Pawlik TM, Abdalla EK, Barnett CC, Ahmad SA, Cleary KR, Vauthey JN, Lee JE, Evans DB, Pisters PWT. Feasibility of a randomized trial of extended lymphadenectomy for pancreatic cancer.
ACTA ACUST UNITED AC 2005;
140:584-9; discussion 589-91. [PMID:
15967906 DOI:
10.1001/archsurg.140.6.584]
[Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
HYPOTHESIS
The required sample size of a prospective randomized trial comparing standard pancreaticoduodenectomy with pancreaticoduodenectomy plus extended lymphadenectomy for pancreatic adenocarcinoma is prohibitively large, making such a trial infeasible.
DESIGN
Retrospective cohort study.
SETTING
Comprehensive cancer center.
PATIENTS
We identified 158 patients who underwent pancreaticoduodenectomy for pancreatic adenocarcinoma with separate pathologic analysis of second-echelon lymph nodes, defined as lymph nodes along the proximal hepatic artery and/or the great vessels.
MAIN OUTCOME MEASURES
To estimate the sample size required for a randomized trial, we devised a biostatistical model with the following assumptions: extended lymphadenectomy can benefit only patients who (1) actually have disease removed from second-echelon nodes, (2) have microscopically negative (R0) primary tumor resection margins, and (3) do not have visceral metastatic (M0) disease.
RESULTS
Seventy-six patients (48.1%) had negative first- and second-echelon lymph nodes, 65 (41.1%) had positive first-echelon and negative second-echelon lymph nodes, and 17 (10.8%) had positive first- and second-echelon lymph nodes. Patients with positive second-echelon lymph nodes had an R0 resection rate of 47.1%. At a median follow-up of 65.1 months, 4 patients with positive second-echelon lymph nodes were alive, but 3 had recurrent disease. This implies that only 1 patient (5.9%) with positive second-echelon lymph nodes may have had true M0 disease. Therefore, only 0.3% of patients (10.8% with positive second-echelon lymph nodes x 47.1% with R0 resection x 5.9% with M0 disease) may achieve a survival benefit from extended lymphadenectomy. A randomized trial of standard pancreaticoduodenectomy vs pancreaticoduodenectomy with extended lymphadenectomy would require 202 000 patients in each study arm to detect such a small difference.
CONCLUSIONS
Definitive evaluation of the potential benefits of extended lymphadenectomy would require a prohibitively large sample size. Adequately powered randomized trials to address the potential benefit of extended lymphadenectomy are infeasible.
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