A Phase III Study Testing Two Dose Escalation Strategies to Increase the Population of Complete Responders After Radiation Therapy in the Context of Organ Preservation for Patients With Rectal Cancer

It is becoming clear that there is a now an international consensus that rectal cancer research efforts need to be more focused in optimizing a non-surgical approach. This concept is very relevant to an ageing patient population with multiple co-morbidities regularly seen at the Jewish General Hospital and across the province. After interim analysis on 40 patients of the pilot study a phase III study is proposed. We are therefore proposing a phase III multicentric study of 145 patients to compare the two best known radiation dose escalation strategies and to achieve a complete clinical response. Patients with a clinical T2-3 N0-1 rectal cancer will be randomized to two arms (arm A: standard chemoradiation (45 Gy in 25 with concomitant 5-FU or Xeloda chemotherapy) and an external beam boost of 9 Gy compared to arm B: standard chemoradiation (45 Gy in 25 with concomitant 5-FU or Xeloda chemotherapy) and followed by a brachytherapy boost of 30 Gy in 3 fractions). Patients that have a high risk of recurrence or with more advanced stages of the disease will be excluded from the study, as only the local disease is being treated. The primary outcome for this proposal is rectum preservation in treated patients.