Cancer risk in patients with psoriasis: should we be paying more attention?

ABSTRACT

Introduction

Psoriasis is a chronic-immune-mediated disease affecting 2–4% of the western population. The disease is associated with several co-morbidities including an increased risk of cancer. Concerns have been raised whether psoriasis itself, the psoriasis-associated risk factors, or the treatment of psoriasis might lead to an increased risk of cancer.

Areas covered

We reviewed the literature on cancers associated with psoriasis and discuss some of the potential mechanisms behind the observed associations.

Expert opinion

Patients with psoriasis have an increased risk of cancers overall and some site-specific cancers especially non-melanoma skin cancer, lymphoma, and lung cancer. The increased risk is most likely due to a combination of the chronic low-grade inflammation in psoriasis, risk factors for cancer associated with psoriasis, and the treatment of psoriasis. Future research should investigate the contribution of the individual mechanisms. Additionally, multiple new specific immunomodulatory treatments for psoriasis have been introduced during recent years and it is important to monitor and investigate whether these treatments confer an increased risk of cancers. Lastly, as patients with psoriasis have an increased alcohol use, smoke more than the general population and as psoriasis has been linked to obesity, promotion of a healthy lifestyle is key in the prevention of certain cancer types.

KEYWORDS:

• Treatment
• biologics
• cancer
• chronic-low grade inflammation
• psoriasis
• non-melanoma skin cancer
• lymphoma
• smoking
• alcohol
• obesity

Article highlights

• Psoriasis has been associated with cancers overall and some site-specific cancers including non-melanoma skin cancer (NMSC), lymphomas, lung, bladder, colon, colorectal, kidney, laryngeal, liver, esophageal, oral cavity, and pancreatic cancer.

• The increased risk is most likely due to a combination of the chronic low-grade inflammation in psoriasis, risk factors for cancer associated with psoriasis, and the treatment of psoriasis.

• Cytokines upregulated in psoriasis include tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-12, IL-17A, IL-22, and IL-23, which have been shown to also play a role in some cancers.

• Several known cancer risk factors such as smoking, obesity, and alcohol use have been associated with psoriasis.

• Some of the treatments for psoriasis confer an increased risk of NMSC including psoralen and ultraviolet A (PUVA) and cyclosporin A. Methotrexate and TNF inhibitors have in some studies been associated with NMSC.

• As we now have multiple treatments available for psoriasis, having the patient’s history in mind is important when choosing treatment.

• As patients with psoriasis have an increased alcohol use, smoke more than the general population, and as psoriasis has been linked to obesity, promotion of a healthy lifestyle is key in the prevention of certain cancer types.

Declaration of interest

ND Loft has been an honorary speaker for Eli Lilly and Janssen Cilag. L Skov has been a paid speaker for AbbVie, Eli Lilly, Novartis, and LEO Pharma, and has been a consultant or has served on Advisory Boards with AbbVie, Janssen Cilag, Novartis, Eli Lilly, LEO Pharma, UCB, Almirall, and Sanofi. She has served as an investigator for AbbVie, Janssen Cilag, Boehringer Ingelheim, AstraZenica, Eli Lilly, Novartis, Regeneron, and LEO Pharma, and has received research and educational grants from Pfizer, AbbVie, Novartis, Sanofi, Janssen Cilag, and LEO Pharma. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.