Lymph node evaluation and survival after curative-intent resection of duodenal adenocarcinoma: A matched cohort study.

ABSTRACT

BACKGROUND: Lymph node (LN) metastasis in patients with duodenal adenocarcinoma is associated with poor prognosis; however, the optimal extent of LN assessment and the interaction between LN assessment and adjuvant systemic therapy is poorly understood. METHODS: Resected non-metastatic duodenal adenocarcinoma patients (n = 1743) were identified in the National Cancer Database (1998-2011). Logistic regression analysis identified covariates associated with LN metastasis. The influence of increasing LN cut-off points on overall survival (OS) was analysed using the log-rank test and Cox proportional hazards modelling. Adjuvant chemotherapy (AC) and surgery alone cohorts were matched (11) by propensity scores based on the likelihood of nodal metastasis or survival hazard on Cox modelling. OS in the matched cohort was compared by Kaplan-Meier estimates. RESULTS: LN metastases were present in 865 (49.6%) patients. Increasing LN assessment was associated with an increased likelihood of nodal involvement (P = 0.008). In node-negative patients, increasing LN assessment was associated with a decreased risk of death, with the largest actuarial survival differences observed for ≥15 LN (hazard ratio [HR] 0.63, 95% confidence interval [CI] 0.48-0.82, P = 0.001). In the propensity score-matched cohort of node-negative patients, AC was associated with non-significant improvements in 5-year actuarial (66.1% versus 58.7%, HR 0.79, 95% CI 0.53-1.18, P = 0.249), and did not vary by adequacy of LN counts (<15 LNs HR 0.79, 95% CI 0.51-1.24, P = 0.305; ≥15 LNs HR 0.90, 95% CI 0.35-2.30, P = 0.900). CONCLUSIONS: The extent of LN identification has prognostic significance in resected node-negative duodenal adenocarcinoma, but cannot be implicated in the selection of node-negative patients for AC.