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Biomedical subjects

Matthew R Smith

Publications and source records attributed to Matthew R Smith.

At least 37 records · Page 2Linked to original sources
PubMed2005

Therapy Insight: osteoporosis during hormone therapy for prostate cancer.

The intended therapeutic effect of gonadotropin-releasing-hormone (GnRH) agonists is hypogonadism, which is a leading cause of osteoporosis in men. Observations are consistent with this effect: GnRH agonists decrease bone mineral density and increase fracture risk in men with prostate cancer. Estrogens play a central role in homeostasis of the normal male skeleton and evidence suggests that estrogen deficiency is primarily responsible for the adverse skeletal effects of GnRH agonists. The mechanism of treatment-related bone loss involves acceleration of physiologic bone turnover. In small, randomized, controlled trials, bisphosphonates (pamidronate, zoledronic acid) and selective estrogen-receptor modulators (raloxifene, toremifene) increased bone mineral density in GnRH-agonist-treated men. Two ongoing large, randomized, placebo-controlled studies will prospectively define fracture outcomes in men with prostate cancer and assess the efficacy of novel pharmacologic interventions (AMG 162, toremifene) in GnRH-agonist-treated men.

Bone Density↗
PubMed2005

Selective estrogen receptor modulators to prevent treatment-related osteoporosis.

The intended therapeutic effect of gonadotropin-releasing hormone (GnRH) agonists is hypogonadism, which is a leading cause of osteoporosis in men. Consistent with this observation, GnRH agonists decrease bone mineral density and increase fracture risk in men with prostate cancer. GnRH agonists markedly decrease serum levels of both testosterone and estrogen. Estrogens play a central role in homeostasis of the normal male skeleton, and the available evidence suggests that estrogen deficiency rather than testosterone deficiency accounts for the adverse skeletal effects of GnRH agonists. The central role of estrogens in male bone metabolism provides a strong rationale to evaluate selective estrogen receptor modulators for prevention of treatment-related osteoporosis in men with prostate cancer. Preliminary evidence suggests that both raloxifene and toremifene increase bone mineral density in GnRH agonist-treated men. An ongoing pivotal study will evaluate the effects of toremifene on fractures and other complications of GnRH agonists in men with prostate cancer.

Journal Article↗
PubMed2004

Rosiglitazone versus placebo for men with prostate carcinoma and a rising serum prostate-specific antigen level after radical prostatectomy and/or radiation therapy.

BACKGROUND: The objective of this study was to assess the biologic activity of rosiglitazone, a peroxisome proliferator-activated receptor gamma agonist that has been approved to treat type 2 diabetes, in men with recurrent prostate carcinoma using change in prostate specific antigen (PSA) doubling time (PSADT) as the primary outcome variable. METHODS: Men with histologically confirmed prostate carcinoma, no recent hormone therapy, a rising serum PSA level after radical prostatectomy and/or radiation therapy, and no radiographic evidence of metastases were assigned randomly to receive either oral rosiglitazone (4 mg twice daily) or placebo. The treatment was continued until the men developed disease progression or adverse effects. A positive outcome was defined as a posttreatment PSADT > 150% the baseline PSADT and no new metastases. RESULTS: One hundred six men were enrolled. The median treatment duration was 315 days for men in the placebo group and 338 days for men in the rosiglitazone group (P = 0.28). Forty percent of men in the in the placebo group and 38% of men in the rosiglitazone group had a posttreatment PSADT > 150% of the baseline PSADT and no new metastases (P = 1.00). In exploratory analyses, the rate of a positive outcome remained higher than expected in the placebo group, even when a positive outcome was redefined using more stringent criteria. The time to disease progression was similar between the groups. CONCLUSIONS: Rosiglitazone did not increase PSADT or prolong the time to disease progression more than placebo in men with a rising PSA level after radical prostatectomy and/or radiation therapy. The unexpected discordance between baseline and posttreatment PSADT in the placebo group reinforced the importance of randomized controlled trials in this setting.

Adult↗
PubMed2004

Prospective, multicenter, randomized phase II trial of the herbal supplement, PC-SPES, and diethylstilbestrol in patients with androgen-independent prostate cancer.

PURPOSE: To evaluate the herbal combination, PC-SPES, and diethylstilbestrol (DES) in patients with androgen independent prostate cancer (AIPC). PATIENTS AND METHODS: A randomized phase II study was conducted with cross-over design. Patients were randomly assigned to receive either three PC-SPES capsules orally three times a day or DES 3 mg orally once a day. Prophylactic warfarin was administered. At clinical or prostate-specific antigen progression, patients received the other therapy. The study closed prematurely after PC-SPES was withdrawn from the market. Chemical analyses were performed on multiple lots of PC-SPES. RESULTS: Ninety patients were enrolled, of whom 85 were assessable for response. Prostate-specific antigen declines > or = 50% were noted in 40% (95% CI, 25% to 56%) with PC-SPES, and 24% (95% CI, 12% to 39%) with DES. Median response duration was not reached with PC-SPES, and was 3.8 months with DES. Median time to progression for randomly assigned patients was 5.5 months for PC-SPES and 2.9 months for DES. Common toxicities included mild fatigue, gynecomastia, and mastodynia. Five thromboembolic events occurred (one PC-SPES, four DES). Responses in the cross-over phase were inconclusive. Four lots of PC-SPES had measurable quantities of DES, ranging from 0.01% to 3.1% of the dose used in the DES arm. Ethinyl estradiol was also detected in PC-SPES lots. CONCLUSION: PC-SPES and DES demonstrate activity in AIPC and are well tolerated. However, the synthetic estrogens, DES and ethinyl estradiol, were detected in various lots of PC-SPES, including those used in this trial. Clinical trials that utilize herbal therapies must account for issues of purity and consistency.

Administration, Oral↗
PubMed2004

Natural history of bone complications in men with prostate carcinoma initiating androgen deprivation therapy.

BACKGROUND: As evidence accumulates in favor of androgen deprivation therapy (ADT) in patients with recurrent or metastatic prostate carcinoma, concern has increased regarding bone loss associated with therapeutic hypogonadism. The current study described the natural history of bone complications in men with prostate carcinoma who have initiated ADT. METHODS: Using 1992-2001 claims data from a 5% national random sample of Medicare beneficiaries, the authors identified men with prostate carcinoma who initiated ADT between 1992 and 1994. They analyzed inpatient, outpatient, and physician claims for bone complications over 7 subsequent years. They stratified the quartile of patients who survived longest into 2 cohorts: those who had received ADT for longer than and those who had received ADT for shorter than the median of 697 days. They evaluated the cumulative proportions of patients in each cohort with claims for pathologic fractures, osteoporosis/osteopenia, and nonpathologic fractures. RESULTS: In the 1992-1994 sample, 4494 men with prostate carcinoma initiated ADT. Of these, 1126 survived > 2028 days (5.5 years). During the first 3 years of evaluation, the proportion of bone events was similar for men with shorter durations of ADT and men with longer durations of ADT. However, by 7 years, more men in the longer ADT cohort (45%) had sustained at least 1 pathologic or nonpathologic fracture compared with men in the shorter ADT cohort (40%). CONCLUSIONS: In the current study, men with prostate carcinoma were found to be at risk for adverse bone effects from both the disease and the treatment. These longitudinal data revealed that fractures are common in this patient population and appear to be linked to the duration of ADT.

Adenocarcinoma↗
PubMed2004

Bicalutamide monotherapy versus leuprolide monotherapy for prostate cancer: effects on bone mineral density and body composition.

PURPOSE: Gonadotropin-releasing hormone agonists decrease bone mineral density, lean mass, and muscle size and increase fat mass in men with prostate cancer. Less is known about the effects of bicalutamide monotherapy on bone mineral density and body composition. PATIENTS AND METHODS: In a 12-month, open-label study, we randomly assigned 52 men with prostate cancer and no bone metastases to receive either leuprolide or bicalutamide (150 mg by mouth daily). Bone mineral density and body composition were measured by dual energy x-ray absorptiometry and quantitative computed tomography. RESULTS: Mean (+/- standard error) bone mineral density of the posterior-anterior lumbar spine decreased by 2.5% +/- 0.5% in the leuprolide group and increased by 2.5 +/- 0.5 in the bicalutamide group from baseline to 12 months (P <.001). Mean changes in bone mineral density of the total body, total hip, femoral neck, and trabecular bone of the lumbar spine also differed significantly between groups (P < or =.003 for each comparison). Fat mass increased by 11.1% +/- 1.3% in the leuprolide group and by 6.4% +/- 1.1% in the bicalutamide group (P =.01). Changes in lean mass, muscle size, and muscle strength were similar between the groups. Breast tenderness and enlargement were more common in the bicalutamide group than in the leuprolide group. Fatigue, loss of sexual interest, and vasomotor flushing were less common in the bicalutamide group than in the leuprolide group. CONCLUSION: In men with prostate cancer, bicalutamide monotherapy increases bone mineral density, lessens fat accumulation, and has fewer bothersome side effects than treatment with a gonadotropin-releasing hormone agonist.

Aged↗
PubMed2004

Contribution of androgen deprivation therapy to elevated osteoclast activity in men with metastatic prostate cancer.

PURPOSE: Biochemical markers of both osteoblast and osteoclast activity are elevated in men with osteoblastic metastases from prostate cancer. Androgen deprivation therapy (ADT), the mainstay of therapy for advanced prostate cancer, increases markers of osteoblast and osteoclast activity, even in the absence of bone metastases. Little is known about the relative contributions of ADT and skeletal metastases to elevated bone turnover in men with prostate cancer. EXPERIMENTAL DESIGN: To evaluate the relative contributions of ADT and skeletal metastases to osteoblast and osteoclast activity, we performed a cross-sectional study in three groups of men with advanced prostate cancer: (a) hormone-naïve men without bone metastases; (b) castrate men without bone metastases; and (c) castrate men with bone metastases. The primary study end points were serum levels of bone-specific alkaline phosphatase (BSAP), a marker of osteoblast activity, and N-telopeptide (NTX), a marker of osteoclast activity. RESULTS: Serum levels of both BSAP and NTX were significantly higher in groups of castrate men (groups 2 and 3) than in hormone-naïve men (group 1; P < 0.01 for all comparisons). Among castrate men, serum BSAP was significantly higher in men with bone metastases than in men without bone metastases (P = 0.01). In contrast, serum levels of NTX were similar in groups 2 and 3 (P = 0.33). CONCLUSIONS: The unintended effects of ADT on the skeleton are sufficient to explain increased osteoclast activity in castrate men with bone metastases. These results may have important implications for the optimal timing and schedule of osteoclast-targeted therapy in men with advanced prostate cancer.

Aged↗
PubMed2004

Osteoporosis in men with prostate carcinoma receiving androgen-deprivation therapy: recommendations for diagnosis and therapies.

BACKGROUND: Androgen-deprivation therapy (ADT) is prescribed with increasing frequency for men with prostate carcinoma. There is growing concern about the effects of such therapy on the skeleton. In the current review, the authors addressed the current research, diagnostic methods, and treatment recommendations for bone loss and osteoporosis in men with prostate carcinoma who received ADT. METHODS: Data were obtained from electronic literature searches (for the years 1986 through 2002) and from abstracts and meeting proceedings. All randomized and nonrandomized clinical trials, retrospective studies, and cross-sectional studies of osteoporosis in men with prostate carcinoma who received ADT with or without other therapies were reviewed. RESULTS: The findings confirmed that ADT resulted in significant bone loss in men with prostate carcinoma. Bone mineral density (BMD) of the hip, as measured by dual-energy X-ray absorptiometry (DXA), is considered the preferred site of assessment in older men. Spinal BMD is equally important, although careful interpretation of spinal DXA values is required, because of coexisting facet joint disease and extravertebral calcification. Osteoporosis is diagnosed when BMD is > 2.5 standard deviations below a reference mean. Men with prostate carcinoma who were treated with ADT had average BMD measurements below those of eugonadal men. Rates of bone loss ranged from 2% to 8% in the lumbar spine and from 1.8% to 6.5% in the femoral neck during the initial 12 months of continuous ADT. Retrospective data indicated an increased risk of fracture in men with prostate carcinoma who were treated with ADT. CONCLUSIONS: For men with prostate carcinoma who are at high risk for osteoporosis and fractures, clinical management should be dictated by the results of radiographic and DXA skeletal assessment.

Age Distribution↗
PubMed2004

Osteoclast-targeted therapy for prostate cancer.

Skeletal complications are a major cause of morbidity in men with metastatic prostate cancer. Bone metastases cause pain, fractures, spinal-cord compression, and ineffective hematopoiesis. Men without bone metastases are also at risk for skeletal complications. Androgen deprivation therapy (ADT), the mainstay of treatment for metastatic prostate cancer and a routine part of the management for many men with nonmetastatic prostate cancer, decreases bone mineral density, and increases fracture risk. Pathological osteoclast activation plays a central role in both disease and treatment-related skeletal morbidity. Bisphosphonates, potent inhibitors of osteoclast activity, are now an important part of the management for many men with prostate cancer. Zoledronic acid, a potent intravenous bisphosphonate, decreases the risk of skeletal complications in men with hormone-refractory prostate cancer and bone metastases. Zoledronic acid and pamidronate preserve bone mineral density in men receiving ADT for nonmetastatic prostate cancer. Ongoing clinical trials will evaluate the role of osteoclast-targeted therapy in other settings including prevention of treatment-related fractures, prevention of bone metastases in men with high-risk nonmetastatic prostate cancer, and prevention of skeletal complications in men with hormone-sensitive metastatic disease.

Adult↗
PubMed2004

Changes in fat and lean body mass during androgen-deprivation therapy for prostate cancer.

OBJECTIVES: To assess the effects of androgen deprivation therapy on body composition in men with nonmetastatic prostate cancer. METHODS: In a multicenter study, men with Stage M0 prostate cancer were prospectively evaluated during initial androgen deprivation therapy (gonadotropin-releasing hormone agonist or bilateral orchiectomy). The main outcomes were changes in weight, percentage fat mass, and percentage lean mass from baseline to 12 months. RESULTS: Seventy-nine subjects were assessed. Serum testosterone concentrations decreased by 79.7% +/- 3.0% (P <0.001). Weight increased by 1.8% +/- 0.5% (P <0.001). The percentage fat mass increased by 11.0% +/- 1.7%, and the percentage lean mass decreased by 3.8% +/- 0.6% (P <0.001 for each comparison). CONCLUSIONS: Androgen deprivation therapy increased weight and fat mass and decreased lean mass in men with nonmetastatic prostate cancer.

Adipose Tissue↗
PubMed2004

Osteoporosis and obesity in men receiving hormone therapy for prostate cancer.

PURPOSE: A presentation on osteoporosis, obesity and obesity related disease at the Conference on Innovations and Challenges in Prostate Cancer: Prevention, Detection and Treatment is summarized. MATERIALS AND METHODS: A focused literature review was done. RESULTS: Gonadotropin-releasing hormone (GnRH) agonists decrease bone mineral density and increase fracture risk. GnRH agonists also increase weight and fat mass, and decrease lean body mass. Treatment related changes in body composition may contribute to fatigue and fracture risk. The phenotype of men with GnRH agonist shares some features with the insulin resistance syndrome, raising the possibility that GnRH may also increase the risk of diabetes mellitus and cardiovascular disease. CONCLUSIONS: The routine use of GnRH agonists in men with long life expectancy increases the importance of understanding and preventing the unintended adverse effects of treatment. Some adverse effects have the potential to impact not only quality of life, but also noncancer mortality. Additional research is needed to characterize better the unintended effects of androgen deprivation therapy and develop optimal strategies to prevent osteoporosis, obesity and obesity related disease.

Antineoplastic Agents, Hormonal↗
PubMed2004

Raloxifene to prevent gonadotropin-releasing hormone agonist-induced bone loss in men with prostate cancer: a randomized controlled trial.

GnRH agonists decrease bone mineral density and increase fracture risk in men with prostate cancer. Raloxifene increases bone mineral density in postmenopausal women, but its efficacy in hypogonadal men is not known. In a 12-month open-label study, men with nonmetastatic prostate cancer (n = 48) who were receiving a GnRH agonist were assigned randomly to raloxifene (60 mg/d) or no raloxifene. Bone mineral densities of the posteroanterior lumbar spine and proximal femur were measured by dual energy x-ray absorptiometry. Mean (+/-se) bone mineral density of the posteroanterior lumbar spine increased by 1.0 +/- 0.9% in men treated with raloxifene and decreased by 1.0 +/- 0.6% in men who did not receive raloxifene (P = 0.07). Bone mineral density of the total hip increased by 1.1 +/- 0.4% in men treated with raloxifene and decreased by 2.6 +/- 0.7% in men who did not receive raloxifene (P < 0.001). Similar between-group differences were observed in the femoral neck (P = 0.06) and trochanter (P < 0.001). In men receiving a GnRH agonist, raloxifene significantly increases bone mineral density of the hip and tends to increase bone mineral density of the spine.

Aged↗
PubMed2004

The role of bisphosphonates in men with prostate cancer receiving androgen deprivation therapy.

Primary and secondary osteoporosis are prevalent in more than 2 million American men. One of the main causes of this is hypogonadism, in turn brought upon by early androgen deprivation therapy used in prostate cancer treatment. Androgen deprivation therapy produces a host of adverse effects on the skeleton, including an increase in bone turnover, a decrease in bone mineral density, and an increase in fracture risk. In addition, based on observations in preclinical models, these adverse effects on the skeletal integrity may promote the development of or progression of metastasis to bone. Loss of bone due to androgen deprivation therapy is an important clinical issue for many men with prostate cancer, but osteoporosis is not an inevitable consequence of androgen deprivation therapy. Because of interpatient variations in peak bone mass as well as differences in rates of treatment-related bone loss, not all men with prostate cancer require treatment for osteoporosis. All men on androgen deprivation therapy should receive calcium and multivitamin supplements and should be considered for bisphosphonate therapy; this is particularly so for men with either a low baseline BMD or observed high rates of bone loss during androgen deprivation therapy.

Androgen Antagonists↗
PubMed2003

Combined analysis of two multicenter, randomized, placebo-controlled studies of pamidronate disodium for the palliation of bone pain in men with metastatic prostate cancer.

PURPOSE: 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. PATIENTS AND METHODS: 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: 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. CONCLUSION: 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.

Adult↗
PubMed2003

Diagnosis and management of treatment-related osteoporosis in men with prostate carcinoma.

Osteoporosis is a complication of androgen deprivation therapy in men with prostate carcinoma. Androgen deprivation therapy, caused by either bilateral orchiectomy or treatment with a gonadotropin-releasing hormone agonist, decreases bone mineral density and increases fracture risk. Other factors including diet and lifestyle may contribute to bone loss. There is limited information regarding the best strategy to prevent osteoporosis in men with prostate carcinoma. Lifestyle modification including smoking cessation, moderation of alcohol consumption, and regular weight-bearing exercise should be encouraged. Supplemental calcium and vitamin D are also recommended. Additional treatment may be warranted for men with osteoporosis, fractures, or high rates of bone loss during androgen deprivation therapy. Intravenous pamidronate, a second-generation bisphosphonate, prevents bone loss during androgen deprivation therapy. Zoledronic acid, a more potent third-generation bisphosphonate, not only prevents bone loss but also increases bone mineral density during androgen deprivation therapy. Other bisphosphonates may be effective although they have not been evaluated in this clinical setting. Treatment with estrogens or selective estrogen receptor modulators may also be effective. Monotherapy with bicalutamide or other antiandrogens may cause less bone loss than androgen deprivation therapy.

Absorptiometry, Photon↗