Tumor Size and Depth Predict Rate of Lymph Node Metastasis and Utilization of Lymph Node Sampling in Surgically Managed Gastric Carcinoids
Riad H. Al Natour1, MD, Mandeep S. Saund1, MD, Qin Huang1, MD, Valia Boosalis2, MD, Jason S. Gold1, MD
1VA Boston Healthcare Systems, 2Brigham and Women’s Hospital, West Roxbury, MA
PURPOSE OF STUDY
Radical resection with regional lymph node dissection is recommended for all sporadic gastric carcinoids. Local resection, however, is accepted for carcinoids from other sites. Rates and predictors of lymph node metastasis (LNM) for gastric carcinoids are not known. We sought to determine the relation of tumor size and depth to LNM and to quantify the utilization of lymph node sampling (LNS).
The Surveillance Epidemiology and End Results Registry was used to identify 984 patients with localized gastric carcinoids who underwent cancer directed surgery between 1983-2005. SPSS was used for statistical analysis.
SUMMARY OF RESULTS
Tumor size and depth predicted probability of LNM for gastric carcinoids (p<0.001, p<0.001). While 2.0% of all tumors <1cm had LNM (Table), this rate was 6.4% for tumors <1cm with LNS. Applying the AJCC classification, 1.5% of all Tis tumors had LNM (11.8% for tumors with LNS). For Tis tumors, all patients with LNM were ≥2cm. For T1 tumors <1cm, 3.4% had LNM (5.6% of T1 tumors <1cm with LNS). Excluding Tis tumors <2cm and T1 tumors <1cm, all other subgroups based on size and depth had rates of LNM >7%. Smaller tumors and superficial tumors were less likely to have LNS (p<0.001, p<0.001). Time period and race also predicted LNS (p=0.04, p<0.001). Overall, only 21% of tumors had LNS. Excluding Tis tumors <2cm and T1 tumors <1cm, only 43% had LNS.
Tumor size and depth predict LNM for gastric carcinoids and may help select patients for local resection. LNS is underused for gastric carcinoids at risk for LNM.
TABLES AND CHARTS
Table. Rate of Lymph Node Metastasis of Gastric Carcinoids Subgrouped by Tumor Size and Depth