A case controlled study of risk factors for metastatic squamous cell carcinoma in organ transplant recipients: single academic medical center.

Solid organ transplant recipients (SOTRs) are at high risk of cutaneous squamous cell carcinoma (cSCC) metastasis. Despite prior studies identifying risk factors, mortality remains high. Understanding additional risk factors may aid in reducing mortality in this population. This study aimed to investigate risk factors and predictive variables for metastatic cSCC in SOTRs. The primary goal was to accurately identify transplant patients at increased risk of metastatic cSCC. A retrospective case-control study in a single institution of 3576 cases of organ transplants were identified from January 1991 to July 2022. A cohort of metastatic cancer patients and two randomly generated age and organ matched control cohorts were identified. 16 SOTR patients developed metastatic cSCC. The majority were male, with high-risk tumor sites. Tumor depth varied and half exhibited perineural invasion. Cylex® (p = 0.05) and white blood cell counts (p = 0.04) were significantly lower in these patients compared to control. Lung transplants were at highest risk relative to other solid organ transplants. Voriconazole exposure was also associated with increased metastatic risk (p = 0.04). Small sample size at a single institution. Close monitoring of SOTR, especially those with lung transplants given their increased risk, reducing immunosuppression, and limiting exposure to voriconazole can improve outcomes in SOTRs with metastatic cSCC.