Variation in Hospital-Specific Rates of Suboptimal Lymphadenectomy and Survival in Colon Cancer: Evidence from the National Cancer Data Base

Background. Little is known about between-hospital differences in the rate of suboptimal lymphadenectomy. This study characterizes variation in hospital-specific rates of suboptimal lymphadenectomy and its effect on overall survival in a national hospital-based registry. Methods. Stage I-III colon cancer patients were identified from the 2003-2012 National Cancer Data Base. Bayesian multilevel logistic regression models were used to assess the impact of patient-and hospital-level factors on hospital-specific rates of suboptimal lymphadenectomy (<12 lymph nodes), and multilevel Cox models were used to estimate the effect of suboptimal lymphadenectomy at the patient (yes vs. no) and hospital level (quartiles of hospital-specific rates) on overall survival. Results. A total of 360,846 patients across 1345 hospitals in the US met the inclusion criteria, of which 25 % had a suboptimal lymphadenectomy. Wide variation was observed in hospital-specific rates of suboptimal lymphadenectomy (range 0-82 %, median 44 %). Older age, male sex, comorbidity score, no insurance, positive margins, lower tumor grade, lower T and N stage, and sigmoid and left colectomy were associated with higher odds of suboptimal lymphadenectomy. Patients treated at lower-volume and non-academic hospitals had higher odds of suboptimal lymphadenectomy. Patient-and hospitallevel factors explained 5 % of the between-hospital variability in suboptimal lymphadenectomy, leaving 95 % unexplained. Higher suboptimal lymphadenectomy rates were associated with worse survival (quartile 4 vs. quartile 1: hazard ratio 1.19, 95 % confidence interval 1.16-1.22). Conclusion. Large differences in hospital-specific rates of suboptimal lymphadenectomy were observed, and this variation was associated with survival. Quality improvement initiatives targeting hospital-level adherence to the national standard may improve overall survival among resected colon cancer patients.