Somatostatin analogs therapy in gastroenteropancreatic neuroendocrine tumors: current aspects and new perspectives.

Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are rare tumors that present many clinical features secreting peptides and neuroamines that cause distinct clinical syndromes such as carcinoid syndrome. However most of them are clinically silent until late presentation with mass effects. Surgical resection is the first line treatment for a patient with a GEP-NET while in metastatic disease multiple therapeutic approaches are possible. GEP-NETs are able to express somatostatin receptors (SSTRs) bounded by somatostatin (SST) or its synthetic analogs, although the subtypes and number of SSTRs expressed are very variable. In particular, SST analogs are used frequently to control hormone-related symptoms while their anti-neoplastic activity seems to result prevalently in tumor stabilization. Patients who fail to respond or cease to respond to standard SST analogs treatment seem to have a response to higher doses of these drugs. For this reason, the use of higher doses of SST analogs will probably improve the clinical management of these patients.

Gene variants associated to malignant thyroid disease in familial adenomatous polyposis: a novel APC germline mutation.

BACKGROUND AND AIM: Familial adenomatous polyposis (FAP) is an autosomal inherited syndrome characterized by hundreds to thousands colorectal adenomatous polyps with oncological transformation lifetime risk of 100%. FAP is mainly associated with mutations in APC (autosomal dominant inheritance) or MUTYH (autosomal recessive inheritance) genes. Affected individuals are at increased risk of developing extra-intestinal tumors. Lifetime risk of developing thyroid carcinoma has been described in previous reports of about 2-12%, mainly in females, and the mean age is below 30 yr. About 95% of cancers are papillary thyroid carcinomas (PTC), mostly multifocal. The aim of this study was to evaluate the frequency of PTC among our series of FAP patients and to assess the type of gene mutation associated with the disease. METHODS: Fifty-four subjects from 36 FAP families were selected (29 females/25 males) and the mean age (±SD) at diagnosis was 28.8±10.8 yr. All patients underwent blood examination for thyroid hormones and antibodies, germline mutational analysis of APC and/or MUTYH genes, thyroid ultrasound, and endocrinological evaluation. RESULTS: In 13/54 (24.1%) subjects, an eumetabolic thyroid disease was found: plurinodular disease in 7/54 (13.0%); single nodule in 4/54 (7.4%); in 2/54 patients (3.7%), we found a malignant nodule characterized after total thyroidectomy as a classical PTC. Both patients were female and showed a classic FAP phenotype. Mutational analysis revealed in the first patient the APC germline mutation 3183_87del ACAAA and in the second patient the del9-10 (del9080dup11) novel APC variant; the first mutation has been already reported in association with PTC; to our knowledge the second mutation has never been previously reported in association with FAP. CONCLUSIONS: In the population examined, the estimated prevalence of thyroid malignant diseases was 3.7%. In both patients, the identified APC gene pathogenetic variants mapped within the 5' region of the gene, previously reported as a PTC-associated mutational hot spot. Both patients had classic FAP phenotype and genetic analysis revealed two pathogenetic APC mutations: c.3183_87delACAAA, a recurrent pathogenetic variant and del9-10 (del9080dup11), a novel, not previously described genomic rearrangement. In agreement with previous studies, the morpho-functional surveillance of thyroid in FAP series should be recommended. A better insight into the overall genotype-phenotype correlation of APC gene mutations would be helpful for the identification of at-risk individuals.

Medullary thyroid cancer: a promising model for targeted therapy.

In recent years, the clinical validation of molecular targeted therapies inhibiting the action of pathogenic tyrosine kinase (TK) has been one of the most exciting developments in cancer research. In this context, medullary thyroid carcinoma (MTC) represents a promising model. It is well known that in MTC, the RET receptor TK and its signal transduction pathways, lead to subsequent neoplastic transformation. Several strategies aimed at blocking the activation and signaling of RET have been preclinically tested. The most advanced results have been obtained by competitive inhibition of RET-TK activity by tyrosine kinases inhibitors (TKI). However, although the inhibition of the RET pathway is actually one of the most studied for therapeutic purposes, other signal transduction pathways have been recognized to contribute to the growth and functional activity of MTC and are considered attractive therapeutic targets. To date, surgery represents the only curative treatment of MTC. Despite promising initial results, studies on targeted agents are in early stages and several issues regarding preclinical evaluations and clinical trials of new targeted agents in MTC are still unresolved. Now, available mouse models bearing mutations of RET or other genes, which spontaneously develop MTC, promise to improve preclinical evaluation of activity of targeted compounds. Furthermore, the rarity of the disease and the number of patients available for enrollment may lessen the relevance of clinical trials. A major effort needs to be made by endocrinologists and oncologists to refer their patients for multi-institutional trials in order to optimize them, perform translational studies and expedite the availability of novel beneficial selective therapies.

Hurthle cell tumours of the thyroid. Personal experience and review of the literature.

Hurthle cell carcinoma represents about 5% of differentiated thyroid carcinomas. The prognosis of the malignant type of the tumour is still under debate as some Authors have reported that Hurthle cell adenoma occasionally behaves like Hurthle cell carcinoma. Aim of the present study was to evaluate previously reported data and personal experience on the clinical and pathological features of patients affected by Hurthle cell tumour that may predict disease progression and death. In the literature, factors potentially associated with decreased survival were identified and include: age, disease stage, tumour size, extra-glandular invasion, lymph node disease, distant metastases, extensive surgery, radioiodine treatment. From 1992 to 2003, the Authors identified 28 patients affected by Hurthle cell tumour, 9 with Hurthle cell adenoma and 19 with Hurthle cell carcinoma. Of these, 22 were females and 6 males. Mean age of patients affected by adenoma was 49.7 years (range 30-72) vs. 49.3 years (range 15-72) in Hurthle cell carcinoma patients. In all patients, total thyroidectomy was performed. At histology, 9 adenomas, 5 "minimally invasive" and 14 invasive carcinomas were found. Post-operatively, in Hurthle cell carcinoma patients, TNM staging showed 9 patients with stage I, 5 stage II, 4 stage III and one stage IVa (UICC, 2002). All invasive carcinomas underwent (131)I therapy (91-585 mCi). One Hurthle cell carcinoma patient received external beam radiotherapy. The mean follow-up period was 62 months (range 6-324). Relapse was not observed in any of the cases with adenoma. Only one Hurthle cell carcinoma patient showed distant lung metastases at 60 months' follow-up. In conclusion, Hurthle cell carcinoma was not found to present a more aggressive behaviour than follicular carcinoma, when risk factors, including extent of tumour invasion, were taken into account. None of the patients with Hurthle cell adenoma showed a relapse or death caused by the tumour.

Malignant insulinoma presenting as metastatic liver tumor. Case report and review of the literature.

Insulin-secreting tumors are the commonest hormone-producing neoplasm of the gastrointestinal tract. They occur with an incidence of 4 cases per million per year. About 10% of them are metastatic and malignant insulinomas very rarely observed in children and in elderly. We report a rare case of very large malignant insulinoma in a 71-year-old woman admitted in our Oncological Institute on October 2005. She presented with fasting hypoglicemia (blood glucose 35 mg/dl) and high serum insulin levels (insulin 115.9 microU/ml). A computerized tomographic scan showed a pancreatic tail lesion of about 6 cm in max diameter and multiple liver metastases. A whole body scintiscan using 111In-DTPA-D-Phe1-octreotide was made and an increased uptake in the tail of the pancreas has been found. The patient was submitted to liver biopsy and the diagnosis of a metastatic insulin-secreting tumor was immunoistochemically confirmed. Due to the presence of some hypoglicemic episodes uncontrolled by medical treatment, on December 2005 the patient was admitted to surgical intervention with a body and tail pancreatic resection. Post-operatively the patient experienced again syncope with hypoglycemia and hyperinsulinemia. It was then decided to start a schedule of treatment with somatostatin analog (octreotide subcutaneously 500 microg three times a day) with a good control of blood glucose levels (101 mg/dl). A trans-arterial chemioembolization was planned but the patient died for pancreatic and cardiovascular complications before this treatment started.

Effect of acute and chronic administration of tamoxifen on GH response to GHRH and on IGF-I serum levels in women with breast cancer.

Tamoxifen, an estrogen antagonist, is usually employed in the treatment of breast cancer. Its mechanism of action is not well known because an antiproliferative effect of the drug has been shown also in estrogen receptor negative tumors, most likely mediated by the inhibition of local growth factors and particularly IGF-I. However, the action of tamoxifen on the GH-IGF-I axis is still open to investigation. We have investigated the influence of acute and chronic treatment with tamoxifen on GH response to GHRH and IGF-I serum levels in six postmenopausal women with metastatic breast cancer. A GHRH test (50 microg i.v. at time 0, GH determinations at 0, 15, 30, 60, 90 and 120 min) was performed (a) basally, (b) 3 h after 40 mg oral administration of tamoxifen and (c) after 8 weeks of 20 mg twice a day oral tamoxifen treatment. IGF-I was measured basally and after chronic tamoxifen therapy. No significant modifications in GH response to GHRH were observed after acute or chronic treatment with tamoxifen vs the basal test. On the contrary, chronic tamoxifen treatment induced a significant decrease in serum IGF-I levels. Basal pretreatment levels of 123+/-18 microg/l were suppressed to 65+/-11 microg/l (mean suppression 47%, P < 0.001). These preliminary data confirm the inhibitory effect of tamoxifen on IGF-I production but seem to exclude the possibility that this effect may be due to an inhibition of GH secretion.