Prognostic Factors Including Proliferation Markers Ki-67, bax, and bcl-2 in Temporal Bone Paraganglioma

Valuable criteria with which to predict the clinical behavior of the temporal bone paraganglioma or the response to treatment are lacking. The analysis of markers of cell proliferation is a possibility to estimate the prognosis. Extensive patient data on 40 temporal bone paragangliomas were gathered over the years and correlated with the data obtained by staining histologic sections with bcl-2, bax, and MIB I markers of cellular proliferation. The immunohistochemistry was in all cases negative for bcl-2, positive for bax, and for Ki-67 positive in 20% of tumors. The scores for Ki-67 did not correlate with the majority of clinical parameters, except for treatment modality, preoperative hearing loss, and cranial nerve involvement. The tendency toward poorer hearing and a higher incidence of preoperative lower cranial nerve palsies was demonstrated in patients with higher Ki-67 scores. Furthermore, the higher rate of subtotal tumor removals in these patients reveals technical difficulties in accomplishing a radical removal, although the incidence of residual tumors was thus not affected. In view of the present information obtained with proliferation markers, the site of tumor origin still remains the most predictive variable for the course of the disease.