Ingrid Norheim

Malignant carcinoid tumors. An analysis of 103 patients with regard to tumor localization, hormone production, and survival.

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 gonadotropin % 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.

Neuropeptide K: A major tachykinin in plasma and tumor tissues from carcinoid patients

Evidence is presented for the presence of an entire family of tachykinin-immunoreactive peptides in plasma and tumor tissues from patients with carcinoid tumors. The peptides include in addition to substance P and neurokinin A; neurokinin B, an eledoisin like peptide and neuropeptide K--a 36 amino acid long tachykinin which contains neurokinin A at its C-terminus. Neuropeptide K seems to be the tachykinin which is present in highest concentrations in plasma as well as in acetic acid extracts of tumor tissues. It is highly biologically active, and may therefore contribute to the clinical symptoms of carcinoid tumors.

Antisera raised against eledoisin and kassinin detect immunoreactive material in rat tissue extracts: tissue distribution and chromatographic characterization

Radioimmunoassays were developed for the tachykinins eledoisin (ELE) and kassinin (KAS) using antisera raised in rabbits. The antisera exhibited low (less than 0.1%) cross-reactivities to substance P (SP) and physalaemin (PHY), but crossreacted (with one exception, antiserum K7) to varying extents with neurokinin A (NKA) and neurokinin B (NKB). In the rat, the tissue distribution of the immunoreactive material detected by antiserum (E7) raised against ELE and by another antiserum (K1) raised against KAS both resembled that previously described for SP. Using the highly KAS-specific antiserum K7, no or only very low levels of immunoreactivity could be detected in extracts of various rat tissues. Gel permeation chromatography and ion-exchange chromatography of tissue extracts indicated that all antisera (except K7) detected the same population of immunoreactive molecules. One of the components was chromatographically indistinguishable from NKA. The tissue distribution of this component also resembled that of SP. Another immunoreactive component co-chromatographed with NKB at cation exchange chromatography. Acid tissue extracts, but not neutral tissue extracts, were found to contain immunoreactive components which appeared more basic than NKA and NKB. The total levels of immunoreactivity were higher in neutral than in acid tissue extracts. However, the ratio between the amounts of immunoreactivities in the two types of extracts varied considerably between tissues, indicating that tachykinin immunoreactive components may be present in different relative proportions in various tissues.

Cytotoxic Treatment in Patients with Malignant Carcinoid Tumors: Response to streptozocin—alone or in combination with 5-FU

Thirty-one patients with malignant carcinoid tumors were treated with streptozocin--alone (n = 7) or in combination with FU (n = 24). The responses to treatment were followed by the determination of tumor markers, urinary 5-HIAA, serum PP, HCG-alpha and -beta subunits, as well as determination of the size of liver metastases on computerized tomography or ultrasonography. Three patients (9.7%) showed objective responses with a mean remission time of 2.7 months. Eighteen patients (58%) showed stable disease, whereas ten patients (32.3%) showed progressive disease directly from the start of therapy. A good correlation was found between the changes in tumor markers and tumor size, although the changes occurred earlier in the markers than in the size. Estimated median survival from the time of histologically verified carcinoid tumor was 41 months and from start of therapy 22 months. Our data indicate that combination treatment with streptozocin and 5-fluorouracil is of little value for patients with malignant carcinoid tumors.

Treatment of Malignant Midgut Carcinoid Tumours with A Long-Acting Somatostatin Analogue Octreotide

Treatment with the somatostatin analogue octreotide, SMS 201-995 (Sandostatin), has been carried out in a series of 23 patients with malignant midgut carcinoid tumours. The patients received initially 50 micrograms twice a day for six months, thereafter a median of 100 micrograms twice daily. Six of 22 evaluable patients (28%) showed objective tumour response lasting for 6 to 30 months. Stable disease was observed in 8 of the 22 patients (36%) and progressive disease in a further 8 patients (36%). A subjective response with decrease of diarrhoea or flushing was noted in 11 out of 22 patients (50%). Two out of 6 patients with objective response demonstrated a significant decrease of tumour size lasting for 6 and 30 months respectively. In order to maintain the clinical response, the dose had to be increased in all 6 responders. The adverse effects included development of diabetic blood glucose levels in 8 out of 22 patients (36%). Albumin-modified serum calcium levels were significantly reduced after treatment with octreotide 50 micrograms twice a day. One patient developed symptoms of hypocalcemia which was reversed by supplementation with calcium and D-vitamins. The somatostatin analogue SMS 201-995 has a beneficial effect in the treatment of patients with the carcinoid syndrome. However, the precise role of the drug in the long-term management of these patients has to be further investigated.

Bronchoconstrictor and hypotensive effects in relation to pharmacokinetics of tachykinins in the guinea-pig —evidence for extraneuronal cleavage of neuropeptide K to neurokinin A

Summary1. The biological effects of the tachykinins substance P (SP), neurokinin A (NKA) and neuropeptide K (NPK) were studied in relation to their pharmacokinetic properties in the guinea-pig in vivo. 2. NKA and NPK exerted a considerably larger bronchoconstrictor effect than SP. The effect of NPK was slow in onset and had a long duration. The three tachykinins showed similar hypotensive effects although NPK had a longer duration of action than SP and NKA. 3. The disappearance of NPK-like immunoreactivity (-LI) from plasma after i. v. infusion of synthetic NPK was biphasic with apparent half-lives of 0.9 min and 6 min. The plasma half-life of NKA-LI was less than 2 min, while plasma SP-LI was degraded before biochemical analysis could be performed. 4. In guinea-pig plasma at 37°C in vitro, NKA- and NPK-LI were stable for 10 min, while SP-LI disappeared with a half-life of 10 s. 5. Reversed phase HPLC analysis of plasma collected after an i. v. infusion of NPK for 25 min, indicated a partial cleavage of NPK into NKA. 6. It is concluded that potency of the biological effects of SP, NKA and NPK in the guinea-pig in vivo, may not only be attributed to activation of multiple tachykinin receptors but must also be related to the marked differences in pharmacokinetical properties between the tachykinins. Furthermore, whereas SP is rapidly degraded in plasma, NKA and NPK seem to be metabolized in other compartments.

Treatment of malignant carcinoid tumors: a randomized controlled study of streptozocin plus 5-FU and human leukocyte interferon

In a randomized controlled study, 20 patients with malignant carcinoid tumors were included. Ten patients received streptozocin plus 5-fluorouracil for 6 months and another 10 human leukocyte interferon (IFN). After 6 months of treatment, an objective tumor response was noted in five of the patients treated with IFN (50%) but in none of the patients on chemotherapy. Stable disease was found in five patients (50%) on IFN treatment and four (40%) on chemotherapy. Progressive disease was noted in six of the patients (60%) receiving chemotherapy. A statistical analysis using the chi-square test showed a significantly higher proportion of responders and stable disease in the IFN treated group (P = 0.0039). Furthermore, three of eight patients who had previously received chemotherapy showed later on an objective response to IFN. The objective responses were mainly noted in decreased tumor markers; however, two patients also showed a significant reduction of tumor size. Subjective responses were noted in 72% of patients treated with interferon, but only in 9% of those treated with streptozocin plus 5-fluorouracil. The results indicate that interferon treatment is superior to the combination of streptozocin plus 5-fluorouracil. Considering both the therapeutic effects and adverse reactions, human leukocyte interferon is a promising alternative for treatment of patients with malignant carcinoid tumors.

Antisera raised against eledoisin and kassinin detect elevated levels of immunoreactive material in plasma and tumor tissues from patients with carcinoid tumors

Radioimmunoassays based on antisera raised against the tachykinins eledoisin (antiserum E7) and kassinin (antiserum K12) were used to measure the concentration of tachykinin-like immunoreactivity (TKLI) in plasma from 52 healthy subjects. 65 patients with carcinoid tumors (of which 46 had symptoms of both flushing and diarrhoea), and 6 patients with endocrine pancreatic tumors. The antisera did not crossreact with substance P (SP). Elevated concentrations of TKLI, as compared with healthy subjects, were found in 75% of the carcinoid patients, but in none of the patients with pancreatic tumors. Tumor metastases from 8 of the carcinoid patients all contained TKLI. Ion-exchange chromatography of plasma samples and tumor tissue extracts indicated the presence of several immunoreactive molecular forms. The elution patterns of the immunoreactivity detected by antisera E7 and K12 were similar, indicating that the same molecular species are measured by these antisera. None of the components coeluted with synthetic SP. One of the immunoreactive components in carcinoid tumor extracts coeluted with synthetic NKA. The major immunoreactive components in plasma from the patients eluted in a position different from that of all currently known mammalian tachykinins. Tachykinin immunoreactive material detected in tumor tissue and plasma of patients with carcinoid tumor may play a role in the symptomatology of the carcinoid syndrome.

Tachykinin production by carcinoid tumours in culture

Tissue specimens from 5 patients with metastatic midgut carcinoid tumours were kept in organ culture for up to 6 months. The tumour cells were confined to the suspension in the form of condensed cell clusters and appeared to retain their endocrine characteristics. Radioimmunoassay for tachykinin immunoreactivity showed high concentrations in 4 out of 5 culture media. The concentrations were highest in the beginning of the experiment, but subsequently decreased. The 4 patients from which these tumours were taken had all elevated tachykinin concentrations in extracted plasma. The fifth culture medium had low tachykinin concentration, and the concentration in extracted plasma from this patient was within the normal range. Reversed-phase high-performance liquid chromatography of the culture media with elevated tachykinin concentrations revealed immunoreactive components with the characteristics of synthetic neuropeptide K, neurokinin A and eledoisin, components also found in plasma and tumour tissues of carcinoid patients. Our findings indicate that carcinoid tumour cells produce tachykinins. These peptides are biologically very active, resulting in flush and hypotension when infused intravenously into normals, and might contribute to the clinical symptoms of the carcinoid syndrome.

Nuclear DNA in intestinal carcinoid tumors: a study before and after cytotoxin (streptozotocin and 5-fluorouracil) treatment

Imprint cytology specimens of metastases of intestinal carcinoids obtained by percutaneous biopsy were analysed cytofluorometrically with regard to nuclear DNA records. All untreated tumors (nine cases) exhibited diploid DNA values with a relatively low proliferative activity (less than 2% nuclei in Sphase region). The mean number of tetraploid cells was 5%. Cytofluorometry also was performed on five tumor metastases treated with the cytotoxin streptozotocin and 5‐fluorouracil. After treatment, an increase in the number of tetraploid cells (mean value, 30%) was noted, indicating that the cytotoxin treatment (possibly streptozotocin) on the tumor cells in vivo blocked progression from G2 to M phase. The current cytofluorometric analyses show that diploid nuclear DNA records and a low proliferative activity is a characteristic of malignant carcinoid tumors of the intestine. Due to regular DNA histograms in the carcinoid tumors, it is suggested that reliable studies are permitted of the effect of cytotoxins on the different phases of the cell cycle in vivo.