Ambar Banerjee, MD, Lee Coghill, BS, Elango Edhayan, MD, Richard Berri, MD. Department of Surgery, Division of Surgical Oncology, St John Hospital and Medical Center Detroit, MI, USA.
Surgical resection of pancreatic adenocarcinoma is associated with low survival rates, even with curative resections. Our study investigated the impact of positive to recovered lymph node ratio (LNR) as a predictor of survival following pancreatic resection at an independent academic center.
Materials and Methods
Following Institutional Review Board (IRB) approval, retrospective analysis of a prospective pancreatic cancer database was conducted. The study population underwent surgical resection of pancreatic ductal adenocarcinoma between 2001 and 2011. The interval between the dates of pancreatic resection until death was considered as the duration of disease-specific survival. Metastatic lymph node ratio (LNR) was calculated as the ratio of the number of lymph nodes harboring metastatic cancer to the total number of nodes examined. Demographics and patient characteristics were analyzed with descriptive statistics. Chi-square test and t-test assessed nominal and continuous variables. Univariate survival statistics were analyzed by Kaplan-Meier method with log-rank test. P-value < 0.05 was considered significant.
44 patients (mean age 65.7yrs) who underwent resection for pancreatic ductal adenocarcinoma were included in the study. The patient population comprised of 24 females. The mean tumor size was 3.47 ± 1.82 cms. The average number of nodes examined and nodes involved with cancer were 11.11 ± 6.8 and 1.7 ± 3.5 respectively. Subjects were divided into 3 subgroups based on their LNR status: Group 1 – 0 ; Group 2 – > 0 to 0.2, and Group 3 – >0.2. 21 of 44 patients did not demonstrate any lymph node involvement in final pathology. The mean survival in patients with LNR ≤ 0.2 was 694 ± 123 days while that in those with LNR > 0.2 was 311 ± 118 days (p=0.094)
The LN ratio may be an independent predictor of survival after pancreatic cancer resection. The routine estimation of the LN ratio may help formulation of appropriate adjuvant therapy regimens to improve the long-term outcome and survival in this population.