eP727 - Adoption of Total Neoadjuvant Therapy for Patients with Locally Advanced Rectal Cancer Within a Tertiary Healthcare Center

Purpose/Background: Total Neoadjuvant Therapy (TNT) is increasingly being used as a preferred strategy for the treatment of locally advanced rectal cancer. Factors associated with TNT uptake within the hospitals are unclear. We evaluated the uptake of TNT and clinical factors associated with TNT use within a single institution.Methods/Interventions: Patients with Stage II/III rectal adenocarcinoma who received neoadjuvant therapy and were seen by one of seven colorectal surgeons at a tertiary hospital in the deep south from 2018-2022 were included. Our primary outcome was receipt of TNT defined as chemoradiotherapy (short or long course) with additional 3-4 months of systemic chemotherapy prior to surgery. Bivariate comparisons and multivariable logistic regression were used to determine patient, disease, and system factors associated with TNT use. Secondary outcome of this study was to evaluate differences between outcomes of TNT versus traditional chemoradiation (CRT).Results/Outcomes: Of 272 patients included, 29% had stage II and 71% had stage III disease. TNT was overall utilized in 34% of cases and significantly increased over time: 6.4% in 2018, 25% in 2019, 21.3% in 2020, 49.2% in 2021, and 85.4% in 2022 (Figure 1, p < 0.05). The use of TNT was more likely in patients who had nodal involvement (81.5% vs 66.5%, p=0.01) and in patients who were discussed at a multidisciplinary clinic (76.9% vs 40.2%, p < 0.01). On multivariable regression, advanced stage and MDC discussion were the factors strongly associated with TNT use (Stage 3 vs Stage 2: OR 3.6, 95% CI 1.41-10.04; MDC yes vs no: OR 5.73, 95% CI 2.67-13.11). Moreover, TNT administration was associated with increased complete clinical response and subsequent enrollment in ‘watch and wait’ protocol. Lastly, use of TNT was also associated with increased rates of pathologic complete response in patients who underwent surgery after completing neoadjuvant treatment (34.4% vs 10.9%, p < 0.001).Conclusion/

Discussion: TNT is increasingly being used for locally advanced rectal cancer patients, especially with nodal involvement. Multidisciplinary case review is an important driver for TNT adoption. Use of TNT has been associated with increased rates of complete clinical response and use of ‘Watch & Wait’ protocol. Patients who underwent surgery after TNT were more likely to have pathologic complete response.Use of TNT for rectal cancer over the years at a tertiary care institution TNT is increasingly being used for locally advanced rectal cancer patients, especially with nodal involvement. Multidisciplinary case review is an important driver for TNT adoption.