7582 Background: Genotype-based stratification is essential to improve cancer treatment. We have developed a multiplexed tumor genotyping panel for detecting gene alterations relevant to molecular targeted therapies. We applied this genotyping panel to malignant pleural mesothelioma (MPM) and evaluate the relationship between clinical outcome and gene alterations. Methods: Surgical specimens and tumor biopsies from 40 patients with MPM were collected from 2003 to 2012. Pathological diagnoses were confirmed by immunohistochemistry in addition to HE stain. 37 patients were genotyped with multiplexed tumor genotyping panel developed to assess 9 gene mutations (EGFR, KRAS, BRAF, PIK3CA, NRAS, MEK1, AKT1, PTEN and HER2) and 5 genes amplifications (EGFR, MET, PIK3CA, FGFR1 and FGFR2) using pyrosequencing plus capillary electrophoresis, and qRT-PCR, respectively. Other 3 patients were analyzed by ultra-deep targeted sequencing with next generation sequencer. 5 fusion genes (EML4-ALK, CD74-ROS1, SLC34A2-ROS1, KIF5B-RET and CCDC6-RET) were tested in 2 patients with fresh frozen specimens. Results: Gene alterations were detected in 6 patients (Table shown below). These patients harboring gene alterations showed poorer survival than the patients in whom gene alterations were not detected (median survival time (MST): 583 vs 164 days, log-lank: p=0.009). Moreover, the patients with PIK3CA amplification/mutation showed poorer survival than the patients without PIK3CA amplification/mutation (MST: 583 vs 103 days, log-lank: p=0.031). Conclusions: Gene alterations which could be a target for molecular targeted therapy were detected in MPM. Especially, PIK3CA pathway is a potential target. [Table: see text]
Clinical outcome of postoperative highly conformal versus 3D conformal radiotherapy in patients with malignant pleural mesothelioma
