Total neoadjuvant treatment (CAPOX plus radiotherapy) for patients with locally advanced rectal cancer with high risk factors: A phase 2 trial

Background and purpose To evaluate the safety and efficacy of Total neoadjuvant treatment (TNT) in patients with rectal cancer with high risk factors. Methods and materials We did this phase 2 trial in patients who were diagnosed with stage II–III rectal cancer with at least one of the high risk factors. Three cycles of induction CAPOX were followed by pelvic radiotherapy of 50.4 Gy/28 fractions and two cycles of concurrent CAPOX. Three cycles of consolidation CAPOX were delivered after radiotherapy. Primary endpoints were pathological complete response (pCR) and R0 resection. Results Fifty patients were enrolled and 47 patients were evaluable. A total of 34 patients (72.3%) completed 6 to 8 cycles of chemotherapy and 46 patients (98%) completed the planned radiotherapy. 17 patients (36%) achieved a pCR or clinical complete response (cCR). Three cCR patients (6.4%) refused the operation and selected a watch-and-wait approach. The most common grade 3 or worse adverse events were leucopenia (10.6%) and radiation dermatitis (6.4%). The major surgical complications included pelvic abscesses/infection in 2 patients (4.3%), anastomotic leakage and hemorrhage in1 patient (2.2%), respectively, which were all addressed with conservative management. Conclusions TNT is effective and safe in patients with locally advanced rectal cancer with high risk factors. Long-term efficacies of TNT need to be further evaluated. This trial is registered with Chinese Clinical Trial Registry, number ChiCTR-OIN-17012284.