Resumen
Total neoadjuvant therapy is a strategy developed to improve the efficacy of chemotherapy in locally advanced rectal cancer by anticipating all the chemotherapy before surgery. This improves compliance, early exposure to micrometastatic disease, and local tumor response. In two recent randomized studies, the rates of patients developing distant metastases were indeed reduced, and the proportions of patients showing complete tumor regression at surgery doubled with two different regimens of total neoadjuvant treatment compared to preoperative long-course chemoradiation. Other studies showed that this strategy facilitates rectal preservation with increased rates of clinically complete tumor disappearance without surgery. However, the optimal chemotherapy regimen, radiotherapy schedule, and timing of chemotherapy and radiotherapy are yet to be defined and may not be the same for all risk groups. Additionally, TNT may result in overtreatment for low-risk patients. Indications for this strategy and specific TNT regimens should thus be adapted to different clinical scenarios.