Radiotherapy then chemotherapy before surgery may be best in rectal cancer

Reuters Health - 21/12/2020 - In patients with locally advanced rectal cancer, a short course of radiotherapy followed by chemotherapy preceding surgery appears to provide better results than the standard protocol of long-course chemoradiotherapy, surgery, and optional adjuvant chemotherapy, according to the RAPIDO trial.

The current standard approach has improved locoregional control, but occurrence of distant metastases has not decreased accordingly, Dr. Geke A. P. Hospers of University Medical Center Groningen, in the Netherlands, and colleagues note in The Lancet Oncology.

Surgery, they add, can safely be delayed after short-course radiotherapy, creating a window of opportunity to deliver chemotherapy preoperatively instead of postoperatively. This might reduce distant metastases without increasing the risk of locoregional failure.

To investigate, the researchers randomized 920 patients to an experimental group who before surgery received short-course radiotherapy (5x5 Gy over a maximum of eight days) followed by chemotherapy or to the standard-of-care group who received radiotherapy in up to 28 daily fractions and concomitant chemotherapy. If stipulated by hospital policy, the latter group also received adjuvant chemotherapy. The study was not blinded.

At three years after randomization, the cumulative probability of disease-related treatment failure was significantly lower in the experimental group (23.7%) than in the standard of care group (30.4%). This was also the case for distant metastases (20.0% vs. 26.8%). There were four treatment-related deaths in each group.

Given these findings, the researchers conclude that "preoperative short-course radiotherapy followed by chemotherapy and total mesorectal excision could be considered as a new standard of care in high-risk locally advanced rectal cancer."

In an accompanying editorial, Dr. Avanish Saklani of Homi Bhabha National Institute, in Mumbai, India, and colleagues agree, observing, "The landscape of total neoadjuvant therapy for locally advanced rectal cancers looks promising, and the RAPIDO protocol is likely to be the new standard of care."

Dr. Saklani told Reuters Health by email, "In resource-limited economies, especially in the current climate of COVID-19 with long waiting lists for radiotherapy, this treatment protocol will not only help in rationing resources but also improve the oncological outcomes. The future looks exciting for the evolving treatment paradigm for rectal cancers."

Dr. Hospers did not respond to requests for comments.

SOURCE: https://bit.ly/3gWja6W and https://bit.ly/3p0qYHJ The Lancet Oncology, online December 7, 2020.

By David Douglas



Posted on 21 December 20205 January 2021