Influence of droloxifene on metastatic breast cancer as first-line endocrine treatment.

The effect of droloxifene (3-hydroxytamoxifen) given as first-line endocrine treatment was evaluated in 39 postmenopausal women with advanced receptor-positive or receptor-unknown breast cancer. The patients had not received any previous anticancer therapy apart from adjuvant treatment. The overall response rate (CR + PR) was 51% (8% CR, 43% PR), 95% confidence interval+/-15.7%. Median time to progression (all patients) was 8 months, the median time to response 2 months, while the median duration of response was 10 months. The drug was well tolerated with no major side effects recorded; 16% of the patients experienced hot flushes. The response to droloxifene recorded in the present study is in accordance with the response rates to tamoxifen as first-line treatment in identical groups of patients.

Influence of treatment with the anti-oestrogen 3-hydroxytamoxifen (droloxifene) on plasma sex hormone levels in postmenopausal patients with breast cancer.

Plasma levels of oestradiol (Oe2), oestrone (Oe1) oestrone sulphate (Oe1S), androstenedione, testosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), sex hormone-binding globulin (SHBG) and the gonadotrophins (FSH and LH) were determined in 20 postmenopausal women with breast cancer treated with the anti-oestrogen droloxifene (3-hydroxytamoxifen). Plasma oestrogens were measured before and after 3, 6 and 12 months of therapy. The other hormones were measured before and after 6 months of therapy. Droloxifene treatment had no significant influence on plasma levels of Oe2. Plasma levels of Oe1 and Oe1S increased during treatment (mean increase of 11.9-15.9% and 24.5-69.4% respectively after different time-intervals on treatment). The Oe1S/Oe1 and Oe1S/Oe2 ratios increased by mean values of 13.8-45.2% and 25.9-52.4% respectively. Plasma SHBG increased significantly by a mean value of 73.9%, while FSH and LH fell non-significantly by 19.7% and 20.4% respectively. Plasma levels of testosterone, androstenedione, DHEA and DHEAS all increased during treatment, but none of these alterations were of statistical significance. While the influence of droloxifene on plasma SHBG resembled that which is seen during treatment with tamoxifen, its influence on plasma oestrogens and the gonadotrophins seems to be different. Possible explanations of such differences and the clinical implications of alterations in plasma hormones during treatment with droloxifene are discussed.

Interferon-alpha, 5-FU and prednisone in metastatic renal cell carcinoma: a phase II study.

BACKGROUND: Due to the possibility of a synergistic effect between Interferon (IFN-alpha) and 5-fluorouracil (5-FU), a phase II trial was conducted in metastatic renal cell carcinoma (MRCC) combining recombinant IFN-alpha, 5-FU and prednisone. Prednisone has been shown to decrease IFN-alpha-related toxicity without reducing the response rate. PATIENTS AND METHODS: Thirty-one patients with measurable MRCC were entered into the trial; 16 of them had lung metastases only. In 26 patients (nos. 6-31) the following dose schedule was applied during an 8-week treatment cycle: IFN-alpha (Roferon, Roche, Basel, Switzerland): 12 x 10(6)U s.c. 3 times weekly; Days 1-5: 5-FU: 600 mg/m2/day continuous i.v. infusion; Weeks 3-8: 5-FU 600 mg/m2 x 1 weekly (bolus i.v.); prednisone: 10 mg x 2 per os daily for 2 weeks, and thereafter 5 mg x 2. In the first 5 patients higher doses of 5-FU led to unacceptable toxicity and subsequent dose alteration of the trial schedule. All 31 patients were evaluable for response. Seventy treatment cycles were given. RESULTS: One complete and 6 partial responses were observed (response rate: 23%, 95% CI: 10%-41%), with a median response duration of 11 months. Except in one patient, hematological toxicity was confined to grades I and II. Eight patients developed grade III oral mucositis. Adverse cardiac events were observed in 3 patients. Dose modifications of 5-FU were necessary in 16 cycles. The IFN-alpha doses were transiently reduced during 8 cycles. CONCLUSION: The assessed combination of IFN-alpha, 5-FU and prednisone is moderately active in MRCC, with response rates similar to those seen in patients on IFN-alpha monotherapy. The latter treatment approach seems preferable, as 5-FU-related toxicity (mucositis, cardiac toxicity) is averted.

Droloxifene--a new anti-estrogen. A phase II study in advanced breast cancer.

Twenty-six patients with advanced breast cancer were treated with a new anti-estrogen, Droloxifene (3-hydroxy-tamoxifen). They had all used tamoxifen either in the adjuvant or the advanced situation. The dose schedule was 100 mg orally daily. Partial remissions were observed in 4 (15%) of the patients, and in another 5 patients stable disease (greater than 24 weeks of duration) was observed. Three of the responders were resistant to tamoxifen. Fourteen of the 26 patients had no side-effect. In 2 patients therapy had to be stopped due to fatigue. Droloxifene seems to be an interesting new anti-estrogen which should be further exploited.

Androgen regulation of polyamine synthesis in seminal vesicle and in different lobes of the rat prostate.

Endogenous levels of the polyamines putrescine, spermidine, and spermine have been examined in the 10(6) m/s2 supernatant of different lobes of the rat prostate and in the seminal vesicles of castrates, androgen-stimulated castrates, and intact controls. Content of the polyamines varied between the lobes, with spermidine highest in intact animals. After castration, the content of polyamines fell significantly in all lobes but the coagulating gland (CG). Spermidine levels were highest, except in the lateral prostate (LP) and CG, where the content of putrescine was highest. In castrated animals treated with testosterone propionate for 72 h, the amount of the three polyamines examined increased dramatically in the ventral prostate (VP) and moderately in the CG and seminal vesicle (SV). Concerning individual polyamines, spermidine increased significantly in all lobes, while putrescine increased significantly only in the two saccular parts of rat prostate, i.e., CG and SV. Spermidine content decreased significantly in the DP. Major differences in the content of the three polyamines--putrescine, spermidine, and spermine--in the various tissues studied have been found. Moreover, distinct differences among intact, castrated, and testosterone-treated castrated animals have been revealed.

The effects of graded doses of a cholecystokinin-like peptide with and without secretin on pancreatic growth and synthesis of RNA and polyamines in rats.

The dose dependence of a cholecystokinin-like peptide (CCK-LP) on the trophic response in the rat pancreas was studied. Graded doses of Thr28Nle31CCK25-33 (0.02, 0.1, 0.5, 2.5, and 12.5 micrograms/kg/h) or saline were given as a continuous intravenous infusion to conscious and fed rats for 8 and 48 h. Secretin (5.0 micrograms/h) was given alone or combined with the three highest doses of CCK-LP for 48 h. CCK-LP showed a dose-dependent stimulating effect on pancreatic growth and synthesis of RNA and polyamines. The threshold dose ranged from 0.02 to 0.5 micrograms/kg/h and was lowest for stimulation of ornithine decarboxylase (ODC). The maximal effects on protein, RNA, and DNA contents were achieved with 2.5 micrograms/kg/h. These same variables markedly decreased with 12.5 micrograms/kg/h, whereas marked further increases were found for the activities of RNA polymerase, DNA polymerase, and thymidine kinase. This same dose of CCK-LP caused after 8 h of treatment a marked and transient increase in pancreatic weight, activity of ODC, and concentration of putrescine. When secretin was added to 0.5 and 2.5 micrograms/kg/h of CCK-LP, no additional effect (except for ODC) was found. When secretin was added to the highest dose of CCK-LP, the decreased contents of protein and RNA were significantly increased, and the markedly increased activities of RNA- and DNA-synthesizing enzymes were significantly decreased. The present study shows a clear dose-response relationship for the trophic effect of CCK-LP on the rat pancreas and indicates that the growth effect of a supramaximal dose includes components of regeneration secondary to damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of polyamine synthesis by alpha-difluoromethylornithine and its effects on pancreatic secretion and growth in the rat.

The role played by the polyamines in mediating the pancreatic growth and secretory responses to hormonal stimulation is uncertain. The effect of an inhibitor of ornithine decarboxylase (ODC), alpha-difluoromethylornithine (DFMO), on rat pancreatic protein secretion and synthesis and on growth in response to hormonal stimulation was therefore studied. Anesthetized rats were given an intravenous injection of DFMO (50, 100, or 150 mg/kg), followed by a 7-h continuous infusion (15, 25, or 35 mg/kg/h, respectively). After a basal 1-h period an intravenous infusion of 2.5 micrograms/kg/h of the cholecystokinin-like peptide Thr28Nle31CCK25-33 (CCK-LP) was added and continued for 6 h. The control rats received CCK-LP only. The ODC activity in the pancreas was markedly reduced by DFMO, but DFMO did not affect pancreatic juice volume or protein output. In another series conscious rats were given a continuous intravenous infusion of 2.5 micrograms/kg/h of CCK-LP for 8, 24, and 48 h or 5.0 micrograms/kg/h of secretin for 8 and 48 h, with or without DFMO (100 mg/kg as an injection initially and thereafter 25 mg/kg/h). The ODC activity and putrescine concentration in the pancreas were significantly reduced by DFMO at 8 and 24 h but not at 48 h. DFMO also significantly reduced the activities of RNA polymerase, DNA polymerase, and thymidine kinase at 24 h, but not at 48 h. The present study thus indicates that polyamines play a role in the initiation of the growth response to hormonal stimulation but does not support a similar dependence for early pancreatic protein synthetic and secretory responses.

Short- and long-term effects of secretin and a cholecystokinin-like peptide on pancreatic growth and synthesis of RNA and polyamines.

Little is known about the cellular mechanisms responsible for the trophic effects of cholecystokinin (CCK) and secretin on the rat pancreas, and controversy exists with regard to the interaction between these two peptides. In the present study attempts were made to elucidate the time course of events leading to pancreatic growth and to clarify the interaction between the peptides when given as continuous, long-term intravenous infusions to rats. A cholecystokinin-like peptide (CCK-LP) and secretin were given as a continuous intravenous infusion to conscious and unrestrained animals with free access to food and water for 0.5, 1, 2, 4, 6, 8, 12, 24, 48, and 96 h. The pancreas was quickly removed and analyzed for variables indicating synthesis and accumulation of DNA, RNA, and polyamines. CCK-LP increased the activity of RNA polymerase already after 1 h, whereas an increase in the activity of ornithine decarboxylase (ODC) and the level of putrescine was seen at 4 h. Spermidine was increased after 12 h. The activities of DNA polymerase and thymidine kinase were increased at 12 and 24 h, respectively, whereas the total contents of DNA and RNA were first increased at 48 h. Secretin alone showed a marked but short-lived effect on polyamine synthesis and a weak effect on the variables indicating protein synthesis and growth. When the two peptides were given together, a large but transient potentiation of ODC activity was observed, whereas no interaction was seen on polyamines, RNA synthesis, or pancreatic growth. The present study confirms the trophic effects of CCK and secretin on the rat pancreas but fails to confirm an interaction between the two peptides on growth. Both peptides stimulate polyamine synthesis, and ODC appears to be an early and sensitive indication of their trophic effect. The initiation of RNA synthesis appears to be independent of the ODC activity.

Interaction between secretin and a cholecystokinin-like peptide on pancreatic protein secretion and synthesis in the rat.

The effects of secretin and a cholecystokinin-like peptide alone and in combination on pancreatic protein secretion and synthesis were examined in anesthetized rats. L-[75Se]selenomethionine was given as an i.v. shot (5 microCi) followed by a continuous infusion (1 microCi/h). Pancreatic juice was collected basally for 1 h and then during a 4-h i.v. infusion of 0.5, 2.5, and 12.5 micrograms/kg/h of Thr28Nle31CCK25-33 (CCK-LP) alone or combined with 5 micrograms/kg/h of secretin, as well as during an infusion of secretin alone. The protein-bound radioactivity in pancreatic juice was taken to indicate secretion of newly synthesized proteins. The free and protein-bound radioactivity remaining in the gland after 2 h of stimulation was also investigated. Secretin alone slightly increased both protein secretion and secretion of newly synthesized proteins. Considerably greater effects were found with CCK-LP. The two lowest doses behaved similarly, whereas the volume and protein responses to 12.5 micrograms/kg/h were significantly lower and associated with large amounts of free radioactivity in pancreatic juice, suggesting leakage and cell damage. The addition of secretin transiently potentiated protein discharge and secretion of newly synthesized proteins and permanently increased the amount of protein-bound radioactivity per milligram of protein in response to all doses of CCK-LP. Secretin markedly increased volume and reduced the amount of free radioactivity in pancreatic juice with the largest dose of CCK-LP. The peptides were not found to influence amino acid uptake or incorporation of radioactivity into tissue proteins. This study demonstrates an interaction between the effects of secretin and those of CCK-LP on pancreatic protein secretion and synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

The trophic effect on the pancreas of long-term continuous intravenous infusion of secretin and a cholecystokinin-like peptide in rats.

Rats were treated for 5 days with continuous intravenous infusion of different doses of secretin and Thr28Nle31CCK25-33 (CCK-LP) alone and combined. The trophic effect on the pancreas was evaluated by means of pancreatic weight and contents of DNA, RNA, and protein. The acute effects on pancreatic protein secretion were studied in anesthetized rats. The findings generally confirmed the trophic effects of secretin and CCK-like peptides on the pancreas. No convincing evidence of potentiation was found between small doses of secretin and CCK-LP for either pancreatic growth or protein secretion. The maximal dose of CCK-LP was the same for pancreatic growth and for protein secretion (2.5 micrograms/kg-h). Potentiation was demonstrated between secretin and the maximal dose of CCK-LP for protein secretion. The maximal effect of CCK-LP on pancreatic growth, however, was not enhanced by secretin.

Effects of a cholecystokinin-like peptide on DNA and polyamine synthesis in the rat pancreas.

The trophic effect of one or multiple subcutaneous injections of two different doses of a cholecystokinin-like peptide (CCK-LP) on the rat pancreas was evaluated by determination of ornithine decarboxylase (ODC) activity, the concentrations of the polyamines putrescine, spermidine, and spermine, and the activities of DNA polymerase and thymidine kinase, in addition to the contents of DNA, RNA, and protein. ODC activity was increased 10- to 20-fold already 2 h after a single injection of CCK-LP. The activity thereafter decreased and approached the control level after 6 to 8 h. The concentration of putrescine also showed a marked increase after a single injection, approaching maximum at 8 h. A slight increase was found for spermidine as well. DNA polymerase and thymidine kinase increased after 2 days of treatment. The DNA content was still normal at that time. The study suggests that the trophic effect of CCK is initiated very early. It shows that ODC activity and putrescine concentrations are early and sensitive determinants of the effect of CCK on the pancreas.