Risk Factors for Incomplete Chemoradiation of Total Neoadjuvant Therapy for Rectal Cancer

Abstract Purpose Total Neoadjuvant Therapy (TNT) is increasingly used in Stage II and III rectal cancer. The PRODIGE 23 and RAPIDO trials showed upfront chemoradiation improves disease-free survival, pathologic complete response, local control, and reduces metastasis, underscoring importance of treatment completion. Failure to complete TNT may lead to worse outcomes. This study aims to identify factors associated with failure to complete TNT, specifically concurrent chemoradiation. Methods A retrospective NCDB analysis (2018–2020) included Stage II–III rectal adenocarcinoma patients undergoing TNT and resection. TNT was defined as multiagent chemotherapy and radiation prior to resection, with radiation > 90 days after diagnosis. We analyzed patients following the PRODIGE 23 model. Demographics (age, sex, race/ethnicity, comorbidities, insurance, income, rurality) were included.. Fisher’s Exact tests assessed bivariate associations. Logistic regression modeled radiation discontinuation: Cox proportional hazards models assessed survival. Results Of 3,267 patients, 58 (1.78%) did not complete radiation. Ages were 18–49 (26.7%), 50–64 (47.4%), ≥ 65 (25.9%); 62.6% were male. Insurance included private (57.9%) and Medicare (24.5%). Academic facilities treated 39.2%. Males (OR = 0.52) and patients at academic centers were more likely to complete radiation (p = 0.0133, p < 0.0001). Patients at community (OR = 6.12), comprehensive (OR = 3.09), and integrated (OR = 4.3) centers were more likely to discontinue. Ages 50–64 were significantly more likely to complete therapy than 18–49 or ≥ 65 (p = 0.0069). Private insurance also correlated with higher completion (p < 0.05). Conclusion Completion of neoadjuvant radiation correlates with pCR in TNT. Patients < 50 or ≥ 65, females, and those treated outside academic centers were at higher risk for discontinuation.