Evaluation of the National Accreditation Program for Rectal Cancer and Association with Oncologic Outcomes After Proctectomy.

Abstract

Circumferential resection margin (CRM) positivity is a validated predictor of local recurrence and survival in rectal cancer and reflects multidisciplinary care quality. The National Accreditation Program for Rectal Cancer, launched in 2017, standardizes rectal cancer care, but national oncologic outcome data remain limited. We performed a retrospective National Cancer Database analysis of clinical stage I to III rectal adenocarcinoma (2015 to 2022) treated with curative-intent proctectomy using a stacked difference-in-differences design. Hospitals accredited between 2018 and 2021 were compared with inverse probability of treatment weighting-matched nonaccredited hospitals. The primary endpoint was annual hospital-level CRM positivity (CRM ≤ 1 mm). Secondary endpoints were pretreatment CEA measurement and treatment initiation more than 60 days. Models included hospital, calendar year, and accreditation year fixed effects with robust SE clustered by hospital. Among 58,510 patients treated at 800 hospitals, 57 hospitals (7.1%) achieved accreditation, exposing 2,716 patients to accreditation. CRM positivity declined from 14.9% to 12.0% at accredited hospitals vs 14.4% to 12.6% at nonaccredited hospitals, yielding a -1.1 percentage point difference-in-differences (95% CI 0.2 to 2.0; p = 0.03), corresponding to an 8.7% relative reduction. CEA measurement increased from 84.0% to 89.5% vs 84.0% to 85.3%, a +4.2 percentage point difference-in-differences (95% CI 3.6 to 4.8; p < 0.001). There was no significant differential change in treatment delays (+0.7 percentage points; p = 0.15). National Accreditation Program for Rectal Cancer accreditation was associated with reduced CRM positivity and increased adherence to pretreatment CEA testing without prolonging treatment initiation. These findings suggest that structured multidisciplinary accreditation is associated with measurable improvements in rectal cancer surgical quality at the national level.