Cytokeratin 18 for chemotherapy efficacy in gastric cancer

Abstract

Cytokeratin 18 (CK18) is the major component of intermediate filaments in epithelial cells and released into the blood in either intact (M65) or caspase-cleaved forms (M30) during apoptotic and necrotic cell death. M30 and M65 are relatively described as novel sandwich ELISA assays that determine different circulating forms of the protein CK18 in either plasma or serum and are proposed to be surrogate endpoints of different forms of cell death. Serum M65 and M30 levels have shown to be elevated in patients with different types of carcinoma. The measurement of M30 or M65 values from epithelial-derived tumors could be a simple, noninvasive way to monitor or predict tumor progression and prognosis. Recently, predictive significance of the increase in the serum M30 and M65 values after chemotherapy in patients advanced non-small cell lung cancer (NSCLC) and gastric cancer have been evaluated. It shown that increased serum M65 levels, 48 hours after chemotherapy, could be predicted tumor response in advanced-gastric cancer patients. Although these assays may be useful for evaluating treatment effects and survival in patients with gastric cancer, their importance should be tested after multiple chemotherapy sessions in larger prospective studies with long follow-up time. In this review, prognostic and predictive significance of CK18 for advanced-gastric cancer are summarized in the light of recent advances.