Adjuvant therapy for clinical localized prostate cancer treated with surgery or irradiation

OBJECTIVE

Because of efficacy demonstrated with chemotherapy in patients with metastatic disease, the National Prostate Cancer Project in 1978 initiated two protocols evaluating adjuvant therapy following surgery (Protocol 900) and irradiation (Protocol 1000) for patients with localized disease at high risk for relapse.

METHODS

All patients underwent staging pelvic lymph node dissection. Following definitive treatment, patients were randomized to either cyclophosphamide 1 g/m2 intravenously every 3 weeks for 2 years, estramustine phosphate 600 mg/m2 orally daily for 2 years or to observation only. Accession closed in 1985 and included 184 patients in Protocol 900 (170 evaluable) and 253 in Protocol 1000 (233 evaluable).

RESULTS

Nodal involvement was identified in 198 patients (49% of total): 29% in Protocol 900 and 63% in protocol 1000. Median progression-free survival (PFS) and survival have been greater for patients in Protocol 900 regardless of adjuvant, reflecting their lower pathologic stage. Median PFS is significantly greater for patients in Protocol 1000 receiving estramustine (52.2 months) compared to cyclophosphamide (35.0 months). Median PFS for patients with nodal involvement in Protocol 1000 receiving estramustine is increased (43.5 months) compared to no treatment (21.5 months). Patients with limited nodal involvement in Protocol 1000 have a longer median PFS (45.6 months) compared to patients with extensive disease (23.6 months). But in the latter group patients receiving estramustine experienced a significantly longer median PFS (43.5 months) compared to cyclophosphamide (29.1 months) or no adjuvant (13.5 months). Increased PFS with estramustine adjuvant was also noted in stage C patients (only Protocol 900) and in those with high-grade (grade 3) tumors (both protocols).

CONCLUSIONS

With now over 10 years mean follow-up for this series of patients, we conclude that adjuvant estramustine is beneficial for prostate cancer patients receiving definitive irradiation. This benefit is particularly noted in those patients with extensive nodal involvement (N+, D-1).

Evaluation of adjuvant estramustine phosphate, cyclophosphamide, and observation only for node-positive patients following radical prostatectomy and definitive irradiation. Investigators of the National Prostate Cancer Project

In 1978 the National Prostate Cancer Project launched two protocols evaluating adjuvant therapy following surgery (Protocol 900) or irradiation (Protocol 1,000) for clinically localized prostate cancer. All patients underwent staging pelvic lymphadenectomy. Following definitive treatment, patients were randomized to either cyclophosphamide 1 gram/m2-IV every 3 weeks for 2 years, estramustine phosphate 600 mg/m2-po daily for up to 2 years, or to observation only. Patient accession closed in 1985 and includes 184 to Protocol 900 (170 evaluable) and 253 to Protocol 1,000 (233 evaluable). Lymph node involvement was identified in 198 patients (49% of total), 29% in Protocol 900, 63% in Protocol 1,000. Median progression-free survival (PFS) for patients with nodal involvement in Protocol 1,000 receiving estramustine phosphate adjuvant was longer (37.3 mo) compared to cyclophosphamide (30.9 mo) and to no treatment (20.9 mo). Median PFS for patients with limited nodal disease in Protocol 1,000 was longer (39.9 mo), regardless of adjuvant, compared to extensive nodal disease (20.7 mo). However for patients with extensive nodal involvement, those receiving adjuvant estramustine phosphate experienced a significantly longer median PFS (32.8 mo) compared to adjuvant cyclophosphamide (22.7 mo) and no adjuvant (12.9 mo). We conclude that adjuvant estramustine phosphate is of benefit in prostate cancer patients with extensive pelvic node involvement receiving irradiation as definitive treatment.

Estramustine-binding protein (EMBP) in renal cell carcinoma immunohistochemistry, immunoscintigraphy and in vitro estramustine effects

The present report shows that the human renal cell carcinoma (RCC) cell lines, A498 and CAKI-2, express the estramustine-binding protein (EMBP). The RCC cell lines investigated were highly sensitive for estramustine, with cell arrest in atypical metaphase. In vitro experiments using a fluorimetric cytotoxicity assay (FMCA) showed a pronounced cytotoxic effect mediated by estramustine. Immunohistochemical analysis of tumour specimens from patients with RCC showed positive staining for EMBP in 12/16 cases. Immunoscintigraphy was performed in an experimental system in nude mice, heterotransplanted with the CAKI-2 cell line. A radiolabelled monoclonal anti-EMBP antibody was used. The results show a specific uptake of the antibody in the RCC tumour, expressed as a percentage of the injected dose per gram tissue, which ranged from 4.03 to 6.9. The results obtained form the basis for clinical studies on the feasibility of utilizing estramustine in the management of RCC. Immunoscintigraphy using the monoclonal anti-EMBP antibody is of potential use for in vivo characterization of the malignancy and in the selection patients suitable for treatment with estramustine.

External radiation therapy of prostatic carcinoma and its relationship to hormonal therapy

From 1980 to 1990, a total of 54 patients with prostatic carcinoma were treated with external radiation therapy at the Kumamoto National Hospital. Ten patients were classified as Stage B, 22 as Stage C, and another 22 as Stage D according to the American Urological Association Clinical Staging System. The 5-year survival for all 54 patients was 30%. The 5-year disease-specific survival was 67% for Stage B, 47% for Stage C, and 26% for Stage D. The 5-year survival was 43% for patients in whom radiation therapy was initiated immediately after the first diagnosis or with less than one year of hormonal therapy, while it was 0% for patients in whom radiation therapy was initiated after more than one year of hormonal therapy (p = 0.01). The cause of intercurrent death was acute myocardial infarction in four patients and acute cardiac failure in one. Four of these patients received hormonal therapy for more than one year. The incidence of radiation-induced proctitis was not severe. This study suggests that long-term hormonal therapy prior to radiation therapy worsens the prognosis of patients with prostatic carcinoma.

[A case of huge prostate cancer]

An 89-year-old man with bilateral leg edema and a huge abdominal mass was admitted for further evaluation. CT scan showed a hugh prostatic mass which occupied the whole pelvis cavity accompanying multiple pelvic bone metastases. Suprapubic needle biopsy revealed that the mass was well differentiated adenocarcinoma of prostate origin. The treatment was initiated by 500 mg per day of estramustine phosphate combined with injectable LH-RH analogue 2 months later. The serum levels of tumor markers were markedly elevated at the first visit; PSA 210ng/ml, PAP 110ng/ml, gamma-Sm 800ng/ml. They became normalized 3 months after the initiation of the treatment, and the mass was reduced to 11.5% of the initial size, which lead to removal of indwelling urethral catheter. The patient and his family, however, refused further treatment and the patient died of disseminated disease 8 months later.

Neoadjuvant hormonal therapy before radical prostatectomy decreases the number of positive surgical margins in stage T2 prostate cancer: interim results of a prospective randomized trial. The Belgian Uro-Oncological Study Group

PURPOSE

We investigated the effect of neoadjuvant treatment before radical prostatectomy for clinically localized prostate cancer.

MATERIALS AND METHODS

A total of 130 patients with stages T2b and T3 prostate cancer was randomized in a multicenter study: 62 underwent immediate radical prostatectomy and 65 received 560 mg. estramustine phosphate daily for 6 weeks preoperatively.

RESULTS

For clinical stage T2b tumors the neoadjuvant treatment resulted in a significant decrease in positive surgical margins compared to the nonpretreated group. This difference was not found for clinical stage T3 tumors. The impact on progression and survival still must be analyzed.

CONCLUSIONS

Neoadjuvant treatment can be beneficial for clinical stage T2 prostate cancer. Optimal treatment for stage T3 tumors remains controversial.

Preoperative endocrine therapy in patients with locally advanced prostate cancer

Recently, there has been increased interest in the application of preoperative endocrine therapy prior to radical prostatectomy for locally advanced cancer in order to enhance surgical curability and increase survival. Between 1986 and 1993, 40 patients with prostate cancer were given endocrine therapy before radical prostatectomy. Fifteen patients had stage B2 disease and 25 stage C. The median duration of preoperative endocrine therapy was 3.8 months, and all the patients subsequently underwent radical prostatectomy, pelvic lymphadenectomy and castration. There was an average 25.5% (0-71.8%) decreases in the maximal cross-sectional area of the prostate gland as determined by transrectal ultrasonography. Twenty-four of 25 patients with elevated levels of serum prostate-specific antigen (PSA) showed normal values after preoperative endocrine therapy. Evaluation of treatment-related histological effects, divided into three grades, revealed that 17 patients had pronounced, 11 moderate and 12 poor or no regression. Thirteen of the 40 patients (33%) demonstrated pathological downstaging of disease status from the diagnosis made at the initial clinical examination. After a median follow-up period of 36 months (3-100 months), 36 of the 40 patients are disease-free; two died of cancer 43 and 50 months after surgery, respectively. These results suggest that preoperative endocrine therapy may play an important role in the management of locally advanced prostatic cancer.

Estramustine phosphate sodium. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy in prostate cancer

Estramustine phosphate sodium (estramustine phosphate), a unique antitumour agent, is selectively taken up by prostate cells and exerts antineoplastic effects by interfering with microtubule of dynamics and by reducing plasma levels of testosterone. In noncomparative studies of estramustine phosphate in patients with hormone-refractory disease, objective response rates ranging from 19 to 69% have been reported. Preliminary clinical investigations indicate that combining estramustine phosphate with vinblastine, etoposide or paclitaxel improves objective response rates over single-agent treatment, although no survival benefit over single-agent treatment has been demonstrated to date. In comparative studies, estramustine phosphate produces similar objective response rates to conventional antineoplastic agents in patients with hormone-refractory prostate cancer. In previously untreated patients with advanced metastatic hormone-responsive prostate cancer, objective responses are achieved in approximately 80% of patients. Estramustine phosphate appears to be at least as effective as estrogen or flutamide therapy in these patients. Nausea and vomiting are the most frequently observed adverse effects of treatment with estramustine phosphate. While these symptoms are usually mild to moderate in nature, they may occasionally be more troublesome to the patient and necessitate withdrawal of treatment. Cardiovascular complications are a more serious, though less frequently encountered, adverse effect of the drug. However, these complications may be avoided by careful patient selection and prophylactic treatment measures. Unlike some other antineoplastic agents, estramustine phosphate is rarely associated with myelosuppression. In addition to producing similar objective response rates to other established agents, estramustine phosphate improves the subjective status of many patients and has been shown to reduce the intensity of pain and improve the performance status of patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Immediate estrogen or estramustine phosphate therapy versus deferred endocrine treatment in nonmetastatic prostate cancer: a randomized multicenter study with 15 years of followup. The South Sweden Prostate Cancer Study Group

From November 1978 to July 1984, 285 men with previously untreated, localized prostate cancer were consecutively randomized in an open multicenter study. The main objective was to determine if early endocrine treatment prolongs the interval to metastasis and/or cancer related or overall survival. Patients were randomized to receive either 80 mg. polyestradiol phosphate by intramuscular injection every 4 weeks plus 50 micrograms ethinylestradiol 3 times daily or 280 mg. estramustine phosphate 2 times daily, or for surveillance only but with deferred endocrine treatment at progression to metastatic disease. From 1983 further inclusion into the polyestradiol phosphate plus ethinylestradiol group was closed because of a high frequency of cardiovascular complications and thereafter 13 patients were instead randomized to a new treatment group with 80 mg. polyestradiol phosphate only by intramuscular injection every 4 weeks. Mean age was 70 years for 228 evaluable patients: 66 in the polyestradiol phosphate plus ethinylestradiol group, 74 in the estramustine phosphate group and 88 in the deferred treatment group, respectively. Mean followup for 100 patients alive on August 31, 1993 was 144 months (range 111 to 180). During the observation period 51 patients had metastasis. There was no difference in interval to metastasis (p = 0.07) among the 3 groups, although there was a tendency for a higher probability of metastases in the deferred treatment group. A total of 128 patients (56%) died during the observation period and prostatic cancer was considered to be the cause of death in 46 (20%). There was a significant difference (p = 0.03) among the 3 groups in the probability of dying of prostatic cancer, with the highest risk in the surveillance group but we found no significant difference in overall survival. The relevance of different prognostic factors and their interaction with treatment was also evaluated. These analyses were applied to the entire patient group as well as to the different subgroups. We found that patients with moderately well differentiated cancer (stage greater than T0a) who received early treatment with estramustine phosphate had the lowest risk of metastases or death from prostatic cancer, while those with well differentiated cancer (stage greater than T0a) did best on early polyestradiol phosphate plus ethinylestradiol treatment.

[Estramustinphosphate in the treatment of prostatic cancer]

OBJECTIVES

This study describes our experience in the treatment of disseminated prostatic cancer with stramustine phosphate.

METHODS

We reviewed our series of 41 patients with disseminated prostatic cancer; of these, 6 were treated with stramustine phosphate. Patient age, clinical features, tumor stage and diagnostic methods utilized were analyzed. All patients received 600 mg/day oral stramustine in two doses.

RESULTS

All 6 patients treated with stramustine phosphate showed clinical improvement, the levels of tumor markers returned to normal and bone metastasis disappeared. Moreover, no side effects were observed.

CONCLUSIONS

Further research is necessary on the effective use of stramustine phosphate and at the appropriate time in order to obtain the best results as there is no other alternative except radical surgery and at an early stage.

Goserelin. A review of its pharmacodynamic and pharmacokinetic properties and therapeutic efficacy in prostate cancer

Goserelin is a gonadotrophin-releasing hormone (GnRH) analogue which during long term administration reduces circulating levels of gonadotrophins (luteinising hormone and follicle stimulating hormone) and sex hormones. Goserelin is administered subcutaneously as a biodegradable depot formulation incorporating 3.6mg of the drug, which is released continuously over 4 weeks. In men with untreated advanced prostate cancer, monthly goserelin 3.6mg has been confirmed as similar in efficacy to surgical castration and diethylstilbestrol (stilboestrol) 3mg daily taken orally. Goserelin is better tolerated than diethylstilbestrol and appears to have a more favourable effect on quality of life than surgical castration. Treatment of prostate cancer with a combination of goserelin and an antiandrogen remains controversial as a result of inconsistent findings, despite extended data from a large trial which indicated an advantage for the combined regimen over surgical castration with respect to duration of time to progression and survival. Combination therapy also minimises the initial increase in signs and symptoms (disease flare) that occurs in up to 4% of patients at the beginning of treatment with a GnRH analogue. Surgical castration remains the treatment of choice in patients at risk of metastatic compression of the spinal cord or ureteric obstruction. However, goserelin is an effective alternative to surgery, or estrogen therapy, in men with previously untreated advanced prostate cancer. Goserelin seems to be preferred to surgery by the majority of patients given a choice of treatment, and importantly in a palliative care situation where there are no survival advantages for treatment alternatives, it appears to have a more beneficial effect on the quality of life than surgery.

Estramustine phosphate for preventing flare-up in luteinizing hormone-releasing hormone analogue depot therapy

The usefulness of estramustine phosphate (ECT) for preventing flare-up in goserelin acetate depot therapy for advanced prostate cancer was studied. Pretreatment with ECT 560 mg daily for 3 weeks almost completely prevented the rise in testosterone level seen in goserelin acetate depot therapy and no signs or symptoms of tumor flare were observed. Long-term ECT completely blocked the rise in luteinizing hormone and testosterone level, but ECT at this dosage was likely to cause complications. The administration of ECT 560 mg daily for 3 weeks prior to goserelin acetate depot therapy was considered sufficient to prevent tumor flare, and its effect was considered to be more marked than that of short-term treatment with antiandrogens.

Epirubicin and medroxyprogesterone acetate versus estramustine phosphate in hormone-resistant prostatic cancer: a prospective randomized study

The effect of a medroxyprogesterone acetate (MPA) plus epirubicin combination versus estramustine phosphate was evaluated in 149 prospectively randomized patients with hormone-resistant prostatic cancer. The estimated probability of being free from progression after 1 year was 17% for the patients treated with estramustine and 29% for the MPA-epirubicin group. There is a significant difference between the two groups regarding risk of progression (p = 0.013). However, no difference in survival was recorded (p > 0.30) with about 60% of the patients dead during the first year in both groups. Progression was highly correlated to sedimentation rate (p < 0.001) and to performance index (p = 0.002). Heart failure occurred in a substantial number of patients in both groups which must be considered before starting therapy.

Interaction of the antiemetics ondansetron and granisetron with the cytotoxicity induced by irradiation, epirubicin, bleomycin, estramustine, and cisplatin in vitro

At cancer treatment, the use of antiemetics are often needed due to induction of nausea and vomiting. Some antiemetics have been shown to interact with the direct cytotoxic effects. The newly developed antiemetics have, as far as we know, not been studied in this respect. In the present study, the effects of the 5-HT3 receptor antagonists ondansetron and granisetron were evaluated on the cytotoxicity, induced by irradiation, bleomycin, epirubicin, estramustine, and cisplatin using fibroblasts (V79) and lung cancer cells (P31) in vitro. Ondansetron or granisetron (10(-5) mol/l) had no effect on the survival of irradiated cells. Granisetron (10(-5) mol/l) significantly potentiated cytotoxicity of 2.5 mg/l epirubicin on fibroblasts whereas the effect of granisetron (10(-7) mol/l) on the cytotoxic effect of 25 mg/l bleomycin, and estramustine (80 mg/l) seemed additive to lung cancer cells. Ondansetron was non-interactive with the cytotoxicity induced by any of the anti-cancer drugs. Although the encountered observation with an enhancing effect of granisetron on the epirubicin-induced cytotoxicity is seen in a specific experimental situation in vitro, the fact that 5-HT3 receptor antagonists are routinely used during cancer treatment indicate that attention should be given to a possible interaction with the antineoplastic action of cancer treatment.

Morphologic and immunohistochemical changes in prostate cancer after preoperative hormonal therapy. A comparative study of radical prostatectomies

BACKGROUND

Estramustine phosphate (EMP) and flutamide (FL) were used as reversible preoperative hormonal drugs in the surgical treatment of patients with localized prostate cancer.

METHODS

The authors descriptive and quantitatively examined the morphologic and immunohistochemical changes in 40 of 200 step-sectioned radical prostatectomies, obtained after treatment with EMP (25 patients) and with FL (15 patients). Of these, 28 pretreatment needlecore biopsies were available.

RESULTS

Every specimen contained adenocarcinoma. Understaging was found in 50% of the cases and a higher Gleason score in 70%. Benign glands underwent atrophy and squamous metaplasia. Treated tumors showed cytoplasmic vacuolization, nuclear pyknosis, fibrosis and lymphocytic infiltrates. The EMP group had an 84% (P < 0.05) higher mean total regression score than the FL group. Estramustine phosphate induced a 56% (P < 0.05) and a 34% decrease in tumoral prostate specific antigen and prostate specific acid phosphatase intensity scores, respectively, versus 29% and 32% after FL. The mean proliferating cell nuclear antigen (PCNA) labeling index and the mean mitotic index of the EMP group were 52% (P < 0.05) and 70% (P < 0.05) lower than those measured in the FL group. Each FL-treated tumor and 92% of EMP-treated tumors expressed chromogranin A (ChrA); ChrA labeling correlated significantly with PCNA labeling. Seventy-six percent of EMP-treated specimens revealed venous thrombosis.

CONCLUSIONS

Estramustine phosphate induces important morphologic and immunohistochemical changes in prostate cancer with an apparent decrease of secretory and proliferative activity when compared with FL-treated tumors. These changes represent pitfalls in the diagnosis and grading of treated carcinomas. Nearly every treated adenocarcinoma of the prostate has neuroendocrine differentiation, showing increasing ChrA labeling with higher tumor stage. A significant correlation between tumor proliferation and neuroendocrine differentiation was noticed in this small cohort of patients. There was a high incidence of periprostatic venous thrombosis after EMP treatment.

Prostate specific antigen and prostate acid phosphatase declines after estramustine phosphate withdrawal: a case report

We report a case of advanced prostate cancer in which an initial response to hormonal therapy with surgical castration and estramustine phosphate (EMP) was followed by disease progression, as shown by sequential elevations in serum prostate specific antigen (PSA) and prostate acid phosphatase (PAP) and the development of new symptoms, during maintenance endocrine and anti-cancer chemotherapy. Discontinuation of EMP resulted in sustained reductions in serum PSA and PAP levels and a sustained improvement in symptoms.

Clinical and biological studies of estramustine phosphate as a novel radiation sensitizer

PURPOSE

Estramustine phosphate (EMP), a nor-nitrogen mustard carbamate derivative of estradiol-17 beta-phosphate, causes G2/M phase arrest in treated cells through its specific binding to microtubule associated proteins. Since cells in the G2/M phase are the most radiosensitive, cell culture experiments were performed to determine whether EMP would enhance the radiosensitivity of related human tumor cells. Based on the cell culture findings and well known pharmacokinetic data in humans, a Phase II prospective study of concomitant radiotherapy (RT) and EMP plus Velban for locally advanced carcinoma of the prostate was carried out.

METHODS AND MATERIALS

Three established human tumor cells, DU-145 cells (prostate), MCF-7 cells (breast), and U-251 cells (malignant glioma), were used to determine cell survival curves with and without the drug. Flow cytometry was used to obtain the cell cycle distribution of cells that were exposed to the drug for periods of 1 day to 1 week. Patients with locally advanced prostate cancer (Stages B2, C, D1) were entered into the Phase II study. All patients received a total tumor dose of 65-70 Gy over 7 weeks. Oral EMP was administered daily and Velban was administered weekly, concomitantly during the course of RT.

RESULTS

Radiosensitization was dependent on the exposure time and the drug concentration prior to radiation. No radiosensitization was obtained when cells were exposed to the drug after irradiation. The enhancement ratios varied from 1.3-1.6 at the 10% survival level. All patients who received the combined RT and EMP plus Velban achieved complete response (n = 27). The rate of PSA (prostate specific antigen) reduction was very prompt compared to that of the RT alone group. There was not disproportionately enhanced side effects for the combined regimen.

CONCLUSION

EMP enhances radiation induced cytotoxicity in several human tumor cells in culture. The effect is most significant after prolonged exposure to the drug before irradiation. Documented G2/M phase cell cycle block by EMP is the likely mechanism of radiosensitization. The preliminary clinical findings with the combined RT and drugs are highly encouraging.

[Prostate-specific antigen as an evaluation method in the treatment of hormone-refractory cancer of the prostate]

Out of 62 patients with hormone-refractory metastatic prostate cancer, 34 received rescue treatment with estramustine phosphate and 28 received non-steroidal symptomatic treatment. All patients undergoing symptomatic treatment experienced increased PSA levels while in 16 (47%) patients treated with estramustine phosphate, PSA decreased between 13-96%. In 11 cases (32.3%) the decline in PSA was higher than 50%. In 5 (14.7%) the decline was lower than 50% and in 18 cases (53%) PSA levels were increased. SCR rate was 82%, 60% and 6% respectively while OCR were 36.4%., 0% and 0% respectively. No clinical response was seen in patients undergoing symptomatic treatment. A decline in PSA levels higher than 50% 12 weeks after treatment appears to be a "good prognosis" factor related to the best clinical response rates and survival.

P-glycoprotein binding and modulation of the multidrug-resistant phenotype by estramustine

BACKGROUND

Previous preclinical studies of combinations of estramustine and vinblastine or paclitaxel (Taxol) have shown that it is possible to achieve a greater than additive cytotoxicity with these antimicrotubule drug combinations. Phase II studies in hormone-refractory prostate cancer have demonstrated clinical antitumor activity of sufficient magnitude to stimulate further laboratory and clinical studies of these drugs combinations.

PURPOSE

Our purpose was to characterize the interactions of estramustine with P-glycoprotein and to determine its effects.

METHODS

Standard laboratory techniques were used to study the effects of estramustine on intracellular drug concentrations, cytotoxicity, and induction of messenger RNA (mRNA) for the MDR1 (also known as PGY1) gene. Using a photoaffinity analogue of estramustine 17-0-[[2-[3-(4-azido-3-[125I]-iodophenyl) propionamido]ethyl]-carbamyl]estradiol-3-N-bis(2-chloroethyl)ca rba mate ([125I]AIPP-estramustine), binding to the membrane proteins of human ovarian (SKOV3) and their multidrug-resistant counterpart SKVLB1 cells was studied. Southern-blot analysis was performed on DNA extracted from human prostate carcinoma wild-type DU145, estramustine-resistant cell line (E4), and SKVLB1 cells.

RESULTS

Membrane fractions from SKOV3 and SKVLB1 cells were analyzed for proteins that could be photoaffinity labeled with [125I]AIPP-estramustine. Competitive inhibition of this binding was achieved with excess concentrations of (in order of efficacy) estramustine, vinblastine, verapamil, progesterone, and to a lesser degree, by paclitaxel but not with estramustine phosphate, estradiol, and estriol. SKVLB1 cells accumulated much less [3H]vinblastine and [3H]paclitaxel than did SKOV3 cells. Estramustine caused a concentration-dependent enhancement of drug accumulation in the SKVLB1 cells to a maximum of approximately 12-fold. No effect of estramustine was apparent for the wild-type SKOV3 cells. In comparison with verapamil, estramustine was less effective as a modulator; however estramustine demonstrated good chemosensitizing activity in combination with actinomycin D and vinblastine. Neither short-term, low-dose no longer-term, higher concentration were found to produce measurable transcript (mRNA for the MDR1 gene levels. Such data suggest that, at least levels. Such data suggest that, at least for two distinct human cell line (SKOV3 and DU145), estramustine does not induce the overexpression of the MDR1 gene.

CONCLUSION

It is apparent from the P-glycoprotein data that estramustine interacts with this efflux pump, altering intracellular drug accumulation. Overall, the nonempiric basis for including estramustine in clinical protocols that contain other multidrug-resistant drugs is strengthened by the present data.

[Hormone therapy before radical prostatectomy. Effects on surgical method and resection margins. Belgian Uro-Oncological Study Group (B.U.O.S.)]

127 patients with a clinical stage T2b and T3 prostate cancer were randomized in order to undergo either a radical prostatectomy alone or a radical prostatectomy after hormonal treatment (560 mg of estramustine phosphate daily for 6 weeks) in a prospective multi-center study. The clinical or radiological evaluation of an eventual downstaging being extremely difficult, the authors compared in the 2 groups the influence on the surgical act and the number of positive surgical margins at pathological examination of the resected specimen. There was no significant difference between the 2 groups concerning the surgery (duration of the procedure, blood transfusion, degree of difficulty). For clinical T2 prostate tumors the number of positive surgical margins was significantly lower in the group that had preoperative hormonal treatment. In the group with clinical T3 prostate cancer this difference was not found. The influence of positive margins on the later development of local or systemic recurrence and on survival still has to be awaited. At this moment one could conclude that only patients with a T2 prostate cancer benefit of a preoperative hormonal treatment.

Primary therapy of metastatic prostate carcinoma with depot gonadotropin-releasing hormone analogue goserelin versus estramustine phosphate. The Prostate Cancer Study Group

OBJECTIVE

To determine if initial chemo-hormone therapy (estramustine phosphate) of metastatic prostate carcinomas can lengthen the period until progression, compared with hormone treatment (goserelin) alone? The time to progression, side effects and prognostic factors were assessed.

METHODS

The prospective phase III study (II 86 until V 91) involved 243 patients randomized consecutively in two groups. Progress was assessed according to NPCP criteria.

RESULTS

The following prognostic factors were established to be significant: metastatic status, metastatic bone pain, alkaline phosphatase and performance status. No difference was observed between the two methods of treatment in time to progression. However on stratifying according to groups with the same prognostic factors, progression in the high risk group occurred at a later stage during treatment with estramustine than during pure hormone treatment. The quality of life was clearly more heavily restricted by side effects from estramustine.

CONCLUSIONS

Thus, when comparing these treatments, there were no statistically significant differences. Patients in the high risk groups with unfavorable prognosis factors benefitted from the chemo-hormone treatment with estramustine phosphate.

Experience in advanced prostatic cancer: orchiectomy and flutamide versus orchiectomy and estramustine phosphate

OBJECTIVE

To compare pure hormonal treatment (orchiectomy plus flutamide) versus hormonal plus cytostatic treatment (orchiectomy plus estramustine phosphate [EMP]) as first-line therapy for advanced prostatic cancer.

METHODS

From October 1985 to December 1991 a total of 99 patients were enrolled: 49 received orchiectomy plus EMP, 2 x 280 mg/day; 50 received orchiectomy plus flutamide, 3 x 250 mg/day.

RESULTS

Of the 99 enrolled patients, 93 were evaluable for toxicity and 82 for efficacy. The median time to progression was 161 weeks for EMP versus 120 weeks for flutamide (p = 0.75, not significant). For distant metastases, bone pain, and poor performance status, treatment with EMP showed significantly better results than the flutamide group. The most frequent side effects were gastrointestinal for EMP and hot flushes for flutamide.

CONCLUSIONS

For patients with advanced undifferentiated prostatic cancer and poor prognostic factors, treatment with EMP seems to show significant benefit.

Study of estramustine binding protein: its relationship to androgen dependency and histological differentiation in human prostatic carcinoma tissue

For the purpose of elucidating the clinical significance of estramustine binding protein (EMBP), EMBP concentration in human prostatic carcinoma (PC) tissue was measured by radioimmunoassay (RIA) using an antibody raised against rat EMBP and was compared with dihydrotestosterone (DHT) level and histological differentiation in the same tissue. The mean concentrations of EMBP in 20 untreated and 6 hormonally refractory PC were 112.6 +/- 120.7 and 218.0 +/- 102.3 ng/g tissue, respectively. In the 20 untreated PC, the EMBP concentration was not significantly different between the high and low tissue DHT groups. On the other hand, the EMBP concentration was significantly higher in moderately and poorly differentiated PCs as compared with well-differentiated PC, whereas the DHT level was highest in well-differentiated and lowest in poorly differentiated PC. Furthermore, in the 6 hormonally refractory PC, the EMBP concentration was higher in spite of a lower tissue DHT level in comparison with untreated PC. These results suggest that the EMBP concentration does not reflect androgen status in PC tissue but might reflect the malignant potential of the tumor.

Estrogen mustard induces cell cycle arrest of human epithelial ovarian cancer cell lines

OBJECTIVE

Pharmacologic disruption of microtubule function may provide effective therapy for advanced epithelial ovarian cancer, as has been observed in clinical trials using taxol. However, the limited availability of taxol and taxol's side effects emphasize a need to develop alternative antimicrotubule agents. Estramustine (EM) inhibits binding of microtubule-associated proteins (MAPs) to microtubules, promotes microtubule disassembly, disrupts spindle formation, and induces metaphase arrest in human prostate carcinoma and glioma cells in culture. We studied the effect of EM on DNA synthesis and on the cell cycle in four human ovarian carcinoma cell lines and examined the cell lines for evidence of MAP-like immunoreactivity.

METHODS

The effect of EM on DNA synthesis and on the cell cycle was determined using [3H]thymidine incorporation assays and flow cytometry, respectively. Microtubule-associated protein-like immunoreactivity was determined using monoclonal antibodies directed against MAP 1A, MAP 1B, and MAP 2(2A + 2B) for Western analysis after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

RESULTS

We demonstrated a dose-dependent inhibitory response to EM in BIXLER, DK2NMA, and SKOV3. BIX3 showed a dose-dependent inhibitory response to EM concentrations from 25 micrograms/mL to 100 micrograms/mL, but a stimulatory response at 10 micrograms/mL. Estramustine inhibited exponentially growing cells by causing mitotic arrest with subsequent accumulation of cells in G2/M phase of the cell cycle in all four cell lines. We found MAP 1A, MAP 1B, and MAP 2-like immunoreactivity in all four cells lines studied.

CONCLUSIONS

These results are consistent with a MAP-microtubule mechanism of action for EM in ovarian carcinoma cells and provide reason to conduct further study of EM for potential use in the treatment of human epithelial ovarian cancer.