Endocrine Abstracts

Introduction: During clinical observation the behaviour of pituitary tumours is frequently unpredictable. The work was aimed at evaluating Ki-67 and topoisomerase II alpha indices as markers of tumour invasiveness and prognostic factors for postoperative course of disease.

Material and methods: The Ki-67 and topoisomerase IIα (Topo IIα) indices were determined by immunochemistry in specimens excised from neurosurgically removed pituitary tumours. In 48 examined patients (29 females and 19 males, mean age 46.5±18.9 years) who underwent pituitary tumour surgery, micro- and macroadenoma occurred in 13 and 35 cases, respectively.

Results: The Ki-67 index, unlike the Topo IIα index, was significantly related to tumour size category (median Ki-67 value 0.1 vs 1.8 in micro- and macroadenoma, respectively, P<0.005) while both indices were correlated with tumour size (for Ki-67: r=0.4, P<0.005; for Topo IIα r=0.3, P<0.05). Local tumour invasiveness was significantly related to both Ki-67 and Topo IIα indices. Postsurgery tumour recurrence (confirmed by MRI) was significantly related to Topo IIα (P<0.01) and not related to Ki-67 index (P>0.05). No correlation between Ki-67 and Topo IIα indices, nor between either index and patient age was found.

Conclusion: Ki-67 and topoisomerase IIα expression, as determined in pituitary tumour specimens, is related to the tumour size and invasiveness. Topoisomerase IIα appears to be a more valuable predictor of further disease course than Ki-67 (specifically for local recurrence) and may be helpful in planning postoperative therapy.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.