Patients with Adenocarcinoma of the Small Intestine with 9 or More Regional Lymph Nodes Retrieved Have a Higher Rate of Positive Lymph Nodes and Improved Survival.

PURPOSE: To assess the influence of regional lymph node (RLN) retrieval on stage migration of adenocarcinoma of the small intestine and survival. PATIENTS AND METHODS: From the Surveillance, Epidemiology, and End Results database,1090 patients with nonmetastatic small bowel adenocarcinoma were identified in between 2004 and 2011. The impact of the number of RLNs removed on histopathological staging and oncological outcome was assessed utilizing Cox proportional hazard regression models with and without risk-adjustment, propensity score methods, and joinpoint regression analysis.
RESULTS: The rate of node-positive cancer increased steadily with the number of retrieved RLNs up to 9 RLNs, which suggests that a minimum of 9 (95 % CI 5.5–10.5) retrieved RLNs are needed for the detection of node-positive disease (P < 0.001). From 657 of 1090 patients (60.3 %), 9 or more RLNs were retrieved. While in 2004 only in 46.0 % of all cases 9+ RLNs were retrieved, this rate increased to 69.3 % in 2011 (P < 0.001). The multivariable analysis demonstrated that the retrieval of 9+ RLNs was associated with better overall (hazard ratio of death [HR] = 0.67, 95 % CI 0.55–0.82, P < 0.001) and cancer-specific survival (HR = 0.77, 95 % CI 0.61–0.96, P = 0.022). This finding was confirmed by a propensity score-adjusted analysis, which indicated increased overall (HR = 0.67, 95 % CI 0.50–0.89, P < 0.001) and cancer-specific survival (HR = 0.67, 95 % CI 0.49–0.92, P = 0.013) in patients with the retrieval of 9+ RLNs.
CONCLUSION: To our knowledge, this is the first population-based propensity score-adjusted investigation in small bowel adenocarcinoma. A sufficient number of RLNs should be retrieved to achieve an optimal oncological outcome