The clinical impact of the novel tumor marker DR-70 in unresectable gastric cancer patients

Background: Gastric cancer tumor markers, such as carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA 19-9), have been applied in clinical practice to screen or monitor treatment responses. However, their sensitivity and specificity are unsatisfactory. Therefore, we assessed the novel tumor marker DR-70 and evaluated its performance in screening and response monitoring. Methods: The study included newly diagnosed patients with advanced gastric cancer from March 2012 to October 2015. We measured the DR-70, CEA, and CA 19-9 levels at the time of enrollment. The patients subsequently underwent chemotherapy. We followed-up the patients every 3 months; DR-70 levels and abdominal computed tomography scans were re-evaluated and repeated, respectively, at each follow-up. The correlation between treatment response and DR-70 level after chemotherapy was analyzed. The overall survival and progression-free survival rates were also evaluated. Results: A total of 51 patients with gastric cancer were enrolled. Most (82.4%) had metastatic disease. At enrollment, the sensitivity of DR-70 in our study group was 78.4%, compared with 52.9% and 43.1% for CEA and CA 19-9, respectively. When we used the three tumor markers together, the sensitivity increased to 80.4%. We observed a correlation between treatment response and DR-70 level after chemotherapy. No difference in either overall survival or progression-free survival was observed between the DR-70 positive and negative groups. However, a trend toward poorer overall survival was observed for the high DR-70 group, although this was not statistically significant. Conclusion: DR-70 is a powerful tool not only for screening unresectable gastric cancer but also for treatment response evaluation.