Apolipoprotein E polymorphism and central nervous system tumors: correlation with cell proliferation indices and clinical outcome.

Aims: This study was designed to determine whether the polymorphism of apolipoprotein E (apoE), one of the key regulatory proteins in cholesterol metabolism, is related to varying susceptibility to central nervous system (CNS) neoplasms, and to evaluate any possible interaction between this polymorphism and tumor cell proliferation or clinical outcome.

Methods And Results: 53 CNS tumors were selected. Follow-up and survival data were available for 36 patients. ApoE genotypes and cell proliferation indices (nucleolar organizer regions, MIB-1, PCNA, p53) were determined from paraffin-embedded tissue by standard methods. Each of the indices of cell proliferation correlated positively with tumor grade and negatively with duration of clinical follow-up and survival. There was a non-significant trend for apoE epsilon2 allele carriers to have high-grade tumors and apoE epsilon4 allele carriers to have low-grade tumors. Possession of apoE epsilon4 was associated with a more advanced age of disease presentation (p < 0.01) and a longer duration of follow-up (p < 0.04). No significant correlations were found between possession of either apoE epsilon2 or apoE epsilon4 alleles and indices of cell proliferation.

Conclusions: These preliminary findings suggest that possession of apoE epsilon4 allele may correspond to a more favorable clinical course in terms of more advanced age of disease presentation, and longer duration of follow-up and survival in patients with CNS neoplasms.