Survival after resection of brain metastasis: impact of synchronous versus metachronous metastatic disease

Purpose: Patients with brain metastasis (BM) from solid tumors are in an advanced stage of cancer. BM may occur during a known oncological disease (metachronous BM) or be the primary manifestation of previously unknown cancer (synchronous BM). The time of diagnosis might decisively impact patient prognosis and further treatment stratification. In the present study, we analyzed the prognostic impact of synchronous versus (vs.) metachronous BM occurrence following resection of BM.

Methods: Between 2013 and 2018, 353 patients had undergone surgical therapy for BM at the authors' neuro-oncological center. Survival stratification calculated from the day of neurosurgical resection was performed for synchronous vs. metachronous BM diagnosis.

Results: Non-small-cell lung carcinoma (NSCLC) was the most common tumor entity of primary site (43%) followed by gastrointestinal cancer (14%) and breast cancer (13%). Synchronous BM occurrence was present in 116 of 353 patients (33%), metachronous BM occurrence was present in 237 of 353 patients (67%). NSCLC was significantly more often diagnosed via resection of the BM (56% synchronous vs. 44% metachronous situation, p = 0.0001). The median overall survival for patients with synchronous BM diagnosis was 12 months (95% confidence interval (CI) 7.5-16.5) compared to 13 months (95% CI 9.6-16.4) for patients with metachronous BM diagnosis (p = 0.97).

Conclusions: The present study indicates that time of BM diagnosis (synchronous vs. metachronous) does not significantly impact patient survival following surgical therapy of BM. These results suggest that the indication for neurosurgical BM resection should be made regardless of a synchronous or a metachronous time of BM occurrence.