Somatostatin in medullary thyroid cancer. In vitro and in vivo studies

Abstract

The authors evaluated the presence of somatostatin (SRIF) in the plasma and in the tumor tissue of a total of 22 patients with medullary thyroid cancer (MTC) and studied the effect of exogenous SRIF administration on basal and pentagastrin (PG)-stimulated plasma calcitonin (CT) and carcinoembryonic antigen (CEA) levels.

Mean plasma SRIF concentrations were significantly higher than those found in normal controls, with five of 15 patients having plasma SRIF levels above the mean + 2 SD of normal controls. High immunoreactive SRIF concentrations were found in the extract of three tumor tissues but not in one follicular thyroid cancer or in one toxic diffuse goiter. By immunoperoxidase staining seven of 11 (63.6%) primary MTC and five of 13 (38.5%) metastases expressed SRIF antigen in a low number of cells and with a weak degree of staining.

As expected, CT was expressed in almost 100% of the cases with positivity in most of the cells and strong degree of staining.

Patients with positive SRIF staining in the primary tumor had longer survival than SRIF negative patients.

Infusion of synthetic SRIF (11 micrograms/minute/45 minutes) produced a significant reduction of plasma CT (but not CEA) levels in 12 of the 15 patients submitted to this test. Maximal percent decrease of plasma CT ranged from 10.8% to 72.7% of the basal value and was usually observed between 30 and 45 minutes from the beginning of the infusion.

When infused together with the injection of PG, SRIF was able to significantly (P less than 0.05) inhibit the PG-induced CT release in five of six patients tested.

These results demonstrate the following: SRIF is present in a few cells of many primary MTC and less frequently in their metastases; tentatively, the expression of SRIF antigen in the tumor seems to be associated with longer survival; increased SRIF concentrations are found in the plasma of some patients with metastatic involvement; and treatment with exogenous SRIF reduces the basal and PG-induced CT (but not CEA) release from the tumor.

 

About this publication.

See also:

- Official Web Site: The Di Bella Method;

- The Di Bella Method (A Fixed Part - Somatostatin, Octreotide, Sandostatin LAR, analogues and/or derivatives);

- Somatostatin in oncology, the overlooked evidences - In vitro, review and in vivo publications;

- Publication: Over-Expression of GH/GHR in Breast Cancer and Oncosuppressor Role of Somatostatin as a Physiological Inhibitor (from Di Bella's Foundation);

- Publication: The over-expression of GH/GHR in tumour tissues with respect to healthy ones confirms its oncogenic role and the consequent oncosuppressor role of its physiological inhibitor, somatostatin: a review of the literature (from Di Bella's Foundation);

- Publication: The Entrapment of Somatostatin in a Lipid Formulation: Retarded Release and Free Radical Reactivity (from Di Bella's Foundation);

- The Di Bella Method (A Fixed Part - Calcium, 2 grams per day, orally);

- The Di Bella Method DBM improved survival objective response and performance status in a retrospective observational clinical study on 23 tumours of the head and neck;

- Recurrent Glioblastoma Multiforme (grade IV – WHO 2007): a case of complete objective response achieved by means of the concomitant administration of Somatostatin and Octreotide – Retinoids – Vitamin E – Vitamin D3 – Vitamin C – Melatonin – D2 R agonists (Di Bella Method – DBM) associated with Temozolomide;

- Somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide in advanced non-small-cell lung cancer patients with low performance status;

- Somatostatin, retinoids, melatonin, vitamin D, bromocriptine, and cyclophosphamide in chemotherapy-pretreated patients with advanced lung adenocarcinoma and low performance status;

- Observations on the Report of a case of pulmonary adenocarcinoma with lymph node, hepatic and osseus metastasis;

- Neuroblastoma: Complete objective response to biological treatment;

- Oesophageal squamocellular carcinoma: a complete and objective response;

- Pancreatic Adenocarcinoma: clinical records on 17 patients treated with Di Bella's Method;

- The Di Bella Method Increases by the 30% the survival rate for Pancreas tumors and for this reason should be proposed as first line therapy for this type of cancer.