Background: The frequency of lymph node metastasis in each T stage of gastric cancer has not been as well described for Western populations as it has for Asian populations. This study aimed to determine these frequencies and to investigate risk factors associated with lymph node metastases in a racially diverse U.S.
Methods: A prospectively maintained database of 8260 patients with gastric or gastroesophageal junction adenocarcinoma treated at our institution from 1995 to 2013 was reviewed to identify those who underwent surgical resection without preoperative therapy. Associations between clinicopathologic variables and lymph node metastasis were tested with uni- and multivariate analyses.
Results: The study identified 218 patients with a pathologic diagnosis of gastric adenocarcinoma who underwent upfront gastrectomy. These study subjects included 115 white (53 %), 19 black (9 %), and 41 Asian (19 %) patients. At least 15 lymph nodes were examined in 148 (68 %) of the patients. The lymph node metastasis rates were 10 % for stage T1a, 34 % for stage T1b, 44 % for stage T2, 73 % for stage T3, and 95 % for stage T4 tumors. Univariate analysis showed that submucosal invasion, race, 15 or more lymph nodes examined, and lymphovascular invasion were associated with lymph node metastasis in T1 and T2 tumors. The multivariate analysis showed all but lymphovascular invasion to be independent risk factors for nodal metastasis.
Conclusions: The rates of lymph node metastasis observed in this study were higher than those reported in Asian reports. Race was an independent risk factor for lymph node metastasis. Caution is therefore needed when evidence from Asian countries is extrapolated to more racially diverse Western countries.