[Advances of optimized neoadjuvant therapy in the treatment of locally advanced rectal cancer]

Neoadjuvant chemoradiotherapy is the current standard of care for locally advanced rectal cancer. However, this modality is facing more and more challenges. The research progress on this issue around the world can be summarized into three aspects. The first is to increase the intensity of treatment to obtain better tumor regression, such as adding a second drug during the neoadjuvant chemoradiotherapy, prolonging the interval and receiving sufficient chemotherapy before surgery. Current research data are not sufficient to support strategies for adding drugs or receiving sufficient chemotherapy before surgery, but it may be worth looking forward to adding irinotecan during neoadjuvant chemoradiotherapy, and an appropriate extension of the interval before surgery may also be a good option. Secondly, we can reduce the intensity of treatment to improve the quality of life of patients with a non-inferior clinical outcome, such as non-surgical approach, local excision rather than total mesorectal excision and removal of preoperative radiotherapy. The data of the International Watch & Wait Database (IWWD) suggest that patients with a Watch & Wait strategy have similar long-term survival outcomes as those who have undergone surgery and have pathologic complete response, meanwhile the data are still inadequate to support using local excision instead of total mesorectal excision, or removal of preoperative radiotherapy strategies. Finally, to achieve a precise individual treatment, some potential biomarkers are investigated via genomics, metabolomics and radiomics. But so far, there is no recognized biomarker for clinical treatment in the field of neoadjuvant therapy for rectal cancer. This article summarizes the clinical research progress of locally advanced rectal cancer in recent years from the above three aspects.