Long-acting lanreotide induces clinical and biochemical remission of acromegaly caused by disseminated growth hormone-releasing hormonesecreting carcinoid

Abstract

Ectopic GHRH-secreting tumors, such as carcinoid, rarely cause acromegaly. As protracted exposure to high levels of GH is associated with considerable morbidity and mortality, these patients require early and effective medical therapy to control hormonal hypersecretion. We employed a prolonged release somatostatin analog, lanreotide, to treat a patient with disseminated GHRH-producing carcinoid. Before treatment, the patient had a biochemical profile characteristic of active acromegaly. Plasma GHRH levels were markedly elevated (200-fold), and urinary 5-hydroxyindolacetic acid (5HIAA) levels were increased (4-fold). Magnetic resonance imaging revealed a large asymmetrical pituitary mass consistent with somatotroph hyperplasia. Somatostatin receptor scintigraphy revealed multiple bony and soft tissue lesions as well as striking pituitary uptake. Lanreotide (30 rag) was administered weekly by im injection for 12 weeks. Rapid and sustained symptomatic clinical improvement with diminished soft tissue swelling and hyperhidrosis was observed. GHRH levels decreased by 70%; glucose-suppressed GH and insulin-like growth factor I levels were reduced by 90% and 75%, respectively, to near normal values; urinary 5-HIAA levels normalized; and the pituitary mass remained unchanged. Unfortunately, the patient died due to complications of osteogenic sarcoma. In conclusion, prolonged release lanreotide induced clinical and biochemical remission in this patient with diffusely metastatic GHRH-producing carcinoid. This long-acting drug thus offers an effective, well tolerated, and convenient medical therapy for control of hormonal hypersecretion induced by excess GHRH.