A population-based cohort study “indicates that more extensive lymph node clearance during surgery for esophageal cancer may not improve survival,” Maartje van der Schaaf, MD, PhD, of the Karolinska Institutet, Stockholm, and colleagues reported in the Journal of the National Cancer Institute. “These results challenge current clinical guidelines, and further research is needed to change clinical practice,” the researchers asserted.
The study included 1,044 patients with esophageal cancer who had undergone esophagectomy between 1987 and 2010 in Sweden and were followed until 2012. Most patients (84.9%) were younger than 75 years old and male (74.8%).
“Analyzed as a linear variable, a higher number of lymph nodes removed did not influence the overall 5-year mortality,” the investigators stated. The adjusted hazard ratio (HR) was 1.00, with a 95% confidence interval (CI) of 0.99 to 1.01. “Patients in the third (7–15 nodes) and fourth (16–114 nodes) quartiles of removed nodes did not demonstrate any decreased overall 5-year mortality compared with those in the lowest two quartiles (< 7 nodes; HR = 1.13, 95% CI = 0.95–1.35 and HR = 1.17, 95% CI = 0.94–1.46, respectively).”
The authors noted that their results “are in line with two well-designed studies that found no survival difference between a more extensive lymphadenectomy via transthoracic esophagectomy and a more limited lymphadenectomy by a transhiatal approach.” In addition, “a randomized trial comparing two-field with three-field lymphadenectomy found no difference in survival.”
The current study, the authors added, “indicates that extensive lymphadenectomy might even increase mortality in early tumor stages.” In stages Tis to T1, “the hazard ratios indicated a worse survival with more lymphadenectomy using the median as cutoff (HR = 1.53, 95% CI = 1.13–2.06),” the researchers reported.
“Increased lymph node removal did not decrease mortality in any specific T stage. A greater number of metastatic nodes and a higher positive-to-negative node ratio were associated with strongly increased mortality. All results were similar when disease-specific mortality was analyzed,” according to the study report.
“A tailored lymphadenectomy that enables selective removal of metastatic nodes while leaving nonmetastatic nodes in place might be ideal, but it is currently difficult to identify metastatic nodes,” the investigators wrote. “Improvements in preoperative nodal staging and new biomarkers that can visualize metastatic nodes could tailor future nodal removal.” ■
van der Schaaf M, et al: J Natl Cancer Inst 107(5):djv043, 2015