Cutaneous squamous cell carcinoma tumor accrual rates in immunosuppressed patients with autoimmune and inflammatory conditions: A retrospective cohort study

BACKGROUND: Immunosuppression is a known risk factor for the development of cutaneous squamous cell carcinoma (CSCC), especially in solid organ transplant recipients and chronic lymphocytic leukemia. However, this risk is less well defined in autoimmune and inflammatory conditions.

OBJECTIVE: Assess the impact that disease-type, duration of immunosuppression, and systemic medications have on CSCC accrual rates, defined as the number of CSCCs a patient develops per year, in autoimmune and inflammatory conditions.

METHODS: Retrospective review of 94 immunosuppressed (rheumatoid arthritis (RA): 31[33.0%], inflammatory bowel disease (IBD): 17[18.1%], psoriasis (PsO): 11[11.7%], autoimmune other (AO): 24[25.5%], inflammatory other (IO): 21[22.3%]) and 188 immunocompetent controls to identify all primary, invasive CSCCs diagnosed from 2010 to 2020.

RESULTS: Immunosuppressed patients had higher CSCC accrual rates than immunocompetent controls (0.44±0.36): total cohort (0.82±0.95, p<0.01), RA (0.88±1.10, p<0.01), IBD (0.94±0.88, p<0.01), PsO (1.06±1.58, p<0.01), AO (0.72±0.56, p<0.01), and IO (0.72±0.61, p<0.01). There was an association between increased tumor accrual rates and exposure to systemic medications including, immunomodulators, TNF-inhibitors, non-TNF inhibitor biologics, and corticosteroids, but not with number of systemic medication class exposures or duration of immunosuppression.

LIMITATIONS: Retrospective, single-center study CONCLUSION: Patients with autoimmune and inflammatory conditions accrue CSCCs at higher rates than immunocompetent patients.