Facility Variation in Local Staging of Rectal Adenocarcinoma and its Contribution to Underutilization of Neoadjuvant...

Guidelines recommend neoadjuvant therapy (NT) for clinical stage II-III (locally advanced) rectal adenocarcinoma, but utilization remains suboptimal. The causes of NT omission remain poorly understood.

The main outcomes in this study of patients with resected clinically non-metastatic rectal adenocarcinoma in the 2010-2015 National Cancer Database were local staging utilization in patients with non-metastatic tumors (i.e., undocumented clinical stage/pathologic stage I-III) and NT utilization for locally advanced tumors. Multivariable regression was used to examine predictors of these outcomes. Facility-specific risk- and reliability-adjusted local staging and NT rates were calculated. Positive margins and overall survival (OS) were examined as secondary outcomes.

Local staging was omitted in 7737/43,819 (17.7%) patients with clinically non-metastatic tumors and NT was omitted in 5199/31,632 (16.4%) patients with locally advanced tumors. NT was utilized in 24,826 (91.1%) locally advanced patients who had local staging vs. 1607 (36.6%) patients who did not; 2785 (53.6%) locally advanced patients with NT omitted also had local staging omitted. Treatment at facilities with lowest quintile local staging rates was associated with NT omission (relative risk 2.41, 95% confidence interval 2.11, 2.75). Adjusted facility local staging rates varied sixfold (16.1-98.0%), facility NT rates varied twofold (43.9-95.9%), and they were correlated (r = 0.58; P < 0.001). Local staging omission and NT omission were independently associated with positive margins and decreased OS.

Local staging omission is a common care process in over half of cases of omitted NT. These data emphasize the need for quality improvement efforts directed at providing facilities feedback about their local staging rates.