Tumor Size and Depth Predict Rate of Lymph Node Metastasis and Utilization of Lymph Node Sampling in Surgically Managed Gastric Carcinoids

Abstract

Radical resection with regional lymphadenectomy is recommended for all sporadic gastric carcinoids. Local resection, however, is accepted for some carcinoids from other gastrointestinal sites (i.e., appendix and rectum). We sought to examine the relation of tumor size and depth to lymph node metastasis to determine whether gastric carcinoids can be selected for endoscopic resection. We also sought to quantify the utilization of lymph node sampling. 984 patients with localized gastric carcinoids who underwent cancer-directed surgery between 1983 and 2005 were identified from the Surveillance, Epidemiology, and End Results (SEER) registry database. Tumor size and depth predicted probability of lymph node metastasis. Lymph node metastasis was not seen in intraepithelial (IE) tumors <2 cm. Of tumors <1 cm invading into the lamina propria or submucosa (LP/SM), 3.4% had lymph node metastasis. Excluding IE tumors <2 cm and LP/SM tumors <1 cm, all other subgroups based on size and depth had rates of lymph node metastasis ≥ 8%. Tumor size and depth predicted probability of lymph node sampling. Overall, only 21% of tumors had lymph node sampling. Excluding IE tumors <2 cm and LP/SM tumors <1 cm, only 43% of tumors had lymph node sampling. Tumor size and depth predict lymph node metastasis for gastric carcinoids. Endoscopic resection may be appropriate for intraepithelial (IE) tumors <2 cm and perhaps tumors <1 cm invading into the lamina propria or submucosa. Lymph node sampling is underused for gastric carcinoids at high risk for lymph node metastasis.