Pre-operative total neoadjuvant therapy in locally advanced rectal cancer patients: Initial results of Vietnamese patients.

Purpose: To evaluate the initial results of neoadjuvant chemoradiation followed by consolidation chemotherapy (total neoadjuvant therapy - TNT) in locally advanced rectal cancer (LARC) and its side effects.

Material And Method: A prospective study in 75 patients with stage II and III rectal cancer at 108 Military Central Hospital and Nghe An Oncology Hospital from April 2022 to January 2024 who received total neoadjuvant therapy (preoperative chemoradiation of 50.4 Gy concurrent with Capecitabine 825 mg/m², twice a day for 5 days per week, then added neoadjuvant chemotherapy with the mFOLFOX6 or CAPEOX regimen) and subsequently underwent surgery.

Results: The median age was 60.07. Males accounted for 58.7%. Most patients in the study group exhibited tumor stage T3, accounting for 88.0% of the total. The percentages for lymph node stages N0, N1, and N2 were 14.7%, 40.0%, and 45.3%, respectively. 20.09% of patients exhibited a positive result for CRM on magnetic resonance imaging. CEA levels measured before and after using TNT were stati-stically significantly lower than before TNT. After treatment, 25 out of 75 patients (33.3%) had a pathological complete response (pCR). Side effects were mainly grade 1 or 2. Leukopenia was the most common side effect in both neoadjuvant chemoradiotherapy and consolidation chemotherapy. The patients underwent TME (60%), Miles (26.7%), LAR-RAR (12%), and ISR (1.3%). 10.6% of the patients experienced postoperative complications.

Conclusion: Total neoadjuvant therapy is an effective and safe treatment and results in acceptable rates of pathological complete response.