Identification of Factors That Determine Adherence for Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer

Background: Locally advanced rectal cancer (LARC) treatment has shifted from the utilization of neoadjuvant chemoradiation (NACRT), followed by total mesorectal excision (TME) and adjuvant chemotherapy (AC) to the implementation of total neoadjuvant therapy (TNT). This transition was influenced by data from multiple studies reporting suboptimal compliance rates to adjuvant chemotherapy. As a result, a paradigm shift to TNT occurred, consisting of chemoradiation with chemotherapy, based on the RAPIDO and PRODIGE-23 studies. Methods: Following IRB approval, a single-institution retrospective chart review was conducted at a tertiary care academic institution for patients with LARC. Demographic, clinical, and treatment data were collected using REDCap. Patients were excluded if under 18 years of age, pregnant, or had stage 1 or metastatic rectal cancer. The primary objective was to evaluate TNT adherence; secondary objectives assessed adherence associations with demographic and clinical variables. Results: Two hundred twenty-nine patients with rectal cancer were initially included in the database, including 153 patients with LARC from 2019 to 2024. One hundred twenty-seven patients underwent TNT with an adherence rate of 87.5%. Statistically significant variables that contributed to adherence include male gender (p = 0.04) and non-use of recreational drugs (p = 0.04). Conclusions: This is the first real-world study assessing TNT adherence. The observed 87.5% adherence rate represents a significant improvement over historical data in which patients were treated with NACRT/TME/AC. Statistically significant variables that contributed to TNT adherence included male gender and non-use of recreational drugs. These factors may provide insight into gender differences and behavioral patterns that put patients in an at-risk category for non-adherence.