Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0005940 (bone disease)
 7,459 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Postmenopausal loss of 17 beta-estradiol (E2) in women is associated with decreased bone mineral density and increased susceptibility to osteoporotic bone fracture. These changes in bone status are assumed to be due to circulating levels of the hormone; therapeutic replacement of E2 can alleviate the bone disease. However, recent reports have shown that human osteoblastic (OB) cells are able to synthesize estrogens locally, via expression of the enzyme aromatase. In this study, we have characterized the expression and activity of aromatase and 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) in rat OB cell lines. Aromatase activity in ROS 17/2.8, ROS 25/1, and UMR 106 cells was similar to that shown in human OB cells, with the highest levels of activity observed in the more differentiated ROS 17/2.8 cells (Vmax = 45 pmol/h/mg of protein). The rat OB cells also showed 17 beta-HSD activity, with the predominant metabolism in all three cell lines being estrone (E1) to E2. As with aromatase, the highest activity was observed in ROS 17/2.8 cells (Vmax = 800 pmol/h/mg of protein). Northern analyses indicated the variable presence of transcripts corresponding to the type 1, 2, 3, and 4 isoforms of 17 beta-HSD. Further analysis of androstenedione metabolism indicated that the net effect of aromatase and 17 beta-HSD activity varied with cell type and culture treatment. All three OB cell lines were able to synthesize E1, E2, and testosterone from androstenedione, although activity varied between OB cell types. Regulatory effects were observed with 1,25-dihydroxyvitamin D3 (positive) and dexamethasone (negative). These data suggest that local synthesis of sex hormones is an important function of OB cells and may play a key role in the modulation of bone turnover independent of circulating hormone concentrations.
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PMID:Characterization of aromatase and 17 beta-hydroxysteroid dehydrogenase expression in rat osteoblastic cells. 962 31

Adjuvant systemic treatments have greatly improved the prognosis of women with early breast cancer. Combination chemotherapy and, for patients with oestrogen receptor-positive (ER+) tumours, endocrine treatment has been found to reduce the frequency of relapse and improve survival. New adjuvant strategies include the introduction of taxanes into adjuvant chemotherapy schedules, the use of aromatase inhibitors in place of, or in addition to, tamoxifen, and the use of adjuvant bisphosphonates. Combination chemotherapy has been found to reduce the annual odds of recurrence and death in pre- and postmenopausal women. The benefits, however, are on average less in older patients. Anthracycline-based regimens are more effective than traditional regimens of cyclophosphamide, methotrexate, and fluorouracil (CMF). The benefits of adjuvant cytotoxic and endocrine treatments are additive. There is considerable debate as to the role of taxanes in adjuvant therapy. Improved outcome has been observed in one large trial, especially in those patients with ER-negative tumours. High-dose chemotherapy has not fulfilled its early promise. Ovarian suppression and/or tamoxifen remain the treatments of choice. The annual odds of relapse and death have been reduced by approximately one-third and one-quarter, respectively. Several very large studies are in progress to assess the potential of aromatase inhibitors in the adjuvant setting. Direct comparisons with tamoxifen, as well as switching after several years from tamoxifen to an aromatase inhibitor, are strategies under evaluation. Early results from one of these trials evaluating anastrozole (the Arimidex, Tamoxifen, Alone or in Combination [ATAC] trial) has reported a reduced relapse rate after a median follow-up of 3 years in favour of anastrozole. However, this was at the expense of accelerated bone loss, and strategies to minimise this side effect of aromatase inhibitors are under investigation. Although many studies have indicated that bisphosphonates prevent the development of metastatic bone disease in animals, the clinical role of prophylactic bisphosphonates in early breast cancer is not clearly defined. Three studies with oral clodronate have been published, two of them indicating a protective effect on the development of bone metastases and improved survival, and one suggesting a disadvantage to the use of adjuvant clodronate. Further large adjuvant trials with clodronate and zoledronic acid are in progress. Adjuvant bisphosphonates also have been found to reduce bone loss associated with cancer treatments and preserve skeletal health. It may be possible to replace the current oral regimens for prevention of bone loss with a single annual infusion of the highly potent bisphosphonate zoledronic acid.
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PMID:Current and future status of adjuvant therapy for breast cancer. 1254 90

Breast cancer represents a major health problem, with more than 1,000,000 new cases and 370,000 deaths yearly worldwide. In the last decade, in spite of an increasing incidence, breast cancer mortality has been declining in the majority of developed countries. This is the combined result of better education, widespread screening programmes and more efficacious adjuvant treatments. Better knowledge of breast cancer biology now allows the cosmetic, physical and psychological consequences of radical mastectomy to be spared in the majority of breast cancer patients. Use of the sentinel node technique is rapidly expanding and this will further reduce the extent and the consequences of surgery. Several clinico-pathological factors are used to discriminate between patients at low (<10%), average (10-40%) and high risk of relapse. Nodal status, tumour size, tumour grade and age are accepted universally as important factors to define risk categories. Newer factors such as uPA/PAI-1, HERer2-neu, proliferative indices and gene expression profile are promising and will allow better discrimination between patients at different risk. Endocrine manipulation with tamoxifen, ovarian ablation or both is the preferred option in the case of endocrine-responsive tumours. Tamoxifen administered for 5 years is the standard treatment for postmenopausal patients; tamoxifen plus ovarian ablation is more effective than tamoxifen alone for premenopausal women. Recent data demonstrate that, for postmenopausal patients, the aromatase inhibitors are superior to tamoxifen, with a different safety profile. At present, anastrozole can be used in the adjuvant setting in cases of tamoxifen intolerance or toxicity. Chemotherapy is the treatment of choice for steroid receptor-negative tumours. Polychemotherapy is superior to single agents and anthracycline-containing regimens are superior to CMF. Six courses of FEC or FAC or the sequential administration of four doses of anthracycline followed by four of CMF are the recommended regimens. New regimens including the taxanes have produced a further improvement in risk reduction and are reasonable therapeutic options. The taxanes have been approved for adjuvant therapy in the USA, while European approval is pending. Combined endocrine-chemotherapy is the standard adjuvant treatment in high-risk patients with endocrine-responsive tumours. Endocrine manipulation is usually administered after completion of the chemotherapy programme. For HER2-neu overexpressing tumours, several rapidly accruing trials are exploring the potential additive effect of trastuzumab, a monoclonal antibody directed against the extramembrane portion of the HER2 receptor. Primary chemotherapy is increasingly used in the treatment of locally advanced and operable breast cancer, with increased rates of breast-conserving surgery. A proportion of patients achieve a pathological complete response and these patients have significantly better long-term outcomes. Twenty-five to forty percent of breast cancer patients develop distant metastases. At this stage the disease is incurable; however, treatments can assure a significant prolongation of survival, symptomatic control and maintenance of quality of life. In the case of hormone receptor positivity and in the absence of visceral, life-threatening disease, endocrine manipulation is the treatment of choice. Active treatments include tamoxifen, ovarian ablation, aromatase inhibitors, pure anti-oestrogens and progestins. Aromatase inhibitors are the most active agents, but the choice and the sequence of endocrine therapies are also dictated by prior adjuvant treatment. Chemotherapy has to be preferred in cases of receptor-negative tumours, acquired resistance to hormones and aggressive visceral disease. Combination regimens are usually associated with higher response rates and sometimes survival prolongation, and this approach should be recommended in young patients with good performance status and visceral disease. On the other hand, single agents have a better tolerability profile and should be tand should be the treatment of choice when a careful balance between activity and tolerability is needed. For HER2-neu positive tumours, the combination of trastuzumab and chemotherapy is significantly superior to chemotherapy alone in terms of both response rates and survival. Other useful palliative treatments include bisphosphonates for the control of metastatic bone disease and radiotherapy for painful bone lesions or local relapses.
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PMID:The curability of breast cancer and the treatment of advanced disease. 1510 48

After osteoporotic fracture or low bone mineral density measurements, it is necessary to look for secondary causes of osteoporosis, such as drugs. Corticosteroids are the most common cause of drug-induced metabolic bone disease. Other drugs responsible for bone disease include: aromatase inhibitors, GnRH agonists, anticonvulsants, heparin, and L thyroxin at TSH-suppressive doses. Confirmation is required of data about neuroleptics and antivitamin K.
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PMID:[Non-corticosteroid drug-induced metabolic bone disease]. 1702 24

Bisphosphonates are effective inhibitors of osteoclast activity and bone resorption, and are standard treatments for osteoporosis, hypercalcemia of malignancy, and metabolic bone disease. Bisphosphonates have also been established to effectively reduce skeletal-related events due to malignancy metastatic to bone. Bisphosphonates are now being incorporated into breast cancer treatment regimens in order to combat osteoporosis caused by ovarian suppression, chemotherapy treatment, aromatase inhibitors and the postmenopausal state itself. A large body of evidence suggests that African-American women are at higher risk for osteoporosis-related morbidity than their Caucasian counterparts. In this review, we highlight recommendations toward screening for osteoporosis in high-risk populations. We summarize the mechanisms of action of bisphosphonates in the treatment of osteoporosis and then summarize national recommendations toward incorporating the use of bisphosphonates as support for the bone health of breast cancer patients, as well as patients at high risk for osteoporosis.
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PMID:Bisphosphonate therapy for women with breast cancer and at high risk for osteoporosis. 1730 67

The therapeutic opportunities for an improved management of malignant bone disease are currently extensively studied. The conventional management of symptomatic bone lesions in patients with advanced cancer involves various combinations of local and systemic standard anticancer therapies and the symptomatic treatment of skeletal complications. In recent years, bisphosphonates have demonstrated high efficacy to avoid skeletal complications from metastatic bone lesions and to prevent cancer treatment-induced bone loss. Especially in the treatment of patients with bone metastases, secondary to breast cancer, a widespread use of bisphosphonates has been established. With the development of highly potent new-generation bisphosphonates, such as zoledronate, the therapeutic opportunities for bisphosphonates are going to expand. Several current studies have investigated the benefit of zoledronate therapy for bone metastases from a variety of tumor types, including prostate cancer, lung and renal cell cancer and multiple myeloma. Furthermore, bisphosphonates have been shown to significantly reduce antineoplastic therapy-induced bone loss. According to recently published data, it is suggested that bisphosphonates not only play a role in the inhibition of osteoclast-mediated bone resorption, but also have antitumor effects inhibiting tumor cell proliferation, adhesion and invasion, as well as angiogenesis and induction of apoptosis. Further preclinical and clinical investigations are necessary to elucidate the role of bisphosphonates, and large randomized clinical trials should be conducted to confirm the clinical value of bisphosphonates for the prevention of relapse, as well as for the maintainance of net bone density, e.g. during aromatase inhibitor therapy.
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PMID:Clinical value of bisphosphonates in cancer therapy. 1764 70

The biochemical markers of bone remodeling reflect the rates of bone resorption and bone formation in the whole body rather than in segments of the skeleton. The markers cannot be used for a diagnosis of bone disease. However, they are a valuable tool in the differential diagnosis, in the assessment of fracture risk independent of bone mineral density and, in the monitoring treatments of metabolic and neoplastic bone diseases as well as the side effects of some drugs on bone (e.g., adjuvant treatment with selective inhibitors of aromatase). This review provides characteristics of the markers currently used to assess neoplastic bone diseases and, their clinical values for stratification and monitoring treatments. Currently used markers provide sufficient specificity. However, their sensitivities under various clinical situations have to be respected. The clinical utility of the markers requires their standardization and availability.
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PMID:[Clinical utility of bone markers in the evaluation and follow-up in patients with neoplastic bone diseases]. 1832 37

Bone health is an important issue for women with all stages of breast cancer, but especially those with early-stage breast cancer receiving aromatase inhibitors (AIs). AIs have been shown to reduce bone mineral density and are associated with an increased incidence of fractures. Although AIs significantly improve survival times in early-stage breast cancer patients, many of these patients eventually develop metastatic bone disease. Therefore, identifying effective strategies for preventing bone metastases is needed. Results of preclinical studies with bisphosphonates show increased tumor cell kill in several breast cancer cell lines, but study results evaluating this class of drugs for prevention of bone metastases in women with early-stage breast cancer receiving adjuvant therapies have been inconsistent. However, several large studies to clarify the role of bisphosphonates in maintaining or improving bone health in these women are under way.
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PMID:Bone health issues in women with early-stage breast cancer receiving aromatase inhibitors. 1836 57

(1) While a number of medications have been shown to induce bone loss, the actual incidence and prevalence of medication-induced osteoporosis has not been well quantified. (2) Oral corticosteroids contribute to an increased prevalence of osteoporosis and an increased incidence of fracture in a number of different populations. The increased incidence of fracture in patients receiving inhaled corticosteroids for respiratory disease may be attributed to disease pathogenesis rather than the effects of medication. (3) Other therapies that increase the incidence and/or prevalence of medication-induced osteoporosis and fracture include androgen-deprivation therapy, aromatase inhibitors, protease inhibitors, selective serotonin reuptake inhibitors and prolactin-raising antiepileptic agents. (4) It is difficult to make definitive conclusions on the actual increase in the prevalence and/or incidence of osteoporosis in patients receiving certain medications, as values are often reported differently and studies are mainly retrospective and are therefore open to inherent selection biases and other confounders. Furthermore, there is little available information as to whether specific medications within a class are associated with a higher rate of bone disease than others.
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PMID:Incidence and prevalence of medication-induced osteoporosis: evidence-based review. 1852 57

Great strides have been made over the last 20 years in the treatment of breast cancer and despite an increasing incidence, the number of deaths has fallen sharply since the late 1980s. The advent of new therapies, including taxanes and aromatase inhibitors, and exciting results announced recently using trastuzumab in the adjuvant treatment of HER2-positive patients should decrease this even further. However, although most patients present with disease that appears to be localized to the breast, a significant proportion of women will eventually develop metastatic breast cancer. Therefore, the detection and treatment of micrometastatic disease represents perhaps the most important remaining challenge in breast cancer management, and is the focus of extensive ongoing research. Bone is the most frequent site of distant relapse, accounting for approximately 40% of all first recurrences. In addition to the well recognized release of bone cell-activating factors from the tumor, it is now appreciated that the release of bone-derived growth factors and cytokines from resorbing bone can attract cancer cells to the bone surface and facilitate their growth and proliferation. Bisphosphonates are potent inhibitors of bone osteolysis and the inhibition of bone resorption could therefore have an effect on the development and progression of metastatic bone disease. They could represent an adjuvant therapeutic strategy of potential importance. Clinical trial results with the early bisphosphonate, clodronate, have proved inconclusive. A large, randomized, controlled trial has recently completed accrual and should provide the definitive answer to the question of the role of clodronate in this setting. More potent second- and third-generation bisphosphonates have also shown enhanced antitumor effects in preclinical evaluation and further studies are required to determine whether this antitumor potential of bisphosphonates translates to the clinical setting. Adjuvant bisphosphonates are, therefore, currently only recommended in the research setting and clinical trials evaluating the adjuvant use of these newer compounds are currently recruiting or being established. This article will review in more detail the rationale for the adjuvant use of bisphosphonates, the results of early trials, the progress of the later trials and the potential future role of bisphosphonates in the adjuvant treatment of breast cancer. In addition, it is increasingly acknowledged that many cancer treatments have detrimental effects on bone and can increase the risk of fracture. The increasing use of aromatase inhibitors, in particular, will become a major cause of treatment-induced bone loss. This bone loss can be prevented with bisphosphonate treatment and this will also be discussed.
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PMID:Bisphosphonates as adjuvant therapy for breast cancer. 1980 32


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