People with psoriasis have an increased risk of cancer incidence and cancer-related mortality, a new study found. The systematic reviews and meta-analysis included 58 unique observational studies. Pooled relative risk (RR) estimates for cancer incidence and cancer mortality for psoriasis cohorts were compared with people without psoriasis. Researchers found:
- The overall risk of developing cancer was significantly elevated in people with psoriasis and for several site-specific cancers, including colon, colorectal kidney laryngeal, liver, lymphoma, non-Hodgkin lymphoma, esophageal, and pancreatic.
- The risk of cancer mortality was found to be elevated in those with severe psoriasis.
Trafford AM, et al. Association of psoriasis with the risk of developing or dying of cancer: A systematic review and meta-analysis. [Published online ahead of print October 16, 2019]. JAMA Dermatol. doi:10.1001/jamadermatol.2019.3056.
The risk of cancer as a comorbidity such as lymphoma with psoriasis has been previously reported. This study reports the elevation of site-specific cancers in severe psoriasis such as lymphomas, pancreatic, esophageal, and pancreatic cancers. There could several reasons to explain this association. Because psoriasis is a chronic inflammatory condition, there is a link with inflammation and malignancies. There is also the increased prevalence of known cancer risk factors such as smoking, excessive alcohol consumption, and obesity in people with psoriasis that has been postulated as an explanation for an association with cancer. What is important is that preliminary studies have suggested little to no increased risk of cancer incidence in patients with psoriasis receiving biologic agents some of which have malignancy warnings. However, further studies will be necessary to examine the risk of site-specific cancers with these agents. In contrast, there is an association between phototherapy to treat psoriasis and increased risk of squamous cell carcinoma and basal cell carcinoma. —Paul S. Yamauchi, MD, PhD; Clinical Assistant Professor of Dermatology David Geffen School of Medicine at UCLA; Harbor-UCLA Medical Center Division of Dermatology; Adjunct Associate Professor John Wayne Cancer Institute.