JCOG2202: Randomized phase III trial of laparoscopic versus open distal pancreatectomy for pancreatic cancer

INTERVENTION: Arm A: Open distal pancreatectomy with regional lymph node dissection + adjuvant chemotherapy (S‐1 X4 cycle) Arm B: Laparoscopic distal pancreatectomy with regional lymph node dissecton + adjuvant chemotherapy (S‐1 X4 cycle) *Robot‐assisited distal pancreatectomy is allowed in arm B *S‐1: 80‐120 mg/body, day 1‐28, by mouth, twice daily CONDITION: Resectable pancreatic cancer PRIMARY OUTCOME: Overall survival SECONDARY OUTCOME: Recurrence‐free survival, Proportion of patients with R0 resection, Operation time, Estimated blood loss, Maximum incision length, Proportion of patients with completion of laparoscopic surgery, Incidence of surgical adverse events, Perioperative mortality rate, Length of postoperative hospital stay INCLUSION CRITERIA: (1) Pancreatic tumor diagnosed by contrast‐enhanced abdominal computed tomography (CT) meeting either one of the following conditions. (i) Histologically proven invasive ductal carcinoma (adenocarcinoma or adenosquamous carcinoma) (ii) Cytologically proven Class IV or Class V In case of the following conditions, pancreatic tumor radiologically compatible with invasive ductal carcinoma is eligible without pathological diagnosis. (a) No neoadjuvant chemotherapy (b) Endoscopic ultrasound‐guided tissue acquisition or endoscopic retrograde cholangiopancreatography can not be performed safely. (2) Tumor located in the body or tail of the pancreas. (3) Resectable pancreatic cancer by contrast‐enhanced CT. Patients treated with preoperative chemotherapy fulfill both (i) and (ii). (i) Resectable pancreatic cancer before chemotherapy. (ii) Resectable pancreatic cancer after chemotherapy. (4) Muximum length of the tumor <= 8 cm. (5) Curative re