Expression and significance of Her2 and Ki-67 in gastric adenocarcinoma without distant metastasis: a cohort study

Abstract

BackgroundThe significance of human epidermal growth factor receptor 2 (Her2) and nucleus-associated antigen Ki-67 expression remains controversial in gastric adenocarcinoma (GaC). The aim of this study was to investigate the expression and clinicopathologic and prognostic significance of Her2 and Ki-67 in resected GaC without distant metastasis.MethodsMalignant tissues and clinicopathologic data were obtained from 195 patients with resected non-metastatic GaC. Immunohistochemistry staining was performed to examine the expression of Her2 and Ki-67; their association with clinicopathologic factors were investigated using logistic regression, and their association with survival was explored using Kaplan–Meier analysis and Cox proportional hazards regression.ResultsHer2 was majorly expressed in cell membrane and Ki-67 in cell nucleus in non-metastatic GaC. Stronger Her2 expression was significantly associated with better tumor differentiation, neurovascular invasion, less advanced pathological tumor (pT) stage, and more advanced pathological node (pN) stage; while Ki-67 expression was not significantly associated with any investigated clinicopathologic factors. Patients with both negative Her2 and negative Ki-67 expression had poorer tumor differentiation, and more advanced pT and pathological tumor-node-metastasis (pTNM) stages; the association with pT and pTNM stages were further confirmed by multivariable analyses, especially in node-negative disease. Her2 or Ki-67 alone was not significantly associated with pTNM stage. A strongly positive (+++) Her2 expression was associated with poorer survival in multivariable analysis only (P = 0.047); while Ki-67 or combined expression was not significantly associated with prognosis.ConclusionsIn non-metastatic GaC, Her2 expression and combined expression of Her2 and Ki-67 were associated with several clinicopathologic factors including tumor differentiation and stage, and only a +++ Her2 expression was associated with poorer prognosis in multivariable analysis with marginal significance in this study; while Ki-67 alone had both limited clinicopathologic and prognostic values.