Abstract 4930: Ki-67 serves as a prognostic marker in early gastric cancer, but not in advanced gastric cancer

Abstract

Abstract Ki-67 protein is a cellular marker for proliferation. The role of Ki-67 as a prognostic factor has not been established in gastric cancer. We previously demonstrated that CD44v plays an important role in EThe present study was performed toinvestigate the significance of Ki-67 expression as a biomarker in early gastric cancer (EGC), but not advanced gastric cancer (AGC). With the study, we foundthat there is correlation between CD44v and Ki67. Here, evaluated the clinical significance with tissue microarray of gastric cancer by performing immunohistochemical staining for Ki-67. Its clinical significance was analyzed with adjustment via the propensity score-matching. The median follow-up duration was 72 months (range: 3 - 120 months). Ki-67 positive group showed worse prognosis than Ki-67-negative group in EGC (5-YSR, 78.9% vs. 92.0%, p = 0.018), but not in advanced gastric cancer (AGC) (5-YSR, 58.5% vs. 59.2%, p = 0.951). Interestingly, in the patients with well-differentiated histology, prognosis for Ki-67-positive group was considerably worse than that for Ki-67-negative group (5-YSR, 67.0% vs. 94.4%, p = 0.012), but not in those with moderately differentiated (p = 0.504) and poorly-differentiated histology (p = 0.905). In this cohort, there was a strong correlation between the proportion of EGC and well-differentiated histology (r = 0.215, p = 0.002). Multivariate analysis also revealed that the positive-Ki- 67 expression serve as a poor prognostic factor in EGC (HR 4.346, 95% CI 1.397 - 13.515, p = 0.011), but not in all the patients (p = 0.171). With bootstrap resampling, we internally validated these results (p = 0.011). In conclusion, this study suggests that Ki-67 expression may be a good biomarker for prognosis prediction for EGC, but not for AGC. [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, Gyung Hyuck Ko, Se-Il Go, Jeong-Hee Lee, Sang-Ho Jeong, Young-Joon Lee, Soon Chan Hong, Woo Song Ha. Ki-67 serves as a prognostic marker in early gastric cancer, but not in advanced gastric cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4930.