Metastatic Cutaneous Squamous Cell Carcinoma in Immunosuppressed Patient: A Systematic Review

Patients who are immunosuppressed, such as solid organ transplant recipients (SOTRs), are at a higher risk of developing cutaneous squamous cell carcinoma (cSCC). This population is at a higher risk of metastasis and worse disease-specific survival. The objective of this review is to better characterize the immunosuppressed population with metastatic cSCC. A literature search was conducted to identify reports of lymphatic metastases in immunosuppressed patients with cSCC. Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed during creation of a cohort with desired inclusion and exclusion criteria. One hundred and thirty-five articles met the inclusion/exclusion criteria, yielding 1020 total cases. We discovered that the most common forms of immunosuppression within the cohort were solid organ transplantation and hematologic malignancy. White males and cSCC tumors involving the head and neck comprised most cases. Using Brigham and Women's Hospital and Eighth edition of American Joint Committee on Cancer tumor staging criteria, we observed a trend toward higher stage tumors in SOTR than in patients with hematologic malignancy. This review confirms that known clinical risk factors for metastatic cSCC appear to be similar among the immunosuppressed population and the cSCC population at large. Interestingly, our data suggest that current staging systems may not accurately reflect metastatic risk among patients with hematologic malignancy.