Abstract
BACKGROUND: Surgical resection with lymph node dissection is the primary therapeutic modality for gastric cancer. National Cancer Database (NCDB) was used to determine the extent of lymph nodes (LNs) dissection for gastric cancer. METHODS: The NCDB was queried from 2004-2013 for patients with margin-negative, invasive resected gastric cancer. The optimal number of LNs dissected was determined using a univariate χ(2) cut-point analysis. Multiple sensitivity analyses were utilized to decrease bias. RESULTS: A total of 17,851 patients were included. For all patients, the optimal number of LNs needed to be examined was 20+ nodes. When correcting for stage migration (<7 LNs removed), the optimal cut-off value was 20+ LNs. When stratifying by pathologic nodal stage, the cut-off point was 10+ LNs for pN1 and pN2. The 5-year survival was 30.6%±1.6% for 0-9 removed LNs compared to 48.2%±1.2% for 10+ removed LNs (P<0.001) in pN1 disease and 18.3%±1.7% for 0-9 removed LNs compared to 32.6%±1.2% for 10+ removed LNs (P<0.001) in pN2 disease. For pN3 disease, the optimal cut-off point was 20+ LNs; the 5-year survival was 17.2%±1.3% for 0-19 removed LNs compared to 28.5%±1.7% for 20+ removed LNs (P<0.001). Moreover, the outcome was inferior among patients who had >10% positive dissected LNs (P<0.05). CONCLUSIONS: The extent of dissected lymph nodes of 20 or greater lymph nodes was associated with superior survival. Extended LN dissection is to be considered especially in patients with clinical lymphadenopathy.