Is there an increase in elective utilization of non-operative management for rectal cancer?

e15533 Background: There is growing evidence for the efficacy of a watch-and-wait or nonoperative management (NOM) strategy following chemoradiation with or without total neoadjuvant therapy for rectal cancer as an approach to organ preservation. Consequently, there has been growing interest and acceptance of this approach among both patients and providers. This study aims to analyze the use of the NOM strategy for patients with non-metastatic rectal cancer over the past decade and the patient and facility-level factors associated with its utilization. Methods: We performed an observational cohort study identifying patients from the National Cancer Database diagnosed between 2010-2020 with invasive, non-metastatic rectal adenocarcinoma. Patients who received chemotherapy and radiation without surgery were categorized as having received NOM. All other patients who received curative-intent surgery with or without chemotherapy and radiation were classified as the standard of care (SOC) cohort. Utilization of NOM was analyzed over time. Logistic regression analysis was utilized to identify patient and facility-level factors associated with NOM. Results: In total, 107,786 patients were included for analysis, of which 14,870 (13.8%) received NOM over the study period and 92,916 (86.2%) received SOC. The use of NOM steadily increased over the study period, from 10.3% in 2010 to 20.7% in 2020. Compared to SOC, NOM was associated with patients who were Black (16.9% vs 13.6% White, p < 0.001), had Medicaid or no insurance (15.3% vs 13.4% Private/Medicare insurance, p < 0.001), were older than 75 years (18.9% vs 12.8% younger than 75, p < 0.001), and had high Charlson-Deyo comorbidity score (16.2% vs 14.0% no comorbidities, p < 0.001). Facility factors associated with greater use of NOM included treatment at community cancer programs (OR 1.44, 95% CI 1.35-1.54, p < 0.001) compared to treatment at comprehensive cancer centers. Facilities stratified by incident rectal cancer patient volume demonstrated an inverse relationship with NOM management, with low volume institutions having the highest NOM rate (p < 0.001). Subgroup analysis of patients < 75 years old, with private insurance, and without co-morbidities treated at institutions in the top quartile of volume showed NOM rates to similarly increase over the study period, from 6.4% to 13.7% (p < 0.001). Conclusions: The use of the NOM strategy for patients with non-metastatic rectal cancer has increased over the past decade. While traditionally an approach for patients who were poor surgical candidates, the increasing trend for NOM among younger patients with fewer comorbidities and private insurance suggests that there is growing interest in elective NOM over the past decade. Ongoing prospective studies of NOM will shed light regarding the long-term efficacy of this approach compared to traditional surgical SOC.