vasoactive-intestinal-peptide and Carcinoma--Small-Cell

Vasoactive intestinal peptide (VIP) is a neuropeptide of multiple functions affecting development and aging. In cancer, for example, VIP was found to function as an autocrine growth factor in nonsmall cell lung cancer (NSCLC) promotion. Furthermore, a VIP hybrid antagonist (neurotensin(6-11)-VIP(7-28)) was found to inhibit NSCLC growth. In the present study, the expression of VIP mRNA was studied using human lung cancer cells. RNA prepared from 19 cell lines was fractionated by 1% agarose gel electrophoresis followed by blotting onto nitrocellulose membranes and hybridization to a VIP-specific RNA probe. VIP mRNA was detected in about 50% of the cell lines tested with a greater abundance in NSCLC. Cultures of the NSCLC NCI-H727 cell line were treated with forskolin, an activator of cyclic AMP (cAMP), and separately with the tumor promoter phorbol 12-myristate 13-acetate (PMA). Northern blot hybridization analysis showed an increase in VIP mRNA levels after 4 h treatment with 50 microM forskolin. Incubation with PMA also showed a significant increase in the levels of VIP transcripts. Cultures were then incubated with PMA in the presence of actinomycin D, a transcription blocker. Results indicated that PMA treatment may induce both VIP mRNA synthesis as well as VIP mRNA stabilization, and suggested a 4-5 h half-life for the VIP mRNA in the absence of PMA. Thus, lung cancer tumor proliferation may be regulated, in part, at the level of VIP gene expression.

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Cell Division; Colforsin; Cyclic AMP; Dactinomycin; Female; Gene Expression Regulation; Humans; Lung Neoplasms; Male; Neoplasm Proteins; Neurosecretory Systems; Nucleic Acid Synthesis Inhibitors; Organ Specificity; Rats; RNA, Messenger; RNA, Neoplasm; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

Gut peptide secreting tumours originate most commonly from the pancreatic Islets of Langerhans. Tumours at a variety of other sites have also been shown to synthesize and release these peptides, reflecting the wide distribution of the peptide secreting cells of the diffuse neuroendocrine system. Tumours such as the glucagonomas, insulinomas, VIPomas and gastrinomas are associated with characteristic clinical syndromes resulting from the effects of the peptide they secrete. The majority of the islet cell tumours in fact secrete a number of different peptides and many of these are present in several molecular forms, some of which may not be biologically active. This may explain the lack of clinical sequelae in association with tumours such as the somatostatinomas. The clinical features, methods of diagnosis, localisation and treatment of these tumours will be discussed.

Topics: Adenoma, Islet Cell; Bombesin; Bronchial Neoplasms; C-Peptide; Carcinoma, Small Cell; Diagnosis, Differential; Endocrine System Diseases; Erythema; Gastrointestinal Hormones; Glucagon; Glucagonoma; Humans; Insulin; Insulin Secretion; Insulinoma; Male; Neoplasms; Neurotensin; Pancreatic Hormones; Pancreatic Neoplasms; Pancreatic Polypeptide; Somatostatinoma; Vasoactive Intestinal Peptide; Zollinger-Ellison Syndrome

Topics: Appendiceal Neoplasms; Carcinoid Tumor; Carcinoma, Small Cell; Cholecystokinin; Digestive System; Duodenum; Endocrine Glands; Fetus; Gastric Mucosa; Gastrins; Humans; Ileum; Peptides; Rectal Neoplasms; Respiratory System; Secretin; Substance P; Vasoactive Intestinal Peptide

Topics: Animals; Antineoplastic Agents, Hormonal; Carcinoma, Small Cell; Cyclic AMP; Growth Hormone-Releasing Hormone; Humans; Lung Neoplasms; Mice; Receptors, Neuropeptide; Receptors, Pituitary Hormone-Regulating Hormone; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

Small-cell lung carcinoma (SCLC) is an aggressive, rapidly growing and metastasizing, and highly fatal neoplasm. We report that vasoactive intestinal peptide inhibits the proliferation of SCLC cells in culture and dramatically suppresses the growth of SCLC tumor-cell implants in athymic nude mice. In both cases, the inhibition was mediated apparently by a cAMP-dependent mechanism, because the inhibition was enhanced by the adenylate cyclase activator forskolin and the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine in proportion to increases in intracellular cAMP levels, and the inhibition was abolished by selective inhibition of cAMP-dependent protein kinase. If confirmed in clinical trials, this antiproliferative action of vasoactive intestinal peptide may offer a new and promising means of suppressing SCLC in human subjects, without the toxic side effects of chemotherapeutic agents.

Topics: 1-Methyl-3-isobutylxanthine; Adenylyl Cyclases; Animals; Carcinoma, Small Cell; Cell Division; Colforsin; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Enzyme Inhibitors; Humans; Lung Neoplasms; Mice; Mice, Nude; Phosphodiesterase Inhibitors; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

The effects of PACAP on c-fos mRNA using small cell lung cancer (SCLC) cell was investigated. PACAP-27 (100 nM) increased c-fos mRNA 5-fold using NCI-N417 cells. The increase was concentration dependent with 0.1 nM PACAP-27 half maximally increasing c-fos mRNA. Also the increase in c-fos mRNA caused by PACAP was time dependent; being maximal after 1 hour and returning to basal values after 4 hours. PACAP-38 but not PACAP(28-38) increased c-fos mRNA. One uM PACAP(6-38), a PACAP receptor antagonist, inhibited the increase in c-fos mRNA caused by 1 nM PACAP. These data indicate that PACAP stimulates nuclear oncogene expression in SCLC cells.

Topics: Carcinoma, Small Cell; Dose-Response Relationship, Drug; Genes, fos; Humans; Kinetics; Lung Neoplasms; Neuropeptides; Neurotransmitter Agents; Peptide Fragments; Pituitary Adenylate Cyclase-Activating Polypeptide; Proto-Oncogene Proteins c-fos; RNA, Messenger; Transcription, Genetic; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

Topics: Animals; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Cell Count; Cell Division; Cell Line; DNA, Neoplasm; Dose-Response Relationship, Drug; Female; Humans; Lung Neoplasms; Mice; Mice, Nude; Thymidine; Transplantation, Heterologous; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

Our goal was to define the incidence of neuroendocrine carcinomas of the colon and rectum, the patterns of neuroendocrine expression, and the cellular subtype within neuroendocrine tumors. We attempted to determine whether differences in neuroendocrine expression or specific cell type influenced survival.. Over a ten-year period, 988 patients had resections for colorectal cancer. Using immunohistochemical staining methods specific for neuroendocrine markers, 39 (3.9 percent) neuroendocrine cancers were identified retrospectively. Tumors were also stained with monoclonal antibody A-80 which is specific for exocrine differentiation. In this way we were able to determine the extent of neuroendocrine differentiation such as pure neuroendocrine, predominant neuroendocrine, and equal neuroendocrine-exocrine expression.. Average patient age was 65.5 (range, 28-89) years; there were 25 males and 14 females. Nineteen tumors were located in the right colon, 11 in the left, and 9 were in the rectum. Three histopathologic patterns were identified: pure neuroendocrine (n = 11), predominantly neuroendocrine (n = 17), and cancers with equal exocrine and neuroendocrine differentiation (n = 7). Three cellular subtypes were seen: small-cell (n = 15), intermediate-cell (n = 15), and well-differentiated neuroendocrine cancers (n = 5). There was one Dukes A cancer, 7 Dukes B, 16 Dukes C, and 15 patients had metastases to distant sites at the time of diagnosis. As a group, neuroendocrine tumors have a poor prognosis: six-month survival was 58 percent, three-year survival was 15 percent, and five-year survival was 6 percent. Survival statistically correlated with tumor stage (P = 0.01) but not with age, sex, tumor location, histopathologic pattern, or neuroendocrine subtypes. Median survival for pure neuroendocrine carcinomas was seven months and for predominantly neuroendocrine carcinomas was five months. Tumors with equal neuroendocrine and exocrine differentiation had a median survival of 22 months (P = 0.3). Small-cell neuroendocrine carcinomas had a median survival of five months, intermediate-cell had 11 months, and well-differentiated had a median survival of 22 months (P = 0.1).. Neuroendocrine differentiation is found in at least 3.9 percent of colon and rectal cancers. Many of these tumors were initially diagnosed as "carcinoids," the diagnosis was changed to "neuroendocrine carcinoma" after immunohistochemical staining. Overall survival is poor especially for small-cell and pure neuroendocrine carcinomas.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Biomarkers, Tumor; Carcinoma, Neuroendocrine; Carcinoma, Small Cell; Colonic Neoplasms; Female; Follow-Up Studies; Humans; Incidence; Male; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Phosphopyruvate Hydratase; Rectal Neoplasms; Serotonin; Survival Rate; Time Factors; Vasoactive Intestinal Peptide

Small-cell lung cancer (SCLC) is a common and highly fatal malignancy for which there is no satisfactory treatment. The amphibian peptide bombesin and its mammalian counterpart, gastrin-releasing peptide, serve as autocrine growth factors for the SCLC cells, but little is known about endogenous substances that inhibit the growth and proliferation of these tumor cells. We report that the neuropeptide vasoactive intestinal peptide (VIP) markedly inhibits the growth and multiplication of SCLC cell lines NCI-H345 and NCI-H69, and that the closely related peptide helodermin inhibits the proliferation of NCI-H345 cells with even higher efficacy. In the latter cells, the inhibition by VIP and isobutyl methyl xanthine paralleled their ability to stimulate cyclic adenosine monophosphate production within the cells. The peptide-induced suppression of SCLC proliferation is enhanced in the presence of an anti-bombesin monoclonal antibody. The antimitogenic activities of VIP and helodermin, and their enhancement by anti-bombesin antibody, offer the potential for a new approach to the pharmacologic control of SCLC.

Topics: Antibodies, Monoclonal; Bombesin; Carcinoma, Small Cell; Cell Division; Cell Line; Dose-Response Relationship, Drug; Humans; Intercellular Signaling Peptides and Proteins; Kinetics; Lung Neoplasms; Peptides; Time Factors; Tumor Cells, Cultured; Vasoactive Intestinal Peptide; Venoms

The concentrations of immunoreactive (IR) corticotropin-releasing hormone (CRH) in 218 neuroendocrine tumors were determined by CRH radioimmunoassay. The tumors examined were 86 pancreatic endocrine tumors (PET), 22 neuroblastic tumors (NBT), 26 carcinoid tumors (CA), 24 pheochromocytomas (PHEO), 40 small cell lung carcinomas (SCLC) and 20 medullary thyroid carcinomas (MTC). IR-CRH was detectable in 21 neuroendocrine tumors (10 PET, four NBT, three CA, two PHEO and two SCLC) at levels of 10-2,700 ng/g wet weight (9.6%). The 21 patients with these CRH-producing tumors showed no clinical symptoms suggestive of Cushing's syndrome. The levels of plasma IR-CRH extracted by immunoaffinity chromatography were < 7.5 pg/ml in five normal subjects and a patient with a neuroblastic tumor containing 55 ng/g wet weight IR-CRH, but in a patient with a thymic carcinoid tumor containing 1,000 ng/g wet weight IR-CRH, the plasma level was elevated to 180 pg/ml. This patient did not have Cushing's syndrome nor an elevated plasma adrenocorticotropic hormone (ACTH) level. The concentrations of nine peptides (growth hormone-releasing hormone, somatostatin, ACTH, calcitonin, gastrin-releasing peptide, glucagon, vasoactive intestinal peptide, neuropeptide tyrosine and pancreatic polypeptide) were determined in extracts of the 21 IR-CRH-producing tumors. Some of these peptides were frequently found to be produced concomitantly with CRH. The results indicate IR-CRH to be produced by various neuroendocrine tumors, but Cushing's syndrome, due to the CRH, to be very rare. The results also show that CRH-producing tumors produce multiple hormones.

Topics: Adenoma, Islet Cell; Adrenal Gland Neoplasms; Adrenocorticotropic Hormone; Bombesin; Calcitonin; Carcinoid Tumor; Carcinoma, Small Cell; Chromatography, Gel; Corticotropin-Releasing Hormone; Gastrin-Releasing Peptide; Gastrins; Humans; Hypothalamus; Lung Neoplasms; Neoplasms; Neuroblastoma; Pancreatic Neoplasms; Peptides; Pheochromocytoma; Somatostatin; Thyroid Neoplasms; Vasoactive Intestinal Peptide

High levels of BN/GRP are present in classic SCLC and lung carcinoids, whereas BN immunoreactivity is absent in variant SCLC, adenocarcinoma, large cell carcinoma, squamous cell carcinoma, and mesothelioma cell lines. BN-like peptides are secreted from classic SCLC into the tissue culture medium. The secretion rate of BN-like peptides from cell line NCI-H345 was increased 3-fold by VIP (1 microM). Also, VIP increased the cAMP levels in cell line NCI-H345 by an order of magnitude. Therefore, SCLC cells have functional VIP receptors which regulate the secretion of BN-like peptides. Also, SRIF (100 nM) inhibits the VIP-stimulated increase in cAMP levels and secretion rate of BN-like peptides from SCLC cells. Because BN stimulates colony formation, VIP and/or SRIF may be able to alter the growth of SCLC cells. BN-like peptides are secreted from SCLC cells into the plasma. The levels of BN immunoreactivity in the plasma of SCLC patients with extensive disease is 2- to 40-fold greater than that of patients with limited disease. Secretin infusion into patients with extensive disease produces a transient increase (7-fold) in the plasma concentration of BN-like peptides. BN-like peptides are also present in the CSF of SCLC patients. When released from SCLC cells, BN-like peptides may interact with cell surface receptors. [Tyr4]BN binds with high affinity (Kd = 0.5 nM) to a single class of sites (1500/cell) on cell line NCI-H345. The carboxyl terminus of BN or GRP is essential for high-affinity binding activity. BN-like peptides elevate cytosolic Ca2+ levels as a result of increased phosphatidylinositol turnover. The putative BN receptor antagonist [D-Arg1, D-Pro2, D-Trp7,9, Leu11]substance P inhibits high-affinity [Tyr4]BN binding, the ability of BN to elevate cytosolic Ca2+ levels, and colony formation of SCLC cells. Therefore, BN receptor antagonists may serve as useful agents to inhibit the growth of SCLC.

Topics: Bombesin; Carcinoma, Small Cell; Cell Line; Gastrin-Releasing Peptide; Humans; Lung Neoplasms; Peptides; Receptors, Bombesin; Receptors, Neurotransmitter; Secretin; Vasoactive Intestinal Peptide

The effects of somatostatin (SRIF) on small cell lung cancer (SCLC) cell line NCI-H345 was investigated. SRIF had no effects on the basal cAMP levels or the secretion rate of bombesin-like peptides. VIP (1 microM) increased the cAMP levels approximately 10-fold and the secretion rate of bombesin-like peptides 3-fold. SRIF and its analogues inhibited the increase in the cAMP levels and the secretion rate of bombesin-like peptides caused by VIP. The order of peptide potency was (D-Trp8)SRIF > SRIF-28 = (Tyr11)SRIF > SRIF. These data suggest that functional SRIF receptors may be present on SCLC cells.

Topics: Bombesin; Carcinoma, Small Cell; Cyclic AMP; Lung Neoplasms; Peptides; Receptors, Gastrointestinal Hormone; Receptors, Vasoactive Intestinal Peptide; Somatostatin; Tumor Cells, Cultured; Vasoactive Intestinal Peptide

The light microscopic, electron microscopic and immunohistochemical features of a small cell undifferentiated carcinoma of the minor salivary gland are presented. The tumor was composed predominantly of undifferentiated small cells with focally admixed neuroendocrine, exocrine and squamous cells, occasionally arranged in an organoid manner. The presence of vasoactive intestinal polypeptide in the tumor was found immunohistochemically. In addition, the tumor cells stained with Grimelius' impregnation. Immunohistochemically the tumor contained cells that reacted positively with the antibodies to carcinoembryonic antigen, 66K keratin polypeptide, or human salivary amylase. These findings indicate that a small cell undifferentiated carcinoma of the minor salivary gland, reported here, exhibits focally multidirectional differentiation as well as neuroendocrine cell derivation.

Topics: Amylases; Carcinoembryonic Antigen; Carcinoma, Small Cell; Histocytochemistry; Humans; Immunoenzyme Techniques; Keratins; Male; Microscopy, Electron; Middle Aged; Salivary Gland Neoplasms; Salivary Glands; Salivary Glands, Minor; Vasoactive Intestinal Peptide

The ability of bombesin-like peptides to elevate intracellular Ca2+ levels in small cell lung cancer cells was investigated using the fluorescent Ca2+ indicator Fura 2. Nanomolar concentrations of bombesin elevated cytosolic Ca2+ levels in the absence or presence of extracellular Ca2+. Potent bombesin receptor agonists, such as gastrin releasing peptide (GRP) or (GRP)14-27 elevated cytosolic Ca2+ levels whereas inactive compounds such as (D-Trp8)bombesin or (GRP)1-16 did not. Furthermore, the bombesin receptor antagonist (D-Arg1, D-Pro2, D-Trp7,9, Leu11) substance P (30 microM) had no effect on the Ca2+ levels by itself but antagonized the increase in Ca2+ caused by 10 nM or 100 nM bombesin. These data suggest that bombesin receptors may regulate the release of Ca2+ from intracellular organelles in small cell lung cancer cells.

Topics: Benzofurans; Bombesin; Calcium; Carcinoma, Small Cell; Cell Line; Cytosol; Fura-2; Gastrin-Releasing Peptide; Humans; In Vitro Techniques; Oligopeptides; Peptides; Receptors, Bombesin; Receptors, Neurotransmitter; Somatostatin; Structure-Activity Relationship; Substance P; Vasoactive Intestinal Peptide

Plasma samples from 21 patients with small cell carcinoma of the lung were screened for pancreatic polypeptide, somatostatin, motilin, and vasoactive intestinal polypeptide. One patient had severe impairment of both renal and liver function. In the 20 remaining subjects vasoactive intestinal polypeptide concentrations were normal, and only two patients had increased concentrations of somatostatin. Increases in pancreatic polypeptide were detected more commonly (7/20), but these may have been non-specific age related increases. The major finding was high concentrations of motilin (greater than 496 pg/ml) in 17 of 20 patients. Plasma motilin was subsequently assayed in 16 more patients with lung cancer, including 10 patients with non-small cell carcinoma of the lung. At concentrations over 900 pg/ml plasma motilin appears to be a tumour marker for small cell carcinoma of the lung with acceptable sensitivity (59%) and specificity (78%). The origin of increased plasma motilin in small cell carcinoma of the lung was investigated. Bombesin (gastrin releasing peptide), a peptide known to stimulate the release of motilin in man, was, as in previous studies, detected in tumour but not in plasma, except in one patient out of 21. Immunohistochemical studies failed to detect motilin antigen in biopsy samples. Motilin tumour content was found to be low in tumour tissue from three patients with small cell carcinoma of the lung who had appreciable hypermotilinaemia and from three patients with non-small cell carcinoma of the lung who had either normal or slightly raised plasma motilin concentrations. The stimulus to motilin secretion in patients with small cell carcinoma of the lung remains unclear.

Topics: Adult; Aged; Biomarkers, Tumor; Carcinoma, Small Cell; Female; Humans; Lung Neoplasms; Male; Middle Aged; Motilin; Pancreatic Polypeptide; Prospective Studies; Retrospective Studies; Somatostatin; Vasoactive Intestinal Peptide

Paraffin-embedded specimens from a total of 94 small-cell carcinomas of the lung (SCCL) were screened for immunoreactivity to nine different peptide hormones (ACTH, calcitonin, gastrin, glucagon, growth hormone, human chorion gonadotropin, insulin, somatostatin and vasoactive intestinal peptide, VIP) using an indirect immunoperoxidase technique with commercially available kits. Special attention was focused on the prognostic significance of the peptide immunoreactivity. A total of 32 carcinomas (34%) showed immunoreactivity to one or more peptide hormones, the cases with ACTH reactivity (24.5%) far outnumbering those with reactivity to calcitonin (1.1%), somatostatin (1.1%), VIP (3.3%) or multiple peptides (4.3%). The mean survival of the patients was 8.4 months, being shorter (7.3 months) for the SCCLs with peptide reactivity than for the nonreactive carcinomas (9.2 months). The most favorable survival was found in VIP-reactive tumors (20.5 months), and the worst (2.0 months) in cases reactive to multiple peptides. The results suggest that immunohistochemical screening of the SCCL biopsies for the peptide hormones might be of benefit in predicting the clinical outcome of the disease.

Topics: Adrenocorticotropic Hormone; Calcitonin; Carcinoma, Small Cell; Histocytochemistry; Hormones; Humans; Immunoenzyme Techniques; Lung Neoplasms; Prognosis; Somatostatin; Vasoactive Intestinal Peptide

Bombesin/gastrin releasing peptide-like immunoreactivity (BLI) is found in the majority of small cell carcinoma of the lung (SCCL) cell lines examined. Because BLI is present in high concentration in SCCL we studied the mechanism of BLI secretion from several SCCL cell lines and in patients with SCCL. In cell line NCI-H345 the structurally related polypeptide hormones secretin, vasoactive intestinal peptide, and peptide histidine isoleucine as well as theophylline, a phosphodiesterase inhibitor, N6,O2'-dibutyryl cyclic adenosine 3':5'-monophosphate, a cyclic nucleotide analogue, increased BLI release by 16-120% and cyclic adenosine 3':5'-monophosphate by 36-350%. Similar results were obtained in SCCL cell line NCI-H209. i.v. injection of secretin (2 units/kg) significantly increased plasma BLI in 2 patients with extrapulmonary SCCL. These data suggest that SCCL cells possess receptors for secretin/vasoactive intestinal peptide and that receptor occupation stimulates in vitro and in vivo BLI secretion.

Topics: Alprostadil; Bombesin; Bucladesine; Carcinoma, Small Cell; Cyclic AMP; Gastrin-Releasing Peptide; Humans; Lung Neoplasms; Peptide PHI; Peptides; Secretin; Secretory Rate; Theophylline; Time Factors; Vasoactive Intestinal Peptide

A primary duodenal small-cell neuroendocrine carcinoma was found in an elderly man who presented with upper abdominal pain. Although metastatic small-cell carcinoma was documented by liver biopsy, the primary lesion was not identified until postmortem examination. The latter tumor, which ulcerated the duodenal mucosa, was composed of small ovoid cells with sparse cytoplasm and granular chromatin. Electron microscopy revealed cytoplasmic dense-core granules. Immunocytochemical study demonstrated the presence of neuron-specific enolase, Leu 7 antigen, chromogranin, epithelial membrane antigen, and vasoactive intestinal polypeptide within tumor cells. However, there was no evidence of a clinical endocrinopathy. This case emphasizes the need to include the duodenum as a possible primary site when metastatic small-cell neuroendocrine carcinoma is seen in the absence of apparent pulmonary disease.

Topics: Aged; Carcinoma, Small Cell; Duodenal Neoplasms; Duodenal Ulcer; Histocytochemistry; Humans; Immunoenzyme Techniques; Male; Neoplasm Metastasis; Vasoactive Intestinal Peptide

The watery diarrhea-hypokalemia-achlorhydria syndrome associated with ectopic secretion of vasoactive intestinal peptide has only been conclusively documented with tumors originating in the pancreas or sympathetic chain. We report here the case of a 50-yr-old woman who developed this syndrome 3 wk after an apparently effective course of radiotherapy for an obstructing, mixed-cell carcinoma of the esophagus. High concentrations of vasoactive intestinal peptide were found in plasma (100-200 pmol/L; normal less than 20 pmol/L) and in the metastatic skin nodules (750 pmol/g) that later developed and that contained one of the two cell types from the original tumor. Stool volumes reached a plateau of 15-20 L/day, and potassium requirements were greater than 1000 mmol/day. Symptoms failed to respond to any of the regimens previously described as effective in this syndrome. After 14 wk of massive fecal fluid and electrolyte losses, symptoms resolved dramatically with the first dose of 5-fluorouracil. Plasma vasoactive intestinal peptide concentration returned to normal, where it remained despite subsequent evidence of renewed tumor spread. This case illustrates the unpredictability of the response of this syndrome to medical treatment, and suggests that vasoactive intestinal peptide secretion may occur in a wider range of tumors than has so far been described.

Topics: Achlorhydria; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Chromatography, High Pressure Liquid; Diarrhea; Esophageal Neoplasms; Female; Fluorouracil; Humans; Hypokalemia; Middle Aged; Streptozocin; Syndrome; Vasoactive Intestinal Peptide