RT Journal Article T1 The Distinctive Features behind the Aggressiveness of Oral and Cutaneous Squamous Cell Carcinomas A1 Alonso Juarranz, Miguel A1 Mascaraque, Marta A1 Carrasco, Elisa A1 Gracia Cazaña, Tamara A1 Sen, Oscar de la A1 Gilaberte, Yolanda A1 Gonzalez, Salvador A1 Juarranz, Ángeles A1 Falahat Noushzady, Farzin AB Squamous cell carcinomas arise from stratified squamous epithelia. Here, a comparative analysis based on recent studies defining the genetic alterations and composition of the stroma of oral and cutaneous squamous cell carcinomas (OSCC and CSCC, respectively) was performed. Both carcinomas share some but not all histological and genetic features. This review was focused on how mutations in tumor suppressor genes and protooncogenes cooperate to determine the differentiation, aggressiveness, and metastatic potential of OSCC and CSCC. In fact, driver mutations in tumor suppressor genes are more frequently observed in OSCC than CSCC. These include mutations in TP53 (encoding pP53 protein), CDKN2A (encoding cyclin dependent kinase inhibitor 2A), FAT1 (encoding FAT atypical cadherin 1), and KMT2D (encoding lysine methyltransferase 2D), with the exception of NOTCH (encoding Notch receptor 1), whose mutation frequency is lower in OSCC compared to CSCC. Finally, we describe the differential composition of the tumor microenvironment and how this influences the aggressiveness of each tumor type. Although both OSCC and CSCC tumors are highly infiltrated by immune cells, high levels of tumor-infiltrating lymphocytes (TILs) have been more frequently reported as predictors of better outcomes in OSCC than CSCC. In conclusion, OSCC and CSCC partially share genetic alterations and possess different causal factors triggering their development. The tumor microenvironment plays a key role determining the outcome of the disease. PB MDPI SN 2072-6694 YR 2023 FD 2023-06-17 LK https://hdl.handle.net/20.500.14352/103705 UL https://hdl.handle.net/20.500.14352/103705 LA eng NO Alonso-Juarranz, M.; Mascaraque, M.; Carrasco, E.; Gracia-Cazaña, T.; De La Sen, O.; Gilaberte, Y.; Gonzalez, S.; Juarranz, Á.; Falahat, F. The Distinctive Features behind the Aggressiveness of Oral and Cutaneous Squamous Cell Carcinomas. Cancers 2023, 15, 3227. https://doi.org/10.3390/ cancers15123227 NO Instituto de Salud Carlos III NO Ministerio de economía y competitividad (España) DS Docta Complutense RD 25 abr 2025