Incorporating Surgical Quality into the AJCC 7th Edition Improves Staging Accuracy in Gastric Cancer

BACKGROUND:The staging of gastric cancer has become increasingly complex. With an emerging 15-node quality measure and a revised American Joint Committee on Cancer (AJCC) staging system, we evaluated the need for more intricate staging systems to predict survival outcomes in gastric cancer.METHODS:The Surveillance, Epidemiology and End Results Program (SEER) database was used to identify 124,972 patients with gastric cancer between 2000 and 2010. Primary endpoints were 5-year disease-specific survival (DSS) and overall survival (OS). Analysis was performed on patients with ≥15 nodes evaluated. Multivariable regression with/without the inclusion of lymph node (LN) assessment and LN ratio were compared using the Akaike information criterion.RESULTS:The number of patients included in the final analysis was 12,096. The proportion of patients with an adequate lymphadenectomy increased markedly from 27 % in 2000 to 52 % in 2010. Overall 5-year DSS and OS was 61.9 and 48.8 %, respectively, for patients with ≥15 nodes examined, versus 57.7 and 39.9 %, respectively, for those with <15 sampled nodes (p < 0.0001). In patients with ≥15 nodes evaluated, the addition of LN evaluation and LN ratio to the existing staging model improved its ability to predict 5-year DSS and OS (p < 0.0001). LN evaluation and LN ratio were comparable in their ability to supplement the existing AJCC 7th edition (AJCC7) staging system.CONCLUSION:The inclusion of a minimum 15-LN quality measure improves the prognostic ability of the AJCC7 staging system, without adding significant complexity.