Retrospective Cohort Study of Treatment Patterns and Outcomes for Patients With Locally Advanced Rectal Cancer Across Three Metropolitan Hospitals in Brisbane

AIM: We aim to provide an overview of treatment patterns and outcomes in high-risk rectal cancer patients with a particular focus on total neoadjuvant therapy (TNT) use. METHODS: Patients with locally advanced rectal cancer who commenced pre-operative treatment at the Royal Brisbane and Women's Hospital, the Princess Alexandra Hospital, and Redcliffe Hospital between 2020 and 2023 were included in this retrospective cohort study. Data collected included demographics, cancer stage, tumour details, treatment undertaken, disease progression, and survival. Data were analyzed using R Studio version 1.4.1717. RESULTS: 124 patients were included, with 47 having undergone TNT and long-course chemoradiotherapy (LCCRT) and 77 having undergone LCCRT alone ± adjuvant chemotherapy. Those who received TNT were significantly more likely to have high-risk features such as extramural venous invasion, T4 tumor, and N2 disease. 89.5% of TNT patients across our centres received FOLFOX chemotherapy, and 77.1% received ≥6 cycles. 14.7% of TNT patients went on to receive adjuvant chemotherapy compared to 35.5% of non-TNT patients, with the most common adjuvant chemotherapy in the TNT group being FOLFOX (85.7%). 15% of TNT patients achieved a pathological complete response compared with 13.8% in the non-TNT group. Disease-free survival favored the non-TNT group with a median value of 39.4 months versus 36.9 months, though this was not statistically significant. CONCLUSION: This retrospective cohort study undertaken across multiple metropolitan centres shows increased uptake of TNT, particularly in high-risk patient cohorts, consistent with changes in international guidelines for treatment of rectal adenocarcinoma.