Effect of total number of harvested lymph nodes on survival outcomes after curative resection for gastric adenocarcinoma: findings from an eastern high-volume gastric cancer center.
BACKGROUND
Greater lymph node retrieval in gastric cancer improves staging accuracy and may improve survival from increased clearance of nodal micrometastasis. This retrospective cohort study investigated if more lymph nodes removed in gastric cancer increases survival and if such effect is stage-specific due to differential risks of nodal micrometastasis and systemic disease.


METHODS
The prospectively collected database of curatively resected gastric cancer patients in National Cancer Center, South Korea between 2000 and 2009 was reviewed. Disease-free survival (DFS) and overall survival (OS) for all patients and for each stage according to number of lymph nodes examined (1-30, 31-45, > 45) were analyzed.


RESULTS
Of 4049 patients, 96.6% and 98.4% underwent D2 (perigastric and extragastric) lymphadenectomy and had ≥ 15 lymph nodes examined. Mean number of nodes examined was 43. Five-year OS & DFS rates were 83.3% and 80.7%. Patients with > 45 nodes examined had significantly lower DFS (p = 0.002) and OS (p = 0.007) compared to those with 1-30 and 31-45 nodes. However, proportion of patients with > 45 nodes examined increased with stage (p = 0.0005). Per stage, there was no significant difference in DFS and OS according to number of nodes examined except for stage IIIA favoring more nodes (p = 0.018 and p = 0.044, respectively). Similar trend was seen in stage IIB. Number of examined nodes positively correlated with number of pathologic nodes for all patients (r = 0.144, p < .001) but not for stage IIB and IIIA. Number of nodes examined was a significant survival predictor in stage IIIA.


CONCLUSION
Greater lymph node harvest showed improved survival in intermediate-stage gastric cancer.
['Macalindong|Shiela S|SS|', 'Kim|Kwang Hee|KH|', 'Nam|Byung-Ho|BH|', 'Ryu|Keun Won|KW|', 'Kubo|Norihito|N|', 'Kim|Ja Yeon|JY|', 'Eom|Bang Wool|BW|', 'Yoon|Hong Man|HM|', 'Kook|Myeong-Cherl|MC|', 'Choi|Il Ju|IJ|', 'Kim|Young Woo|YW|']
D000230:Adenocarcinoma D000328:Adult D000368:Aged D018572:Disease-Free Survival D005260:Female D005743:Gastrectomy D006801:Humans D053208:Kaplan-Meier Estimate D008197:Lymph Node Excision D008198:Lymph Nodes D008207:Lymphatic Metastasis D008297:Male D008875:Middle Aged D061206:Neoplasm Micrometastasis D011379:Prognosis D056910:Republic of Korea D012189:Retrospective Studies D013274:Stomach Neoplasms
Survival Gastric cancer Lymph node harvest/retrieval