Treatment of R-3327 prostate tumors with a somatostatin analogue (somatuline) as adjuvant therapy following surgical castration

Abstract

This study addresses, in an animal tumor model, the clinical problem of "escape from castration inhibition." Somatuline (BIM-23014C), an octapeptide analogue of somatostatin with enhanced potency and longer duration of biological activity was administered as a therapeutic agent, over a period of 90 and 197 days, to male Copenhagen rats bearing syngeneic Dunning R-3327-H prostate tumors.

Androgen sensitivity was confirmed by the response of tumors to castration and by the significant inhibition of tumor growth in intact animals by treatment with a luteinizing hormone-releasing hormone antagonist (BIM-21009).

Inhibition of tumor growth resulting from castration persisted for 102 days, after which progressive regrowth occurred, indicating an escape from castration inhibition.

When Somatuline treatment was initiated as an adjuvant therapy 5 days after castration, the rate of tumor regrowth during escape was significantly retarded. During the period of 197 days postcastration, tumors in the vehicle-treated, intact controls grew to an average diameter of 38.6 +/- 7.6 mm and tumors in vehicle-treated castrate controls grew to an average diameter of 23.3 +/- 4.1 mm (60% test/control).

Treatment with the luteinizing hormone-releasing hormone antagonist induced no significant additional tumor inhibitory effects in castrated animals which developed tumors having an average diameter of 30.2 +/- 8.2 mm (78% test/control).

Treatment of tumors in castrate animals with Somatuline, on the other hand, induced a significant (P less than 0.01) tumor-inhibitory effect that was greater than that produced by castration alone, developing an average tumor diameter of only 14.3 +/- 2.6 mm, (37% test/control).

A growth inhibitory effect was also inducible in animals having tumors that had already escaped castration inhibition.

The relative nontoxicity of a somatostatin analogue such as Somatuline suggests that chronic or maintenance therapy of slow-growing prostate cancers may be both feasible and acceptable in a clinical setting.

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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, 2018 Jul: Over-Expression of GH/GHR in Breast Cancer and Oncosuppressor Role of Somatostatin as a Physiological Inhibitor (from Di Bella's Foundation);

- Publication, 2018 Sep: 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, 2019 Aug: The Entrapment of Somatostatin in a Lipid Formulation: Retarded Release and Free Radical Reactivity (from Di Bella's Foundation);

- Publication, 2019 Sep: Effects of Somatostatin and Vitamin C on the Fatty Acid Profile of Breast Cancer Cell Membranes (from Di Bella's Foundation);

- Publication, 2019 Sep: Effects of somatostatin, curcumin, and quercetin on the fatty acid profile of breast cancer cell membranes (from Di Bella's Foundation);

- Publication, 2020 Sep: Two neuroendocrine G protein-coupled receptor molecules, somatostatin and melatonin: Physiology of signal transduction and therapeutic perspectives (from Di Bella's Foundation);

- The Di Bella Method (A Fixed Part - Bromocriptine and/or Cabergoline);

- The Di Bella Method (A Fixed Part - Cyclophosphamide 50mg tablets and/or Hydroxyurea 500mg tablets, one or two per day);

- The Di Bella Method (DBM) in the treatment of prostate cancer: a preliminary retrospective study of 16 patients and a review of the literature;

- The Synergism of Somatostatin, Melatonin, Vitamins Prolactin and Estrogen Inhibitors Increased Survival, Objective Response and Performance Status In 297 Cases of Breast Cancer;

- Complete objective response, stable for 5 years, with the Di Bella Method, of multiple-metastatic carcinoma of the breast;

- Evaluation of the safety and efficacy of the first-line treatment with somatostatin combined with melatonin, retinoids, vitamin D3, and low doses of cyclophosphamide in 20 cases of breast cancer: a preliminary report;

- The Di Bella Method (DBM) improved survival, objective response and performance status in a retrospective observational clinical study on 122 cases of breast cancer;

- Complete objective response to biological therapy of plurifocal breast carcinoma;

- 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;

- 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;

- 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.