Predicting the presence of extracranial metastases in patients with brain metastases upon first diagnosis of cancer

This study aimed to determine factors allowing the prediction of extracranial metastases in patients presenting with brain metastases at the first diagnosis of cancer. Data from 659 patients with brain metastases upon first diagnosis of cancer were retrospectively analyzed. The parameters age, gender, Karnofsky performance score (KPS), primary tumor type and number of brain metastases were compared between 359 patients with extracranial metastases and 300 patients without extracranial metastases. Additional analyses were performed for patients with the most unfavorable and those with the most favorable characteristics. The comparison of patients with versus without extracranial metastases revealed significant differences between the groups in terms of KPS (p < 0.001) and number of brain metastases (p < 0.001). Of the study patients, 113 had both most unfavorable characteristics, i.e. KPS ≤ 50 and ≥ 4 brain metastases. The sensitivity for identifying patients with extracranial metastases was 82 %; specificity was 51 %. A total of 50 patients had KPS ≥ 90 and only one brain metastasis. The sensitivity for identifying patients without extracranial metastases was 86 %; specificity was 58 %. The combination of KPS and the number of brain metastases can help to predict the presence or absence of extracranial metastases.