Long-term outcomes of standard versus extended lymphadenectomy in pancreatoduodenectomy for pancreatic ductal adenocarcinoma: A Chinese multi-center prospective randomized controlled trial

INTRODUCTION: The value of extended lymphadenectomy in pancreatoduodenectomy (PD) has been discussed by five randomized controlled studies. However, the limitations in the studies made their conclusions not sufficiently reliable. OBJECTIVES: This multi-center randomized controlled study was designed to clarify the efficacy of extended lymphadenectomy in PD for pancreatic ductal adenocarcinoma (PDAC). METHODS: From December 2016 to October 2018, 170 consecutive patients undergoing PD were enrolled and randomized to standard or extended lymphadenectomy for the treatment of PDAC from three high-volume institutions in China. Demographic, pathological characteristics and survival data of these patients were collected and analyzed. No neoadjuvant treatment was performed. The primary endpoint was the 3-year overall survival. RESULTS: For all patients, the 3-year survival rate was 25.88 %. There was no between-group difference in 3-year survival rate (27.16 % vs 24.72 % p = 0.717). The median survival time for the standard group was 18 months, while for the extended group it was 15 months. The demographic and pathological characteristics were similar between groups. More positive lymph nodes could be found in the extended group (2.34 ± 3.46 vs 1.41 ± 2.12, p = 0.035), which led to nodule stage migration. All patients received chemotherapy. But patients in extended group were more likely to fail in completion of all-cycles chemotherapy before recurrence (31.46 % vs 17.28 %, p = 0.032). Incomplete chemotherapy before recurrence, higher N status and abnormal CA125 were independent risk factors for 1-year survival (p < 0.001, 95 % CI 0.076–0.368; p = 0.017, 95 % CI 1.113–3.021; p = 0.021, 95 % CI 1.136–4.960, respectively), which was higher in the standard group (75.31 % vs 58.43 %, p = 0.020). CONCLUSION: The extended lymphadenectomy in PD did not improve the long-term survival in patients with PDAC. Patients with extended lymphadenectomy had a worse 1-year overall survival. However, the nodule stage migration facilitated by the extended lymphadenectomy contributed to the precise tumor staging.