Clinical and genetic characterization of pituitary gigantism: an international collaborative study in 208 patients.

Despite being a classical growth disorder, pituitary gigantism has not been studied previously in a standardized way. We performed a retrospective, multicenter, international study to characterize a large series of pituitary gigantism patients. We included 208 patients (163 males; 78.4%) with growth hormone excess and a current/previous abnormal growth velocity for age or final height >2 s.d. above country normal means. The median onset of rapid growth was 13 years and occurred significantly earlier in females than in males; pituitary adenomas were diagnosed earlier in females than males (15.8 vs 21.5 years respectively). Adenomas were ≥10 mm (i.e., macroadenomas) in 84%, of which extrasellar extension occurred in 77% and invasion in 54%. GH/IGF1 control was achieved in 39% during long-term follow-up. Final height was greater in younger onset patients, with larger tumors and higher GH levels. Later disease control was associated with a greater difference from mid-parental height (r=0.23, P=0.02). AIP mutations occurred in 29%; microduplication at Xq26.3 - X-linked acrogigantism (X-LAG) - occurred in two familial isolated pituitary adenoma kindreds and in ten sporadic patients. Tumor size was not different in X-LAG, AIP mutated and genetically negative patient groups. AIP-mutated and X-LAG patients were significantly younger at onset and diagnosis, but disease control was worse in genetically negative cases. Pituitary gigantism patients are characterized by male predominance and large tumors that are difficult to control. Treatment delay increases final height and symptom burden. AIP mutations and X-LAG explain many cases, but no genetic etiology is seen in >50% of cases.

Could different treatment approaches in acromegaly influence life expectancy? A comparative study between Bulgaria and Campania (Italy).

BACKGROUND: Mortality in acromegaly strictly depends on optimal control of GH and IGF1 levels. Modern medical therapy with somatostatin analogs (SSAs) and GH receptor antagonists (GHRAs) is not available in many countries due to funding restrictions. This retrospective, comparative, cohort study investigated the impact of different treatment modalities on disease control (GH and IGF1) and mortality in acromegaly patients. METHODS: Two cohorts of patients with acromegaly from Bulgaria (n=407) and Campania, Italy (n=220), were compared, and mortality rates were evaluated during a 10-year period (1999-2008). RESULTS: The major difference in treatment approach between cohorts was the higher utilization of SSAs and GHRAs in Italy, leading to a decreased requirement for radiotherapy. Significantly more Italian than Bulgarian patients had achieved disease control (50.1 vs 39.1%, P=0.005) at the last follow-up. Compared with the general population, the Bulgarian cohort had a decreased life expectancy with a standardized mortality ratio (SMR) of 2.0 (95% CI 1.54-2.47) that was restored to normal in patients with disease control - SMR 1.25 (95% CI 0.68-1.81). Irradiated patients had a higher cerebrovascular mortality - SMR 7.15 (95% CI 2.92-11.37). Internal analysis revealed an independent role of age at diagnosis and last GH value on all-cause mortality and radiotherapy on cerebrovascular mortality. Normal survival rates were observed in the Italian cohort: SMR 0.66 (95% CI 0.27-1.36). CONCLUSIONS: Suboptimal biochemical control was associated with a higher mortality in the Bulgarian cohort. Modern treatment options that induce a strict biochemical control and reduce the necessity of radiotherapy might influence the life expectancy. Other factors, possibly management of comorbidities, could contribute to survival rates.

Evaluation of prognostic utility of MIB-1 and p53 expression in pituitary adenomas: correlations with clinical behaviour and follow-up results.

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.

Circulating vascular endothelial growth factor and active renin concentrations and prostaglandin E2 urinary excretion in patients with adrenal tumours.

OBJECTIVES: The aim of the present study was to determine vascular endothelial growth factor (VEGF), prostaglandin E(2) (PGE(2)) and active renin levels in patients with hormonally active adrenal tumours. DESIGN: The study was comprised of 16 patients with primary aldosteronism, 13 patients with active Cushing's syndrome due to adrenal adenomas, 8 patients with adrenal carcinomas, 19 patients with phaeochromocytoma and 19 healthy volunteers. METHODS: Active renin in plasma was determined by a two-site immunoradiometric assay. VEGF in sera samples and PGE(2) in 24-h urine were measured by ELISA. RESULTS: VEGF was significantly elevated in all the four groups of patients as compared with the controls. VEGF levels in patients with Cushing's syndrome were higher than those in patients with primary aldosteronism. Patients with adrenal carcinomas had the highest VEGF levels and the differences reached significance as compared with patients with primary aldosteronism and phaeochromocytoma. PGE(2) levels were not significantly different among groups. Active renin was significantly the lowest in patients with primary aldosteronism and significantly the highest in patients with phaeochromocytoma compared with the controls. Active renin in patients with primary aldosteronism was significantly lower than in those with Cushing's syndrome, phaeochromocytoma and adrenal carcinoma. CONCLUSIONS: Our data indicated that the mean level of VEGF in patients with all investigated adrenal tumours was significantly higher than in healthy controls. The cortisol-producing tumours appear to have increased angiogenic potential. Angiogenesis is probably associated not only with malignancy but also with functional activity of the adrenal tumors.