Youichi Seino

Free skin flap reconstruction after partial hypopharyngectomy with laryngeal preservation

Abstract Surgical resection of hypopharyngeal cancer often affects laryngeal function. The aim of this study is to assess the reliability and efficacy of free skin flap transfer after partial hypopharyngectomy with laryngeal preservation. This study designs a retrospective analysis. The subjects were 54 patients who underwent free skin flap reconstruction immediately after partial pharyngolaryngectomy or hypopharyngectomy with laryngeal preservation. The defects were classified into four types based on the location of the hypopharyngeal defect. Functional results were evaluated by routine physical examination findings and parameters related to swallowing function and X-ray barium deglutition examination. Perioperative mortalities and morbidities were reviewed. There were no perioperative mortalities and 98% of the flaps survived. Forty-three patients (80%) were able to eat an unrestricted diet and experienced no aspiration. Restriction of the diet was significantly associated with the extent of oesophageal mucosal resection. In conclusion, free skin flap reconstruction is confirmed to be a safe and effective strategy to maintain laryngeal function and good quality-of-life.

Abstract 325: Mutation analysis of PIK3CA, KRAS, BRAF and Corresponding EGFR status in head and neck squamous cell carcinoma

Background: KRAS, BRAF, PIK3CA activate protein kinase signaling and an important pathway in cancer development. Recent reports show that these downstream signaling molecules are mutated in a number of cancers. However, in head and neck squamous cell carcinoma (HNSCC), the frequency and positions of these molecules mutations are not clear. In this study we detected mutations from the clinical specimens of HNSCC by High-Throughput sequencing KRAS, BRAF, PIK3CA. Next we also intended to discover whether these mutations in downstream signaling molecules of EGFR are corresponding with EGFR status. Patients and Method: The ninety-six tumors for this study were obtained from HNSCC patients surgically treated at the Department of head and neck surgery, Jikei University School of Medicine, Tokyo. The hot-spot regions in exons 1 and 2 of K-RAS, exon 15 of BRAF, exon 9 and 20 of PIK3CA were amplified by PCR and sequenced directly using DNA from samples. Next, we analyzed expression and phosphorylation of the EGFR protein by Western blotting as well as mutations encoding the hot-spot regions in exons 18 to 21. Results: We identified mutations in 6 of the 96 patients (6.2%). 3 mutations (G12A) were found in exon 1 of K-RAS. In PIK3CA, 2 mutations were found in exon 9 (E545K) and one was in exon 20(H1047R). No other mutation was found in BRAF. Overexpression of EGFR protein was observed in all clinical samples with these mutations. On the other hand, hyper-phospholyation of EGFR was confirmed in only one sample. Finally, we tried to elucidate associations between these molecular status and patient characteristics and disease-free survival to asses the prognostic values of these molecules factors. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 325. doi:10.1158/1538-7445.AM2011-325