Einfluss von Tumorrandproben auf das Outcome bei Patienten mit intrakraniellen Metastasen – eine retrospektive Analyse

The role of tumor margin biopsies in the neurosurgical treatment of intracranial metastases has not been sufficiently investigated. Tumor margin biopsies could serve as a predictor for recurrence risk and patient prognosis. The aim of this study is to analyze the impact of positive margin biopsies on clinical outcomes and to identify potential factors influencing the risk of tumor recurrence.

Between December 2008 and July 2021, 297 patients underwent surgery of intracranial metastases and were included in a retrospective study. Tumor margin biopsies were taken from all patients and histopathologically analyzed. A total of 358 metastases were resected, and 1348 tumor margin biopsies were analyzed. Primary endpoints were recurrence rate, overall survival (OS), and time to recurrence.

Tumor cells were detected in 15.5% of the margin biopsies. Metastases from breast cancer and malignant melanoma showed the highest rates of positive margin biopsies (64.9% resp. 44.2%), while renal cell carcinoma had the lowest rate at 7%. Among patients with positive tumor margin biopsies, 68% experienced recurrence within the first-year post-surgery, compared to 45% in the negative biopsy group. The median time to recurrence was 5.8 months for patients with positive biopsies and 8.3 months for those with negative biopsies. Although patients with positive margin biopsies had a higher recurrence rate, this did not translate to a significant difference in overall survival (p=0.443). Adjuvant radiotherapy was associated with a significant reduction in recurrence risk (p<0.001), lowering the recurrence rate by 40%. Particularly for metastases larger than 15 cm³, the risk of recurrence was significantly increased (p=0.009), with a 72% recurrence rate within six months post-surgery. Multivariate analysis confirmed that metastases from breast cancer and malignant melanoma were most likely to show positive margin biopsies and had the highest recurrence risk.

The analysis of tumor margin biopsies provides valuable prognostic information for patients with intracranial metastases. Positive margin biopsies could serve as markers for increased recurrence risk. The combination of surgical resection and adjuvant radiotherapy improves long-term prognosis and should be considered, especially in patients with large metastases.