Multicentre study of short-course radiotherapy, systemic therapy and resection/ablation for stage IV rectal cancer.

Background The optimal treatment sequence for patients with rectal cancer and synchronous liver metastases remains unclear. The aim of this study was to evaluate the feasibility and effectiveness of short-course pelvic radiotherapy (5 x 5 Gy) followed by systemic therapy and local treatment of all tumour sites in patients with potentially curable stage IV rectal cancer in daily practice. Methods This was a retrospective study performed in eight tertiary referral centres in the Netherlands. Patients aged 18 years or above with rectal cancer and potentially resectable liver +/- extrahepatic metastases, treated between 2010 and 2015, were eligible. Main outcomes included full completion of treatment schedule, symptom control and survival. Results In total, 169 patients were included with a median follow-up of 49 center dot 5 (95 pr cent c.i. 43 center dot 6 to 55 center dot 6) months. The completion rate for the entire treatment schedule was 65 center dot 7 per cent. Three-year progression-free survival and overall survival (OS) rates were 24 center dot 2 (95 per cent c.i. 16 center dot 6 to 31 center dot 6) and 48 center dot 8 (40 center dot 4 to 57 center dot 2) per cent respectively. Median OS of patients who responded well and completed the treatment schedule was 51 center dot 5 months, compared with 15 center dot 1 months for patients who did not complete the treatment (P < 0 center dot 001). Adequate symptom control of the primary tumour was achieved in 87 center dot 0 per cent of all patients. Conclusion Multimodal treatment is palliative in most patients, and associated with good survival rates in those able to complete the schedule.