Medical treatment of brain metastases from solid tumours

Brain metastases (BrM) are estimated to occur in 20% to 40% of cancer patients, and two-thirds of them become symptomatic during their lifetime. Although every solid tumour may spread to the brain, the risk of developing BrM is higher in lung cancer, breast cancer and melanoma patients. Several findings suggest that the incidence of BrM is rising as a result of advances in imaging procedures and improvements in therapy, which leaves more cancer patients at risk as survival increases. The prognosis of patients with BrM is dependent on the type of the primary tumour. Breast cancer patients have better prognosis than those with BrM from lung, melanoma or colorectal cancer. Patients with BrM from renal cell carcinoma tend to have a poor prognosis. The optimal treatment of patients with BrM continues to evolve. Several factors interfere with the therapeutic strategy, such as histology of primary tumour, patient compliance, localisation, size and number of BrM, and outcome of extracranial disease. Generally, surgery or stereotactic radiotherapy followed by whole brain radiotherapy (WBRT) are indicated in patients with controlled extracranial disease and good performance status presenting an isolated BrM. Adding chemotherapy in this subset of patients is controversial. Supportive care associated with WBRT remains the standard treatment for all patients with multiple symptomatic BrM or with isolated symptomatic BrM in the presence of uncontrolled extracranial disease. For potentially chemosensitive patients with asymptomatic multiple or isolated BrM with disseminated disease, chemotherapy represents the optimal starting therapy.