New standard in locally advanced rectal cancer

Abstract

In the following review we intend to ascertain the optimal neoadjuvant therapy in patients with locally advanced rectal cancer. In 2004, a study revealed that chemoradiotherapy (CRT) resulted in better local control when performed preoperatively rather than postoperatively, thus neoadjuvant treatment was established as a standard treatment. Subsequently, the Polish study and the Trans-Tasman Radiation Oncology Group showed no statistically significant difference between concomitant CRT over 5 wk vs short-course radiotherapy (RT). Therefore, both were established as standard neoadjuvant treatments. Later, the Stockholm III study demonstrated that short-course RT had a higher complete pathological response than long-course RT. It also showed that a delay between RT and surgery presented fewer complications. This opened a window of time to provide an early and effective systemic treatment to prevent distant metastases. Studies show that short-course RT plus oxaliplatin-based chemotherapy could achieve this. When comparing this total neoadjuvant treatment (TNT) vs concomitant CRT, the former showed greater complete pathological response and lower acute toxicity. Studies presented during 2020 have also shown the benefits of TNT in terms of complete pathological response, as well as disease and metastasis-free survival. Our review suggests that probably TNT should be the new standard treatment for these patients. However, we will have to wait for the full text publications of these studies to confirm this statement.

Keywords: Locally advanced rectal cancer; Long-course radiotherapy; Neoadjuvant chemoradiotherapy; Oxaliplatin; Short-course radiotherapy; Total neoadjuvant treatment.