Weekly doxorubicin in endocrine-refractory carcinoma of the prostate

Multi-Walled Carbon Nanotubes Decorated with Guanidinylated Dendritic Molecular Transporters: An Efficient Platform for the Selective Anticancer Activity of Doxorubicin

An efficient doxorubicin (DOX) drug delivery system with specificity against tumor cells was developed, based on multi-walled carbon nanotubes (MWCNTs) functionalized with guanidinylated dendritic molecular transporters. Acid-treated MWCNTs (oxCNTs) interacted both electrostatically and through hydrogen bonding and van der Waals attraction forces with guanidinylated derivatives of 5000 and 25,000 Da molecular weight hyperbranched polyethyleneimine (GPEI5K and GPEI25K). Chemical characterization of these GPEI-functionalized oxCNTs revealed successful decoration with GPEIs all over the oxCNTs sidewalls, which, due to the presence of guanidinium groups, gave them aqueous compatibility and, thus, exceptional colloidal stability. These GPEI-functionalized CNTs were subsequently loaded with DOX for selective anticancer activity, yielding systems of high DOX loading, up to 99.5% encapsulation efficiency, while the DOX-loaded systems exhibited pH-triggered release and higher therapeutic efficacy compared to that of free DOX. Most importantly, the oxCNTs@GPEI5K-DOX system caused high and selective toxicity against cancer cells in a non-apoptotic, fast and catastrophic manner that cancer cells cannot recover from. Therefore, the oxCNTs@GPEI5K nanocarrier was found to be a potent and efficient nanoscale DOX delivery system, exhibiting high selectivity against cancerous cells, thus constituting a promising candidate for cancer therapy.

A phase I/II study of docetaxel in combination with pegylated liposomal doxorubicin in metastatic castration-resistant prostate cancer

Taxanes and anthracyclines have been among the best-studied chemotherapy classes in castration-resistant prostate cancer (CRPC). Docetaxel (D) 75 mg/m² every 3 weeks has been the standard first line chemotherapy for CRPC. Encapsulation of doxorubicin in polyethylene glycol-coated liposomes (PLD) was developed to enhance the safety and efficacy of conventional doxorubicin. We hypothesize that the combination of weekly low dose-D and PLD would result in a high response rate and low toxicity. Eligibility criteria included metastatic progressive CRPC, no prior D or PLD and good organ function. After a short phase I with no dose-limiting toxicity, D 30 mg/m² was administered on days 1, 8 and 15; and PLD 30 mg/m² on day 1 only, every 28 days. Thirty-seven patients were enrolled. The PSA response rate was 53%. Twenty-two subjects had measurable disease; one (5%) achieved complete response, five (23%) partial response, and twelve (54%) stable disease. Twenty-seven patients (73%) manifested pain relief. The median time to progression was 3.7 months for all patients and 7.9 months for responders. Median overall survival was 16.3 months. Grade 4 neutropenia without infection and anemia occurred in 1 patient each. Grade 3 treatment-related toxicities included: 15% fatigue; 9% neutropenia, anemia and nausea; 6% dehydration and hand-foot syndrome; and 3% infection, febrile neutropenia, thrombosis, stomatitis, headache, vomiting, weight loss and weakness. In this non-comparative study D-PLD demonstrated a higher activity than previously reported with single agent D with favorable side effect profile. A phase 3 study would be needed to evaluate the true benefit of this combination.ClinicalTrials.gov Identifier: NCT00456989.

A combination drug delivery system employing thermosensitive liposomes for enhanced cell penetration and improved in vitro efficacy

Drug-loaded thermosensitive liposomes are investigated as drug delivery systems in combination with local mild hyperthermia therapy due to their capacity to release their cargo at a specific temperature range (40-42 °C). Additional benefit can be achieved by the development of such systems that combine two different anticancer drugs, have cell penetration properties and, when heated, release their drug payload in a controlled fashion. To this end, liposomes were developed incorporating at low concentration (5 mol%) a number of monoalkylether phosphatidylcholine lipids, encompassing the platelet activating factor, PAF, and its analogues that induce thermoresponsiveness and have anticancer biological activity. These thermoresponsive liposomes were efficiently (>90%) loaded with doxorubicin (DOX), and their thermal properties, stability and drug release were investigated both at 37 ^◦C and at elevated temperatures. In vitro studies of the most advantageous liposomal formulation containing the methylated PAF derivative (methyl-PAF, edelfosine), an established antitumor agent, were performed on human prostate cancer cell lines. This system exhibits controlled release of DOX at 40-42 °C, enhanced cell uptake due to the presence of methyl-PAF, and improved cell viability inhibition due to the combined action of both medications.

Weekly Low Dose Epirubicin in Elderly Cancer Patients

Aims and background

The treatment of elderly patients with metastatic solid tumours is still a debated problem. Patients over 75 years are generally excluded from combination chemotherapy trials because of higher toxicity. Several clinical studies have shown that weekly low dose epirubicin is a well tolerated and effective treatment for elderly cancer patients (breast, prostate, lung).

Methods

We report a study of patients aged between 75 and 85 years affected by metastatic anthracyclines-sensible carcinomas, to assess the tolerance of epirubicin given weekly at a dose of 25 mg/m2.

Results

25 patients (13 males, 12 females; ECOG P.S. 0-2) entered the study and were evaluable for side effects. One-hundred and ninety-six cycles of therapy have been administered. Side effects were never severe. Mucositis (9 patients), leucopenia (7 patients), anemia (5 patients) were usually of grade 1 or 2. Grade 1 cardiotoxicity (tachycardia) was observed in only one case. Grade 3 toxicity consisted in anemia (1 patient) and mucositis (1 patient), while grade 4 toxicity never occurred. Nineteen patients were evaluable for response: 0 CR, 4 PR (1 lung, 3 breast), 8 SD (3 lung, 3 breast, 2 prostate) have been observed. Compliance was encouraging and the majority of patients showed a decrease in symptoms and an improvement in performance status.

Conclusions

Weekly low-dose epirubicin is a very well tolerated treatment in elderly cancer patients. In view of the negligible toxicity encountered, it could be of utility to test this regimen in patients aged 75 years or older, affected by anthracyclines-sensible metastatic tumors, also to assess activity.

New NO- and H2S-releasing doxorubicins as targeted therapy against chemoresistance in castration-resistant prostate cancer: in vitro and in vivo evaluations

Chemotherapy for castration-resistant prostate cancer (CRPC) is only temporarily effective due to the onset of chemoresistance. We investigated the efficacy of NO- and H2S-releasing doxorubicins (NitDox and H2SDox) in overcoming drug resistance and evaluated their safety. New and innovative NO- and H₂S-releasing doxorubicins (NitDox and H₂SDox) showed a good intracellular accumulation and high cytotoxic activity in vitro in an androgen-independent and doxorubicin-resistant DU-145 prostate cancer cell line. Nude mice were subcutaneously injected with 4*10⁶ DU-145 cells and treated once a week for 3 weeks with 5 mg/kg doxorubicin, NitDox, H₂SDox or vehicle, i.p. Animal weight, tumor volume, intra-tumoral drug accumulation, apoptosis and the presence of nitrotyrosine and sulfhydryl (SH) groups within the tumor, were evaluated. Cardiotoxicity was assessed by measuring troponin plasma levels and the left ventricular wall thickness. In vivo, NitDox and H₂SDox accumulated inside the tumors, significantly reduced tumor volumes by 60%, increased the percentage of apoptotic cells in both the inner and the outer parts of the tumors and the presence of nitrotyrosine and SH groups. Doxorubicin treatment was associated with reduced body weight and cardiotoxicity. On the contrary, NitDox and H₂SDox were well tolerated and had a better safety profile. Combining efficacy with reduced cardiovascular side effects, NitDox and H₂SDox are promising novel therapeutic agents for reversing chemoresistance in CRCP.

A Triphenylphosphonium-Functionalized Mitochondriotropic Nanocarrier for Efficient Co-Delivery of Doxorubicin and Chloroquine and Enhanced Antineoplastic Activity

Drug delivery systems that target subcellular organelles and, in particular, mitochondria are considered to have great potential in treating disorders that are associated with mitochondrial dysfunction, including cancer or neurodegenerative diseases. To this end, a novel hyperbranched mitochondriotropic nanocarrier was developed for the efficient co-delivery of two different (both in chemical and pharmacological terms) bioactive compounds. The carrier is based on hyperbranched poly(ethyleneimine) functionalized with triphenylphosphonium groups that forms ~100 nm diameter nanoparticles in aqueous media and can encapsulate doxorubicin (DOX), a well-known anti-cancer drug, and chloroquine (CQ), a known chemosensitizer with arising potential in anticancer medication. The anticancer activity of this system against two aggressive DOX-resistant human prostate adenocarcinoma cell lines and in in vivo animal studies was assessed. The co-administration of encapsulated DOX and CQ leads to improved cell proliferation inhibition at extremely low DOX concentrations (0.25 μΜ). In vivo experiments against DU145 human prostate cancer cells grafted on immunodeficient mice resulted in tumor growth arrest during the three-week administration period and no pervasive side effects. The findings put forward the potential of such targeted low dose combination treatments as a therapeutic scheme with minimal adverse effects.

Doxorubicin Conjugated to Immunomodulatory Anticancer Lactoferrin Displays Improved Cytotoxicity Overcoming Prostate Cancer Chemo resistance and Inhibits Tumour Development in TRAMP Mice

Advanced, metastatic, castration resistant and chemo-resistant prostate cancer has triggered change in the drug development landscape against prostate cancer. Bovine lactoferrin (bLf) is currently attracting attention in clinics for its anti-cancer properties and proven safety profile. bLf internalises into cancer cells via receptor mediated endocytosis, boosts immunity and complements chemotherapy. We employed bLf as an excellent functional carrier protein for delivering doxorubicin (Dox) into DU145 cells, CD44+/EpCAM+ double positive enriched DU145 3D prostaspheres and drug resistant ADR1000-DU145 cells, thus circumventing Dox efflux, to overcome chemo-resistance. Successful bLf-Dox conjugation with iron free or iron saturated bLf forms did not affect the integrity and functionality of bLf and Dox. bLf-Dox internalised into DU145 cells within 6 h, enhanced nuclear Dox retention up to 24 h, and proved significantly effective (p < 0.001) in reducing LC₅₀ value of Dox from 5.3 μM to 1.3 μM (4 fold). Orally fed iron saturated bLf-Dox inhibited tumour development, prolonged survival, reduced Dox induced general toxicity, cardiotoxicity, neurotoxicity in TRAMP mice and upregulated serum levels of anti-cancer molecules TNF-α, IFN-γ, CCL4 and CCL17. The study identifies promising potential of a novel and safer bLf-Dox conjugate containing a conventional cytotoxic drug along with bLf protein to target drug resistance.

Treatment of hormone-refractory prostate cancer

Objective. An increasing number of patients with prostate cancer develop hormone-refractory disease after standard treatment modalities. In these patients, early clinical trials with chemotherapy produced disappointing response rates. However, clinical trials that employ response criteria such as prostate-specific antigen (PSA) and clinical benefit response have produced encouraging responses. This article reviews current and future treatment options for the management of hormone-refractory prostate cancer.

Data Sources. A MEDLINE search for the years 1978 to 1998 was completed. The following terms were used in our search: prostate cancer, hormone-refractory, treatment, and chemotherapy. Relevant articles referenced in the literature obtained in our MEDLINE search were reviewed.

Study Selection. Randomized and nonrandomized clinical trials were used in our review. Clinical trials using prostate-specific antigen or a palliation of symptoms as primary criteria for response were given priority.

Data Synthesis. Several genetic alterations, including the overexpression of bcl-2 or mutations in p53, may lead to the development of hormone-refractory prostate cancer. Agents such as estramustine and taxanes, which affect microtubule function and potentially modulate bcl-2, appear to be particularly active in the treatment of hormone-refractory prostate cancer. In addition, mitoxantrone as well as other agents has been shown to be beneficial in improving the quality of life in patients with hormone-refractory prostate cancer.

Conclusion. Hormone-refractory prostate cancer is not a chemotherapy-resistant disease as once believed; significant progress in the treatment of hormone-refractory prostate cancer has been made with new combinations of chemotherapy agents. Promising new treatments are currently under evaluation to assess their potential benefit over the standard treatment modalities that are currently available.

Salvage chemotherapy for hormone-refractory prostate cancer: Association of Adriamycin and ifosfamide

Prostate carcinoma is the most common cancer in men. Hormone-resistance is the natural history of this metastatic disease and requires the use of docetaxel as the standard chemotherapy. At present, there is no approved second-line treatment. Here, we report a combination of treatment with Adriamycin and ifosfamide in a series of 7 relatively young patients with an average age of 57 years at the time of diagnosis. Chemotherapy was administered over 3 days with the following schedule: 20 mg/m(2) Adriamycin per day and 1-1.5 mg/m(2) ifosfamide per day, in association with Uromitexan. Treatment was repeated every 3 weeks. Three biological responses, one CT scan response, one bone scan response and two CT scan stabilizations, were obtained. Mean survival following this combination was 6.6 months, and over 26 months after first-line chemotherapy. Tolerance was good with the use of granulocyte-colony stimulating factors. Our observations clearly show that the use of this type of salvage therapy for relatively young patients in good physical condition should be further assessed in a clinical trial, particularly when different lines of chemotherapy are required.

COOPERATIVE GROUP TRIALS - SOUTHWEST ONCOLOGY GROUP (SWOG) INNOVATIONS IN ADVANCED PROSTATE CANCER

The major goals of the SWOG-GU committee in the area of advanced prostate cancer are to improve the survival and quality of life of patients with advanced prostate cancer. SWOG trials have examined the role of combined androgen blockade, intermittent androgen deprivation, and the early application of chemotherapy in castration-naïve disease. In addition, they have contributed to advancing the current chemotherapy standard of docetaxel plus prednisone, and ongoing trials seek to improve upon that standard. Finally, surrogate endpoints have been identified and markers of treatment response or resistance with novel technology are under active investigation. This review highlights findings from recent SWOG clinical trials for advanced prostate cancer, emphasizing the clinical impact and future applications of the data.

The role of doxorubicin and epirubicin in the treatment of patients with metastatic hormone-refractory prostate cancer

Advanced hormone-refractory prostate cancer (HRPC) is characterized by prevalently osteoblastic bone metastases which are what mostly affect these patients' quality of life and make the assessment of response to treatment particularly difficult by commonly used criteria. HRPC cannot be cured by any available therapeutic option, and chemotherapy has to be still considered as a palliative treatment. The anthracyclines doxorubicin (Dox) and epirubicin (Epi), alone or in combination with other agents, have been extensively used in the treatment of HRPC, but controversial results have been reported. The majority of reviewed studies reported a pain reduction in >50% of patients receiving Dox or Epi, suggesting a substantial palliative effect by their use in metastatic HRPC. The weekly schedule of anthracyclines seemed to achieve similar results to the 3-weekly schedule but with a better toxicity profile. Although the toxic adverse effects were usually manageable when anthracyclines were combined with other agents, toxicity was severe by a number of aggressive regimens. Docetaxel is today approved for the treatment of HRPC, and must be considered the standard platform on which new agents may be combined. Given that HRPC includes a heterogeneous group of patients with variable rates of tumour growth, the combination of docetaxel with active agents such as anthracyclines may deserve further clinical investigation.

A phase I pharmacodynamic trial of bortezomib in combination with doxorubicin in patients with advanced cancer

PURPOSE

This phase I trial sought to define the toxicity, maximally tolerated dose (MTD) and pharmacodynamics of a combination of bortezomib and doxorubicin in patients with advanced malignancies.

PATIENTS AND METHODS

Twenty-six patients were treated with bortezomib intravenously on days 1, 4, 8 and 11, with doxorubicin also administered intravenously on days 1 and 8, both in a 21-day cycle. Dosing ranged from 1.0 mg/m(2) of bortezomib with 15 mg/m(2) of doxorubicin to 1.5 mg/m(2) of bortezomib with 20 mg/m(2) of doxorubicin. Pharmacodynamic studies performed included assessment of levels of 20S proteasome activity and ubiquitin-protein conjugates.

RESULTS

The combination of bortezomib and doxorubicin was generally well tolerated. There were two dose limiting toxicities (DLT) at dose cohort 3 (1.3 mg/m(2) bortezomib, 20 mg/m(2) doxorubicin) and 2 DLT at dose cohort 3a (1.5 mg/m(2) bortezomib, 15 mg/m(2) doxorubicin). DLT seen included neutropenia, thrombocytopenia, and neuropathy. In addition, one patient developed grade 3 central nervous system toxicity in cycle 2 (not a DLT). One patient with hormone refractory prostate cancer had a partial response. Proteasome inhibition in whole blood was demonstrated and an increase in ubiquitin-protein conjugates was observed in peripheral blood mononuclear cells of most patients.

CONCLUSIONS

Bortezomib and doxorubicin can be administered safely. The recommended phase II dose for this 21-day cycle is bortezomib 1.3 mg/m(2 )intravenously on days 1, 4, 8 and 11, and doxorubicin 20 mg/m(2) intravenously on days 1 and 8. This combination may be of special interest in multiple myeloma, given the activity of both drugs in that disease.

Vinorelbine, doxorubicin, and prednisone in androgen-independent prostate cancer

BACKGROUND

Ultimately, patients with metastatic prostate cancer progress on androgen ablation therapy. The investigation of new chemotherapeutic regimens for the treatment of androgen-independent prostate cancer (AIPC) is essential. The authors conducted a Phase II trial with vinorelbine, doxorubicin, and daily prednisone (NAP) to investigate the antitumor activity and palliative response of this regimen in patients with AIPC.

METHODS

Forty-six patients entered this Phase II combination chemotherapy trial. Patients were treated with both vinorelbine and doxorubicin at doses of 20 mg/m2 on Days 1, 8, and 15 every 28 days and prednisone 5 mg twice daily. Endpoints included prostate-specific antigen (PSA) response and palliation, as measured by the Functional Assessment of Cancer Therapy-Prostate (FACT-P) instrument, the Brief Pain Inventory Scale, and a narcotic analgesic log.

RESULTS

The median follow-up for all 46 patients was 13.4 months. Fifty-two percent of patients had impaired performance status at baseline. One responding patient remained on NAP and was progression-free at 11.5 months. Thirty-nine patients progressed, 3 patients died prior to response assessment, and 3 patients refused therapy. The median overall survival was 57 weeks (95% confidence interval [95% CI], 36-76 weeks), and the median time to disease progression was 17 weeks (range, 11-24 weeks). The PSA response among the 36 patients who completed 3 cycles of NAP was 42% (95% CI, 26-59%). There was a statistically significant improvement in quality of life measured both by the FACT-General instrument (P = .03) and the FACT-P instrument (P = .0006) over the 3 months compared with baseline measurements. Pain medicine use also improved: The median morphine equivalents among patients who were taking pain medications at the time of study enrollment showed a substantial decline after 1 cycle of treatment that was maintained. Pain (as assessed by the Brief Pain Inventory) improved compared with baseline pain at the 2nd-month assessment (worst pain, P = .08; least pain, P = .02; and average pain, P = .003). Overall, the regimen was tolerated well. The most common side effects were mild fatigue and gastrointestinal complaints (all of which were Grade 1 or 2 [according to Version 2.0 of the Expanded Common Toxicity Criteria]). Seventeen patients (37%) experienced Grade 3 or 4 neutropenia. Five patients (11%) developed a cardiac ejection fraction of <50% during treatment and had doxorubicin discontinued. No patients developed clinical congestive heart failure.

CONCLUSIONS

The NAP combination produced substantive palliation and a moderate response rate in men with AIPC.

Combination of LHRH analog with somatostatin analog and dexamethasone versus chemotherapy in hormone-refractory prostate cancer: a randomized phase II study

OBJECTIVES

To evaluate prospectively the combination of a luteinizing hormone-releasing hormone analog with a somatostatin analog and dexamethasone in patients with hormone-refractory prostate cancer (HRPC) in a randomized Phase II study. HRPC presents a challenging therapeutic problem. Salvage chemotherapy is the usual approach at this stage of the disease. The combination of a luteinizing hormone-releasing hormone analog with a somatostatin analog and dexamethasone has produced objective clinical responses in HRPC.

METHODS

Forty patients with HRPC were randomized to receive one of two treatments. Group 1 underwent chemotherapy (estramustine 140 mg three times daily and etoposide 100 mg orally for 21 days) and group 2 the combination of a somatostatin analog (lanreotide 30 mg intramuscularly every 14 days) and dexamethasone (4 mg tapered to 1 mg), in addition to androgen ablation by orchiectomy or a luteinizing hormone-releasing hormone analog (triptorelin 3.75 mg intramuscularly every 28 days). The clinical and prostate-specific antigen (PSA) response, overall survival, time to progression, and toxicity were compared between the two groups.

RESULTS

The data of 20 patients in group 1 and 18 in group 2 were analyzed. The demographic and clinical data were similar in the two groups at study entry. A PSA response (decrease of greater than 50%) was observed in 45% of group 1 and 44% of group 2. The difference was not statistically significant. A partial clinical response was observed in 29% and 30% of groups 1 and 2, respectively. Again, the difference was not statistically significant. Changes in performance status and pain score during treatment were not significantly different in the two groups. Hematologic toxicity was more frequent in group 1 (80% of patients), and mild diabetes was more frequent in group 2 (22% of patients). The overall survival was 18.8 months in group 1 and 18 months in group 2 (not statistically significant). The time to progression was 6 versus 4 months and, in the PSA responder subgroup, it was 8 versus 7.7 months in groups 1 and 2, respectively (neither difference was statistically significant).

CONCLUSIONS

The results of our randomized Phase II study indicated that the new combination treatment (luteinizing hormone-releasing hormone analog, somatostatin analog, and dexamethasone) may be equally effective as salvage chemotherapy in patients with HRPC in terms of the clinical and PSA response, overall survival, and time to progression. A larger prospective Phase III trial is required to confirm our observations.

Prostate cancer and bone metastases: medical treatment

Prostate cancer is the most common malignancy in men in the United States. With the long natural history of the disease, management of skeletal morbidity related to advanced prostate cancer becomes a major public health issue. The standard of care in advanced prostate cancer is androgen deprivation therapy. This may accelerate the development of osteoporosis and further exacerbate the risks of having adverse skeletal-related events develop. Recently, the use of bisphosphonates in men who have not responded to androgen deprivation therapy has been shown to reduce the incidence of skeletal-related events with time. Questions remain as to whether bisphosphonates should be broadly applied to earlier stages of the disease or tailored to men at higher risk of having bone-related morbidity. Work is ongoing to improve other approaches to the medical treatment of bone metastases in patients with advanced prostate cancer including the use of radiopharmaceuticals and combined chemotherapy.

A Phase I/II study of strontium-89 combined with gemcitabine in the treatment of patients with androgen independent prostate carcinoma and bone metastases

BACKGROUND

The objectives of the current study were to determine the maximum tolerated dose and to evaluate the efficacy of gemcitabine given in combination with strontium-89 to patients with androgen independent prostate carcinoma.

METHODS

Patients with androgen-independent prostate carcinoma and painful osteoblastic bone metastases were eligible. On a 12-week course, patients received gemcitabine (600 mg/m(2) or 800 mg/m(2)) on Days 1, 8, 15, 43, 50, and 57. A single dose of strontium-89 (55 microCi/kg) was administered on Day 8.

RESULTS

Fifteen patients were registered, and all were assessable for response and toxicity. Four patients were treated at Dose Level 1 (gemcitabine 600 mg/m(2)) without dose-limiting toxicity. Eleven patients received a total of 13 courses at Dose Level 2 (gemcitabine 800 mg/m(2)). Platelet nadirs of 25000-50000 platelets per microL were common at Dose Level 2, and 1 patient had Grade 4 thrombocytopenia that was dose-limiting. Granulocyte nadirs up to < 500 granulocytes per microL occurred in 4 patients at Dose Level 2 and were reversible. There were no responses, as measured by prostate specific antigen concentration, although 6 patients (40%) had stable disease.

CONCLUSIONS

The authors concluded that 800 mg/m(2) gemcitabine was the maximum tolerated dose for the combination. The study was terminated on the basis that an overall response rate > than 10% was unlikely. Further study at this dose level and schedule is not warranted. .

State-of-the-art treatment of metastatic hormone-refractory prostate cancer

Initial therapy for advanced prostate cancer includes androgen ablation by surgical or medical castration. Still, nearly all men with metastases will progress to hormone-refractory prostate cancer (HRPC). Current U.S. Food and Drug Administration-approved agents for the treatment of HRPC include mitoxantrone and estramustine, although the vinca alkaloids and the taxanes have shown promising activity in single-agent phase II trials. Combinations of these agents induce a biochemical response in greater than 50% of patients, but the median duration of response is approximately 6 months. Overall survival of patients treated with these combinations is approximately 18-24 months. Studies are ongoing to develop novel therapies that target specific molecular pathways or mechanisms of chemotherapy resistance. Novel agents under development include growth factor receptor inhibitors, antisense oligonucleotides, bisphosphonates, and cell differentiating agents. Evaluation and incorporation of these agents into existing treatment regimens will guide us in the development of more active regimens in the treatment of HRPC.

Weekly epirubicin in patients with hormone-resistant prostate cancer

The aim of this study was to investigate the benefit of weekly epirubicin in the treatment of metastatic hormone-resistant prostate cancer. One hundred and forty-eight patients with metastatic hormone-resistant prostate cancer received weekly 30-min intravenous infusions of epirubicin 30 mg m(2) of body surface area. The primary end-point was palliative response, defined as a reduction in pain intensity and an improvement in performance status. The secondary end-points were the duration of the palliative response, quality of life and survival. Fifty-seven (44%) of the 131 evaluable patients met the primary criterion of palliative response after six treatment cycles and 73 (56%) after 12 cycles; the median duration of the response was 9 months (range 1-11). The median global quality of life improved in 52% of the patients after six cycles and in 68% after 12 cycles. The 12- and 18-month survival rates were respectively 56 and 31%, with a median survival of 13+ months (range 1-36). The treatment was well tolerated: grade 3 neutropenia was observed in 8% of the patients, grade 3 anaemia in 7%, and grade 3 thrombocytopenia in 3%. None of the patients developed grade 4 toxicity or congestive heart failure. Weekly epirubicin chemotherapy can lead to a rapid and lasting palliative result in patients with metastatic HRPC, and have a positive effect on the quality of life and survival.

Liposomal Doxorubicin for the Treatment of Hormone-Refractory Prostate Cancer

There is a pressing need for new agents to treat hormone-refractory prostate cancer (HRPC). Doxorubicin has shown modest activity in this setting, but its use is limited by its toxicities. Liposomal encapsulation of doxorubicin appears to promote enhanced tumor accumulation in some tumor types, and toxicity appears to be reduced. A phase II trial of liposomal doxorubicin was therefore conducted in patients with HRPC. Fourteen patients with progressive HRPC were treated. For the first dose only, patients were randomized to receive either doxorubicin 50 mg/m2 or liposomal doxorubicin 50 mg/m2 in order to evaluate exploratory pharmacokinetics. For all subsequent cycles, all patients received liposomal doxorubicin 50 mg/m2. Response to therapy was assessed with serial measurements of serum prostate-specific antigen (PSA) and sequential imaging studies. All 14 patients were evaluable for response and toxicity. Two patients (14%) had declines in serum PSA of > or = 50%. The first patient had a baseline PSA of 34.7 ng/mL and a nadir of 17.0 ng/mL. The second patient had a baseline PSA of 5580.0 ng/mL and a nadir of 200.7 ng/mL. The latter of these 2 patients had an unambiguous improvement in bone scan and a reduction in pain. Treatment was well tolerated overall. One patient was removed from treatment after the development of a grade 3 infusion reaction with the first cycle of liposomal doxorubicin. Neutropenia was the most common toxicity; in only 1 case was it grade 3, and no cases of grade 4 were seen. Doxorubicin plasma concentrations were best fit by a linear, two-compartment model. Liposomal doxorubicin plasma concentrations were best fit by a linear, one-compartment model. Treatment with liposomal doxorubicin was well tolerated overall. While monotherapy with liposomal doxorubicin has only modest activity in the treatment of HRPC, it may be of interest to study this agent as part of combination chemotherapy.

Treatment options in hormone-refractory prostate cancer: current and future approaches

Prostate cancer is the second leading cause of cancer mortality among men in Western countries. The initial treatment of advanced prostate cancer is suppression of testicular androgen production by medical or surgical castration, but nearly all men with metastases will develop disease progression. Patients with hormone refractory prostate cancer (HRPC) have a median survival of approximately 18 months and no therapy has yet demonstrated a definitive survival advantage. However, in the past several years, a number of promising new treatment strategies have emerged. One of the most important new treatment strategies involves secondary hormonal manipulation after the failure of primary androgen deprivation. This approach is predicated on the recognition that HRPC is a heterogeneous disease and some patients may respond to alternative hormonal interventions despite the presence of castrate levels of testosterone. Until recently, cytotoxic chemotherapy was felt to be relatively ineffective in the treatment of HRPC. Combination regimens incorporating new active agents have demonstrated significant activity in this setting, renewing interest in the use of chemotherapy to treat HRPC. Recent advances in the understanding of prostate cancer biology have led to the development of drugs directed against precise molecular alterations in the prostate tumour cell. Biologic agents now in development include those capable of altering signal transduction, blocking angiogenesis, inhibiting cell cycle progression, and stimulating apoptosis. In addition, many types of immune therapies are showing promise. Evaluating these agents, and incorporating them into existing regimens, are major goals of ongoing clinical research in advanced prostate cancer.

Progressing prostate carcinoma

In the Karnell Cancer Center Grand Rounds, we present a patient who underwent radical prostatectomy with bilateral pelvic lymphadenectomy, but had positive margins and subsequently developed local recurrence and then systemic disease. Pathologic and radiologic aspects of his disease are discussed. Therapeutic options at different stages of the disease are examined from the point of view of the urologist, radiation oncologist, and medical oncologist. The surgical portion of the discussion focuses on the selection of initial therapy. Both the selection of surgical candidates and choice of pre- or post-operative therapy in patients can be aided by prognostic tools looking at several variables, including prostate-specific antigen (PSA) level, Gleason score of the tumor, seminal vesicle invasion, extracapsular invasion, and lymph node involvement. Low-risk patients can be treated with monotherapy, such as radical prostatectomy, external beam radiation therapy, prostate brachytherapy, or cryosurgical ablation of the prostate. Higher risk patients may require adjuvant and possibly neoadjuvant therapy in addition. The radiation portion of the discussion focuses on the use of radiation therapy as salvage for relapsing disease. Of particular importance is the point that treating high-risk patients whose PSA levels have started to rise but are less than 1 ng/ml results in a long-term PSA control rate as high as 75%, but that limiting the use of salvage radiation therapy to patients with high PSA levels or biopsy confirmation of local recurrence in the face of a negative bone scan results in biochemical long-term control of less than 40%. In the medical oncology part of the discussion, the major focus is on the use of chemotherapy to treat patients whose disease has become resistant to hormonal therapy. Mitoxantrone plus a corticosteroid has been found to offer significant palliation for such patients. Combination therapy with estramustine plus taxanes, other microtubule inhibitors, or other agents such as topoisomerase II inhibitors, has been found to cause shrinkage of measurable soft tissue disease and diminution of serum PSA levels. The development of effective hormonal and chemotherapeutic drugs for treatment of metastatic disease has led to new interest in adjuvant and neoadjuvant therapy of high-risk patients.

Phase II evaluation of menogaril in advanced prostate cancer: Eastern Cooperative Oncology Group EST P-A885

Menogaril is a semisynthetic anthracycline that is less cardiotoxic than doxorubicin in a preclinical model. We conducted a phase II trial to determine the activity of menogaril in hormone-refractory prostate cancer. Between October 1985 and November 1987, 32 eligible patients were enrolled and were divided into good- and poor-risk categories, the latter being defined by prior radiotherapy to less than one third of the marrow-containing skeleton. Good-risk patients received a starting dose of 200 mg/m2 by 60-minute IV infusion, whereas the poor-risk patients received 160 mg/m2. Treatment was repeated every 3 weeks until disease progression. Menogaril caused leukopenia in 90% of patients, of whom 47% had grade III or IV toxicity. Thrombocytopenia was uncommon and mild, with only three patients (9%) experiencing grade II toxicity. Nonhematologic toxicity included mucositis (9%), and mild weight loss in 33% of patients. Nine patients (28%) had stable disease of 3 or more months' duration. There were no objective partial or complete responses. The median time to progression for the entire group was 10 weeks, and the median survival time for all patients was 24 weeks. Because of appreciable toxicity and limited antitumor activity, further study of menogaril cannot be recommended in hormone-refractory prostate cancer.

Phase II pilot study of combined chemohormonal therapy with doxorubicin and estramustine in metastatic prostate cancer

Twenty-nine patients with progressive hormone-refractory metastatic adenocarcinoma of the prostate were treated with daily estramustine phosphate at 10 mg/kg, and I.V. doxorubicin 50 mg/m2 every 3 weeks. Twenty-six patients were evaluable. Four of seven patients with nonosseous measurable disease had partial responses lasting 3 to 10 months. Eleven of 19 patients with osseous metastases had stable disease or improvement on bone scan, 6 of these for 7 months or longer. Median time to progression was 20 weeks, and the median survival was 43 weeks.

Combination of epirubicin and cisplatin in hormone-refractory metastatic prostate cancer

Anthracyclines and cisplatin have been shown separately to have modest activity in prostate cancer. The synergism between anthracyclines and cisplatin, with the lack of overlapping toxicities, led to the conduct of this phase II trial of the combination of epirubicin and cisplatin in hormone-refractory metastatic prostate cancer. Twenty-one evaluable patients with hormone-refractory metastatic prostate cancer received epirubicin 100 mg/m2 followed by cisplatin 80 mg/m2 with prehydration and mannitol diuresis. Epirubicin and cisplatin produced a biochemical response (>50% decrease in tumor marker) in 32% of patients, symptomatic improvement in 38%, and a response in measurable and evaluable disease sites in 14%. Toxicities were mainly hematologic, with 77% and 41% >grade 2 neutropenia and thrombocytopenia, respectively. Greater than grade 2 toxicities were: cardiac (three), renal secondary to sepsis (one), nausea and vomiting (two), weakness (one), mucositis (one), and diarrhea (one). The combination of epirubicin and cisplatin was associated with manageable toxicities in this elderly population; however, antitumor activity was marginal in this disease. Participation in clinical trials should continue to be offered to patients with hormone-refractory metastatic prostate cancer.

Phase II trial of circadian infusion floxuridine (FUDR) in hormone refractory metastatic prostate cancer

Circadian administration of chemotherapy has been reported to decrease toxicity and possibly enhance efficacy. Between March 1991 and December 1993, 18 evaluable patients with progressive, hormone-refractory metastatic prostate cancer were treated in this phase II trial of circadian infusion floxuridine (FUDR). The drug was delivered through a central venous catheter using a CADD-Plus computerized pump such that approximately 70% of the drug was administered between 3 and 9 p.m. and the rest (30%) was administered between 9 p.m. and 3 p.m. The dose of FUDR was 0.15 mg/kg/day x 14 days every 4 weeks. A total of 79 complete cycles was administered. Two of 18 evaluable patients (11.1%) had decreases in PSA lasting five and eight months. No objective responses or improvement in bone scans was noted. The major toxicity observed was diarrhea. Although circadian infusion FUDR is feasible and tolerable, it has limited activity in hormone refractory prostate cancer.

Chemotherapy for hormone refractory prostate cancer

New combinations have been developed that show significant activity in therapy for hormone refractory prostate cancer. Several of these are designed to address specific cellular targets unique to prostate cancer. To date, the major benefits of these therapies have been palliative in nature, resulting in an improvement in quality of life, particularly with the combination of mitoxantrone and prednisone. None of these agents or regimens have been shown to affect survival significantly, and none can be considered to be standard therapy for this disease. Nonetheless, the success of these regimens in inducing response has challenged the skepticism concerning the appropriateness of chemotherapy for patients with advanced prostate cancer. The ability to slow and even reverse the growth of far advanced disease raises the possibility that the application of these regimens earlier in the course of the disease will have a more significant impact on the morbidity and, in the long run, on the mortality of prostate cancer. It is hoped that the enrollment of patients into properly designed clinical trials of new agents and combinations will result in the development of therapy with proven efficacy in the near future.

Management of Hormone-Sensitive and Hormone-Refractory Metastatic Prostate Cancer

BACKGROUND: Prostate cancer is a significant health problem in the United States and is the focus of increasing attention in our society. With the aging of the US population, it is likely that prostate cancer will continue to grow in importance. The options for systemic therapy of metastatic prostate cancer should be familiar to physicians, including nonspecialists, whose patients seek their advice and counsel. METHODS: Past and recent literature was surveyed to provide an understanding of the systemic treatment of advanced prostate cancer. The author presents a review of the systemic treatment of metastatic prostate cancer in different clinical circumstances and addresses the current status of chemotherapy in the management of advanced prostate cancer. RESULTS: Early androgen deprivation used over prolonged periods appears to be modestly superior to delayed androgen deprivation with a small potential survival advantage and an advantage in delaying disease progression in advanced prostate cancer. Patients with hormone-refractory prostate cancer may benefit from secondary hormonal therapy (eg, adrenal enzyme inhibitors, antiandrogens, glucocorticoids) and chemotherapy. CONCLUSIONS: The choices of therapy for metastatic prostate cancer depend on individual patient preference. Patients and physicians should be aware of the possible side effects associated with the therapeutics options for treatment of metastatic prostate cancer.

Evaluation of estramustine phosphate combined with weekly doxorubicin in patients with androgen-independent prostate cancer

Thirty-one patients with progressive metastatic prostate cancer refractory to first- or second-line hormonal therapy were treated with a combination of daily oral estramustine phosphate (600 mg) and weekly intravenous doxorubicin (20 mg/m2). Eighteen (58%) patients demonstrated a biologic response with a 50% or more serum prostate-specific antigen decline. The median duration of biologic response was three months. Five (45%) of the 11 patients with measurable lesions achieved a partial response in liver or retroperitoneal lymph nodes. The median duration of these objective responses was four months. Of 22 patients who required analgesics at the onset of the study, six (27%) achieved a significant reduction of pain. The combination of doxorubicin and estramustine phosphate was tolerated on an outpatient schedule. The occurrence of severe toxicities required suspension of therapy in six patients. At the end of the observation time, all patients but one had died, 29 of progressive prostatic cancer and one of toxicity. The median survival time from the onset of chemotherapy was 12 months. The administration of weekly doxorubicin with phosphate estramustine appears to be a safe combination for those patients with hormone-resistant prostate cancer who require chemotherapy. The benefit of chemotherapy should be investigated using relevant quality-of-life criteria in future trials.

Evolving strategies of cytotoxic chemotherapy for advanced prostate cancer

Despite the use of cytotoxic chemotherapy for advanced prostate cancer for half a century, its clinical utility in this setting remains undefined. Based on traditional methods of assessment, the list of the most active cytotoxic agents includes cyclophosphamide, doxorubicin, mitoxantrone and cisplatin. With the introduction of more structured methods of assessment, including careful assessment of indices of quality of life and serial measurement of serum prostate-specific antigen (PSA), the role of cytotoxic agents is being re-assessed. In view of the cell cycle characteristics of prostate cancer, there appears to be an emerging role for combination inhibitors of mitosis, including estramustine in combination with the vinca alkaloids, etoposide or paclitaxel.

Is "off-protocol" chemotherapy for androgen-independent carcinoma of prostate warranted?

It is acceptable to treat HRPC patients with off-protocol chemotherapy if these patients do not accept protocol therapy or are ineligible for such therapy. The choice of cytotoxic agent needs to be individually assessed, depending on range of tolerable toxicities and personal preferences of the physician and patient. At the present time, single-agent therapy with oral or intravenous cyclophosphamide or mitoxantrone/prednisone may offer optimal palliation without undue side effects in a predictable number of patients.

Treatment of Androgen-Independent Prostate Cancer

Androgen-ablative therapy for metastatic prostate cancer is effective for 60%-80% of men, but its effects are always finite and the majority of men develop androgen-independent disease within two years. Although current therapies for androgen-independent disease have not been shown to impact on survival, recent clinical and laboratory insights offer hope for effective therapy. For instance, recent data indicate that androgen-independent disease may still be dependent on hormonal stimulation, suggesting that hormonally based therapies may provide continued benefit. Chemotherapy, especially with estramustine and etoposide, seems to be an effective combination for a majority of patients. Treatment with suramin had been hampered by its side effects, but new dosing schedules are effectively circumventing toxicity. Radioisotopes such as strontium 89 have been shown to provide effective palliation for a majority of androgen-independent patients. Overall, these and other emerging efforts may be the foundation for therapies that offer hope for a significant survival benefit.

Acute presynaptic inhibition by doxorubicin of negative chrono- and inotropic responses to parasympathetic nerve stimulation in isolated, blood-perfused dog atrium

The clinical use of doxorubicin, an anthracycline antineoplastic agent, is limited by its cardiotoxicity. Although several previous reports have shown neurotoxic effects of doxorubicin, there is little information about the acute effects of doxorubicin on the autonomic nerve functions in the heart. Accordingly, to evaluate the effects of doxorubicin on the cardiac responses to autonomic nerve activation, we studied the effects of doxorubicin on the negative chrono- and inotropic responses to intracardiac parasympathetic nerve stimulation and acetylcholine (ACh), and the positive chrono- and inotropic responses to norepinephrine (NE) in the isolated, blood-perfused dog atrium. Doxorubicin (0.01-3 mumol), injected into the sinus node artery of the isolated atrium, induced negative inotropic effects dose dependently and weak negative chronotropic effects. Doxorubicin inhibited the negative chrono- and inotropic responses to parasympathetic nerve stimulation dose dependently. However, doxorubicin affected neither the negative chrono- and inotropic responses to ACh nor the positive chrono- and inotropic responses to NE. These results indicate that doxorubicin interacts with neither muscarinic receptors nor beta-adrenoceptors and suggest that doxorubicin inhibits the negative cardiac responses to parasympathetic nerve activation due to the inhibition of ACh release from nerve varicosities in the heart.

Combination adriamycin and suramin induces apoptosis in bcl-2 expressing prostate carcinoma cells

Bcl-2 expression has been associated with progression of prostate cancer from androgen-dependence to androgen-independence and may contribute to the relative drug-resistant phenotype typically observed in androgen-independent prostate cancer. Dunning-G rat prostate cancer cells transfected with a bcl-2 expression vector demonstrated resistance to apoptosis induced by adriamycin and, to a lesser extent, suramin. Use of adriamycin and suramin in combination, however, circumvents this bcl-2 associated drug resistance. Our findings indicate that combination drug actions may induce apoptosis in resistant malignant cell types with defective apoptotic pathways.

Post-therapy change in prostate-specific antigen levels as a clinical trial endpoint in hormone-refractory prostatic cancer: a trial with 10-ethyl-deaza-aminopterin

OBJECTIVES

Serial changes in prostate-specific antigen (PSA) correlate with disease status in all stages of prostatic cancer. For hormone-refractory disease, post-therapy declines of 50% and 80% from baseline are associated with an improved survival. This study sought to evaluate edatrexate, a synthetic antifolate, in hormone-refractory prostatic cancer using post-therapy PSA change as the initial endpoint.

METHODS

Fourteen patients with progression of disease despite castrate levels of testosterone received edatrexate. Serial changes in PSA were monitored and correlated with other parameters of outcome.

RESULTS

Stabilization of a rising PSA level in parallel with clinical stabilization of disease was observed in one patient; disease in all others progressed. Toxic reactions were acceptable.

CONCLUSIONS

With no objective evidence for antitumor activity as assessed by post-therapy PSA changes in any of the patients treated, edatrexate seems a poor candidate for future study. The use of post-therapy PSA change as the initial screening modality allows treatments to be evaluated rapidly in patients without measurable disease. The methodology proposed will require validation in prospective phase III investigations using survival as the endpoint.

Experiences with doxo/epirubicin and medroxyprogesterone acetate (MPA) in prostatic cancer

Maximal androgen blockade (MAB) has been reported to prolong the time to progression and the duration of survival in metastatic prostatic cancer. The addition of epirubicin to MAB in such patients seems to improve the therapeutic results further. The beneficial effect of combining castration with epirubicin in metastatic cases appears questionable. In comparing the time to progression in patients treated with MAB +/- epirubicin versus castration +/- epirubicin or estramustine, many studies reveal similar figures. Whether the results after treatment are actually improved remains controversial. In hormone-refractory cases, medroxyprogesterone acetate (MPA) alone seems superior to estramustine or prednisolone treatment. Combining MPA and epirubicin improves the results, but even if the improvement is of clinical value, it is nonetheless of limited magnitude.

Doxorubicin, mitomycin C and 5-fluorouracil in the treatment of hormone refractory adenocarcinoma of the prostate: a Southwest Oncology Group study

In a Southwest Oncology Group phase II clinical trial, 68 patients with hormone refractory carcinoma of the prostate were treated with a combination of doxorubicin, mitomycin C and 5-fluorouracil. Of the patients 11 were classified as good risk and 57 as poor risk. There were 1 complete and 10 partial remissions for a response rate of 16.2% (exact 95% confidence interval 8.4 to 27.1%). Median survival was 9 months (maximum 14) for good risk patients and 10 months (maximum 42) for poor risk patients. Toxicity was significant with leukopenia identified as dose limiting. Because of the low rate of response and significant toxicity, this regimen cannot be recommended as standard therapy for metastatic hormone refractory prostate cancer.

Weekly chemotherapy in advanced prostatic cancer

This randomised phase II study was performed in order to evaluate the effectiveness of a weekly chemotherapy regimen in advanced prostatic carcinoma patients (stage D2) refractory to hormonal therapy. Seventy-two cases were studied: they were randomised in a 2:1 ratio to receive either epirubicin (30 mg m-2 weekly) or doxorubicin (25 mg m-2 weekly); 48 patients received epirubicin and 24 received doxorubicin. After 12 courses of chemotherapy, the 45 evaluable patients in the epirubicin arm showed a response rate of 37.7% and the 21 evaluable patients in the doxorubicin arm showed a response rate of 33.3% (P = 0.51). Pain intensity, bone and prostatic tumour markers rapidly and significantly decreased in responders. An improvement in physical symptoms, functional conditions and in emotional well-being was observed in the majority of the treated patients. The histological analysis of bone metastases, performed before and after 12 courses of chemotherapy showed a significant reduction in neoplastic invasion and in new bone formation in responders. Cardiac performance worsened in five out of 45 patients and in ten out of 21 during the first 12 courses of epirubicin or doxorubicin respectively (P = 0.014). The median survival was 12.5 months in the epirubicin arm and 8.0 months in the doxorubicin arm (P = 0.042). Our data indicate that in advanced prostatic carcinoma, a weekly epirubicin regimen may give rapid palliative results, similar to that of doxorubicin, but with less side-effects.

Phase II trial and pharmacokinetic assessment of intravenous melphalan in patients with advanced prostate cancer

Alkylating agents have been reported to yield response rates of up to 20% in hormone-refractory prostate cancer. Melphalan was studied in four small trials in which the drug was given orally. In this phase II trial, melphalan (30 mg/m2) was given intravenously every 28 days to 27 patients with hormone-refractory prostate cancer. Pharmacokinetic sampling was performed so as to describe the clearance of melphalan in this population and in an attempt to carry out pharmacodynamic modeling for toxicity and response. Prostate-specific antigen (PSA) was also assessed prospectively. No objective responses to this regimen were documented. The median survival for patients on this trial was 11.5 months. There was no correlation between drug clearance and measured creatinine clearance and no relationship between systemic exposure and toxicity. A decrease of > 50% in serum PSA that was sustained for > 6 weeks was documented in two patients, most notably in one patient who has survived for more than 29 months. Intravenous melphalan is not an active agent in hormone-refractory prostate cancer.

Phase II study of epirubicin in advanced hormone-resistant prostatic carcinoma

Twenty-nine patients with metastatic prostate cancer that had progressed following orchiectomy were treated with intravenous epirubicin 90 mg/m2 every 28 days. Their median age was 71 years (range 49-78) and the median Zubrod scale (WHO score) was 1. Two patients had soft tissue lesions, 20 had bone metastases and 7 had both. Tumour response was assessed according to the National Prostatic Cancer Project criteria. Of 29 patients, 11 (38%) achieved a partial remission. The median duration of response was 6 months and the median survival time of all patients was 9 months (range 2-27). It seemed that treatment with epirubicin was not associated with an increase in survival. Toxicity was moderate and consisted of alopecia and mild nausea/vomiting. There was no significant haematological toxicity and no clinical cardiotoxicity. It was concluded that epirubicin was active in hormone-resistant metastatic prostate cancer in approximately 33% of the patients.

Phase III trial of cyclophosphamide versus cyclophosphamide, doxorubicin, and methotrexate in hormone-refractory prostatic cancer. A Hoosier Oncology Group study

BACKGROUND

Between August 1984 and November 1989, the Hoosier Oncology Group conducted a Phase III study comparing cyclophosphamide (CTX) with cyclophosphamide, doxorubicin, and methotrexate (CAM) in patients with hormone-refractory metastatic prostatic cancer to determine whether the addition of doxorubicin and methotrexate to the cyclophosphamide regimen conferred any survival advantage.

METHODS

One hundred three patients were registered and randomized, 99 were evaluable for response, and all were evaluable for survival results. All had histologically confirmed metastatic prostatic cancer and had not responded to hormonal therapy. Fifty-three patients received CTX alone, and 50 received CAM. Seventy-one patients (69%) had evaluable disease, and 32 (31%) had measurable disease.

RESULTS

There were no complete responses and only four (13%) partial responses in the patients with measurable disease. There was no difference in overall survival time between the two treatment arms in either patients with a Karnofsky performance status (KPS) of 80-100 (median survival, 9.0 versus 9.5 months; P = 0.93) or in those with a KPS of 50-70 (median survival, 5.0 versus 6.0 months; P = 0.51). There was no difference in overall time to progression between the two treatment arms (median time to progression; 4.4 versus 6.2 months; P = 0.07). Toxicity was tolerable in both regimens.

CONCLUSIONS

It was concluded that there was no survival advantage to CAM over CTX alone. New chemotherapeutic agents with greater activity against prostatic cancer must be identified.

Experience with weekly doxorubicin (adriamycin) in hormone-refractory stage D2 prostate cancer

One hundred eleven patients with endocrine-refractory Stage D prostate cancer were treated with weekly administration of 20 mg/m2 body surface area of doxorubicin hydrochloride (Adriamycin). Fifty-seven were part of a randomized study comparing doxorubicin and prednisone to prednisone alone. There were significantly more subjective responders in the doxorubicin group than in the prednisone group (p less than 0.01). The number of patients with evidence of stable disease was also higher during the chemotherapy arm compared with prednisone alone (p = 0.02). Patients taking doxorubicin had a slightly longer period of stable disease than did those taking prednisone (p = 0.08). Overall survival, however, was not prolonged (p = 0.26). Fifty-four patients took part in an open trial and 69 percent responded to treatment. All of these had clinical improvement. Side effects were minimal with cardiotoxicity noted in less than 15 percent among patients with side effects. Over 35 percent had no side effects. Thus single agent, weekly doxorubicin therapy as evaluated in our experience, while well tolerated and of subjective benefit, does not provide the patient with a significant longer progression-free survival or improved overall survival.

The use of adriamycin and its derivatives in the treatment of prostatic cancer

Adriamycin and the other anthracyclines are amongst the most effective cytotoxic agents at the clinician's disposal. At least one of the reasons for their efficacy is the large number of mechanisms by which they can induce potentially lethal damage in a dividing malignant cell. Adriamycin and epirubicin are amongst the more effective agents in advanced hormone-independent prostate cancer. When given in full doses, they produce a reasonable number of objective as well as subjective responses, but the resultant toxicity precludes their use at high dose in many patients. In a number of well-documented studies, lower doses of these agents have yielded useful subjective responses with minimal toxicity.