Distant metastasis occurs when cancer cells adapt to a tissue microenvironment that is different from the primary organ. This process requires genetic and epigenetic changes in cancer cells and the concomitant modification of the tumor stroma to facilitate invasion by metastatic cells. In this study, we analyzed differences in the epigenome of brain metastasis from the colon (n = 4) and lung (n = 14) cancer and we compared these signatures with those found in primary tumors. Results show that CRC tumors showed a high degree of genome-wide methylation compared to lung cancers. Further, brain metastasis from lung cancer deeply activates neural signatures able to modify the brain microenvironment favoring tumor cells adaptation. At the protein level, brain metastases from lung cancer show expression of the neural/glial marker Nestin. On the other hand, colon brain metastases show activation of metabolic signaling. These signatures are specific for metastatic tumors since primary cancers did not show such epigenetic derangements. In conclusion, our data shed light on the epi/molecular mechanisms that colon and lung cancers adopt to thrive in the brain environment.
1 February 2026 in Journal of Neurosurgical Sciences
Background: High-grade glioma (HGG) is the most common primary malignant brain tumor, with peak incidence in the fifth and sixth decades of life. Although HGG is rare in children, the prognosis remains poor, with a median overall survival (OS) of less than two years. Recently, TRK inhibitors have been approved for the treatment of tumors harboring NTRK gene fusions. In this review, we analyzed data from early clinical trials investigating the use of these agents in patients with HGG. Methods: A systematic literature search was performed in the PubMed database. Studies involving patients with HGG treated with TRK inhibitors were included. We analyzed progression-free survival (PFS), 24-week disease control rate, and complete or partial radiological responses according to the Response Assessment in Neuro-Oncology (RANO) criteria. Results: Sixteen studies comprising 55 patients with HGG harboring NTRK gene fusions (19 adults and 36 children) were included. A statistically significant difference in PFS was observed between pediatric and adult patients treated with TRK inhibitors (17 vs. 8.5 months; p < 0.001). Pediatric patients also exhibited a higher rate of complete or partial radiological response compared to adults (94% vs. 57%). Discussion: Although the available evidence on TRK inhibitors in HGG is limited, the findings of this review highlight a potentially promising role for these agents, particularly in the treatment of pediatric HGGs.
Background/Objectives: Recurrent glioblastoma has a poor prognosis and no universally accepted standard of care. Regorafenib has been investigated in this setting, but its use may be limited by treatment-related toxicity. This study evaluated the feasibility, safety, and clinical outcomes of reduced-dose regorafenib in patients with recurrent IDH-wildtype glioblastoma. Methods: We retrospectively analyzed 21 patients with recurrent IDH-wildtype glioblastoma (WHO 2021) treated at a single center after progression according to the Stupp protocol. Regorafenib was started at 80 mg/day on the standard 3-weeks-on/1-week-off schedule. We assessed overall survival from diagnosis (OS1) and from first progression (OS2), progression-free survival from diagnosis (PFS1) and from first progression (PFS2), treatment exposure, dose modifications, and treatment-related adverse events (CTCAE v5.0). Results: Median PFS2 was 5 months (95% CI, 3–8), median OS2 was 6 months (95% CI, 5–10), and median OS1 was 21 months (95% CI, 15–27). No grade ≥ 3 adverse events occurred, and no patient discontinued treatment permanently because of toxicity. Conclusions: In this retrospective single-center cohort, reduced-dose regorafenib was feasible and well tolerated in selected patients. These descriptive, hypothesis-generating findings warrant prospective studies to define the role of individualized regorafenib dosing in recurrent glioblastoma.