Introduction:
Patients with psoriasis have a higher incidence of keratinocyte cancers; with risk factors including photochemotherapy and ciclosporin. Unlike methotrexate and other biological medications, the use of apremilast for psoriasis in patients with malignancy is not contraindicated.
Methods:
We report two cases of eruptive squamous cell carcinoma(SCC) and keratoacanthoma(KA) development shortly after commencing apremilast in patients with psoriasis.
Findings:
Patient A had rapid SCC development despite recommencing acitretin whilst on apremilast. Patient B underwent nbUVB therapy throughout her treatment for psoriasis, with no SCC development except during concomitant therapy with apremilast. Neither patient developed further rapidly progressing SCCs after being commenced on risankizumab for their psoriasis.
The role of psoriasis severity on the rapid development of SCCs amongst our patients cannot be discount; as although both patients had severe psoriasis prior to commencing apremilast with a lower incidence of SCCs, they had flares of their condition prior to cessation of apremilast. A recent study noted a shorter time to first keratinocyte cancer amongst those with psoriasis than rheumatoid arthritis whilst on TNF inhibitors, suggesting this was due to phototherapy and other disease-related factors. Comparatively in our patients, phototherapy did not appear to affect the development of SCCs.
Research has suggested an association with ‘rebound’ SCC development during interruption of acitretin therapy in organ-transplant recipients. A retrospective study noted six patients with organ-transplants had interruptions of acitretin therapy, ranging from 3 to 6 months, had a mean increase of 4.67 SCCs in the 12 months post-interruption. Patient A did have an interruption to acitretin therapy of 3 months, with 4 SCCs in the 12 months pre-interruption and 32 SCCs in the 12 months post-interruption. This significantly outnumbers reports in the literature in an immunocompetent individual.
Conclusion:
This case report highlights a potential unclear mechanism of rapid SCC development associated with apremilast.