Abstract 2854: Clinical significance of inhibin beta A expression in gastric cancer

Abstract

Abstract Objective: Inhibin beta A (INHBA), a glycoprotein belonging to the TGF-β superfamily, has recently been reported to participate in cancer-cell proliferation. We comprehensively studied the ratio of INHBA gene expression in gastric cancer tissue to that in adjacent normal mucosa by DNA microarray analysis and found that that INHBA gene expression was 12.8-fold higher in gastric cancer tissue. To extend our previous results, we investigated the clinical significance of INHBA gene expression in gastric cancer. Methods: We studied 227 patients with gastric cancer followed up for at least 5 years postoperatively. The disease stage was I in 29 patients, II in 59, III in 88, and IV in 51. Of the 147 patients with stage II or III disease, 80 postoperatively received S-1 adjuvant chemotherapy, and 67 received surgery alone. We extracted mRNA from frozen specimens of gastric cancer and adjacent normal mucosa from these patients, calculated relative expression levels of the INHBA gene (quantitative PCR analysis), and studied the relations of INHBA expression to clinicopathological factors and treatment outcomes. We also examined the relation between S-1 adjuvant chemotherapy and INHBA gene expression in patients with Stage II or III gastric cancer, for which adjuvant chemotherapy is standard treatment. Results: INHBA gene expression was significantly higher in gastric cancer than in adjacent normal mucosa (P<0.0001) and was significantly related to the clinicopathological factors of invasion depth, disease stage, and vascular invasion. High INHBA gene expression was significantly related to poor outcomes (P=0.0320). In stage II and III gastric cancer, survival rates did not differ according to INHBA gene expression in patients who underwent surgery alone. In contrast, survival was significantly poorer in gastric cancer with high INHBA gene expression in patients who received S-1 adjuvant chemotherapy (P=0.003). Conclusions: INHBA gene expression was suggested to be a useful predictor of poor outcomes in patients with resected gastric cancer. In patients given S-1 adjuvant chemotherapy, INHBA gene expression may be a useful biomarker. Citation Format: Takashi Oshima, Toshio Imada, Naoto Yamamoto, Tsutomu Sato, Norio Yukawa, Manabu Shiozawa, Takaki Yoshikawa, Yasushi Rino, Chikara Kunisaki, Makoto Akaike, Munetaka Masuda. Clinical significance of inhibin beta A expression in gastric cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2854. doi:10.1158/1538-7445.AM2014-2854