Prolactin levels and gender are associated with tumour behaviour in prolactinomas but Ki-67 index is not.

ABSTRACT

INTRODUCTION: The objective of this study was to investigate the effects of some clinical and pathological features of prolactinomas on tumour behaviour. MATERIAL AND METHODS: The study included 113 patients with prolactinoma (27 male, 86 female), with a mean age at diagnosis of 34.4 ± 10.0 years (40.3 ± 12.6 in males, 32.6 ± 8.3 in females). Patients were grouped as invasive or non-invasive according to radiological imaging findings. Ki-67 levels were evaluated if possible. RESULTS: The mean adenoma size (longest dimension) was 38.6 ± 21.6 mm and 10.8 ± 9.4 mm in male and female patients. Pre-treatment serum levels of prolactin were defined as mean 1,926 ± 6,662 ng/mL in all, 124.8 ± 63.4 and 4,675 ± 10,049 ng/mL in the noninvasive and invasive groups (p < 0.05). A positive correlation was found between the serum levels of prolactin and tumour size. The rate of patients with Ki-67 ≥ 0.03 was 37.5% and 47.8% in the noninvasive and invasive groups. The reduction rates were 60.8% and 80.4% in tumour sizes and 81.1% and 93.8% in prolactin level in the noninvasive and invasive groups, respectively, (p < 0.05). CONCLUSIONS: We found a strong correlation between prolactin levels and invasiveness in male patients compared to females. Ki-67 index was not found to have a place in defining the prognosis.