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

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.

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 (1:1) 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.

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).

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.