title: Evaluation of prognostic utility of MIB-1 and p53 expression in pituitary adenomas: correlations with clinical behaviour and follow-up results.
abstract: Pituitary adenomas (PAs) show a broad clinicomorphological spectrum. The proliferation activity, evaluated by MIB-1 labelling index (LI), and p53 expression have been pointed as predictive markers for invasiveness and progression. The aim of this study was to evaluate the proliferation rate and p53 expression and to look for any relationships with the clinical behaviour and follow-up results in a series of Bulgarian patients with PAs. A total of 93 patients with PAs (81 hormone-secreting, 12 non-functioning), who were operated on and followed up for a period of five years, were included. The MIB-1 LI and p53 expressions were determined by immunohistochemistry and correlated with various clinical and tumour variables. The whole group of PAs showed a low proliferation rate with evident variations in a small number of cases (MIB-1 LI - 0.50 ± 0.56, from 0.1 to 3.30). MIB-1 LI correlated with tumour size (p= 0.012) and was positively related with male gender (p= 0.23) and partial surgical resection (p= 0.036). We found no significant differences regarding the age, functional activity, invasion (n= 33), expansion (n= 37) and tumour recurrences (seven cases). Only 10 cases (10.8%) showed a focal, nuclear p53 immunoreactivity. The p53 positive tumours had higher proliferation rate (p= 0.0001) but no relationship with the other clinical and tumour variables. Among all cases, there was only one case with higher MIB-1 LI (3.3%), positive p53 expression and tumour recurrence after surgery. Our results show that most PAs have a low proliferation rate and lack of p53 expression, as well as no relationship with tumour invasion or postsurgical progression.
authors.affiliation: Department of Neurosurgery, University Hospital 'St. Ivan Rilsky', Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Asen
authors.initials: A
authors.lastname: Hadzhiyanev
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Radina
authors.initials: R
authors.lastname: Ivanova
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Emil
authors.initials: E
authors.lastname: Nachev
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Atanaska
authors.initials: A
authors.lastname: Elenkova
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Maria
authors.initials: M
authors.lastname: Yaneva
authors.affiliation: Clinical Center of Endocrinology and Gerontology, Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Sabina
authors.initials: S
authors.lastname: Zaharieva
authors.affiliation: Department of Neurosurgery, University Hospital 'St. Ivan Rilsky', Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Marin
authors.initials: M
authors.lastname: Marinov
authors.affiliation: Department of Neurosurgery, University Hospital 'St. Ivan Rilsky', Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Jivko
authors.initials: J
authors.lastname: Surchev
authors.affiliation: Medical University of Sofia , Sofia , Bulgaria.
authors.forename: Asya
authors.initials: A
authors.lastname: Ivanova
keywords: immunohistochemistry; p-53 expression; pituitary adenoma; proliferation rate