Somatotroph tumor progression during pegvisomant therapy: a clinical and molecular study.
J Clin Endocrinol Metab
; 96(2): E251-9, 2011 Feb.
Article
in En
| MEDLINE
| ID: mdl-21068147
ABSTRACT
CONTEXT There is concern that pegvisomant could be associated with a higher risk of tumor growth. The rate and possible determinants of this tumor growth are unknown. OBJECTIVE:
The objective of the study was to investigate the clinical, immunohistological, and molecular factors conditioning tumor growth in patients taking pegvisomant. DESIGN ANDSETTING:
This was a cross-sectional study performed from 2004 to 2010 in four university hospitals in Spain. PATIENTS Seventy-five acromegalic patients with active disease resistant to somatostatin analogs treated with pegvisomant were followed up for a mean of 29 ± 20 months. MAIN OUTCOMEMEASURES:
Magnetic resonance images before initiation of pegvisomant, at 6 months, and then yearly were examined in all patients. Immunohistological and molecular studies were performed in tumors that grew.RESULTS:
A significant increase in tumor size was observed in five patients (6.7%). Absence of previous irradiation (P = 0.014) and shorter duration of prepegvisomant somatostatin analog therapy (P < 0.001) were associated with an increased risk of tumor growth. A stepwise multivariate linear regression analysis (R(2) = 0.334, P < 0.001) identified the duration of somatostatin analog therapy prior to pegvisomant (beta = -4.509, P = 0.014) as the only significant predictor of tumor growth. In those tumors that grew, GH expression and insulin receptor expression were higher (P = 0.033 in both cases) than in the control group.CONCLUSIONS:
No previous radiotherapy, shorter duration of prepegvisomant somatostatin analog therapy, and higher tumor expression of GH and insulin receptor could be risk factors for tumor growth during pegvisomant therapy.
Full text:
1
Database:
MEDLINE
Main subject:
Receptors, Somatotropin
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Adenoma
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Human Growth Hormone
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Growth Hormone-Secreting Pituitary Adenoma
Type of study:
Clinical_trials
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Diagnostic_studies
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Etiology_studies
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Observational_studies
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Prevalence_studies
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Prognostic_studies
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Risk_factors_studies
Limits:
Adolescent
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Adult
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Aged
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Aged80
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Female
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Humans
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Male
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Middle aged
Language:
En
Journal:
J Clin Endocrinol Metab
Year:
2011
Type:
Article
Affiliation country:
Spain