Significant regional variation in adequacy of lymph node assessment and survival in gastric cancer

BACKGROUND. Lymph node (LN) status is a major determinant of prognosis and treatment of gastric adenocarcinoma. The 1997 American Joint Commission on Cancer/Union Internationale Contre le Cancer guidelines were revised, requiring examination of >= 15 LN for staging. METHODS. We investigated compliance with these guidelines and the correlation with overall survival (OS) by analyzing 10,807 resected gastric cancers in the Surveillance, Epidemiology and End Results (SEER) database, 1988-2002. Kaplan-Meier survival curves were constructed; survival was compared by using Cox proportional hazards. RESULTS. Overall, 29% of cases had >= 15 LN examined. After 1997, the median number of LN assessed increased from 9 to 10 (P < .0001). Factors predictive of adequate LN assessment (ALNA) were higher stage, worse grade, age < 74 years, later year of diagnosis, nonwhite race, more extensive surgery, female sex, and SEER region. Differences in the rate of ALNA between regions were noted, ranging from 19.7-53% (P < .0001). Of T1N0 patients, 19% had ALNA. Improved OS was predicted by earlier stage, lower grade, marital status, Asian race, younger age, T-stage, female sex, SEER region, and ALNA. Median OS was highest in the region with the best ALNA rate and worst in the region with the lowest (33 mos vs. 17 mos, P < .0001). Inadequate LN assessment led to poorer survival at every stage (P < .001). CONCLUSION. The overwhelming majority of patients have an inadequate LN assessment. ALNA was associated with improved OS, with significant variation across regions. Understaging due to inadequate LN assessment may affect eligibility for adjuvant therapy. Education is required to improve LN retrieval.