Early initiation of chemotherapy after histological diagnosis to improve the prognosis of metastatic pancreatic ductal adenocarcinoma.
273 Background: Since pancreatic ductal adenocarcinoma (PDAC) shows aggressive progression, we speculate that prolonged waiting time after detection of disease until initiation of treatment may relate to prognosis of patients with advanced diseases. Methods: We included patients diagnosed to have metastatic PDAC in Fukushima Medical University between September 2006 and January 2014. All patients underwent more than 2 cycles of gemcitabine treatment (1,000 mg/m2 on days 1, 8, and 15 of a 28-day cycle) after confirming histological diagnosis. We classified waiting time as Time A (detection-to-diagnosis waiting time) and Time B (diagnosis-to-treatment waiting time). Each period was further divided into 2 groups (shorter [-short] or longer [-long] waiting time than median length of each waiting time group). Kaplan-Meier methods, log-rank test and Cox proportional hazard methods were used to analyze overall survival (OS). Results: Twenty three patients were included. Median age was 64 (49-75) and length of waiting time was 19.5 days (4-78) in Time A and 9.0 days (2-34) in Time B. Regarding Time A, there was no significant difference in median OS between Time A-short and Time A-long (198.5 vs. 197.0 days; hazard ration [HR] 1.096; 95% confidential interval [CI] 0.4822-2.537; P=0.81). On the other hand, median OS was significantly better in Time B-short than Time B-long (median OS 290 vs. 160 days; HR, 0.381; 95% CI, 0.096-0.622; P= 0.0078). Conclusions: We foundthat waiting time between disease detection and diagnosis didn’t impact on prognosis of metastatic PDAC contrary to our speculation. However, patients with short waiting time (less than 9 days) after diagnosis until initiation of first chemotherapy had better prognosis than patients who had long waiting time. These findings suggest that early initiation of chemotherapy after histological diagnosis can improve the prognosis of metastatic PDAC.