Authors' Affiliations: Liver Cancer Institute and Zhongshan Hospital, Institutes of Biomedical Science, Department of Biostatistics, School of Public Health, Fudan University; Key Laboratory of Carcinogenesis and Cancer Invasion (Fudan University), Ministry of Education; Department of Abdominal Surgery, Fudan University Shanghai Cancer Center, Shanghai, China; Lombardi Cancer Center, Georgetown University, Washington, District of Columbia; and Laboratory of Human Carcinogenesis, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, Maryland.
To evaluate the value of serum midkine (MDK) as a diagnostic biomarker in hepatocellular carcinoma, particularly for those with negative alpha-fetoprotein (AFP) and at an early stage.
EXPERIMENTAL DESIGN: MDK expression in tumors was assessed by immunohistochemistry from 105 patients with hepatocellular carcinomas or liver cirrhosis. Serum MDK levels were detected by ELISA in 933 participants including hepatocellular carcinomas and hospital controls from different medical centers. Sensitivities and specificities of serum MDK in diagnosing hepatocellular carcinoma according to AFP level and Barcelona Clinic Liver Cancer (BCLC) stage were analyzed.
RESULTS: MDK levels were significantly elevated in hepatocellular carcinoma tissues as well as serum samples. The sensitivity of serum MDK for hepatocellular carcinoma diagnosis was much higher than that of AFP (86.9% vs. 51.9%) with similar specificities (83.9% vs. 86.3%). Notably, serum MDK had an outstanding performance in distinguishing AFP-negative hepatocellular carcinomas from different controls: In those AFP-negative hepatocellular carcinomas, the sensitivity could reach as high as 89.2%. Moreover, receiver operating characteristic (ROC) curve analysis also showed that serum MDK had a better performance compared with AFP in distinguishing early-stage hepatocellular carcinomas as well as small hepatocellular carcinomas. Even in very early-stage hepatocellular carcinomas, MDK showed an obviously higher sensitivity compared with AFP (80% vs. 40%). Furthermore, serum MDK level was significantly decreased in patients with hepatocellular carcinomas after curative resection and re-elevated when tumor relapse occurred.
CONCLUSIONS: Serum MDK is significantly elevated in most hepatocellular carcinomas, including those with negative AFP and at an early stage, which may serve as a novel diagnostic marker in early diagnosis and postoperative monitoring of hepatocellular carcinomas.