Patients with psoriasis have a higher risk for cancer, yet there does not appear to be an increased risk for cancer in patients with psoriasis who are treated with biologic agents. This is according to findings from a meta-analysis that were published in JAMA Dermatology.
The analysis included 112 observational cohort studies with a total of 2,053,932 patients with psoriasis or psoriatic arthritis. Only studies that reported incidence or prevalence of cancer in their psoriasis population were included. The main outcome of the analysis was cancer, including overall and specific subtypes of cancer. Measures of prevalence, incidence, and risk estimates for cancer were assessed.
Overall, the prevalence of cancer in patients with psoriasis was 4.78% (95% CI, 4.02%-5.59%). When keratinocyte cancer was excluded, the overall cancer prevalence decreased to 4.06% (95% CI, 3.31%-4.87%). For overall cancer, the incidence rate per 1000 person-years was 11.75 (95% CI, 8.66-15.31), which substantially decreased to 7.61 (95% CI, 6.53-8.77) after the exclusion of keratinocyte cancer. The risk ratio (RR) of overall cancer was 1.21 (95% CI, 1.11-1.33), which decreased to 1.14 (95% CI, 1.04-1.25) when keratinocyte cancer was excluded.
In patients with psoriasis, there was an increased risk for keratinocyte cancer (RR, 2.28; 95% CI, 1.73-3.01; P <.001), lymphomas (RR, 1.56; 95% CI, 1.37-1.78; P <.001), lung cancer (RR, 1.26; 95% CI, 1.13-1.40; P <.001), and bladder cancer (RR, 1.12; 95% CI, 1.04-1.19; P =.002). In 3 studies that included >12,000 patients with psoriasis who were treated with biologic agents, there was no increased risk for cancer compared to patients who received conventional therapy (RR, 0.97; 95% CI, 0.85-1.10; P =.30). In addition, there was no significant association in psoriatic arthritis and an increased risk for cancer overall (RR, 1.02; 95% CI, 0.97-1.08; P =.64).
Limitations of the analysis were the inclusion of heterogenous studies, the limited number of studies that provided data on biologic agents, and the variability in studies in terms of available risk factor data.
The researchers suggest that clinicians who treat patients with psoriasis should know about the increased risk for cancer, “especially for lymphomas, as immunogenic treatment might be associated with exacerbations.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Vaengebjerg S, Skov L, Egeberg A, Loft ND. Prevalence, incidence, and risk of cancer in patients with psoriasis and psoriatic arthritis: a systematic review and meta-analysis [published online February 19, 2020]. JAMA Dermatol. doi: 10.1001/jamadermatol.2020.0024