Phosphorylated AMP-activated protein kinase expression associated with prognosis for patients with gastric cancer treated with cisplatin-based adjuvant chemotherapy

Purpose The present study analyzed the expression of phosphorylated AMP-activated protein kinase (pAMPK), Fyn kinase, and pyruvate dehydrogenase kinase-1 (PDK-1) and their impact on the survival of patients with resected gastric cancer who received cisplatin-based adjuvant chemotherapy. Patients and methods Korean patients with stage II-IV (M0) gastric adenocarcinoma who underwent a gastrectomy with D2 lymph node resection and received a combination regimen of cisplatin and S-1 were enrolled. Immunohistochemistry was carried out to determine the expression of pAMPK, Fyn kinase, and PDK-1 in operative specimens of gastric cancer. The expression was divided into two groups according to the intensity score (negative: 0 or 1+ and positive: 2+ or 3+). Results From January 2006 to July 2010, 73 tumor samples obtained from 74 patients were analyzed. Forty patients were included in the pAMPK-positive group, while 33 patients were included in the pAMPK-negative group. Meanwhile, positive Fyn kinase expression was observed in only 10 patients (13.7 %), and there was no or very weak PDK-1 staining. The clinicopathologic characteristics were similar between the two groups according to the expression of pAMPK. With a median follow-up duration of 26.5 months (2.6-73.2), the estimated 3-year relapse-free survival (RFS) and overall survival rates were 55.0 and 78.4 %, respectively. In a multivariate analysis adjusted for age, sex, Lauren classification, and stage, the pAMPK-negative group was significantly associated with improved RFS (Hazard ratio = 0.459, 95 % CI 0.109-0.711, P = 0.043). Conclusion A low expression of pAMPK was found to be correlated with better RFS in patients with resected gastric cancer treated with adjuvant cisplatin-based chemotherapy.