In a prospective study of 103 patients with
carcinoid tumors consecutively referred for medical treatment, the most common sites of the primary
tumors were the ileum (73%), bronchi (7%), and jejunum (4%). All patients had local
metastases, and 96 (93%) also had liver
metastases. The most common initial symptoms were
diarrhea (32%),
ileus (25%), and flush (23%). The overall frequency of
diarrhea was 84% and of flush was 75%. Heart insufficiency caused by cardiac valve disease was seen in 33% of the patients. The
carcinoid syndrome, including flush,
diarrhea, and elevated urinary
5-hydroxyindole acetic acid (5-HIAA) concentrations, was manifested by 69 patients (67%), 64 of whom (93%) had
carcinoid tumors of mid-gut origin. Elevated urinary
5-HIAA was found in 91 patients (88%), of which 89 displayed liver
metastases. The plasma concentration of the
tachykinin neuropeptide K (NPK) was elevated in 67 patients (66%), 63 of whom had
tumors of the mid-gut region. Serum
pancreatic polypeptide (PP) and human chorionic gonadotrophin alpha levels were elevated in 43% and 28% of the patients, respectively, and the highest levels were found in patients with metastatic bronchial
carcinoid tumors. Thirty-nine of the 103 patients are now dead; 18 died of
tumor progression, whereas 14 patients died of
heart failure secondary to a
carcinoid tricuspidal valve insufficiency. The estimated median survival from the time of histologic diagnosis was 14 years, and from the time of
carcinoid syndrome was 8 years.