Radiotherapy in patients with metastatic breast cancer

The available clinical data on patients with metastatic breast cancer is compatible with the hypothesis that a local treatment of the primary tumour with or without regional treatment prolongs survival. Prevention of life-threatening local complications and prevention of continuous seeding of new distant disease originating from the primary tumour have been proposed as possible mechanisms that apply for local radiotherapy and surgery. Recently published experimental data indicate that radiation-induced necrosis of the primary tumour may result in an antitumoral immune response. However, no data from randomised trials are available and the substantial survival benefits observed in retrospective comparisons may have been influenced by a number of biases. For the time being, the decision whether or not to integrate locoregional treatment of the primary tumour into the therapeutic concept needs to be done on an individual basis. In principle, the identical mechanisms described above also apply for local treatment of distant metastases in metastatic breast cancer. Clinical experience in the local treatment of acutely life-threatening distant disease, for example, in symptomatic brain metastasis, undoubtedly suggests a prolongation of survival, particularly in the case of response to treatment. Aside from this situation, clinical trials and retrospective comparisons of local treatments of distant metastases in metastatic breast cancer typically compared different radiation schedules with or without additional surgery in symptomatic patients, without utilising a control group. As a result, a general survival benefit from the local treatment of distant metastasis has not been scientifically proven and should be the subject of further investigations. © 2011 Elsevier Ltd.