Radiotherapy of the Primary Disease for Synchronous Metastatic Cancer: A Systematic Review

SIMPLE SUMMARY: Local radiation treatment of the main tumors in patients with synchronous metastatic illness has traditionally only been used for palliative purposes. The management of patients with de novo metastatic cancer is undergoing a revolution with the advent of new systemic therapies enabling longer overall survival with enhanced quality of life. Numerous studies have looked into the potential survival advantage of treating localized primary tumors at the oligometastatic or oligopersistent stage. ABSTRACT: In the case of synchronous metastatic disease, the local treatment of primary tumors by radiotherapy has long been reserved for palliative indications. The emergence of the concept of oligometastatic and oligopersistent diseases, the advent of new systemic therapies enabling longer overall survival with an enhanced quality of life, a better understanding of the biologic history of metastatic spread, and technical advances in radiation therapy are revolutionizing the management of patients with de novo metastatic cancer. The prognosis of these patients has been markedly improved and many studies have investigated the survival benefits from the local treatment of various primary tumors in cases of advanced disease at the time of diagnosis or in the case of oligopersistence. This article provides an update on the place of irradiation of the primary tumor in cancer with synchronous metastases, and discusses its interest through published or ongoing trials.