Standard Versus Extended Lymphadenectomy in Pancreatoduodenectomy for Patients With Pancreatic Head Adenocarcinoma

Pancreatic cancer is a common malignant disease of the digestive system, and its incidence has been steadily increasing recently. Currently, the only potential curative treatment for pancreatic cancer is radical surgery. However, due to the peculiarity of the anatomical location of pancreas (in the retroperitoneum, surrounded by peripheral nerves and blood vessels) and its biological characteristics (neurotropic, highly malignant, and with probable skip metastasis), it is difficult to achieve R0 resection in patients with pancreatic cancer. High postoperative recurrence and distant metastasis rate are key factors in reducing long-term survival of patients with pancreatic cancer. The radical surgery modalities for pancreatoduodenectomy to achieve R0 resection involve extended lymphadenectomy, multivisceral resections, with or without simultaneous vein removals. Currently, the lymphadenectomy extent and approaches used to achieve R0 status are diverse. In 2014, the International Study Group for Pancreatic Surgery (ISGPS) reached a consensus to strive to resect lymph nodes (LNs) 5, 6, 8a, 12b1, 12b2, 12c, 13a, 13b, 14a, 14b, 17a, and 17b in standard lymphadenectomy for pancreatoduodenectomy. However, no consensus was reached on dissection of LN 16 due to variation in the literature and different expert opinions. On the current evidence, benefit of extended lymph node dissection seems to be outweighed by the risks. But deficiencies exist in the design of previous RCTs, such as insufficient sample size, lack of certain critical data for statistical analysis, inclusion of other pathological types of pancreatic neoplasms and variable retroperitoneal lymph node resection and nerve plexus dissection . Therefore, the power of evidence was low. Most studies report a high frequency of lymph node metastasis to LNs 13, 14, 17, 12 and 16 in pancreatic cancer, and tendency to metastasis from LNs 13, 14 to LN 16. In a lot of case reports, only nodal station 16a2 and 16b1 were positive in LN 16. This study is performed to confirm whether pancreatoduodenectomy with extended lymphadenectomy could improve survival. Subjects undergoing surgery will be randomized to pancreatoduodenectomy with extended lymphadenectomy including nerve tissues around CHA and the SMA and nodes around the celiac trunk and SMA (No.16a2, 16b1) versus standard pancreatoduodenectomy. Subjects will be followed every three months for survivorship or death. The primary endpoint of 5-year overall or disease-free survival survival will be determined at five year post surgery.