Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer: Insights from the Western Australian Context.

Background: Recent studies have associated total neoadjuvant therapy (TNT) with better treatment adherence, decreased toxicity, improved complete clinical response and anal sphincter preservation rates in patients with locally advanced rectal cancer (LARC). However, real-world experience with TNT in the management of LARC remains limited.

Aim: This study aimed to evaluate the efficacy and safety outcomes of TNT for LARC in Western Australia.

Methods: Patients with LARC (cT2-4 and/or cN1-2) who underwent induction chemotherapy followed by neoadjuvant chemoradiotherapy or neoadjuvant chemoradiotherapy followed by consolidation chemotherapy, followed by surgery were recruited from two hospitals in Western Australia. Efficacy outcomes assessed included clinical response (complete, partial, no response), and pathologic complete response (pCR) rate, R0 resection rate, and R1 resection rate were evaluated. Those patients who achieved clinical complete response following TNT were given the option of active surveillance. The safety and tolerability of TNT were assessed.

Results: 32 patients with LARC were treated with TNT. In total, 17 patients (53%) received chemoradiotherapy followed by consolidation chemotherapy and 15 patients (47%) received induction chemotherapy followed by chemoradiotherapy. Nine (28%) of the patients with LARC treated with TNT had a complete clinical response, twenty-one (66%) patients had a partial clinical response, and two (6%) patients had no response to TNT. Of the 32 patients, 27 (84%) underwent surgery. There was a 100% R0 resection rate. The pCR rate was 15%. pCR, clinical response, and the R0 resection rate were similar between the two TNT regimens. TNT was well tolerated, with the majority of patients (88%) completing the chemotherapy course with grade 1 and 2 adverse effects.

Conclusions: In conclusion, TNT emerges as a promising approach for the management of LARC. However, further research is warranted to refine the optimal TNT protocols, determine its long-term outcomes, and identify patient populations who would benefit the most from this innovative therapeutic strategy.