Lymph Node Involvement in Standard Lymphadenectomy for Resectable Pancreatic Head Adenocarcinoma

Abstract

Introduction: The treatment of pancreatic cancer (PC) is an interdisciplinary challenge as its prognosis remains poor and long-term survival is only 1-5%. At first diagnosis, only 10%-20% of PC patients present with primarily resectable disease while there is locally advanced, non-metastatic PC in up to 30% of the cases. This prospective study was designed to access the lymph node involvement in 116 patients with resectable pancreatic head or uncinate process carcinoma undergoing pancreaticoduodenectomy (PD) with standard lymphadenectomy followed by adjuvant chemotherapy and external beam radiation therapy. Method(s): The medical records of 116 consecutive patients (83 males and 33 females aged between 28 and 73 years) treated for pancreatic head or uncinate process adenocarcinoma at the Naval Hospital of Varna, Bulgaria between January 2004 and December 2013 were analyzed. A distal gastrectomy (classicWipple's procedure) was done in 81 patients but pylorus preservation in 35 ones. Vascular resection was performed in 18 patients. For the standard lymphadenectomy nodes to the right of the hepatoduodenal ligament (12B1, 12B2, and 12C), anterior and posterior pancreaticoduodenal nodes (17A, 17B, 13A, and 13B), nodes to the right of the superior mesenteric artery (14A and 14B), and nodes anterior to the common hepatic artery (8A) were harvested en bloc. Postoperative adjuvant therapy was performed in 80% of the patients without lymph node metastases and in 66,67% of those with such metastases (p < 0.001). Identification of nodal stations was based on the Japan Pancreas Society classification. Result(s): R0 operation was done in 66 cases, R1 - in 46, and R2 - in four only. Morbidity and mortality rates after PD were 53.45% (n = 62) and 5.17% (n = 6), respectively. Local recurrence was observed in 17 patients but distant one in 63 patients. The number of retrieved lymph nodes in the standard lymphadenectomy was >=15. Some 81 (69.82%) patients who underwent PD were lymph-node positive. The lymph-node areas most affected were station 13 (n = 24), 17 (n = 17) and 14 (n = 13) followed by stations 12 (n = 5) and 8A (n = 2) (p = 0.016). Twenty patients presented with lymph node metastases in two or more nodal stations. Our data showed that PC adenocarcinoma tended to metastasize to anterior/posterior pancreaticoduodenal nodes and nodes to the right of the superior mesenteric artery in 77 (66.38% of the cases). Lymph node status was the main risk factor for poor survival. Conclusion(s): Recent prospective randomized trials have convincingly indicated that the limited resection (conventional Whipple's procedure or pylorus preservation with standard lymphadenectomy) accompanied by adjuvant chemotherapy is an acceptable alternative. This change in the surgical dogma reflects the new argument that PC must be managed as a systemic disease, even in patients with evidence of only local or regional disease. Consequently, any effort for local control can exert a little effect on survival only. This finding confirms the fact that the biology of disease remains the most important determining factor affecting the final outcome, despite the progress in surgical technique and systemic therapy.