Claus Rödel, MD, of the Department of Radiotherapy, University of Frankfurt, Germany, discussed the study at the 2016 Gastrointestinal Cancers Symposium.

“The main strength of the Polish II study is clearly its innovative design,” he said. “It sequentially combines effective local radiotherapy and effective combination chemotherapy before delayed surgery, without overlapping toxicity, compared to concurrent treatment. Overall time to surgery was identical between the arms, which allows comparison. Compliance to all components of the treatment was excellent.”

However, he also cited several study limitations, including the lack of mandatory magnetic resonance imaging (MRI) in determining resectability, its unconventional control arm, and its endpoint.

“MRI gives important information, and in this study, it was not mandated and not reported. I am sure many surgeons are unhappy with the term ‘nonresectable,’ as most tumors are resectable,” he commented. “The chemoradiation control arm using bolus fluorouracil was suboptimal, and there are better endpoints than R0 resection. I understand using this, but disease-free survival is more important, and for this endpoint we have a short follow-up.”

Phase III RAPIDO Trial

Dr. Rödel said the randomized phase III RAPIDO trial, which compares a short-course strategy with conventional radiotherapy,” avoids many of these limitations” and will be very informative.

The study enrolls patients according to MRI-defined high-risk criteria and has the “very relevant endpoint” of disease-free survival. It will test short-course radiation (5 5 Gy) followed by six courses of capecitabine/oxaliplatin (CAPOX) against a “well-established” control regimen of 50 Gy of radiation plus capecitabine at 825 mg/m² twice daily.

“I anticipate these results will have a more direct effect on our daily practice than the Polish trial,” he said. ■

Disclosure: Dr. Rödel reported no potential conflicts of interest.