Longitudinal Study of Different Progression Patterns in High-Risk Cutaneous Squamous Cell Carcinoma. / Estudio longitudinal de los diferentes patrones de progresión en el carcinoma cutáneo de células escamosas de alto riesgo.

BACKGROUND AND OBJECTIVE: Cutaneous squamous cell carcinoma (cSCC) is the second leading cause of skin cancer mortality in Europe. Few studies have analyzed the different pathways of this tumor progression in its natural history. The main objective of this study was to analyze the different metastatic and progression pathways and their temporal occurrence in the evolution of cSCC. MATERIAL AND METHOD: We conducted a multicenter, retrospective, and observational study of consecutive high-risk sSCCs included in the SQUAMATA project. RESULTS: A total of 222 out of the 1346 patients included relapsed. The most frequent route of progression was the lymphatic one (62.6%). A total of 20.2% of the cases with lymphatic progression developed distant metastases. Only 1 case (3.1%) of distant metastasis followed local recurrence without previous lymphatic metastasis. The median time to disease-related mortality was longer in patients who developed systemic metastases than in those who died of locoregional progression. CONCLUSIONS: The mortality of patients with cSCC is mostly due to the regional progression of their lymphatic metastases. The appearance of distant metastases is practically always (96.9%) associated with previous lymphatic metastatic progression. Therefore, in the future, new studies will be needed to assess the regional management of cSCC in both surgical and adjuvant therapies.

Clinicopathological features, MCPyV status and outcomes of Merkel cell carcinoma in solid-organ transplant recipients: a retrospective, multicentre cohort study.

BACKGROUND: The proportion of Merkel cell carcinomas (MCCs) in solid-organ transplant recipients (SOTR) harbouring Merkel cell polyomavirus (MCPyV) is unknown, as are factors affecting their outcomes. OBJECTIVE: To describe clinicopathological features of MCC in SOTR, investigate the tumoral MCPyV-status and identify factors associated with tumour outcomes. METHODS: Retrospective, international, cohort-study. MCPyV-status was investigated by immunohistochemistry and polymerase chain reaction. RESULTS: A total of 30 SOTR and 44 consecutive immunocompetent patients with MCC were enrolled. SOTR were younger at diagnosis (69 vs. 78 years, P < 0.001). Thirty-three percent of SOTR MCCs were MCPyV-positive vs. 91% of immunocompetent MCCs (P = 0.001). Solid-organ transplantation was associated with an increased cumulative incidence of progression (SHR: 3.35 [1.57-7.14], P = 0.002), MCC-specific mortality (SHR: 2.55 [1.07-6.06], P = 0.034) and overall mortality (HR: 3.26 [1.54-6.9], P = 0.002). MCPyV-positivity and switching to an mTOR inhibitor (mTORi) after MCC diagnosis were associated with an increased incidence of progression (SHR: 4.3 [1.5-13], P = 0.008 and SHR: 3.6 [1.1-12], P = 0.032 respectively) in SOTR. LIMITATIONS: Retrospective design and heterogeneity of SOTR cohort. CONCLUSIONS: MCPyV appears to play a less prominent role in the aetiopathogenesis of MCC in SOTR. SOTR have a worse prognosis than their immunocompetent counterparts and switching to an mTORi after the diagnosis of MCC does not improve progression.