Androgen influence on exocrine pancreatic cancer

Flutamide in unresectable pancreatic adenocarcinoma: A randomized, double-blind, placebo-controlled trial

PURPOSE

To evaluate the impact of flutamide on survival of patients with unresectable pancreatic cancer.

METHODS

This single institution, randomized, double-blind, placebo controlled study compared flutamide in the dose of 250 mg three times daily (n = 23) versus placebo (n = 23) in patients with histologically proven, previously untreated unresectable pancreatic adenocarcinoma. The primary end point was overall survival; secondary endpoints included 6-month and 1-year survival rates, performance status and response rate.

RESULTS

Both the groups were well matched with regards to demographic, disease related and treatment variables. This small sample sized study, failed to demonstrate a dramatic effect on survival with the use of flutamide. Median overall survival was 151 days with the use of flutamide as compared to 136 with placebo (p = 0.51). The 6-month survival rate was 39.13% in both arms of study and 1-year survival was 4.35% versus 13.04% for the flutamide group. There was no statistically significant difference in time to deterioration of performance status (flutamide 90 days versus placebo 68 days, p = 0.59) and all patients died as a result of tumor progression.

CONCLUSIONS

Anti-androgen drug flutamide in the dose of 250 mg three times daily does not appear to prolong overall survival in unresectable pancreatic cancer.

The significance of somatostatin analogues in the antiproliferative treatment of carcinomas

Somatostatin is a cyclic tetradecapeptide hormone. It was initially isolated from bovine hypothalami. Somatostatin inhibits endocrine and exocrine secretion, as well as tumor cell growth, by binding to specific cell-surface receptors. Its potent inhibitory activity is limited, however, by its rapid enzymatic degradation and the consequently short plasma half-life. Octreotide is a short somatostatin analogue with increased duration of action compared with somatostatin. Preclinical studies have focused on the anticancer effects of octreotide and the related somatostatin analogues. In vitro, at nanomolar concentrations, these analogues inhibit the growth of tumor cells that express high-affinity somatostatin receptors. Accordingly, such analogues potently inhibit the growth of somatostatin receptor-positive tumors in various rodent models. The range of cancers susceptible to octreotide and related somatostatin analogues includes mammary, pancreatic, gastric, colorectal, prostate, thyroid, and lung carcinomas. Moreover, an indirect antiproliferative effect of somatostatin analogues is achievable in somatostatin receptor-negative tumors whose growth is driven by factors (e.g., gastrin, insulin-like growth factor-1) that become down-regulated by somatostatin. The clinical effect of somatostatin analogues in terms of tumor response in cancer patients is a subject of controversy, however. Most responses have been seen in patients with pancreatic cancers.

Octreotide combined with goserelin in the therapy of advanced pancreatic cancer--results of a pilot study and review of the literature

The two hormone analogues octreotide and goserelin have been shown to decelerate growth of human pancreatic cancer in vitro and in vivo. The objective of this pilot study was to investigate the efficacy and toxicity of the combination of these two agents in patients with advanced pancreatic cancer. Octreotide was injected subcutaneously in dosages increasing weekly, starting with 50 micrograms twice daily, until the level of maintenance therapy of 500 micrograms three times a day was reached. In addition, 3.8 mg goserelin acetate was administered subcutaneously at monthly intervals. A median of 7 cycles (range 1-27 cycles) were applied; 13 out of 14 patients entered into the study were evaluable for response and all 14 were evaluated for toxicity. In one patient with initially non-resectable pancreatic cancer, systemic therapy yielded a partial remission lasting 9 months. The degree of tumour regression then allowed a consecutive macroscopic radical tumour resection followed by an additional 6 months of no evidence of disease while the same drug combination was continued. In an additional 9 patients, no change of disease was observed, in some cases for a remarkably long time (up to 27 months). Nevertheless, the objective response rate of 7% (95% confidence interval 0 +/- 21%) was low. In 5 patients a clear improvement in their performance status was seen soon after the start of therapy; 3 patients showed progression of the disease at first evaluation or earlier and 1 patient was not evaluable at the time of study assessment. According to the product-limit method of Kaplan and Meier, the time to progression was 3.0 +/- 1.8 months [median +/- asymptotic standard error (ASE)] and overall survival was 6.0 +/- 1.5 months (median +/- ASE). Toxicity was rare and only of mild to moderate degree. Overall, the regimen under investigation did not meet the criteria for sufficient antitumoural effectiveness. Nevertheless, this study reinforces the concept that pancreatic cancer is principally responsive to endocrine therapy and therefore the further investigation of hormonal manipulation seems worth while in the future.

Hormonal therapy of pancreatic carcinoma. Rationale and perspectives

Exocrine pancreas carcinoma is still diagnosed at a relatively late stage, so that only a few cases can be cured by surgery. Therefore, it is desirable that an effective medical therapy be found first to stall the development of the disease and second to improve the life conditions of patients. On the basis of recent discoveries, a new therapeutic approach seems to derive from hormone manipulation. The growth of pancreatic carcinoma appears to be stimulated by various factors, such as Epidermal Growth Factor (EGF) and Insulin-like Growth Factor I (IGF-I), and by various hormones, such as androgens and cholecystokinin. Several studies performed on cell lines and on animal models of pancreatic carcinoma demonstrated an antitumoral effect of certain antihormones and of somatostatin. Taking such studies as a premise, the first clinical studies were finally started in patients suffering from nonoperable pancreatic cancer. Results are still partial and contradictory, but such research is certainly worthy of further study along the lines already taken.

Hormonal treatment of pancreatic carcinoma: a phase II study of LHRH agonist goserelin plus hydrocortisone

Eighteen consecutive patients with measurable locally advanced or metastatic pancreatic adenocarcinoma were treated with goserelin (Zoladex) 3.6 mg subcutaneously every 4 weeks. Hydrocortisone 20 milligrams twice daily was commenced with the second injection of goserelin. Objective tumour response was monitored by computerised tomography of the abdomen. There was no objective remission in disease sites. Serial measurements of serum tumour markers showed no reduction in serum CA 19-9 and CA 195 concentrations. The median duration of survival of all cases was 5 months. Administration of goserelin resulted in significant reductions in oestradiol, testosterone, androstenedione in males and reductions in FSH and LH in both males and females. The addition of hydrocortisone resulted in further reductions of androstenedione and testosterone levels in males. Thus goserelin showed no anti-tumour effect, but concentrations required for direct inhibitory effects may be higher than those required to produce effects on hormone suppression.

Hormones and pancreatic cancer

Several polypeptide hormones have been demonstrated to stimulate or inhibit cell division in the cells of the pancreas. Therefore, receptors for these hormones have been sought in pancreatic carcinomas, and several examples have been reported. In some instances, stimulation of tumor growth by the corresponding peptide has been demonstrated or growth was blocked by a receptor antagonist. Receptors and binding proteins for steroid hormones also have been reported in carcinomas of the pancreas. In experimental carcinogenesis, the growth of preneoplastic lesions and incidence of neoplasms have been influenced by both peptide and steroid hormones in some species. Experimental manipulation of sex steroid hormones has yielded both inhibition and enhancement of growth of human and rat pancreatic cancers, but thus far, clinical trials have failed to document advantageous approaches for steroid or antihormonal therapy. These observations imply that trophic or growth-inhibiting polypeptide and steroid hormones may serve as promoters or inhibitors of carcinogenesis in the pancreas, and may influence the growth of established carcinomas. Receptor blockers may provide a clinical approach for slowing the growth of some cancers.

Perspectives of CCK antagonists in pancreatic research and clinical use. Part I

Cholecystokinin (CCK) is one of the most important regulators of pancreatic and digestive physiology. Its importance led to research and discovery of a number of CCK receptor antagonists. Some of them are experimentally and clinically used today in order to assess the relative contribution of CCK to different aspects of pancreatic physiology. Furthermore, clinical trials are running with the aim of determining their possible therapeutic indications in pancreatic diseases, such as acute and chronic pancreatitis or pancreatic carcinoma. The rationale and evidence for their use are discussed.

Effects of sex steroid hormones on pancreatic cancer in the rat

The incidence of spontaneous and induced neoplasms of the exocrine pancreas in rats is higher in males than in females. Castration, ovariectomy, and hormone replacement with estradiol and testosterone have been shown to influence the growth of carcinogen-induced preneoplastic foci in the azaserine-rat model of pancreatic carcinogenesis. Similar hormonal treatments have also influenced the growth of an azaserine-induced poorly differentiated acinar cell carcinoma that can be transplanted syngeneically in Lewis rats. The effect on growth of preneoplastic lesions and carcinomas is similar. The preneoplastic lesions and transplanted tumors grow faster in intact male rats than in castrated rats, and the growth of the lesions and tumors is inhibited by estrogen treatment. It appears that testosterone supports the growth of preneoplastic foci and carcinomas, whereas estrogen inhibits such growth. The mechanism is unknown and may be direct, or an indirect effect may be mediated through a peptide hormone. Tamoxifen treatment did not significantly influence the growth of the transplanted carcinomas in the rat model.