Abstract 3413: Assessment of recurrence risk stratification markers after curative resection of stage II or III gastric cancer and potential clinical applications
Authors: Oshima Takashi , Sakamaki Kentaro , Miyagi Yohei , Shiozawa Manabu , Kunisaki Chikara , Yoshikawa Takaki , Rino Yasushi , Imada Toshio , Masuda Munetaka 
Published: August 2015

Objective: Standard treatment for stage II or III gastric cancer is curative resection followed by adjuvant chemotherapy. However, treatment outcomes are expected to be further improved by individualized therapy based on biomarker analysis. We extracted mRNA from frozen specimens of gastric cancer to establish a cDNA bank and have analyzed markers for recurrence risk stratification of after curative resection of stage II or III gastric cancer. We report our currently available results.

Methods: We studied 255 patients who underwent curative resection of stage II or III gastric cancer and were followed up for at least 5 years after surgery. The patients were divided into 2 cohorts: a training set consisting of 145 patients and a validation set consisting of 110 patients. A total of 104 genes were selected as candidate biomarkers on the basis of comprehensive screening by DNA microarray, extraction by SAGE library analysis, and target molecules and their families, including the results of preclinical research. The relative expression levels of each gene in gastric cancer tissue were measured by quantitative polymerase chain reaction. Genes that were found to be independent predictors of poor outcomes in the training set were verified in the validation set, using Cox proportional-hazards models.

Results: In the training set of stage II or III gastric cancer, 38 genes were selected as independent predictors of poor outcomes. On verification analysis using the validation set, the following 11 genes were selected as candidate markers for recurrence risk stratification (P&lt;0.2): SPARC, INHBA, HRBB2, VSNL1, CXCR4, EZH2, CCR7, PDGFRB, P53, MMP11, and CEACAM7. Good reproducibility was obtained for 5 of these genes: SPARC, INHBA, HRBB2, VSNL1, and CXCR4 (P&lt;0.05).

Conclusions: Candidate markers for recurrence risk stratification were identified in patients who underwent curative resection of stage II or III gastric cancer. At present, these markers for recurrence risk stratification are being analyzed at the protein level by tissue microarray, using specimens from a different cohort of about 1000 patients. Our ultimate goal is the development of a rapid test kit for recurrence risk stratification based on combinations of these markers in patients who have undergone radical resection of stage II or III gastric cancer

Citation Format: Takashi Oshima, Kentaro Sakamaki, Yohei Miyagi, Manabu Shiozawa, Chikara Kunisaki, Takaki Yoshikawa, Yasushi Rino, Toshio Imada, Munetaka Masuda. Assessment of recurrence risk stratification markers after curative resection of stage II or III gastric cancer and potential clinical applications. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3413. doi:10.1158/1538-7445.AM2015-3413