Endocrine Abstracts

Pituitary adenomas represent more than 80% of all sella turcica tumors and 10–15% of all intracranial tumors in adults. Topoisomerase II α (TopoIIα) is recognized as a reliable tumor proliferative activity marker. Evaluation of its expression facilitates the identification of more aggressive neoplasms.

Aim: To assess the topoIIα expression in pituitary adenomas as the marker of the tumor aggressiveness, recurrence and progression.

Material and methods: Retrospective study included 60 patients (23 males, 37 females; aged 46.7±17.6 years) operated due to pituitary adenoma, followed-up for 2 years after the surgery. TopoIIα nuclear expression was assessed immunohistochemically in tissue samples in , hot spot’ areas and indexed as % of all nuclei. The tumor recurrence, seen in 36.7% of patients, was assessed on repeated pituitary MRIs.

Results: 73% of samples stained for topoIIα (median index of 0.71%). The statistically significant difference in topoIIα indices was noted between non-secreting and secreting adenomas (0.8 vs 0.41%). The topoIIα indices were also statistically higher in macroadenomas, in tumors causing visual impairment, invading the suprasellar space and cavernous sinuses. TopoIIα index >1% was independent risk factor of tumor recurrence or progression (RR – 4.65, 95% CI – 1.80–11.51); visual chiasm involvement (RR – 5.04, 95% CI 1.11–22.90), cavernous sinuses invasion (RR – 5.22, 95% CI 1.24–21.89), but not of suprasellar growth (RR – 4.01, 95% CI 0.94–17.10). The sensitivity and specificity of the topoIIα index >1% in predicting pituitary adenoma recurrence was 63.6 and 86.8 respectively (area under ROC curve 0.76).

Conclusions: The topoIIα expression in pituitary adenomas is related to the more aggressive tumor behavior. The index of topoIIα higher than 1% is independent risk factor of early pituitary adenoma recurrence and progression. The topoIIα expression should be routinely assessed in pituitary adenomas, as it gives important prognostic data.