Role of para-aortic lymph node sampling for patients with potentially resectable biliary cancer.

Abstract

540 Background: While paraaortic lymph node (PALN) metastasis has been known as poor prognostic indicator for patients with biliary cancer and is regarded as distant metastasis in AJCC staging system. However, preoperative diagnosis of PALN metastasis by current imaging studies is not accurate and the incidence of PALN metastasis among patients with potentially resectable biliary cancer and its impact on their long-term outcomes remain unclear. Methods: The patients who underwent exploratory laparotomy with PALN sampling for potentially resectable biliary cancer at our institution from 2006 through 2018 were included. All patients were appropriately staged preoperatively with CT/MRI and patients with suspected PALN metastasis preoperatively were not considered resectable disease, and thus, such patients were not included. The incidence of PALN metastasis and long-term outcomes (recurrence-free and overall survivals [RFS, OS]) for patients with/without PALN metastasis were compared. Results: Total 383 patients with three types of biliary cancers (164 perihilar cholangiocarcinoma [PHCC], 115 distal cholangiocarcinoma [DCC] and 104 gallbladder cancer [GBCA]) were included. The median age was 71 years and 65% were man. Majority of them (362 patients [95%]) completed planned resection and 9 patients (2%) died of post-operative complications. PALN metastasis was confirmed on 33 patients (9%) among the entire cohort; the yield of positive PALN sampling was the highest in the patients with GBCA (14%), followed by 9% in those with PHCC and 4% in those with DCC. Among 33 patients with positive PALN, 20 underwent tumor resection. Median RFS and OS following resection for the patients with PALN metastasis were 11 months and 22 months, respectively, compared to 46 months and 56 months for those without, respectively ( p< 0.001 for both RFS and OS). There were no survivors beyond 5-years among those with PALN metastasis. Conclusions: The yield of routine intraoperative PALN sampling is not small even among patients with potentially resectable biliary cancer and positive PALN indicates poor long-term outcomes. This procedure can provide the opportunity to avoid morbid operation for patients who unlikely benefits.