Bo Wängberg

Neoadjuvant, adjuvant and palliative treatment of gastrointestinal stromal tumours (GIST) with imatinib : a centre-based study of 17 patients

Malignant gastrointestinal stromal tumours (GIST) have a poor prognosis. Since these tumours are resistant to conventional radiation and chemotherapy, surgery has been the mainstay of treatment. However, surgery is usually inadequate for the treatment of malignant GIST. Imatinib, a KIT tyrosine kinase inhibitor, has recently been found to have a dramatic antitumour effect on GIST. In this centre-based study of 17 consecutive patients with high-risk or overtly malignant GIST, imatinib was used in three different settings – palliatively, adjuvantly, and neoadjuvantly. The treatment was found to be safe and particularly effective in tumours with activating mutations of exon 11 of the KIT gene. Clinical response to imatinib treatment correlated morphologically to tumour necrosis, hyalinisation, and reduced proliferative activity. The value of neoadjuvant imatinib treatment was illustrated in one case.

Orthotopic liver or multivisceral transplantation as treatment of metastatic neuroendocrine tumors

Liver transplantation can be a therapeutic option for individual patients with neuroendocrine tumors metastatic only to the liver. In this consecutive series of 15 patients (5 multivisceral and 10 orthotopic liver transplantations) with well‐differentiated carcinoids, or endocrine pancreatic tumors, we allowed higher proliferation rate (Ki67 <10%), large tumor burden, and higher age than previous studies. Liver transplantation offered good relief of symptoms, long disease‐free intervals, and potential cure in individual patients. The survival of grafts and patients compared well with transplantation for benign disease. The overall 5‐year survival was 90%. The recurrence‐free survival of both multivisceral and liver transplantation related to the time after transplantation (about 20% at 5 years) despite inclusion of patients with higher risk. In conclusion, the critical prognosticators for long‐term outcome still remain to be defined. The experience with multivisceral transplantation for patients with endocrine tumors of the pancreatic head is still limited. Liver Transpl 13:327–333, 2007.

Comprehensive Re-Sequencing of Adrenal Aldosterone Producing Lesions Reveal Three Somatic Mutations near the KCNJ5 Potassium Channel Selectivity Filter

Background Aldosterone producing lesions are a common cause of hypertension, but genetic alterations for tumorigenesis have been unclear. Recently, either of two recurrent somatic missense mutations (G151R or L168R) was found in the potassium channel KCNJ5 gene in aldosterone producing adenomas. These mutations alter the channel selectivity filter and result in Na+ conductance and cell depolarization, stimulating aldosterone production and cell proliferation. Because a similar mutation occurs in a Mendelian form of primary aldosteronism, these mutations appear to be sufficient for cell proliferation and aldosterone production. The prevalence and spectrum of KCNJ5 mutations in different entities of adrenocortical lesions remain to be defined. Materials and Methods The coding region and flanking intronic segments of KCNJ5 were subjected to Sanger DNA sequencing in 351 aldosterone producing lesions, from patients with primary aldosteronism and 130 other adrenocortical lesions. The specimens had been collected from 10 different worldwide referral centers. Results G151R or L168R somatic mutations were identified in 47% of aldosterone producing adenomas, each with similar frequency. A previously unreported somatic mutation near the selectivity filter, E145Q, was observed twice. Somatic G151R or L168R mutations were also found in 40% of aldosterone producing adenomas associated with marked hyperplasia, but not in specimens with merely unilateral hyperplasia. Mutations were absent in 130 non-aldosterone secreting lesions. KCNJ5 mutations were overrepresented in aldosterone producing adenomas from female compared to male patients (63 vs. 24%). Males with KCNJ5 mutations were significantly younger than those without (45 vs. 54, respectively; p<0.005) and their APAs with KCNJ5 mutations were larger than those without (27.1 mm vs. 17.1 mm; p<0.005). Discussion Either of two somatic KCNJ5 mutations are highly prevalent and specific for aldosterone producing lesions. These findings provide new insight into the pathogenesis of primary aldosteronism.

Indications and Results of Liver Transplantation in Patients with Neuroendocrine Tumors

Metastases from neuroendocrine (NE) tumors of the gastrointestinal tract, carcinoids, and endocrine pancreatic tumors (EPTs) can be confined to the liver for long periods and may exhibit slow growth. When considering liver transplantation (LTx) for patients with NE tumors, the expected results with conventional treatment must be weighed against the risk of LTx and immunosuppression. The following indications for LTx may be considered for patients with metastatic NE tumors limited to the liver: (1) tumors not accessible to curative surgery or major tumor reduction; (2) tumors not responding to medical or interventional treatment; and (3) tumors causing life-threatening hormonal symptoms. We excluded patients with poorly differentiated NE carcinoma or well differentiated NE carcinoma with a high proliferation index (Ki 67 > 10%). Over 4 years (1997–2001) we have performed transplants in nine patients (five with EPTs, four with carcinoids) with a mean ± SEM follow-up of 22 ± 5 months (range 4–45 months). Seven patients underwent orthotopic LTx and two multivisceral LTx. Eight patients are alive, six without clinical evidence of disease. Four patients developed recurrent tumors 9 to 36 months after LTx; two were detected at an early stage and underwent resection with curative intent. One patient with multivisceral Tx died after 4 months of posttransplant lymphoproliferative disease without tumor recurrence. In selected series LTx can offer good control of hormonal symptoms, a relatively long disease-free interval, and in individual cases potential cure.

Survival of patients with disseminated midgut carcinoid tumors after aggressive tumor reduction

Abstract. Sixty-four consecutive patients with disseminated midgut carcinoids were treated during an 8-year period according to a single clinical protocol aimed at aggressive tumor reduction by surgery alone or with subsequent hepatic artery embolization. All patients had markedly elevated urinary 5-hydroxyindoleacetic acid (5-HIAA) levels (581 ± 79 μmol/24 h) and hormonal symptoms. Fourteen patients (22%) reached anatomic and biochemical cure by surgery alone. At follow-up, the mean 5-HIAA levels were still normal after 69.0 ± 6.2 months; two patients had died from unrelated causes. With the introduction of somatostatin receptor scintigraphy, subclinical disease was diagnosed in 7 of these 14 patients. Forty patients with bilobar hepatic disease underwent embolization in combination with octreotide. In this group, 5-HIAA levels were still reduced by 55% after 71 ± 11 months of follow-up, and the 5-year survival was 56%, estimated from the total death hazard function. After embolization, two subgroups could be identified with marked differences in their long-term response to treatment. Ten patients were not embolized owing to complicating diseases. The 5-year survival for the entire series was 58%. A significantly increased risk of cardiovascular deaths was seen, which underlines the importance of total survival analysis in a disease with multiple hormonal effects. It is concluded that an active surgical approach must be recommended to patients with the midgut carcinoid syndrome. In patients with bilobar hepatic disease, embolization combined with octreotide treatment markedly reduced the 5-HIAA excretion and suggested a prolonged 5-year survival.

Treatment of liver metastases of carcinoid tumors

Abstract. Liver metastases imply a major problem in patients with carcinoid tumors. Patients with localized disease should always undergo resection for cure. Patients with distant metastatic disease can also undergo resection for potential cure or symptom palliation because of the slow growth rate of many carcinoid tumors. In patients with the midgut carcinoid syndrome and bilobar hepatic disease we have performed primary surgery to relieve such symptoms as intestinal obstruction and ischemia, followed by successive embolizations of the hepatic arteries to reduce functional tumor burden in the liver. For optimal palliation, all patients with residual tumor were treated by octreotide. In a consecutive series of 64 patients with the midgut carcinoid syndrome we thus attained a 5-year survival rate of 70%. Fourteen of the patients underwent intentionally curative surgery (e.g., primary surgery followed by liver surgery). Of these patients, none died from their tumor disease during the period of study. The value of adjunctive interferon therapy is currently under evaluation.

Clinical management of gastric carcinoid tumors.

Four types of gastric carcinoids have been identified: (1) multiple small body-fundus carcinoids associated with chronic atrophic gastritis type A (A-CAG); (2) sporadic solitary lesions without specific pathogenetic background (non-A-CAG); (3) carcinoidosis associated with Zollinger-Ellison/MEN 1 syndrome, and (4) rare tumors, e.g. gastrin cell tumors, neuroendocrine carcinomas and mixed endocrine-exocrine tumors. In a retrospective study of 15 patients with gastric carcinoids (11 A-CAG, 3 non-A-CAG and 1 gastrin cell tumor) over a 10-year period, the histopathological and clinical features were assessed. The A-CAG-type carcinoids were clinically silent with lymph node metastases in 2/11 cases but no hepatic metastases. The non-A-CAG-type carcinoids were malignant with disseminated disease, hormonal symptoms and increased urinary excretion of the main histamine metabolite, MeImAA. Five patients with A-CAG tumors were subjected to antrectomy to remove hypergastrinemia, which is thought to be of pathogenetic importance for these tumors. During the observation period (1.5-8 years) 1 patient developed recurrent tumors, while the other 4 showed persistent argyrophil cell hyperplasia. A prospective treatment protocol of these tumors is suggested with endoscopic removal of less numerous, small lesions as first-step therapy, followed by antrectomy at recurrence. Larger lesions should be excised in combination with antrectomy. Gastrectomy is reserved for the rare cases of invasive tumors with lymph node metastases. As evident from the outcome of patients with non-A-CAG tumors radical surgery should be performed whenever practicable.

Cytotoxic treatment of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare, aggressive tumor that is often detected in an advanced stage. Medical treatment with the adrenotoxic drug mitotane has been used for decades, but critical prospective trials on its role in residual disease or as an adjuvant agent after surgical resection are still lacking. The concept of a critical threshold plasma level of the drug must be confirmed in controlled studies. Because individual responsiveness cannot be predicted, the use mitotane is still advised for nonresectable disease. In case of Cortisol or other steroid overproduction, several drugs (e.g., ketoconazole or aminoglutethimide) may be used. Chemotherapy with single agents (e.g., doxorubicin or cisplatin) have been disappointing, with low response rates (< 30%) and a short response duration. Part of this refractoriness may be explained by the fact that ACC tumors express the multidrug-resistance gene MDR-1. Chemotherapy with multiple agents has been tested in smaller series and has resulted in significant side effects. The best results were achieved by the combination of etoposide, doxorubicin, and cisplatin associated with mitotane, achieving a response rate of 54%, including individual complete responses. To be able to make progress in treating advanced ACC disease, adjuvant multicenter trials must be encouraged. When mitotane-based therapies are used, monitored drug levels are mandatory.RésuméLe cancer de la corticosurrénale (CCS) est une tumeur rare mais agressive, détectée souvent à un stade avancé. Le traitement médical par le mitotane, une drogue adrénotoxique, est utilisée depuis plusieurs décennies, mais, on manque d’essais prospectifs critiques sur son rôle dans la maladie résiduelle ou comme agent adjuvant après résection chirurgicale. Le concept d’un niveau plasmatique dont le seuil critique doit être confirmé par des études contrôlées. Puisqu’on ne peut prédire la réponse individuelle, le mitotane est toujours conseillé dans les maladies nonréséquables. En cas d’hyperproduction de Cortisol, ou d’autres Steroides, d’autres drogues, comme par exemple, le cétoconazole ou l’aminogluthétimide peuvent être utilisées. La monochimiothérapie, avec par exemple la doxorubicine et le cisplatine, est décevante avec un taux de réponse bas (<30%) et une durée de réponse courte. Une partie de cette non-réonse peut être expliquée par le fait que les CCS expriment un gène de résistance multidrogues, le MDR-1. La plurichimiothérapie a été testée dans de plus petites séries avec des effets secondaires importants. Les meilleurs résultats ont été avec la combinaison d’étoposide, de doxorubicine et de cisplatine associés au mitotane: le taux de réponse a été de 54%, avec quelques réponses individuelles complètes. Pour faire des progrès dans le CCS avancé, il faut encourager des essais multicentriques de traitement adjuvant. En cas de thérapie utilisant le mitotane, il faut obligatoirement monitorer le taux des drogues.ResumenEl carcinoma adrenocortical (CAC) es un tumor agresivo poco frecuente que comûnmente se détecta cuando ya esta en etapas avanzadas de su desarrollo. Desde hace décadas se practica tratamiento médico con una droga adrenotöxica, el mitotane, pero no se dispone de ensayos clînicos prospectivos que soporten su valor en enfermedad residual o como adyuvante de la resection quirürgica. También se hace necesario confirmar el concepto de nivelés criticos de la droga mediante estudios controlados. Puesto que no es posible predecir la respuesta individual, todavia se aconseja el uso del mitotane en casos de enfermedad no resecable. Cuando hay superproduction de Cortisol o de otros esteroides, se pueden utilizar algunas drogas como el Ketoconazol o la aminoglutetimida. La quimioterapia con agentes ûnicos, por ejemplo doxorubicina y el cisplatino, ha sido decepcionante, por las bajas tasas (<30%) y la corta duration de la respuesta. Parte de tal situation refractaria puede explicarse por el hecho de que los CAC expresan el gen MDR-1 de resistencia multidroga. La quimioterapia con agentes multiples ha sido ensayada en series mas pequenas, con efectos secundarios significatives. Los mejores resultados se logran con la combination de etopösido, doxorubicina y cisplatino asociada con mitotane, alcanzando una tasa de respuesta del 54%, incluyendo respuestas complétas. Para lograr progreso en el manejo del CAC avanzado se debe estimular la realization de ensayos multi-institucionales. La monitoria de los nivelés de droga son obligatorios cuando se usan terapias con base en mitotane.

A Transplantable Human Carcinoid as Model for Somatostatin Receptor-Mediated and Amine Transporter-Mediated Radionuclide Uptake

A human midgut carcinoid tumor was successfully transplanted into nude mice and propagated for five consecutive generations (30 months) with well-preserved phenotype. Tumor cells in nude mice expressed identical neuroendocrine markers as the original tumor, including somatostatin receptors (somatostatin receptors 1 to 5) and vesicular monoamine transporters (VMAT1 and VMAT2). Because of the expression of somatostatin receptors and VMAT1 and VMAT2 the grafted tumors could be visualized scintigraphically using the somatostatin analogue 111In-octreotide and the catecholamine analogue 123I-metaiodobenzylguanidine. The biokinetics of the somatostatin analogue 111In-octreotide in the tumors was studied and showed a high retention 7 days after administration. Cell cultures were re-established from transplanted tumors. Immunocytochemical and ultrastructural studies confirmed the neuroendocrine differentiation. The human origin of transplanted tumor cells was confirmed by cytogenetic and fluorescence it situ hybridization analyses. Spontaneous secretion of serotonin and its metabolite, 5-hydroxyindole acetic acid, from tumor cells was demonstrated. The tumor cells increased their [Ca2+]i in response to beta-adrenoceptor stimulation (isoproterenol) and K+-depolarization. All somatostatin receptor subtypes could be demonstrated in cultured cells. This human transplantable carcinoid tumor, designated GOT1, grafted to nude mice, will give unique possibilities for studies of somatostatin receptor- and VMAT-mediated radionuclide uptake as well as for studies of secretory mechanisms.

Differential expression of vesicular monoamine transporter (VMAT) 1 and 2 in gastrointestinal endocrine tumours.

Neuroendocrine tumours are characterized by their capacity to produce hormones, which are stored in vesicles and secretory granules. Demonstration of granule/vesicle proteins in tumours is taken as evidence of neuroendocrine differentiation. Vesicular monoamine transporters (VMAT1 and VMAT2) mediate the transport of amines into vesicles of neurons and endocrine cells. The expression of VMAT1 and VMAT2 and the usefulness of VMAT1 and VMAT2 in the histopathological diagnosis of gastrointestinal endocrine tumours have not been fully explored. This study therefore investigated the expression of VMAT1 and VMAT2 in 211 human gastrointestinal tumours by immunocytochemistry and western blotting. VMAT1 and/or VMAT2 were demonstrated in the majority of amine‐producing endocrine tumours of gastric, ileal, and appendiceal origin. Serotonin‐producing endocrine tumours (ileal and appendiceal carcinoids) expressed predominantly VMAT1, while histamine‐producing endocrine tumours (gastric carcinoids) expressed VMAT2 almost exclusively. In peptide‐producing endocrine tumours such as rectal carcinoids and endocrine pancreatic tumours, only a small number of immunopositive tumour cells were observed. No labelling was found in non‐endocrine tumours, including gastric, colorectal and pancreatic adenocarcinomas and gastrointestinal stromal tumours. In conclusion, VMAT1 and VMAT2 are differentially expressed by gastrointestinal endocrine tumours, with a pattern specific for each tumour type, reflecting their neuroendocrine differentiation and origin. VMAT1 and VMAT2 may therefore become valuable markers in the classification of neuroendocrine tumours and may also indicate patients suitable for radioisotope treatment operating via these transporter systems. Copyright