Correlation of hK6 expression with tumor recurrence and prognosis in advanced gastric cancer

Abstract

Background: Human kallikrein gene 6 (KLK6) is a member of the human kallikrein gene family (Kallikreins, KLKs). Human kallikrein-related peptidase 6 (hK6) is a trypsin-like serine protease encoded by the KLK6, has been reported to be highly expressed in several cancers including gastric cancer. In this study, we investigated the the correlation of hK6 expression with clinicopathological characteristics, tumor recurrence and prognosis in advanced gastric carcinoma after curative resection.

Methods: We retrospectively analyzed the clinical data of 129 cases advanced gastric cancer after curative gastrectomy. The expression of hK6 in advanced gastric cancer tissues compared to adjacent noncancerous tissues were examined, and the relationship between hK6 expression and clinicopathological characteristics was evaluated. In additional, these patients were followed up to investigate the relationship between hK6 expression and the survival time.

Results: The positive rate of hK6 expression was significantly higher in advanced gastric cancer tissue, than that in adjacent noncancerous and gastric ulcer tissues (36.5%, 33.3%, respectively, P < 0.001). There was a close relationship between hK6 expression and TNM stage (P = 0.005), vascular invasion (P = 0.037) and perineural invasion (P = 0.035). Furthermore, patients with hK6 positive showed significantly higher recurrence and poorer prognosis than those with hK6 negative. Multivariate analysis showed that hK6 expression was a significant independent factor for tumor recurrence and overall survival.

Conclusion: hK6 is overexpressed in advanced gastric cancer tissues. Its clinical utility may be used as an unfavorable indicator in predicting tumor recurrence and prognosis for advanced gastric cancer after operation. This study also suggests that hK6 might be a potential therapeutic target for gastric cancer.

Virtual slides: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/8558403578787206.

Figure 1

Immunohistochemical staining of hK6 in the advanced gastric carcinoma (A, B) and adjacent noncancerous (C, D) tissues. A hK6 positive expression; B hK6 negative expression; C hK6 positive expression; D hK6 negative expression.

Figure 2

Kaplan–Meier survival curves shows the probability of being free of recurrence (A) and overall survival (B) in patients with hK6-negative and hK6-positive expression. Abbreviations: 95% CI 95% confidence interval, HR hazard ratio, OS overall survival, RFS recurrence-free survival.