Prognostic Significance of RAS Mutations and P53 Expression in Cutaneous Squamous Cell Carcinomas

TP53is considered the most commonly-altered gene in cutaneous squamous cell carcinoma (cSCC). Conversely,RASmutations have been reported in a low percentage of cSCC. The objective of our study was to evaluate the frequency of p53 expression andRASmutations in cSCC and correlate them with clinicopathological features and patient outcome. We performed immunohistochemistry for p53 and genetic profiling forRASmutations in a retrospective series of cSCC. The predictive value of p53 expression,RASmutations, and clinicopathological parameters was assessed using logistic regression models. The overall frequency ofRASmutations was 9.3% (15/162), and 82.1% of the cases (133/162) had p53 overexpression.RASmutations rate was 3.2% (1/31) of in situ cSCCs and 10.7% (14/131) of invasive cSCCs.RASmutations were more frequently associated with an infiltrative than an expansive pattern of invasion (p= 0.046). p53 overexpression was a predictor of recurrence in the univariate analysis. Our results indicate thatRASmutations associate with features of local aggressiveness. Larger studies with more recurrent and metastatic cSCCs are necessary to further address the prognostic significance of p53 overexpression in patients' risk stratification.