Prognostic Significance Of Lymphadenectomy In Patients With Esophageal Cancer Receiving Neoadjuvant Chemoradiation.

87 Background: The optimal number of lymph nodes that should be harvested in esophageal cancer patients remains to be defined, particularly in patients that receive neoadjuvant therapies. We investigated the impact of nodal resection and survival in esophageal cancer patients treated with neoadjuvant chemoradiation (NT). Methods: Using our comprehensive esophageal cancer database we identified patients treated with NT followed by esophagectomy between 2000-2011. Clinical and pathologic data were compared using Fisher’s exact and chi-square while, Kaplan Meier estimates were used for survival analysis. Overall (OS) and disease-free survival (DFS) were compared with varying numbers of lymph nodes resected <10 and ≥10 (ST-1), <12 and ≥12 (ST-2), and <15 and ≥15 (ST-3). Multivariate analysis was analyzed by the Cox proportional hazard model. Results: We identified 358 patients treated with NT and esophagectomy with a median follow-up of 18.5 months (range, 0-116 months). There was no survival benefit demonstrated for patients with increased lymph nodes removed during their surgery (ST-1 OS p=0.400, DFS p=0.8727; ST-2 OS p=0.6833, DFS p=0.6092; ST-3 OS p=0.1798, DFS p=0.4028). Patients were further stratified by pathologic response to NT and nodal harvest. There were no differences in OS or DFS in patients with increased nodal harvest when analyzed by complete (pCR) (ST-1 OS p=0.7278, DFS p=0.3602; ST-2 OS p=0.6182, DFS p=0.3592; ST-3 OS p=0.4489, DFS p=0.6976), partial (pPR) (ST-1 OS p=0.3762, DFS p=0.5061; ST-2 OS p=0.8036, DFS p=0.6497; ST-3 OS p=0.0890, DFS p=0.3364), or non response (pNR) (ST-1 OS p=0.6825, DFS p=0.7161; ST-2 OS p=0.7084, DFS p=0.8351; ST-3 OS p=0.5002, DFS p=0.7314) to NT. Multivariate analysis demonstrated that age (p=0.028), t-stage (p=0.006), pPR (p=0.025), and pNR (p<0.0005) to NT were all independent predictors of mortality. Conclusions: In our experience, the number of lymph nodes resected was not predictive for overall or disease free survival in esophageal cancer patients treated with NT. In addition, extended lymph node resection did not improve survival for those with residual disease.