Concurrent gemcitabine+S-1 neoadjuvant chemotherapy contributes to the improved survival of patients with small borderline-resectable pancreatic cancer tumors

In the surgical treatment of pancreatic cancer, margin-negative status is one of the most important determinants of survival. We conducted this study to explore surgical margin status as well as other factors affecting the survival of borderline-resectable pancreatic cancer (BRPC) patients who received neoadjuvant chemotherapy with gemcitabine and S-1. Eighteen BRPC patients were prospectively treated with concurrent gemcitabine and S-1 neoadjuvant chemotherapy (NAC+) and 15 of these patients underwent resection. We evaluated the safety and efficacy of this treatment regimen by comparing the outcomes of these patients with those of 19 BRPC patients who did not receive neoadjuvant chemotherapy (NAC−) during the same period. Fifteen (83 %) of the NAC+ patients underwent pancreatectomy. The remaining three patients (17 %) had regional tumor progression or liver metastasis. Of the 15 NAC+ patients who underwent resection, 3 (20 %) had margin-positive status, whereas 9 of the 19 (43 %) NAC− patients had margin-positive status (p = 0.002). However, disease-free survival and overall survival were similar in the two groups (MST 21.7 vs. 21.1 months). NAC+ patients with tumors smaller than 30 mm had favorable overall survival (MST 43.9 vs. 23.1 months, p = 0.0321). Most recurrences developed at distant sites rather than locally in both groups. In the neoadjuvant setting, gemcitabine and S-1 improved the negative surgical margin rate in BRPC patients, but it did not improve survival. Thus, neoadjuvant chemotherapy should be given to BRPC patients at an earlier stage.