Prognostic relevance of MIB-1 labeling index in VHL-associated and sporadic spinal hemangioblastomas: a subgroup analysis from a multicentric study.

Spinal hemangioblastomas (sHB) are rare vascular tumors, with distinct clinical courses between von Hippel-Lindau (VHL)-associated and sporadic cases. The MIB-1 labeling index has been proposed as a surrogate marker for tumor proliferation, but its prognostic value remains unclear in this context. In this subgroup analysis from a multicenter retrospective study, we analyzed 116 primary sHB patients with available MIB-1 indices. Patients were stratified by VHL status. Statistical comparisons included ROC analyses for local progression-free survival (PFS) prediction and Kaplan-Meier survival curves for local PFS, stratified by a MIB-1 index cut-off derived from Youden's index. The MIB-1 index was significantly lower in VHL-associated tumors compared to sporadic ones (mean 2.17% vs. 3.02%, p = 0.008). In VHL-associated sHB, a higher MIB-1 index (≥ 2%) correlated with an increased risk of local tumor progression (AUC 0.74, 95% CI 0.49-0.98), whereas this was not observed in sporadic cases (AUC 0.56, 95% CI 0.23-0.88). Kaplan-Meier analysis showed that VHL patients with MIB-1 ≥ 2% had significantly shorter PFS (p = 0.05), while no significant association was found in sporadic tumors (p = 0.87). Our findings suggest that while VHL-associated sHB exhibit lower proliferative indices overall, elevated MIB-1 labeling indices might serve as a prognostic marker of shorter local PFS in this subgroup. In contrast, MIB-1 index appears to have limited prognostic relevance in sporadic sHB. These results highlight the importance of further molecular stratification and proliferation assessment in sHB to better inform clinical decision-making.