Abstract 546: CD44 variant expression is a poor prognostic marker in early gastric cancer and well-differentiated gastric cancer

Abstract

Abstract The present study is to investigate the significance of the expression of CD44 variant (CD44v), a functional cancer stem cell marker, in the primary gastric cancer. We first tested whether CD44v is selectively expressed in gastric cancer tissue. With the tissue microarray samples containing the 6 normal tissue, 6 H. pylori associated gastritis, 12 intestinal metaplasia, 12 low-grade adenoma, 12 high-grade adenoma, 25 early gastric cancer and 26 advanced gastric cancer. The positive expression rates in tumor were 65.3% (49/75) whereas the positive rates in normal and gastritis tissue were 30.4% (p = 0.003). Next, we investigated the clinical significance of gastric cancer with the tissue microarray containing 333 gastric cancer tissue derived from the patients who underwent radical gastrectomy for gastric cancer from 1999 to 2007. The positive expression rates of CD44v (55%, 134/242) were higher in intestinal type gastric cancer than in diffuse type (28%, 21/76). Intestinal type gastric cancer among the CD44v-positive gastric cancer accounted for 82% (134/164). The 5-year survival rate of CD44v-positive gastric cancer was 67.7% whereas that of CD44v-negative gastric cancer was 62.9%. The survival difference was higher as time passed, but it was statistically insignificant (p = 0.219). However, in the subgroup analysis we found that the survival differences were significantly higher in early gastric cancer and well-differentiated gastric cancer (p = 0.013, 5-YSR ; p = 0.046, 5-YSR , respectively). We also investigated the correlation between the expressions of CD44v and EGFR along with the well-known proliferative molecular biomarkers, cylin D1 and Ki-67. Only the expression of Ki-67 were some correlation with CD44v expression in gastric cancer; CD44v-positive rates of the cancers with negative or 1 positive Ki-67 expression were 37% (47/127) whereas those with 2 or 3 positive Ki-67 expression were 57.4% (116/202). This study demonstrates that CD44v can be a good biomarker for early gastric cancer and well-differentiated gastric cancer. [This study was supported by a grant from the National R&D Program for Cancer Control, Ministry for Health, Welfare & Family Affairs, Republic of Korea. (0820050).] Citation Format: Won Sup Lee, Se-Il Go, Jeong-Hee Lee, Sang-Ho Jeong, Young-Joon Lee, Soon Chan Hong, Woo Song Ha, Gyung Hyuck Ko. CD44 variant expression is a poor prognostic marker in early gastric cancer and well-differentiated 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 546. doi:10.1158/1538-7445.AM2014-546