Radiotherapy for the Primary Tumor in Patients with Metastatic Rectal Cancer

Patients with metastatic rectal cancer (mRC) have a poor prognosis and suffer from several symptoms like bleeding, pain, and obstruction. Radiation therapy (RT) has been used both for palliation and improvement of overall survival (OS) in potentially curable patients. However, treatment in this setting is debated and a recent literature review included only studies published before 2000. Therefore, an analysis of literature was performed including only studies published in recent years (2010–2016) to better evaluate the effect of modern RT in these patients. The analysis of nine reviewed studies (six retrospective and three phase II) showed that RT is able to achieve pain, bleeding, and obstruction response rate of 79, 87, and 78%, respectively. Moreover, in patients receiving radio-chemo-surgical combined modality treatment, median survivals ranging between 30 and 38 months were recorded, with 5-year survival up to 55% of patients. RT was generally well tolerated with the most common reported side effect being diarrhea/proctitis. Further studies in this field are needed to establish the best therapeutic sequences, to define the optimal RT dose and fractionation, and to evaluate the clinical results in terms of quality of life (QoL).