Development and characterization of a novel in vivo model of carcinoid syndrome.

PURPOSE: Carcinoid syndrome, characterized by flushing, diarrhea, and valvular heart disease, can occur following carcinoid tumor metastasis to the liver and systemic release of bioactive hormones into the systemic circulation. Treatment of this devastating disease is hampered by the lack of an in vivo model that recapitulates the clinical syndrome. EXPERIMENTAL DESIGN: Here, we have injected BON cells, a novel human carcinoid cell line established in our laboratory, into the spleens of athymic nude mice to establish liver metastases. RESULTS: The majority of mice injected intrasplenically with BON cells developed significant increases in plasma serotonin and urine 5-hydroxyindoleacetic acid, and several mice exhibited mesenteric fibrosis, diarrhea, and fibrotic cardiac valvular disease reminiscent of carcinoid syndrome by both echocardiographic and histopathologic evaluation. Mice pretreated with octreotide, a long-acting somatostatin analogue, or bevacizumab, a vascular endothelial growth factor inhibitor, developed fewer liver metastases and manifestations of carcinoid syndrome, including valvular heart disease. CONCLUSION: We have provided an important in vivo model to further delineate novel treatment modalities for carcinoid syndrome that will also be useful to elucidate the factors contributing to the sequelae of carcinoid disease (e.g., mesenteric fibrosis and valvular heart disease).

Role of hepatic resection for patients with carcinoid heart disease.

OBJECTIVE: To evaluate the effects of resection of hepatic carcinoid metastases on progression and prognosis of carcinoid heart disease. PATIENTS AND METHODS: From our database of 265 consecutive patients diagnosed as having carcinoid heart disease from January 1, 1980, through December 31, 2005, we calculated survival from first diagnosis of cardiac involvement. Hepatic resection during follow-up was entered as a time-dependent covariable in a multivariable analysis. In patients with serial echocardiograms more than 1 year apart without intervening cardiac surgery, a previously validated cardiac severity score was calculated. A score increase that exceeded 25% was considered relevant progression. RESULTS: Hepatic resection was performed in 31 patients (12%) during follow-up. Five-year survival was significantly higher in these patients (86.5%; 95% confidence interval [CI], 73.5%-100.0%) than in patients without hepatic resection (29.0%; 95% CI, 23.3%-36.1%; univariable hazard ratio for hepatic resection, 0.25; 95% CI 0.12-0.53; P<.001). Hepatic resection remained strongly associated with improved prognosis in multivariable analysis (hazard ratio, 0.31; 95% CI, 0.14-0.66; P=.003). Among 77 patients (29%) with serial echocardiograms, 10 (13%) underwent hepatic resection during follow-up; resection was independently associated with decreased risk of cardiac progression (odds ratio, 0.29; 95% CI, 0.06-0.75; P=.03). CONCLUSION: Despite the limitations of this retrospective nonrandomized study, our data suggest that patients with carcinoid heart disease who undergo hepatic resection have decreased cardiac progression and improved prognosis. Eligible patients should be considered for hepatic surgery.

Long-term serotonin effects in the rat are prevented by terguride.

Long-term hyperserotoninemia induces heart valve disease in rats, and cases of cardiac valvulopathies have been reported in patients using ergolines, possibly through activation of the 5-hydroxytryptamine(2B) (5HT(2B)) receptor. The ergoline terguride (transdihydrolisuride) is a 5HT(2B/2C) receptor antagonist. Using a rat model, we have investigated whether terguride could prevent serotonin-induced changes in general and heart disease specifically. During 4 months, twelve Sprague-Dawley rats were given daily subcutaneous serotonin injections; twelve rats received a combination of serotonin injections and terguride by gavage, whereas ten rats were untreated controls. Using echocardiography, rats with aortic insufficiency were found in all 3 groups, while pulmonary insufficiency was only found in two rats injected with serotonin alone. Animals given serotonin alone had significantly higher heart weights compared to the controls (p=0.029) and rats given terguride (p=0.034). Rats injected with serotonin alone developed macroscopic skin changes at the injection sites, histologically identified as orthokeratosis and acanthosis. Terguride completely prevented these changes (p=0.0001, p=0.0003). Liver weights were higher in the animals given serotonin alone compared to controls (p=0.014) and terguride treated animals (p=0.009). Stomach weights were higher in animals given serotonin alone compared to rats given terguride (p=0.012). In the mesenchymal cell-line MC3T3-E1, terguride almost completely inhibited serotonin-induced proliferation (p<0.01). Serotonin increases heart, liver and stomach weights, possibly through enhanced proliferation. Terguride inhibits these effects. We propose that terguride may have beneficial effects in the treatment of diseases such as carcinoid syndrome, where serotonin plays an important pathogenic role.

[Carcinoid cardiopathy]. / La cardiopatia da carcinoide.

A series of 5 males and 2 females aged 23-73 yr with carcinoid cardiopathy is presented, all of them with clinical and instrumental signs of liver metastasis. The main clinical signs were dyspnoea and asthenia rendered ingravescent by effort, and, in the later stage, a frank picture of congestive cardiac decompensation. All subjected presented stethoscopic evidence of tricuspid valvulopathy, combined with pulmonary stenosis in 2 cases. The ECG picture displayed a constant reduction in cardiac potentials, together with right branch bundle block in 3 cases. In cases where an echocardiogram was taken, this confirmed tricuspid involvement. The disease progressed in all cases, and four patients died as a result of terminal liver failure.