SOX2 expression in hypopharyngeal, laryngeal, and sinonasal squamous cell carcinoma.

Squamous cell carcinoma (SCC) of the head and neck display high frequencies of DNA copy number gains at chromosomal region 3q26-27. Recently SOX2 has been postulated as a driver oncogene for these amplifications; however, its role as a prognostic marker is still a matter of debate. The aim of this study was to evaluate the involvement of SOX2 protein expression in three different sublocalizations of head and neck SCC and its possible role as prognostic marker. SOX2 expression was analyzed by immunohistochemistry in 102 pharyngeal, 67 laryngeal, and 51 sinonasal SCCs, and the relation to clinicopathological and follow-up data was studied by χ(2) and Kaplan-Meier analysis. SOX2 expression was significantly (P = .002) more frequent in hypopharyngeal and laryngeal SCC (38%, 39/101) and (42%, 28/67), respectively, compared to sinonasal cancer SCC (14%, 7/51). SOX2 expression did not correlate to disease stage, T or N classification, lymph node metastasis, recurrence or clinical outcome in any of the three sublocalizations. These results indicate that SOX2 expression is a common event in hypopharynx and larynx, but not in sinonasal SCC. The absence of correlation to clinical outcome, may suggest a role for SOX2 in tumor initiation, but not in tumor progression.