P06.01 * PROGESTERONE RECEPTOR EXPRESSION PREDICTS RECURRENCE OF CRANIAL BUT NOT SPINAL MENINGIOMAS

OBJECTIVE: The expression of estrogen receptors (ER) and progesterone receptors (PR) has been studied since 30 years in intracranial meningiomas, whereas only few studies concern spinal meningiomas. The aim of the study is to define whether the ER and PR expression may be associated to recurrence of spinal meningiomas as well as demonstrated for intracranial ones. MATERIALS AND METHODS: The only six patients with spinal meningiomas who experienced recurrence after complete resection (group I) from a surgical series of 140 patients operated on between 1986 and 2010 were reviewed. The investigated factors included tumor size, type of arachnoidal interface, Simpson grade of resection (I versus II), ER and PR expression, proliferation index Ki67/ MiB1. The same factors have also been investigated in 50 consecutive spinal meningiomas with no recurrence (group II), in 50 consecutive intracranial meningiomas which recurred (group III) and in 50 consecutive intracranial meningiomas with no recurrence (group IV). The data were statistically analyzed with the Kaplan-Meier method. RESULTS: The statistical analysis showed that the higher Ki67/MiB1 (p < 0.0001) was the most significant risk factor for recurrence of both spinal and intracranial meningiomas, whereas the invasion of the spinal-arachnoidal interface showed tendency to significance. As expected, the larger tumor size and the Simpson grade II resection were risk factors for recurrence of intracranial but not for spinal meningiomas. The PR expression was positive in all spinal meningiomas (both recurrent and not recurrent); on the other hand, in the groups of intracranial meningiomas the PR expression was negative in 81.5% of cases which recurred and positive in all (100%) cases with no recurrence. The ER expression was not correlated to the recurrence. CONCLUSION: The Ki67/MiB1 is clearly correlated to recurrence of spinal meningiomas; on the other hand the PR expression seems to be not significant, differently from intracranial meningiomas.