Surgeon-Level Variation in Utilization of Local Staging and Neoadjuvant Therapy for Stage II-III Rectal Adenocarcinoma

Introduction: Neoadjuvant therapy (NT) is the standard of care for clinical stage II-III rectal adenocarcinoma, but utilization remains suboptimal. We aimed to determine the underlying reasons for omission of local staging and NT.

Methods: We conducted a retrospective study of patients with clinical stage II-III or undocumented clinical stage/pathologic stage II-III rectal adenocarcinoma who were treated in 2010-2016 in one of nine Intermountain Healthcare hospitals. The outcomes of omission of local staging and NT were examined with multivariable models. Risk- and reliability-adjusted rates of local staging and NT were calculated for surgeons who treated ≥ 3 patients. Pathologic and long-term outcomes were examined after excluding patients who were not resected or who underwent local excision (N = 11).

Results: Local staging was omitted in 43/240 (17.9%) patients and NT was omitted in 41/240 (17.1%). The strongest risk factors for local staging and NT omission were upper rectal tumors and surgeons who treated ≤ 3 cases/year. Thirty-six of 41 (87.8%) cases of omitted NT had local staging omitted. Adjusted surgeon-specific local staging rates varied 1.6-fold (56.3-92.4%) and NT rates varied 2.8-fold (34.1-97.1%). Surgeon local staging and NT rates were strongly correlated (r = 0.92). NT was associated with lower rates of positive circumferential radial margins (7.9 vs. 20.0%; P = 0.02), node positivity (33.3 vs. 55.0%; P = 0.01), and local recurrences (7.6 vs. 14.9% at 5 years; P = 0.0176).

Conclusions: NT omission should be understood as a consequence of surgeon failure to perform local staging in most cases. Quality improvement efforts should focus on improving utilization of local staging.