Implications of inadequate lymph node staging in resectable gastric cancer: a contemporary analysis using the National Cancer Data Base.
BACKGROUND
National guidelines recommend examination of ≥ 15 lymph nodes for adequate staging of resectable gastric adenocarcinoma (GA). The relevance of these guidelines, which were established before the increasing use of multimodality therapy, and the impact of inadequate lymph node staging (LNS) in a contemporary cohort have not been extensively explored.


METHODS
Stage I-III GA patients who underwent gastrectomy from 1998 to 2011 were identified using the National Cancer Data Base. Trends in LNS adequacy, predictors of inadequate LNS (< 15 LN examined) and the relationship between LNS and overall survival (OS) were analyzed.


RESULTS
In 22,409 patients, compliance with LNS guidelines was poor (inadequate LNS in 61.2% of cases, median LN harvested in 11.0%). Subtotal/partial gastrectomy was the strongest predictor of inadequate LNS (OR = 2.01, P < .001). Survival analyses included 9139 patients with minimum 5 years follow-up; median, 1-year, and 5-year survival was 35.6 months, 75.5%, and 39.7%, respectively. LN positivity (HR = 1.90) and age > 76 years (HR = 1.73) were the strongest predictors of worse OS (both P < .001). Inadequate LNS was independently associated with worse OS (HR = 1.33, P < .001). Median OS after inadequate compared to adequate LNS was significantly worse (33.3 months versus 42.0 months, P < .001), regardless of AJCC clinical stage subgroup or tumor T classification (both P < .001).


CONCLUSIONS
Adequate LNS is achieved in a minority of patients. Inadequate LNS was independently associated with worse OS. Examination of ≥ 15 LN is a reproducible prognosticator of gastric cancer outcomes in the United States and should continue to serve as a benchmark for quality of care.
Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
Jashodeep
J
Datta
Russell S
RS
Lewis
Ronac
R
Mamtani
Diana
D
Stripp
Rachel R
RR
Kelz
Jeffrey A
JA
Drebin
Douglas L
DL
Fraker
Giorgos C
GC
Karakousis
Robert E
RE
Roses
D000368:Aged; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D011379:Prognosis; D013274:Stomach Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D015996:Survival Rate
gastric cancer; inadequate; lymph node staging; multimodality therapy; survival