Nuclear medicine improves the sensitivity of conventional radiology when tumor site identification is problematic. OCT offers a good availability/reliability ratio, and FDG-PET was proven useful. 68Gallium-SSTR-PET/CT use was infrequent, despite offering the highest sensitivity.

SummaryThe interplay between vitamin D and IGF-I is complex and occurs at both endocrine and paracrine/autocrine levels. Vitamin D has been shown to increase circulating IGF-I and IGFBP-3, with the consistent finding of a positive correlation between vitamin D and IGF-I serum values in population-based cohorts of healthy subjects. The modulation of IGF-I and IGFBP-3 concentrations by vitamin D may impact recombinant human (rh) GH dosing for the treatment of GHD. It might also underlie some of the extra-skeletal beneficial effects ascribed to vitamin D. On the other hand, IGF-I stimulates renal production of 1,25-dihydroxyvitamin D, which increases calcium and phosphate availability in the body and suppresses PTH secretion. This effect is responsible for an altered calcium-phosphate balance in uncontrolled acromegaly and might also account for the improvement in bone metabolism associated with rhGH treatment in patients with GHD. Data on the paracrine/autocrine vitamin DÀIGF-I interactions are abundant, but mostly not linked to one another. As a result, it is not possible to draw a comprehensive picture of the physiological and/or pathological interrelations between vitamin D, IGF-I and IGF-binding proteins (IGFBP) in different tissues. A potential role of vitamin D action is related to its association with carcinogenesis, a paradigm being breast cancer. Current evidence indicates that, in breast tumours, vitamin D modulates the IGF-I/IGFBP ratio to decrease proliferation and increase apoptosis.

Background/Aim: The neuroendocrine tumor (NET) proliferation-based grading system (ENETS/WHO) for gastroenteropancreatic (GEP) tumors has proved reliable for prognostic stratification. To date, concerns exist regarding Ki-67 heterogeneity within the tumor and little is known on whether grade varies between primary and secondary sites. As tumor heterogeneity may have a significant impact on clinical management, our aim was to retrospectively evaluate Ki-67 on a series of GEP NETs in order to establish whether there is variability in different samples of the same lesion or between primary and metastatic disease (local/distant, synchronous/metachronous). Methods: Sixty patients with multiple samples of tumor were accrued from a total of 338 GEP NETs; 44 of them also had tissue from local/distant metastases and a further 5 had multiple metastatic foci from unknown primary tumors. Immunohistochemistry for Ki-67 was performed on all paraffin blocks from both primary and metastatic tumors. Results: Intratumor Ki-67 heterogeneity sufficient to change grade at first diagnosis was seen in 3/60 cases (5%). Out of 49 patients with primary NETs and/or multiple metastases, discrepancy in grade between sites was identified in 19 (39%) cases and in particular in 11/47 (23%) and in 10/12 (83%) patients with synchronous and metachronous metastases, respectively (p = 0.0002). Change in grade was more frequent in distant compared to locoregional metastases (p = 0.024) and in particular in distant sites other than the liver (p = 0.006). Conclusions: NETs show frequent differences in grade between primary sites and their synchronous/metachronous metastases; assessment of Ki-67 at all sites may prove to be significant for patient management.

Objectives: Previous studies suggested that vitamin D modulates circulating IGF1. We investigated this effect in adults and its clinical relevance in the management of GH deficiency (GHD). Design and methods: IGF1 levels were prospectively measured before and after 12 weeks of treatment with oral vitamin D 3 (5000 or 7000 IU/week) vs no intervention in 39 subjects 61.9G7.9 years old. The frequency of IGF1 values R50th age-and sex-specific percentile in relation to vitamin D status, as determined by the concentration of 25-hydroxyvitamin D (25(OH)D), was retrospectively assessed in 69 GHD patients (57.4G16.6 years) on stable hormone replacement and with 25(OH)D and IGF1 concurrently measured. Results: Treatment with 5000 and 7000 IU vitamin D 3 /week significantly raised 25(OH)D by 12.7G8.4 and 13.1G6.5 ng/ml respectively (both P!0.001 vs baseline). In the 7000 IU group, IGF1 levels also significantly increased by 31.3G36.7 ng/ml (PZ0.01). Neither 25(OH)D nor IGF1 significantly varied in controls. IGF1 was R50th percentile more frequently in GHD patients with 25(OH)D levels R15 than !15 ng/ml (65.9 vs 40.0%, P!0.05). Logistic regression with adjustment for recombinant human GH (rhGH) dose, vitamin D supplements, gender, use of thyroid hormones, corticosteroids or estrogen/testosterone, and season revealed a significant positive association between R15 ng/ml 25(OH)D and IGF1 R50th percentile (OR 4.4, 95% CI 1.0-18.8, P!0.05). A significant negative correlation between 25(OH)D concentrations and rhGH dose was found after correcting for age and IGF1 (b K0.042, P!0.01), but not after further adjusting for sex, thyroid, adrenal or gonadal replacement, and season (b K0.037, PZ0.06). Conclusions: Vitamin D increases circulating IGF1 in adults. As a result, a better vitamin D status may ease the achievement of normal IGF1 values in GHD.

The role of somatostatin and dopamine receptors as molecular targets for the treatment of patients with pituitary adenomas is well established. Indeed, dopamine and somatostatin receptor agonists are considered milestones for the medical therapy of these tumours. However, in recent years, the knowledge of the expression of subtypes of somatostatin and dopamine receptors in pituitary adenomas, as well as of the coexpression of both types of receptors in tumour cells, has increased considerably. Moreover, recent insights suggest a functional interface of dopamine and somatostatin receptors, when coexpressed in the same cells. This interaction has been suggested to occur via dimerisation of these G-protein-coupled receptors. In addition, there was renewed interest around the concept of cell specificity in response to ligand-induced receptor activation. New experimental drugs, including novel somatostatin analogues, binding to multiple somatostatin receptor subtypes, as well as hybrid somatostatin-dopamine compounds have been generated, and recently a completely novel class of molecules has been developed. These advances have opened new perspectives for the medical treatment of patients with pituitary tumours poorly responsive to the present clinically available drugs, and perhaps also for the treatment of other categories of neuroendocrine tumours. The aim of the present review is to summarise the novel insights in somatostatin and dopamine receptor pathophysiology, and to bring these new insights into perspective for the future strategies in the medical treatment of patients with pituitary adenomas.