Psoriasis linked to increased risk for lymphomas, keratinocyte cancer
Patients with psoriasis carry a slightly increased risk for cancer, particularly keratinocyte cancer and lymphomas, according to data published in JAMA Dermatology.
“Epidemiological studies investigating the association between psoriasis or psoriatic arthritis and cancer have reported conflicting results, where some studies report an increased risk of cancer in individuals with psoriasis or psoriatic arthritis and others do not,” Nikolai Dyrberg Loft, MD, of the Herlev and Gentofte Hospital, at the University of Copenhagen in Denmark, told Healio Rheumatology. “Whether individuals with psoriasis or psoriatic arthritis carry an independent risk of cancer is important as this might help in guiding clinical practice.”
To analyze the association and risk for cancer among patients with psoriasis or psoriatic arthritis, Loft and colleagues performed a literature review of PubMed and Embase from inception to Jan. 1, 2019. Search terms included “psoriasis,” “psoriatic,” “neoplasms” and “malignancy,” with the results filtered to feature only human participants and English-language publications. The researchers also limited their analysis to original, observational cohort studies of adults with psoriasis or PsA, and that reported the incidence or prevalence of cancer among the participants.
Among the 365 studies included for full-text assessment, 112 were included in the final analysis. These 112 studies featured 2,053,932 patients. The primary outcome was cancer — overall and specific subtypes. Measures included prevalence, incidence and risk estimate for cancer in patients with either PsA or psoriasis.
According to Loft and colleagues, the overall prevalence of cancer in patients with psoriasis was 4.78% (95% CI, 4.02-5.59), with an incidence rate of 11.75 per 1,000 person-years (95% CI, 8.66-15.31) and a risk ratio of 1.21 (95% CI, 1.11-1.33). Specifically, there was an increased risk for keratinocyte cancer (RR = 2.28; 95% CI, 1.73-3.01), lymphomas (RR = 1.56; 95% CI, 1.37-1.78), lung cancer (RR = 1.26; 95% CI, 1.13-1.4) and bladder cancer (RR = 1.12; 95% CI, 1.04-1.19).
The researchers observed no increased cancer risk among patients with psoriasis treated with biologic agents (RR = 0.97; 95% CI, 0.85-1.1). Psoriatic arthritis was not associated with an overall increased risk for cancer (RR = 1.02; 95% CI, 0.97-1.08).
“Physicians should be aware that individuals with psoriasis have an increased risk of cancers especially lymphomas and keratinocyte cancers,” Loft said. “Notably, some treatments of psoriasis might cause an increased risk of keratinocyte cancers and exacerbations of lymphomas. In addition, obesity, alcohol use, and smoking, which are all associated with cancers, are more prevalent in individuals with psoriasis. Therefore, promoting a healthy lifestyle is important in individuals with psoriasis as this might improve psoriasis and prevent some of the cancers increased in psoriasis.” – by Jason Laday
Disclosure: Loft reports personal fees from Eli Lilly. Please see the study for all other authors’ relevant financial disclosures.