Short Course Radiation Therapy Followed by Pre-operative Chemotherapy and Surgery in High-risk Rectal Cancer

The multicentre, multinational RAPIDO (Rectal cancer And Pre-operative Induction therapy followed by Dedicated Operation, EudraCT number 2010-023957-12) closed patient entry in June 2016 after having randomised the planned number of 920 patients. In the study, patients were randomised to conventional chemoradiotherapy (CRT) to 50 Gy with capecitabine followed by surgery or to short-course radiotherapy (scRT, 5 x 5 Gy), 6 cycles of oxaliplatin-capecitabine (CAPOX) followed by surgery. In the CRT arm, adjuvant chemotherapy with 8 cycles of CAPOX was optional. At the time of closure of the RAPIDO study, it was discussed in Uppsala whether CRT should be the reference treatment for these high-risk rectal cancers, the experimental treatment or an alternative. Influenced by a Polish study reported by Bujko et al in 2016 with a similar design comparing CRT with scRT followed by 3 cycles of FOLFOX), it was decided that the reference treatment for patient with primary rectal cancer at high risk of failing either locally or systemically should be scRT followed by 4 cycles of CAPOX and surgery. This regimen, identical to the experimental arm in a Chinese trial (Stellar trial (ClinicalTrials.gov NCT02533271), preliminarily revealing promising pCR rates has since then been the reference treatment for patients having the same inclusion criteria as in the RAPIDO trial. Other centres in Sweden have also decided to use this regimen as reference treatment. A formal protocol is written and approved.