Psoriasis is associated with a higher cancer risk

A large registry study showed that psoriasis is linked with a higher cancer risk overall and in specific sites, particularly in severe disease. Psoriasis was associated with several cancers beyond those currently regarded as connected.

Lifestyle factors like smoking and alcohol consumption are particularly prevalent

Evidence and understanding of the incident cancer risk in people with psoriasis are lacking. To evaluate the possible relationship, Mr Alex Trafford (University of Manchester, UK) and colleagues aimed to investigate the risk of cancer occurrence in individuals with psoriasis by analysing data from population-based health records from Denmark, England, Israel, and Taiwan. Mr Trafford pointed out that an association is plausible due to the chronic inflammation in psoriasis patients. Moreover, lifestyle factors like smoking and alcohol consumption are particularly prevalent in patients with psoriasis.

Mr Trafford also wanted to explore whether cancer risk is associated with psoriasis severity. “As we had no direct data, we used systemic therapy as an indicator of moderate-to-severe psoriasis,” he explained. Individuals with psoriasis from the registry were matched with up to 6 individuals with no prior record of psoriasis based on a minimum of age, sex, and calendar time. Country-specific risks of cancer overall and site-specific cancers were analysed using Cox proportional hazards models. Previous cancer patients were excluded from the analysis.

The analysis included 702,062 participants with psoriasis and 4,185,596 matched comparators were included. Age and sex were similar between countries. Patients in Denmark were older; in Taiwan, they were more likely to be men. In crude models, individuals with psoriasis and the subgroup with moderate-to-severe psoriasis had a slightly higher risk of cancer overall. Further, people with psoriasis had higher risks for the following site-specific cancers: the oral cavity, pharynx, oesophagus, liver, pancreas, kidney, bladder, keratinocyte, Hodgkin lymphoma, non-Hodgkin lymphoma, and leukaemia.

However, the risk elevation differed between cancer types, from a relatively modest 9% relative risk elevation in pancreas cancer to an almost doubled risk for Hodgkin lymphoma. “The cancer risk was exacerbated in more severe psoriasis. Moreover, additional associations for lung cancer and ovarian cancer were found in these patients,” Dr Trafford said.

In summary, the study established the associated increased risk of developing cancer in psoriasis patients. Associations generally persist, with a more pronounced risk, when limited to people with moderate-to-severe disease. The current study revealed that psoriasis is associated with several cancers, beyond those currently regarded to be linked to the condition. This should be recognised to guide optimal psoriasis care and future research.

Reference
  1. Trafford AM, et al. Psoriasis and the risk of cancer development: pooled population-based cohort studies from Denmark, England, Israel and Taiwan. FC09, Psoriasis from Gene to Clinic 2021, 9–11 December.