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Background: Transoral surgery (TOS) has been widely applied for early T‐stage head and neck cancer (HNC). The resection is performed with a minimum safety margin for function preservation under a limited surgical field; therefore, it is difficult to have a strong conviction about the complete resection. This study aims to evaluate the completeness of the initial TOS procedure; possibility of primary control by TOS alone; and predictive factors in patients with early T‐stage laryngeal, oropharyngeal, and hypopharyngeal cancer. Methods: Patients were treated by TOS at the primary site with or without neck dissection. The patients were divided into two groups based on the pathological evaluation of their surgical specimens: the control (observation) group, in that the resection was considered complete and the intervention (second‐look procedure) group, in that incomplete tumor resection was suspected. The predictive factors for the possibility and/or limitations of complete resection by TOS were then analyzed. Results: The study enrolled 26 and 25 patients in the control and intervention group, respectively. The success rate for single resection was 66% and the predictive factor was tumor depth obtained by enhanced computed tomography (CT) examination (odds ratio, 7.870, P = .0243). The success rate for definitive therapy by TOS alone was 83% and the predictive factor was poor differentiation observed on pathological examination (odds ratio, 6.800, P = .0248). Conclusions: TOS has the potential for both definitive resection and function preservation with minimal invasiveness. Identification of the risk factors for TOS is advantageous for accurate treatment selection in patients with early T‐stage HNC. [ABSTRACT FROM AUTHOR]

Cetuximab is a chimeric IgG1 monoclonal antibody that targets epidermal growth factor receptor (EGFR). Cetuximab binds to EGFR and prevents phosphorylation of EGFR. Moreover, preclinical results have shown the ability of cetuximab to induce either complement-mediated tumor cell killing (CDC) or antibody-dependent cell-mediated-cytotoxicity (ADCC). We previously reported mutation in EGFR regarding head and neck squamous cell carcinoma (HNSCC) cell lines. In the present study, we analyzed the same 16 HNSCC cell lines for mutations in KRAS, PIK3CA, BRAF and PTEN. Furthermore, we evaluated cetuximab-mediated biological activities (antiproliferative effect by the MTT assay and ADCC) regarding these cell lines. Mutations in PIK3CA and PTEN were observed in two cell lines (2/16, 12.5%), but no mutation was observed in KRAS and BRAF. The antiproliferative effect of cetuximab by the MTT assay was not strong, and no correlation was observed between the antiproliferative effect of cetuximab and mutations in EGFR, KRAS, PIK3CA, BRAF and PTEN in these cell lines. Therefore, the mutation status of EGFR and downstream molecules were not useful for predicting the antitumor effects of cetuximab on HNSCC. Cetuximab-mediated ADCC was observed in these cell lines and might have been influenced by the expression of EGFR. Therefore, cetuximab-mediated ADCC seems to be an important part of the antitumor mechanisms of cetuximab and the expression levels of EGFR might influence the antitumor activity of cetuximab. Therefore, besides the antiproliferative effect of cetuximab by the MTT assay, it appeared important to evaluate cetuximab-mediated ADCC as well as EGFR expression in HNSCC cells. ( Cancer Sci 2011; 102: 1717-1723) [ABSTRACT FROM AUTHOR]