EP634 - Regional Variation in Utilization of Nonoperative Management for Locally Advanced Rectal Cancer

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Purpose/Background: Non-operative management (NOM) or a “watch and wait” approach to locally advanced rectal cancer is an option for patients with a complete clinical response to neoadjuvant treatment. NOM was added to the National Comprehensive Cancer Network guidelines as a treatment option in 2022. However, it has been gradually adopted beginning in the early 2000s driven largely by patients’ willingness to accept reduced survival or higher cancer recurrence to avoid changes in quality of life that surgery entails, especially a permanent colostomy. While rates of NOM have increased over time, it has not been implemented consistently as sociodemographic variations have been reported. Geographic variation in rectal cancer treatment remains largely uncharacterized and is critical to understanding how this patient-centered advancement in rectal cancer care is being implemented.

Methods/Interventions: For this retrospective, observational study, we used the National Cancer Database Participant User File to identify patients with clinical stages II and III rectal who were treated with neoadjuvant chemoradiation from 2004-2021. The primary outcome was planned nonoperative management versus surgery. We described rates of NOM over time. We used multivariable logistic regression to assess the association of the 9 reported US geographic regions with planned nonoperative management while controlling for year, clinical stage, Charlson-Deyo score, facility type and volume by quartile, patient distance travelled, insurance, education and income quartiles of the patient’s zip code, and race/ethnicity.

Results/Outcomes: The study sample included 105,259 cases of patients with locally advanced rectal cancer. Of these cases, 14.73% (n=15,505) underwent planned NOM. Nationwide, annual rates of NOM increased from 8.87% in 2004 to 15.61% in 2017 to 29.23% in 2021. Treatment patterns varied across geographic regions: in 2021, non-operative management rates within regions ranged from 19.8 to 40.1% (Fig 1). When controlling for clinical, sociodemographic, and facility factors as listed above, patients in the South Atlantic (reference), Pacific (OR 1.02, 95% CI 0.96-1.09), and Middle Atlantic (OR 1.15, 95% CI 1.09-1.22) regions were most likely to undergo NOM. As compared to South Atlantic, patients in the following regions were less likely to undergo NOM: East North Central (OR 0.75 95% CI 0.70-0.79), Mountain (OR 0.84, 95% CI 0.76-0.92) New England (OR 0.70, 95% CI 0.64-0.77), West North Central (OR 0.60, 95% CI 0.56-0.65), and West South Central (OR 0.70, 95% CI 0.65-0.75).

Conclusion/Discussion: With NOM now included as a treatment option in NCCN guidelines, ensuring equitable and consistent utilization of NOM in rectal cancer treatment is a high priority. Our findings identify significant regional variation in rates of NOM. This variation persists despite controlling for patient socio-demographics and travel distances suggesting it is unlikely to be explained by regional population differences. Future research should explore factors which might drive regional variation, such as patient and physician attitudes or infrastructure for rectal cancer care, including access to specialists and costs of care.