Clinical Features of Precocious, Synchronous, and Metachronous Brain Metastases and the Role of Tumor Resection

Objective: The purpose of this study was to clarify clinical features, outcomes, and the role of tumor resection in precocious, synchronous, and metachronous brain metastases. Methods: Brain metastases were found before primary cancer detection in the precocious group, within 2 months after primary cancer detection in the synchronous group, and 2 months or later after primary cancer detection in the metachronous group. Results: Of 471 patients with brain metastases, 93 (20%) were included in the precocious group, 76 (16%) in the synchronous group, and 302 (64%) in the metachronous group. The precocious group tended to be symptomatic, show a low Karnofsky Performance Status, and have a large single tumor, infrequent extracranial metastases, and frequent tumor resection compared with the other 2 groups. There were no differences in overall survival from the detection of brain metastases among the 3 groups in univariate and multivariate analyses. Of 471 cases, 97 (21%) underwent surgeries. Among this surgical cohort, overall survival from surgery was significantly shorter in the precocious group than in the metachronous group (P = 0.039). After adjustment for age, sex, tumor size, primary cancer, and the Graded Prognostic Assessment score, the hazard ratio for metachronous metastases was 0.52 (confidence interval, 0.29–0.95; P = 0.035). Conclusions: The timing of brain metastasis diagnosis is not a modifiable factor but affects patient demographics and treatment strategies. In particular, the precocious group is a unique subset of brain metastases that require special consideration during clinical decision making.