Neoadjuvant Chemoradiotherapy for Resectable and Borderline Resectable Pancreatic Cancer

Abstract

The standard treatment of potentially resectable pancreatic cancer is surgery followed by adjuvant chemotherapy. Recently there have been some prospective reports that neoadjuvant therapy has improved survival. At our institution, we have been conducting both neoadjuvant chemoradiotherapy (NACRT) and adjuvant chemotherapy (AdjCx) for resectable (R) and borderline resectable (BR) pancreatic cancer patients. The aim of this study is to evaluate outcomes and feasibility of this strategy. From 2008 to 2018, 104 consecutive pancreatic cancer patients who were treated with NACRT at our institution were reviewed retrospectively. NCCN criteria 2016 were used for resectability. All patients were planned to be treated with concurrent chemotherapy (Gemcitabine; GEM, Gemcitabine+S-1;GS or S-1) and radiotherapy (50.4Gy in 28 fractions). Approximately one month after the end of the NACRT, patients were evaluated for resectability using CT and MRI. Patients without newly detected distant metastases or unresectable features were referred for surgery. After surgery, patients were referred to receive AdjCx (S-1 or GEM). Seventy-nine patients were diagnosed as R, and 25 patients were diagnosed as BR. UICC clinical stage IA/IB/IIA/IIB/III were 10/7/65/13/9. Concurrent chemotherapy regimens were GEM/GS/S-1 in 1/1/102 cases. One-hundred two patients completed NACRT, and among them 26 patients needed interruption. There were acute grade 3 hematological and non-hematological toxicities in 10 (10%) and 13 (13%) of cases, respectively. There were no grade 4 or greater toxicities. Resection was performed in 72 (69%) of patients; the reasons for unresectability were as follows, distant metastasis in 14 cases, local progression in 5 cases, patient refusal in 9 cases and other medical condition in 4 cases. The median OS, 2-year OS and 5-year OS for resected patients were 44.6 months, 69% and 35%, respectively, and those for unresected patients were 17.0months, 23% and not available, respectively (p<0.05). Among resected patients, R0 resection rate was 93%. 83% of patients could receive AdjCx. The median OS were 47.0 months for R patients and 18.5 months for BR patients (p<0.05). Recurrence was observed in 39 (54%) of 72 resected patients, the first recurrence in local site were 5 (7%) cases and in distant site were 34 (47%) cases. Based on our results, neoadjuvant chemoradiotherapy was feasible with its favorable prognosis and limited toxicity. Further experience is necessary.