Cumulative incidence and risk factors for cutaneous squamous cell carcinoma metastases in organ transplant recipients: The Skin Care in Organ Transplant Patients in Europe-International Transplant Skin Cancer Collaborative metastases study, a prospective multicenter study.

INTRODUCTION: Solid organ transplant recipients (SOTRs) are believed to have an increased risk of metastatic cutaneous squamous cell carcinoma (cSCC), but reliable data are lacking regarding the precise incidence and associated risk factors. METHODS: In a prospective cohort study, including 19 specialist dermatology outpatient clinics in 15 countries, patient and tumor characteristics were collected using standardized questionnaires when SOTRs presented with a new cSCC. After a minimum of 2 years of follow-up, relevant data for all SOTRs were collected. Cumulative incidence of metastases was calculated by the Aalen-Johansen estimator. Fine and Gray models were used to assess multiple risk factors for metastases. RESULTS: Of 514 SOTRs who presented with 623 primary cSCCs, metastases developed in 37 with a 2-year patient-based cumulative incidence of 6.2%. Risk factors for metastases included location in the head and neck area, local recurrence, size > 2 cm, clinical ulceration, poor differentiation grade, perineural invasion, and deep invasion. A high-stage tumor that is also ulcerated showed the highest risk of metastasis, with a 2-year cumulative incidence of 46.2% (31.9%-68.4%). CONCLUSIONS: SOTRs have a high risk of cSCC metastases and well-established clinical and histologic risk factors have been confirmed. High-stage, ulcerated cSCCs have the highest risk of metastasis.

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: 31[33.0%], inflammatory bowel disease: 17[18.1%], psoriasis: 11[11.7%], autoimmune other (AO): 24[25.5%], inflammatory other: 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 < .01), rheumatoid arthritis (0.88 ± 1.10, P < .01), inflammatory bowel disease (0.94 ± 0.88, P < .01), psoriasis (1.06 ± 1.58, P < .01), AO (0.72 ± 0.56, P < .01), and inflammatory other (0.72 ± 0.61, P < .01). There was an association between increased tumor accrual rates and exposure to systemic medications including, immunomodulators, tumor necrosis factor-alpha inhibitors, non-tumor necrosis factor inhibitor biologics, and corticosteroids, but not with number of systemic medication class exposures or duration of immunosuppression. LIMITATIONS: Retrospective, singlecenter study. CONCLUSION: Patients with autoimmune and inflammatory conditions accrue CSCCs at higher rates than immunocompetent patients.