Reductions of circulating matrix metalloproteinase 2 and vascular endothelial growth factor levels after treatment with pegvisomant in subjects with acromegaly

Ectopic Intrasphenoidal Growth Hormone Releasing Pituitary Adenoma Associated with an Intracranial Aneurysm

Pituitary adenomas are a type of of the most frequent intracranial tumors. These tumors can extend outside the sella, but very rarely originate ectopically to the sellar region. A 71-year-old patient presented to our institution, with prior clinical history of noncontrolled arterial hypertension and new-onset high-intensity pulsatile headache. Upon suspicion of a hypertensive emergency with probable brain compromise, a nonenhanced computed tomography of the head was performed. A mass within the sphenoid sinus was found. Endocrinological workup demonstrated a significant elevation of the growth hormone. As an incidental finding, a brain aneurysm was evidenced, which was treated endovascularly prior to the mass treatment. Subsequently, the patient successfully underwent a gross total resection through an endonasal transsphenoidal approach. Histopathological results were consistent with a pituitary ectopic adenoma. A postoperative improvement in levels of somatomedin C was documented postoperatively.

Acromegaly, inflammation and cardiovascular disease: a review

Acromegaly is characterized by Growth Hormone (GH) and Insulin-like Growth Factor 1 (IGF-1) excess. Uncontrolled acromegaly is associated with a strongly increased risk of cardiovascular disease (CVD), and numerous cardiovascular risk factors remain present after remission. GH and IGF-1 have numerous effects on the immune and cardiovascular system. Since endothelial damage and systemic inflammation are strongly linked to the development of CVD, and have been suggested to be present in both controlled as uncontrolled acromegaly, they may explain the presence of both micro- and macrovascular dysfunction in these patients. In addition, these changes seem to be only partially reversible after remission, as illustrated by the often reported presence of endothelial dysfunction and microvascular damage in controlled acromegaly. Previous studies suggest that insulin resistance, oxidative stress, and endothelial dysfunction are involved in the development of CVD in acromegaly. Not surprisingly, these processes are associated with systemic inflammation and respond to GH/IGF-1 normalizing treatment.

Cerebellopontine Angle Tumors Are Associated with a Greater Incidence of Unruptured Intracranial Aneurysms

OBJECTIVE

We tested the hypothesis that cerebellopontine angle (CPA) tumors are associated with a greater incidence of unruptured intracranial aneurysms (IAs).

METHODS

Patients with intracranial tumors (ITs) undergoing computed tomography angiography and magnetic resonance imaging were enrolled in an observational cohort study that prospectively collected age, sex, hypertension, diabetes, cerebral arteriosclerosis, tumor type, tumor location, hydrocephalus, smoking, alcohol intake, CPA tumor size, cerebral aneurysms, and cerebral arteriosclerosis. Patients with the coexistence of IA and ITwere classified as group II, whereas the others with IT as group I.

RESULTS

We included 1218 patients with IT for analysis. The incidence of IA was 7.1% (86/1218). A total of 31% of patients with aneurysms had CPA tumors. In a multivariate logistic regression model, a greater incidence of IA was found in female patients (odds ratio [OR] 1.726, 95% confidence interval [CI] 1.050-2.836, P=0.031) and in patients with CPA tumors (OR 3.002, 95% CI 1.822-4.947, P=0.000) after adjustment for tumor type, cerebral arteriosclerosis, and age. In female patients, CPA tumors were a unique independent risk factor of a greater incidence of IA (OR 2.270, 95% CI 1.194-4.317, P=0.012). Furthermore, cerebral arteriosclerosis was a unique independent risk factor of IA in patients with CPA tumors (OR 7.626, 95% CI 2.928-19.860, P=0.000).

CONCLUSIONS

These data support the hypothesis that CPA tumors are associated with a greater incidence of unruptured IAs, especially in female patients. Cerebral arteriosclerosis contributed to elevated risk of IA in patients with CPA tumors.

Matrix metalloproteinase 2 (MMP-2) levels are increased in active acromegaly patients

PURPOSE

During follow-up of acromegaly patients, there is a discordance rate of 30% between the measurements of growth hormone and insulin-like growth factor-1 levels. Further tests are required to determine disease activity in patients with discordant results. This study was planned to investigate an association of serum levels of matrix metalloproteinase-2, matrix metalloproteinase-9, and cathepsin B with disease activity in acromegaly patients.

METHODS

In this study, 64 acromegaly patients followed in our clinic were divided into two groups according to the 2010 consensus criteria for cure of acromegaly as patients with active disease (n = 24) and patients with controlled disease (n = 40). Serum matrix metalloproteinase-2, matrix metalloproteinase-9, and cathepsin B levels were measured by the enzyme-linked immunosorbent assay method.

RESULTS

The mean serum matrix metalloproteinase-2 level was significantly higher in the active acromegaly patients than in the controlled acromegaly patients (150.1 ± 54.5 ng/mL vs. 100.2 ± 44.6 ng/mL; p < 0.0001). There was no significant difference between the active and controlled acromegaly patients regarding serum matrix metalloproteinase-9 and cathepsin B levels (p = 0.205 and p = 0.598, respectively). Serum matrix metalloproteinase-2 levels of 118.3 ng/mL and higher had a sensitivity of 75% and a specificity of 77.5% in determining active disease. The risk of active acromegaly was 3.3 fold higher in the patients with a matrix metalloproteinase-2 level of >118.3 ng/mL than in the patients with a matrix metalloproteinase-2 level of <118.3 ng/mL.

CONCLUSIONS

In this study, serum matrix metalloproteinase-2 level is increased in the active acromegaly patients and a threshold value in determining active disease was defined for serum matrix metalloproteinase-2 level. This study is the first to compare acromegaly patients having active or controlled disease in terms of matrix metalloproteinase-2 and matrix metalloproteinase-9 levels. The results need to be confirmed by a study that will be conducted in a larger patient group also including a healthy control group to demonstrate the value of this novel marker in disease activity.

Angiogenic markers: molecular targets for personalized medicine in pituitary adenoma

AIM

Pituitary adenomas are typically slow-growing and histologically benign tumors that can occasionally behave in a malignant-like manner, invading adjacent structures or recurring after treatment. Using protein analysis methods and multiplex xMAP assays, we aimed to find out if these particular types of tumors express angiogenic markers VEGF and basic FGF (bFGF), which are associated with tumor growth and invasiveness, and quantify them in order to establish their usefulness as biomarkers.

MATERIALS & METHODS

We have analysed the expression of angiogenic markers VEGF and bFGF in serum and tissue specimens from 66 pituitary adenomas (43 invasive and 23 noninvasive). For serum analysis, we used xMAP and ELISA, and for tissue analysis, we performed histopathology and immunohistochemistry.

RESULTS & CONCLUSION

We measured the serum angiogenic factors in pituitary adenomas. The quantification methods revealed significant differences between pituitary adenoma patients and controls, for both VEGF (212.4 vs 112.5 pg/ml in controls) and bFGF (mean value of 12.6 vs 10.8 pg/ml in controls), and also differentiated between invasive and noninvasive adenomas (p < 0.05). The tissue expression of VEGF and bFGF strongly correlated with their serum level increase. Our findings can be further developed into methods for selection of patients suitable for personalized, antiangiogenic therapy.

Prevalence of cerebral aneurysm in patients with acromegaly

The prevalence of cerebral aneurysm was retrospectively investigated in 208 patients with acromegaly relative to the rate of cerebral aneurysm in a group of control subjects. Neuroradiological examinations of the cerebral vascular system were conducted in 208 acromegaly patients (101 men; mean age, 48.8 years). The prevalence of cerebral aneurysm in the acromegaly patients was compared to that in a control group consisting of 7,390 subjects who underwent "brain checkup" between 2006 and 2008 (mean age, 51.6 years). In the acromegaly group, cerebral aneurysm was detected in 4.3 % of patients. By sex, the prevalence was 6.9 % in males, a significantly proportion than that in the control group with an odds ratio of 4.40. The prevalence in females did not differ between the two groups. In the acromegaly group, the rate of hypertension was significantly higher in the patients with aneurysm compared to those without aneurysm. Multiple logistic regression identified acromegaly as a significant factor related to the prevalence of cerebral aneurysm in all male subjects; other factors, such as age, hypertension and smoking, were not found to be significant. A significantly higher prevalence of cerebral aneurysm was detected in male patients with acromegaly. This finding indicates that excess growth hormone or insulin-like growth factor 1 affects the cerebral vascular wall, resulting in aneurysm formation. In addition to known systematic complications in the cardiovascular, respiratory, metabolic, and other systems, the risk of cerebral aneurysm should be considered in the management of acromegaly.

Clinical effectiveness and cost-effectiveness of pegvisomant for the treatment of acromegaly: a systematic review and economic evaluation

BACKGROUND

Acromegaly, an orphan disease usually caused by a benign pituitary tumour, is characterised by hyper-secretion of growth hormone (GH) and insulin-like growth factor I (IGF-1). It is associated with reduced life expectancy, cardiovascular problems, a variety of insidiously progressing detrimental symptoms and metabolic malfunction. Treatments include surgery, radiotherapy and pharmacotherapy. Pegvisomant (PEG) is a genetically engineered GH analogue licensed as a third or fourth line option when other treatments have failed to normalise IGF-1 levels.

METHODS

Evidence about effectiveness and cost-effectiveness of PEG was systematically reviewed. Data were extracted from published studies and used for a narrative synthesis of evidence. A decision analytical economic model was identified and modified to assess the cost-effectiveness of PEG.

RESULTS

One RCT and 17 non-randomised studies were reviewed for effectiveness. PEG substantially reduced and rapidly normalised IGF-1 levels in the majority of patients, approximately doubled GH levels, and improved some of the signs and symptoms of the disease. Tumour size was unaffected at least in the short term. PEG had a generally safe adverse event profile but a few patients were withdrawn from treatment because of raised liver enzymes. An economic model was identified and adapted to estimate the lower limit for the cost-effectiveness of PEG treatment versus standard care. Over a 20 year time horizon the incremental cost-effectiveness ratio was pound81,000/QALY and pound212,000/LYG. To reduce this to pound30K/QALY would require a reduction in drug cost by about one third.

CONCLUSION

PEG is highly effective for improving patients' IGF-1 level. Signs and symptoms of disease improve but evidence is lacking about long term effects on improved signs and symptoms of disease, quality of life, patient compliance and safety. Economic evaluation indicated that if current standards (UK) for determining cost-effectiveness of therapies were to be applied to PEG it would be considered not to represent good value for money.