Combined analysis of two multicenter, randomized, placebo-controlled studies of pamidronate disodium for the palliation of bone pain in men with metastatic prostate cancer. Samarium-153-Lexidronam complex for treatment of painful bone metastases in hormone-refractory prostate cancer. A double blind randomized study of oral clodronate in the treatment of bone metastases from tumors poorly responsive to chemotherapy. The PLACORHEN study: a double-blind, placebo-controlled, randomized radionuclide study with (186)Re-etidronate in hormone-resistant prostate cancer patients with painful bone metastases. Placebo Controlled Rhenium Study. Repeated bone-targeted therapy for hormone-refractory prostate carcinoma: tandomized phase II trial with the new, high-energy radiopharmaceutical rhenium-188 hydroxyethylidenediphosphonate. A randomized, placebo-controlled trial of zoledronic acid in patients with hormone-refractory metastatic prostate carcinoma. Palliation of painful bone metastases from prostate cancer using sodium etidronate: results of a randomized, prospective, double-blind, placebo-controlled study. Double-blind controlled trial of oral clodronate in patients with bone metastases from breast cancer.
Bone metastases occur in approximately 80% of patients with advanced prostate cancer. Pain is common in these patients. The purpose of this study was to evaluate the effect of an intravenous bisphosphonate, pamidronate disodium, on pain control in metastatic prostate cancer patients.
                Two multicenter, double-blind, randomized, placebo-controlled trials were conducted in patients with bone pain due to metastatic prostate cancer, with disease progression after first-line hormonal therapy. Intravenous pamidronate disodium (90 mg) or placebo was administered every 3 weeks for 27 weeks. Efficacy was measured via self-reported pain score (Brief Pain Inventory), analgesic use, the proportion of patients with a skeletal-related event (SRE; defined as pathologic fracture, radiation or surgery to bone, spinal cord compression, or hypercalcemia), and a pilot quantitative measurement of mobility. Laboratory evaluations included serum prostate-specific antigen, interleukin-6, bone alkaline phosphatase, and urinary bone resorption markers.
                Results of the two trials were pooled. There were no sustained significant differences between the pamidronate and placebo groups in self-reported pain measurements, analgesic use, proportion of patients with an SRE, or mobility at week 9 or 27. Urinary bone resorption markers were suppressed in the pamidronate group compared with placebo.
                Pamidronate disodium failed to demonstrate a significant overall treatment benefit compared with placebo in palliation of bone pain or reduction of SREs. Evaluation of more potent bisphosphonates in patients with prostate cancer is warranted. A Phase III randomized trial was designed to assess the effectiveness of samarium-153 (153Sm)-lexidronam for palliation of bone pain in patients with hormone-refractory prostate cancer.
                A total of 152 men with hormone-refractory prostate cancer and painful bone metastases were enrolled in a prospective, randomized, double-blind trial comparing radioactive (153Sm) versus nonradioactive (152Sm) lexidronam complexes. Patients were randomized (2:1) to the radioactive (153Sm) agent. Patient diaries recording daily pain and analgesic use were completed during a planned 16-week evaluation period. Nonresponders were informed of the treatment received after 4 weeks of treatment and, if initially treated with placebo, were allowed to receive 153Sm-lexidronam in an open-label fashion. Pain was measured using validated patient-derived visual analog scales and pain descriptor scales.
                153Sm-lexidronam had positive effects on measures of pain relief compared with placebo within 1 to 2 weeks. Reductions in opioid use were recorded at weeks 3 and 4. Because nonresponders were unblinded at week 4, statistical comparisons between the arms beyond week 4 were not possible. Mild, transient bone marrow suppression was the only adverse event associated with 153Sm-lexidronam administration. The mean nadir white blood cell and platelet count (3 to 4 weeks after treatment) was 3800/microL and 127,000/microL, respectively. Counts recovered to baseline after approximately 8 weeks. No grade 4 decreases in either platelets or white bloods cells were documented.
                These findings demonstrate that 1 mCi/kg 153Sm-lexidronam is both safe and effective for the palliation of painful bone metastases in patients with hormone-refractory prostate cancer. Bisphosphonates are used in oncology as a means of decreasing complications due to bone metastases, in association with anticancer treatment, especially in patients with breast cancer, prostate cancer and myeloma. Little is known about the effects of bisphosphonates on bone metastases from other tumors and in particular from tumors for which no effective treatment is available. We conducted a randomized, double-blind placebo-controlled trial of oral clodronate in patients with bone metastases from tumors poorly responsive to chemotherapy, with the aims of evaluating the effects of this drug on symptoms control and bone metastases evolution. Sixty-six patients with poorly responsive tumors such as non-small cell lung cancer (NSCLC), bladder cancer, gastrointestinal cancers, kidney cancer, melanoma and metastatic carcinoma of unknown origin entered the study. Patients were randomized to receive either clodronate 1,600 mg/day for one year or identical placebo-containing tablets. Various parameters such as Karnofsky performance status, pain score (measured by a visual-analogue scale) and analgesic requirement were recorded at monthly intervals. Of the 66 patients enrolled, 9 were observed for one month or less; 7 were followed for two months; only 50 patients were followed for more than 2 months and could be adequately evaluated. At 3 months both clodronate and placebo-treated patients had a decrease in Karnofsky performance status, with the decrease being more evident in the placebo group. Mean pain scores showed an increase of pain in patients receiving placebo and a decrease of pain in patients receiving clodronate, although the difference failed to be statistically significant. Analgesics requirement increased in both groups, but significantly more in patients receiving placebo (p = 0.042), in whom increase in opioid requirements was particularly evident. Toxicity was low, with occasional gastroenteric discomfort in both groups. The main problem of this study was the difficulty in recruiting an adequate number of patients and following them for a sufficient period of time: general conditions rapidly deteriorated in many patients, and approximately 25% of the 66 enrolled were not considered evaluable; few patients survived for the length of the study, one year. This might partly account for the lack of significance of some of the parameters under study. With these limits, oral clodronate demonstrated some efficacy in symptom control and in reducing the need for analgesics. (186)Re-1,1-hydroxyethylidene diphosphonate (etidronate) can be used for the palliative treatment of metastatic bone pain. A randomized, placebo-controlled study using (186)Re-etidronate was conducted on end-stage prostate cancer patients with metastatic bone pain.
                Pain relief was assessed using an electronic diary containing questions reflecting the multidimensional character of chronic pain. The diary was marked twice daily for a maximum of 14 wk (2 wk before and 12 wk after the injection). Pain response was determined using a specific decision rule in which pain intensity, medication index, and daily activities were the core determinants. A positive response day was defined as a day on which pain intensity was reduced > or = 25% compared with baseline values, while medication index and daily activities were at least constant, or on which pain intensity was reduced < 25% and medication index or daily activities improved > or = 25%, without worsening of the remaining factor. The total response (%) was defined as the number of positive response days divided by the number of days of follow-up.
                Of the 111 included patients, 79 were evaluable (43 (186)Re-etidronate, 36 placebo). Thirty-two patients were excluded from the analysis because of incomplete datasets. The total response of the patients treated with (186)Re-etidronate varied from 0% to 96% (mean, 27%, or 23/84 d). In the placebo group, the total response varied from 0% to 80% (mean, 13%, or 11/84 d; Mann-Whitney U test, P < 0.05). The number of patients who requested radiotherapy was higher in the placebo group (67%) than in the (186)Re-etidronate group (44%) (relative risk, 1.51; Fisher's exact test, P = 0.069).
                This randomized controlled trial confirmed that, compared with placebo, (186)Re-etidronate resulted in a significantly longer pain response in the treatment of bone pain from metastasized prostate cancer. We investigated the effect of repeated bone-targeted therapy with rhenium-188 hydroxyethylidenediphosphonate (HEDP) in patients with progressive, hormone-resistant prostate carcinoma and bone pain. The aim of this study was to determine the pain palliation and the antitumor effect of rhenium-188 HEDP treatments.
                Sixty-four patients were randomly assigned to one of two groups for radionuclide therapy with rhenium-188 HEDP; patients of group A received a single injection, patients of group B received two injections (interval, 8 weeks). After therapy, patients were followed-up by assessment of pain palliation and clinical outcome until death.
                In both groups, toxicity was low, with moderate thrombopenia and leukopenia (maximum common toxicity criteria grade of 2). The effectiveness of rhenium-188 HEDP for pain palliation was better in the repeated treatment group (group B), with a response rate and time of response of 92% and 5.66 months, respectively (P =.006 and P =.001). In group B, 11 (39%) of 28 patients had a prostate-specific antigen decrease of more than 50% for at least 8 weeks, compared with two (7%) of 30 patients in the single-injection group (group A). The median times to progression of group A and group B were 2.3 months (range, 0 to 12.2 months) and 7.0 months (range, 0 to 24.1 months), respectively (P =.0013), and the median overall survival times were 7.0 months (range, 1.3 to 36.7 months) and 12.7 months (range, 4.1 to 32.2 months), respectively (P =.043).
                Compared with single-injection therapy, repeated bone-targeted therapy with rhenium-188 HEDP administered to patients with advanced progressive hormone-refractory prostate carcinoma enhanced pain palliation and improved progression-free and overall survival. Larger studies are justified to further evaluate the use of rhenium-188 HEDP. Bone metastases are a common cause of morbidity in patients with prostate carcinoma. We studied the effect of a new bisphosphonate, zoledronic acid, which blocks bone destruction, on skeletal complications in prostate cancer patients with bone metastases.
                Patients with hormone-refractory prostate cancer and a history of bone metastases were randomly assigned to a double-blind treatment regimen of intravenous zoledronic acid at 4 mg (N = 214), zoledronic acid at 8 mg (subsequently reduced to 4 mg; 8/4) (N = 221), or placebo (N = 208) every 3 weeks for 15 months. Proportions of patients with skeletal-related events, time to the first skeletal-related event, skeletal morbidity rate, pain and analgesic scores, disease progression, and safety were assessed. All statistical tests were two-sided.
                Approximately 38% of patients who received zoledronic acid at 4 mg, 28% who received zoledronic acid at 8/4 mg, and 31% who received placebo completed the study. A greater proportion of patients who received placebo had skeletal-related events than those who received zoledronic acid at 4 mg (44.2% versus 33.2%; difference = -11.0%, 95% confidence interval [CI] = -20.3% to -1.8%; P =.021) or those who received zoledronic acid at 8/4 mg (38.5%; difference versus placebo = -5.8%, 95% CI = -15.1% to 3.6%; P =.222). Median time to first skeletal-related event was 321 days for patients who received placebo, was not reached for patients who received zoledronic acid at 4 mg (P =.011 versus placebo), and was 363 days for those who received zoledronic acid at 8/4 mg (P =.491 versus placebo). Compared with urinary markers in patients who received placebo, urinary markers of bone resorption were statistically significantly decreased in patients who received zoledronic acid at either dose (P =.001). Pain and analgesic scores increased more in patients who received placebo than in patients who received zoledronic acid, but there were no differences in disease progression, performance status, or quality-of-life scores among the groups. Zoledronic acid at 4 mg given as a 15-minute infusion was well tolerated, but the 8-mg dose was associated with renal function deterioration.
                Zoledronic acid at 4 mg reduced skeletal-related events in prostate cancer patients with bone metastases. Sodium etidronate is a diphosphonate compound that inhibits bone resorption and mineralization. The drug has been reported to be highly effective for the palliation of painful bone metastasis from prostatic cancer. Fifty-seven patients were entered into a randomized, prospective, double-blind, placebo-controlled study of sodium etidronate. All patients had hormone refractory metastatic prostatic cancer and bone pain requiring analgesics. No difference was seen in the symptomatic response rate or analgesic requirement between patients treated with sodium etidronate and placebo. With the dose scheme used in this study sodium etidronate was ineffective for palliation of bone pain from prostatic cancer. Osteolytic metastases often give rise to hypercalcemia, fracture, and bone pain, and occur commonly in patients with recurrent breast cancer. We assessed the bisphosphonate, clodronate, which has proven to be a useful treatment for hypercalcemia and may be a potent inhibitor of tumor-induced osteolysis, for its effect on reducing the osseous complications of metastatic breast cancer.
                We studied 173 patients with bone metastases due to breast cancer in a randomized, double-blind, placebo-controlled trial of oral clodronate 1,600 mg/d (85 patients) compared with an identical placebo (88 patients).
                The patients in each wing were comparable in their clinical, radiologic, and biochemical characteristics at trial entry. In patients who received clodronate, there was a significant reduction compared with placebo in the total number of hypercalcemic episodes (28 v 52; P < .01), in the number of terminal hypercalcemic episodes (seven v 17; P < .05), in the incidence of vertebral fractures (84 v 124 per 100 patient-years; P < .025), and in the rate of vertebral deformity (168 v 252 per 100 patient-years; P < .001). The combined rate of all morbid skeletal events was significantly reduced (218.6 v 304.8 per 100 patient-years; P < .001). Trends were seen in favor of clodronate for nonvertebral fracture rates and radiotherapy requirements for bone pain (particularly spinal pain). No significant survival differences and no significant differences in side effects were observed between the two groups.
                These findings indicate that oral clodronate has a beneficial effect on the skeletal morbidity associated with breast cancer and should be considered as antiosteolytic therapy in affected patients. It deserves further investigation as an adjuvant therapy in operable breast cancer and in patients with nonosseous recurrence who are at high risk for bone metastases.
Bisphosphonates should be considered for patients with metastatic prostate cancer for the treatment of refractory bone pain and prevention of skeletal events. More research is needed to guide the choice of bisphosphonates, optimal treatment schedule as well as cost-benefit comparisons. Combining results from different studies is difficult because different tools were used to assess pain, and also, bisphosphonates vary considerably in potency. This review highlights the need for standardisation and co-ordination among researchers in cancer pain studies.