Search

8545 Background: This study assessed the clinicopathological background of early-stage KRAS-mutated non-small-cell lung cancer and analyzed the biological process of KRAS-mutated tumor using an RNA sequencing procedure. Methods: We used a cohort of consecutive series of 179 surgically resected early-stage non-small-cell lung cancers harboring KRASmutations and analyzed the clinicopathological features, including the KRAS genotypes, affecting the recurrence-free survival and prognosis. Consequently, we performed RNA sequencing to determine the gene expression profiles of nineteen KRAS-mutated non-small-cell cancers. Results: The most common KRAS genotype was p.G12C (57; 31.8%). A high p-stage (hazard ratio [HR], 4.181; P < 0.0001) and solid predominant adenocarcinoma histology (HR, 2.343; P = 0.0076) were significant independent prognostic factors for the recurrence-free survival. A high p-stage (HR, 3.793; P < 0.0001), solid predominant adenocarcinoma histology (HR, 2.373; P = 0.0147), and KRAS p.G12V genotype (HR, 1.975; P = 0.0407) were significant independent prognostic factors for the overall survival. A gene expression analysis of the two factors revealed the p.G12V genotype to be closer to those of stem cells, and the traits of e an enhanced fatty acid and amino acid metabolism as well as a solid predominant phenotype were shown to an acquired a trait that can withstand hypoxia and the effect of prostaglandin-endoperoxide synthase Conclusions: The KRAS p.G12V genotype and solid predominant adenocarcinoma phenotype may be independent predictive factors of a poor clinical course in resected early-stage non-small-cell lung cancers, possibly due to the differentiation tendency observed in stem cells, the trait of an enhanced fatty acid and amino acid metabolism, and the effect of prostaglandin-endoperoxide synthase.

5544Background: With the progress of immune-oncology, the immunological background of epithelial ovarian carcinoma (EOC) is gradually becoming understood. However, most of the studies have been foc...

96 Background: Immunotherapy using active immunization of tumor associated antigens has been expected to improve the prognosis of malignant tumor patients. We conducted phase I trial to investigate safety and efficacy of autologous tumor lysate-pulsed dendritic cell (DC) vaccination therapy after resection for esophageal cancer. We already reported the clinical results for enrolled 11 patients. All patients completed the protocol therapy and no treatment-related adverse events more than grade 3 was observed (primary endpoint), and recurrence rate within 2 years was 18% (n = 2). In this study, we further analyzed the immune responses in vaccinated patients. Methods: Patients with stage IIA (T2N0 or T3N0, UICC TNM classification 6th edition) esophageal cancer after curative (R0) resection were eligible. Tumor lysate we used for DC vaccines potentially contains mutated proteins (neoantigens) derived from somatic mutations. Patients received DC vaccines (more than 5.0×106 cells) 6 times every 2 weeks. We evaluated neutrophil-to-lymphocyte ratio (NLR) in each patient from CRF data. We identified candidate neoantigens by next generation sequencing and MHC class I binding prediction algorism. We screened the immune responses against those neoantigens using HLA transgenic mice and healthy human PBMCs. Results: Absolute lymphocyte counts, absolute neutrophil counts and NLR were not specifically different between patients with or without recurrence. For specific immune responses, we observed the reactivity in 6 out of 59 candidate neoepitopes identified from two patients in HLA transgenic mouse system. Two out of 6 peptides displayed reactivity in human healthy PBMCs. Conclusions: We analyzed immune responses to predicted candidate neoantigens. We are now investigating immune landscape in the tumor using RNA sequencing data and its relevance to the antigen responses. Clinical trial information: UMIN000002837.

153 Background: Immunotherapy using active immunization of tumor associated antigens has been expected to improve the prognosis of malignant tumor patients. We conducted a phase I trial to investigate safety and efficacy of autologous tumor lysate-pulsed dendritic cell (DC) vaccination therapy after resection for esophageal cancer. Methods: Patients (pts) with stage IIA (T2N0 or T3N0, UICC TNM classification 6th edition) esophageal cancer after curative (R0) resection, ECOG PS 0-2, 20 years or more and adequate organ function were eligible. We used tumor lysate for DC vaccines; the lysates potentially contain mutated proteins or neoantigens derived from somatic mutations in each patient's tumor. Patients received DC vaccines (more than 5.0×106 cells) 6 times every 2 weeks. Primary endpoint was safety and secondary endpoint were efficacy including recurrence rate and immunological responses. Results: A total of 11 pts (median age: 71 years) were enrolled until the trial stopped on March 31, 2016, because standard of therapy for objective patients had changed. No treatment related adverse events of grade 3 or 4 were reported. Recurrence rate within 2 years were 18% (n=2). We performed whole-exome sequence of tumors and adjacent normal tissues with 5 pts, and identified mutated peptide derived from their tumor specific missense mutations. To examine immune responses against those predicted candidate neoepitopes, we immunized HLA-A2 transgenic mice (HHD-II mice) with the synthesized peptides from the 2 pts harboring HLA-A2. Conclusions: This study showed that autologous tumor lysate-pulsed DC vaccination therapy is safe and have expectation of recurrence risk reduction after resection of T2N0 or T3N0 esophageal cancer. Clinical trial information: UMIN000002837.