Variation in Lymph Node Assessment for Colon Cancer at the Tumor, Surgeon, and Hospital Level

We hypothesized that tumor- and hospital-level factors, compared with surgeon characteristics, are associated with the majority of variation in the 12 or more lymph nodes (LNs) examined quality standard for resected colon cancer.

A dataset containing an anonymized surgeon identifier was obtained from the National Cancer Database for stage I to III colon cancers from 2010 to 2017. Multilevel logistic regression models were built to assign a proportion of variance in achievement of the 12 LNs standard among the following: (1) tumor factors (demographic and pathologic characteristics), (2) surgeon factors (volume, approach, and margin status), and (3) facility factors (volume and facility type).

There were 283,192 unique patient records with 15,358 unique surgeons across 1,258 facilities in our cohort. Achievement of the 12 LNs standard was high (90.3%). Achievement of the 12 LNs standard by surgeon volume was 88.1% and 90.7% in the lowest and highest quartiles, and 86.8% and 91.6% at the facility level for high and low annual volume quartiles, respectively. In multivariate analysis, the following tumor factors were associated with meeting the 12 LNs standard: age, sex, primary tumor site, tumor grade, T stage, and comorbidities (all p < 0.001). Tumor factors were responsible for 71% of the variation in 12 LNs yield, whereas surgeon and facility characteristics contributed 17% and 12%, respectively.

Twenty-nine percent of the variation in the 12 LNs standard is linked to modifiable factors. The majority of variation in this quality metric is associated with non-modifiable tumor-level factors.