Zoladex: a sustained-release, monthly luteinizing hormone-releasing hormone analogue for the treatment of advanced prostate cancer.

Zoladex, a sustained-release luteinizing hormone--releasing hormone (LHRH) analogue administered by subcutaneous injection every 28 days, was evaluated at three dose levels in 46 men with untreated advanced prostate cancer. All three Zoladex doses yielded similar endocrinologic effects. After initial transient increases in serum luteinizing hormone, follicle-stimulating hormone, and testosterone concentrations, serum testosterone was suppressed uniformly to castration levels within 22 days. At a median follow-up of 41 weeks, Zoladex had maintained persistent suppression of serum testosterone. Measurements of serum Zoladex levels indicated that release of the drug from the injected depot was sustained over a period of 1 month and that there was no drug accumulation as evaluated over an initial 3-month period. No antibodies to Zoladex were detected. Tumor regression rates and side effects with Zoladex therapy were similar to those reported with daily injections of subcutaneous LHRH therapy. Signs and symptoms consistent with a brief tumor flare after the first injection of the LHRH analogue were noted in eight (17%) of the study entrants. Spinal cord compression was observed in two patients within 1 week from the onset of therapy. Zoladex is considered to be an effective, sustained-release LHRH analogue for the treatment of patients with prostate cancer.

Clodronate. A randomized study in the treatment of cancer-related hypercalcemia.

Malignancy-associated hypercalcemia is a common and recalcitrant problem. Current modes of therapy are often ineffective or prohibitively toxic. Clodronate disodium is a diphosphonate capable of inhibiting bone resorption resulting in a hypocalcemic effect. In this randomized, placebo-controlled study, we investigated the effect of hydration only (Rx-1) vs the effect of hydration plus either intravenously administered clodronate disodium, 4 mg/kg of body weight per day for three days (Rx-2) or intravenously administered clodronate disodium, 12 mg/kg of body weight given once only (Rx-3). By the third day of observation, Rx-2 produced a significant 2.8 mg/dL (0.70 mmol/L) reduction in serum calcium levels, whereas Rx-1 and Rx-3 did not produce a significant hypocalcemic effect when compared with baseline values. There were no toxicities observed. Intravenously administered clodronate appears to be an excellent agent for the acute treatment of malignancy-associated hypercalcemia.

Maintenance etidronate in the prevention of malignancy-associated hypercalcemia.

Normocalcemic patients with cancer who had been successfully treated for an episode of hypercalcemia were enrolled in a randomized, multisite, double-blind, placebo-controlled trial designed to determine the efficacy of maintenance oral etidronate in preventing the recurrence of moderate to severe hypercalcemia (serum calcium level, greater than 11.5 mg/dL [greater than 2.87 mmol/L]). Ten (40%) of 25 etidronate-treated patients and 17 (46%) of 37 placebo-treated patients had recurrence of hypercalcemia within 150 days. Although patients taking etidronate had a longer time to the development of hypercalcemia (median, 55 days vs 28 days), this was not significantly different from the control group. The high attrition rate in this trial from hypercalcemia and other malignancy-related causes represents a major difficulty in conducting studies with agents that may require prolonged administration before producing a therapeutic effect.

Decreased serum phosphate levels after high-dose estrogens in metastatic prostate cancer. Possible implications.

Hypophosphatemia and osteomalacia have been described in patients with metastatic prostate cancer. The mechanism of hypophosphatemia in prostate cancer is not known. A decrease in serum phosphate levels was observed in 16 of 18 patients with metastatic prostate cancer treated with high-dose diethylstilbestrol diphosphate. To determine if the fall in serum phosphate was indeed due to diethylstilbestrol diphosphate, the data from several similar groups of patients treated with chemotherapy and combined chemohormonal therapy that included diethylstilbestrol diphosphate were re-examined. Fifty-eight patients were treated with doxorubicin, doxorubicin plus cis-platinum, doxorubicin plus diethylstilbestrol diphosphate, or diethylstilbestrol diphosphate alone. A significant decrease in serum phosphate levels was seen only in patients treated with diethylstilbestrol diphosphate. Hypophosphatemia and possibly osteomalacia in metastatic prostate cancer may be related to estrogen therapy.

Dynamic studies with 99mTc-HEDP in normal subjects and in patients with bone tumors.

Blood clearance, urinary excretion, and spinal uptake of 99mTc-HEDP have been measured in ten normal control subjects. Blood clearance from 15 min is biexponential. Approximately 70% of the administered activity was excreted in the urine within 6 hr of injection. Spine-to-background ratios rise sequentially with time. Net normal bone uptake rises little after 2 hr and improved visualization of the normal skeleton therafter is due to reduction of blood background activity. In 13 patients with bone tumors, direct measurement of diphosphonate uptake by the tumor-involved and corresponding normal bone showed a continued rise in diphosphonate levels in the tumor-involved bone due to increased metabolic activity.

A clinical comparison of Tc-99m HEDP and Tc-99m MDP in the detection of bone metastases: concise communication.

We have compared bone scintigrams made with Tc-99m-tagged HEDP (1-hydroxyethylidene diphosphonate)and MDP (methylene diphosphonate), the former at 4 hr after injection, the latter at both 2 and 4 hr. In 17 patients with skeletal metastases, there was no significant difference in lesion count or scan quality between the 4-hr images. The tumor-to-bone ratio (T/B) was significantly higher with Tc-HEDP (p less than 0.02). Lesion detection rate and T/B ratios were both lower with Tc-MDP at 2 hr when compared with the 4-hr values for both Tc-HEDP (p less than 0.02, p less than 0.005) and Tc-MDP (p less than 0.02, p less than 0.01). The 4-hr Tc-MDP scan was of significantly higher quality than the 2 hr Tc-MDP scan (p less than 0.01). Although Tc-HEDP produces a higher T/B ratio at 4 hr, the present study does not suggest that either agent is superior in clinical practice.

The use of whole-body retention of Tc-99m diphosphonate in the diagnosis of metabolic bone disease.

The limited role of bone scanning in the diagnosis of metabolic bone disease might be considerably improved by accurate quantification of skeletal uptake of the radiopharmaceutical. Using a standard shadow-shield whole-body monitor, we have measured whole-body retention (WBR) of Tc-99m HEDP up to 24 hr in 11 patients with renal osteodystrophy (mean WBR 88.6% at 24 hr); in ten patients with Paget's disease (mean 56.9%); in seven patients with osteomalacia (mean 40.7%); in five patients with primary hyperparathyroidism (mean 50.7%); in four patients with osteoporosis (mean 21.2%); and in 12 normals (mean 19.2%). The osteoporotic group could not be differentiated from the normal group, but the other groups were significantly different from the normal group at 24 hr (p less than 0.002), and each individual rest for the 24-hr WBR of Tc-99m HEDP in these groups lay outside our normal range. This test may, therefore, provide a sensitive means of detecting conditions with increased bone turnover. We obtained measurements of plasma activity of Tc-99m HEDP in these patients up to 24 hr, and 4-hr bone to soft-tissue ratios from bonescan images, but little additional information resulted.

Eastern Cooperative Oncology Group study 1879: mitotane and adriamycin in patients with advanced adrenocortical carcinoma.

From November 1979 to July 1986, 52 patients (27 women and 25 men; median age 52 years) with advanced adrenocortical carcinoma entered a prospective, nonrandomized study evaluating moderate-dose mitotane and doxorubicin hydrochloride (Adriamycin). Thirty-two tumors (62%) were well differentiated and evidence of hormone production was present in 24 patients (46%). Patients with well-differentiated or functional tumors received mitotane, 6 gm daily; patients for whom mitotane failed or those with poorly differentiated, non-hormone-producing tumors received Adriamycin, 60 mg/m2 every 3 weeks. Initially, 36 patients were treated with mitotane and 16 patients with Adriamycin. Eight patients (22%) responded to mitotane and three (19%) responded to Adriamycin. No response was noted in the 15 patients for whom mitotane failed and who then received Adriamycin. Severe toxicity occurred in 36% of patients who received mitotane and in 26% who received Adriamycin. Overall median survival after onset of treatment was 14 months. We conclude that mitotane or Adriamycin used initially can induce tumor regression in about 22% and 19% of selected patients, respectively. However, Adriamycin is ineffective as second-line chemotherapy for patients with well-differentiated or functioning tumors for whom mitotane is ineffective.

An assessment of the clinical usefulness of plasma ribonuclease assays.

The usefulness of plasma ribonuclease assays was studied in (i) patients with possible protein deficiency, (ii) patients with myelomatosis, (iii) patients with carcinoma of the breast. In each group, the major factor associated with elevation of plasma ribonuclease was impairment of renal function. The assay was therefore of little value in the assessment of patients with myelomatosis or carcinoma of the breast. However, in the patients with possible protein deficiency and normal renal function, an elevation of plasma ribonuclease is, in general, associated with a decrease in serum albumin, transferrin and cholinesterase. Plasma ribonuclease may therefore be a useful parameter in the assessment of protein nutritional status.

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.