with increased mortality among patients with severe psoriasis:

• Liver cancer (RR=1.43; 95% CI, 1.09-1.88)
• Esophageal cancer (RR=2.53; 95% CI, 1.87-3.41)
• Pancreatic cancer (RR=1.31; 95% CI, 1.02-1.69)

The researchers noted that the heterogeneity of estimates was often very high despite stratification. Reduced risk was observed in studies that adjusted estimates for smoking, alcohol consumption, and obesity.

“Future research examining specific lifestyle factors, treatments, and the inflammatory processes that contribute to psoriasis may help provide additional information on the underlying mechanisms for the apparent increased cancer risk,” the researchers concluded.