261 Background: We conducted chemoradiotherapy of gemcitabine plus S-1, key drugs for pancreatic cancer. Methods: Patients were eligible for the study if they had received a histopathological diagnosis of locally advanced pancreatic cancer and were diagnosed as unresectable by multiple clinicians including surgeons due to main arterial invasions and more. Radiation (RT) was perfomed for twenty-eight days continuously except Saturday, Sunday and National holiday in 1.8Gy once daily (total 50.4Gy). PTV was defined as GTV plus 10-15mm. Prophylactic irradiation to regional lymph nodes was not performed. Administration level of the anti-cancer drugs was referred to the following table. Results: A total of fifteen cases were enrolled to the phase I study from February, 2006 through May, 2007. RT was achieved in 13 of 15 cases (87%). Two cases of DLT occurred in level 2 (two cases of emesis) while three did in level 3 (one case of emesis and two of neutropenia of grade 4). We decided level 3 as MTD and level 2 as recommended dose. The overall response rate (more than PR) was 33.3% (5 in 15 cases) and tumor-control (more than SD) was achieved in 13 of 15 cases (87%). The one-year and two-year survival rate was 86.7% and 44.4%, respectively. Conclusions: We conducted the phase 1 study of chemoradiotherapy with two key drugs of pancreatic cancer and achieved the recommended dose in this phase I study. Ongoing study We have already finished the enrollment of 110 cases for a phase II randomized allocated study, comparing the chemoradiotherapy of administration dose decided in this phase 1 study with the combination therapy of gemcitabine plus S-1. Now we are carefully following the patients to compare two-year survival rate as a primary endpoint in phase II study. Clinical trial information: NCT01430052.
A phase 1 study of veliparib, a PARP-1/2 inhibitor, with gemcitabine and radiotherapy in locally advanced pancreatic cancer