Expression of phosphorylated Akt (pAkt) in gastric carcinoma predicts prognosis and efficacy of chemotherapy

Abstract

Background. The Akt signaling pathway controls the survival and growth of human cancers. We investigated the expression of phosphorylated Akt (pAkt) in patients with gastric cancer. Methods. The expression of pAkt was immunohistochemically examined in 140 gastric cancer patients who underwent a gastrectomy. The expression of pAkt was evaluated based on staining intensity, and staining was classified as negative or positive. We examined the expression of pAkt and its association with the clinicopathological findings, prognosis, depth of invasion, the expression of p53, and efficacy of oral fluorouracil chemotherapy after surgery. Results. Expression of pAkt was positive in 81 (58%) patients and negative in 59 (42%) patients. There were no significant correlations between pAkt expression and the clinicopathological findings. The prognosis of patients with pAkt-negative tumors was superior to that of patients with pAkt-positive tumors, and the difference was significant for T3/T4 gastric cancer (P < 0.05). Among the patients with T3/T4 gastric cancer, postoperative oral fluorouracil treatment was effective in those who were pAkt-positive. Multivariate analysis revealed that pAkt expression and lymph node metastasis were independent prognostic factors. In 88 patients with T3 gastric carcinoma who had undergone curative surgery, in whom we studied the prognostic impact of a combined analysis of pAkt and p53 expression, patients with both pAkt- and p53-positive tumors showed a significantly poorer prognosis than patients with either or both pAkt- and p53-negative tumors (P < 0.05). Conclusion. Our results indicate that pAkt expression may be useful for predicting the prognosis and efficacy of fluorouracil treatment in patients with gastric cancer. © 2007 International and Japanese Gastric Cancer Association.