OR27-4 EFFECT OF OCTREOTIDE LAR WITHDRAWAL ON CLINICAL, BIOCHEMICAL AND NEURORADIOLOGICAL FINDINGS IN ACROMEGALIC PATIENTS A PROSPECTIVE STUDY

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: OR27-Pituitary: Acromegaly and Prolactinoma
Clinical
Sunday, June 16, 2013: 11:15 AM-12:45 PM
Presentation Start Time: 12:00 PM
Room 135 (Moscone Center)
Lucio Vilar*1, Luciana Ansaneli Naves2, Patricia Sampaio Gadelha3, Jose Luciano Albuquerque4, Giulliana Nobrega Guimaraes3, Christina Cavalcanti Santana3, Ana Virginia Gomes3, Cyntia Chaves Gomes3, Renan Magalhaes Montenegro5 and Manuel dos Santos Faria6
1Federal University of Pernambuco Medical School, Recife (PE), Brazil, 2University of Brasilia, Brasilia, Brazil, 3Hospital das Clinicas, Federal University of Pernambuco, Recife, Brazil, 4General Hospital Otavio de Freitas, Recife, Brazil, 5Hosp Univ WE UFC, Fortaleza, Brazil, 6Federal Univ of Maranhao, Sao Luis MA, Brazil
BACKGROUND: Somatostatin analogs (SAs) have been considered the most effective drugs for the treatment of acromegaly. A major disadvantage is the expected need to maintain therapy indefinitely in patients not previously irradiated. OBJECTIVE: The aim of the present study was to evaluate the likelihood of discontinuing therapy in well-controlled acromegalic patients treated with octreotide LAR, a long-acting SA, for at least 2 years. DESIGN AND METHODS: Among patients with acromegaly submitted to octreotide LAR therapy, the authors selected those who fulfill the following criteria: two or more years of treatment, a stable dose and injections interval every 4 weeks or longer for the previous year, no history of radiotherapy, no cabergoline or pegvisomant use over the previous 6 months, GH levels <2.5  ng/mL, and normal IGF-1 levels for age. After 12 weeks from octreotide LAR withdrawal, basal GH levels, post-glucose GH nadir, IGF-1 levels, clinical signs/symptoms, and metabolic parameters were evaluated. Patients who experienced disease recurrence, defined as IGF-1 levels greater than 1.2 times the upper limit of normal (ULN) were removed from the study and restarted octreotide LAR at the same previous dose. The patients who remained in remission were followed for at least 12 months and underwent biochemical/hormonal evaluation every 3 months and pituitary magnetic resonance imaging (MRI) every 6 months. RESULTS: Twenty patients (4 de novo and 16 previously operated), 12 women and 10 men, mean age 39.35 ± 8.38 years (range, 22 to 52) treated by 2.74 ± 0.64 years (range, 2.0 to 4.4), were studied. Sixteen patients (80%) relapsed biochemically within 9 months of having stopped octreotide LAR. Four patients (20%) remained without clinical and biochemical/neuroradiological evidence of disease recurrence after up 18 months of follow-up. At withdrawal, non-recurring patients had significantly lower IGF-1 levels (median IGF-1 ULN 0.45 vs. 0.85, respectively, p = 0.03) whereas GH levels and MRI findings were similar in both groups. There were also no significant differences concerning age and gender. Glucose levels improved in both euglycemic and dysglycemic patients after drug discontinuation. CONCLUSION: Our results suggest that withdrawal of octreotide LAR is possible in some acromegalic patients treated by at least 2 years and considered optimally controlled in hormonal and neuroradiological terms, particularly those with lower IGF-1 levels.

Nothing to Disclose: LV, LAN, PSG, JLA, GNG, CCS, AVG, CCG, RMM, MDSF

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