gms | German Medical Science

Objective: Surgery in cases with multiple brain metastases remains controversial. For the present study we have therefore analyzed our institutional experience in order to help with the definition of the role of tumor resections in such patients.

Methods: We searched the departmental database in order to identify all cases with multiple brain metastases who underwent resective surgery 2015-2020. Pertinent clinical data were collected retrospectively and standard methods were employed for statistical analysis.

Results: We studied 133 consecutive patients (156 surgeries) with 2 (36.7%), 3-4 (27.3%), or ≥5 (36.0%) brain metastases. The most frequent primary tumors were lung (51.5%) and breast cancer (20.0%). Median overall survival (mOS) was 9.2 (25-75% IQR: 3.1-26.5 months). 30-day-mortality was 3.8% (5/133). The mean/median pre- and postoperative KPI was 77±19/ 80 and 75±24/ 85. Oligometastatic spread (2-4 metastases) was associated with a better outcome (mOS: 13.6 vs. 5.4 months, P=0.009). Younger age, a good presurgical KPI, and postoperative radio- and chemotherapy were also significant positive prognostic factors. The presence of extracerebral metastases did not influence OS. mOS varied with the patients’ GPA scores (GPA 0-1: 4.8, 1.5-2.5: 14.8, 3-4: 20.2 months; P=NS). Aggressive local therapy (i.e. surgical resection and/or radiosurgery for all CNS lesions) did not correlate significantly with survival. We recorded 12 (7.7%) major surgical, 9 (5.6%) permanent neurological, and 14 (9.0%) medical complications (CTCAE grades III-V). Major complications were strongly associated with an adverse outcome (mOS: 2.8 vs. 11.8 months, P=0.001). Multivariate Cox analysis with all parameters significantly associated with survival in the univariate analysis revealed age, postoperative radio-/chemotherapy, and occurrence of a major complication as independent prognostic factors.

Conclusion: Survival after surgery in patients with multiple brain metastases may not be as bad as often thought, and interindividual variation is high. The role for aggressive local therapy beyond treating mass effect may be limited. This and the prominent prognostic role of radiotherapy and systemic treatment suggests that the primary goal of surgical therapy may be to enable effective adjuvant treatments. Surgery carries a low but significant complication rate, and major complications result in drastically reduced survival.