Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

At the present time, tamoxifen is the most widely used anti-estrogen for adjuvant therapy and metastatic disease in postmenopausal women with breast cancer, a population at high risk for osteoporosis. This prospective study was designed to evaluate the effect of adjuvant tamoxifen on bone mineral density and all biochemical markers concomitantly in women with early-stage breast cancer in one study. Using dual-energy X-ray absorptiometry, prior to and 12 mo after tamoxifen treatment, bone mineral density in lumbar spine and femoral neck was measured in 44 women with T1-T2N0M0 estrogen-receptor-positive breast cancer receiving adjuvant treatment with tamoxifen 20 mg/d. Biomarkers that can affect bone mineral metabolism were measured before and after 3 and 12 mo of tamoxifen treatment. Bone mineral density was minimally increased in lumbar spine and femoral neck after 12 mo treatment with tamoxifen (p = 0.79 and 0.55, respectively). No differences were found in serum levels of calcium, phosphate, creatinine, ALAT, albumin, LDH, calcitonin, or estradiol. A significant decrease in osteocalcin levels was found after 3 and 12 mo (p < or = 0.01). TSH and PTH levels were increased (p < or = 0.05) after 3 mo, returning to baseline after 12 mo. In conclusion, tamoxifen has an estrogen-like effect on bone metabolism in postmenopausal women and is associated with preservation of bone mineral density in lumbar spine and femoral neck. Changes in serum concentration of biochemical markers may reflect decreased bone turnover or bone remodeling and add to the understanding of tamoxifen's effect on bone mineral density.
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PMID:Effects of tamoxifen on bone mineral density and metabolism in postmenopausal women with early-stage breast cancer. 1529 83

Osteoporosis affects many women after menopause. It is a major health problem, as fragility fractures create significant morbidity in this population, especially with advancing age. Available therapies include estrogens, selective estrogen receptor modulators, bisphosphonates, and calcitonin. They all inhibit bone resorption, although through different mechanisms. Several combinations of these agents have been studied in order to determine their effectiveness in comparison with monotherapy. We reviewed eight prospective randomized clinical trials of hormone therapies combined with bisphosphonates (etidronate, alendronate, and risedronate) and one study of a selective estrogen receptor modulator (raloxifene) in combination with a bisphosphonate (alendronate). Bone mineral density change at the lumbar spine was the primary endpoint of all the studies, with one or more measurements of the bone density at the femur as secondary endpoints. None of the studies had the statistical power to determine the relative reduction in fracture risk. All the studies reported greater increases in bone mineral density in patients treated with combination therapies as opposed to single agents. The bone turnover markers were also suppressed to a greater degree in the combination treatment groups, remaining however within normal premenopausal ranges. Four studies reported bone histomorphometry data, indicating no impairment of bone quality by combination therapies. The combination treatments were well tolerated in all the trials and the discontinuation rates did not vary among the groups. However, most patients will not require combination therapy. Combining bisphosphonates with hormone therapy may offer an additional benefit to women who either continue to lose bone mass despite taking estrogen or who need estrogen to control postmenopausal symptoms. The benefit of adding raloxifene to a bisphosphonate is smaller. However, it may be clinically useful if raloxifene reduces the risk of breast cancer.
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PMID:Combining bisphosphonates with hormone therapy for postmenopausal osteoporosis. 1551 Nov 30

Breast cancer is the malignant neoplasm most commonly associated with hypercalcemia. In breast cancer the majority of the hypercalcemia cases result from osteolytic metastatic bone disease of the primary tumor. In a few patients hypercalcemia results from other conditions like primary hyperparathyroidism. Here, we present two female patients who were treated for breast cancer. Hypercalcemia in these two patients was diagnosed as being due to primary hyperparathyroidism. One of them was submitted to surgery and the calcium level dropped to the normal level thereafter. The other one refused surgery and was treated with biphosphonate and calcitonin. We suggest that when hypercalcemia occurs in breast cancer, primary hyperparathyroidism should be considered as possible cause.
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PMID:Breast cancer and concomitant primary hyperparathyroidism: description of two patients. 1551 83

To prevent bone loss that occurs with increasing age, nutritional and pharmacological factors are needed. Traditional therapeutic agents (selective estrogen receptor modulators or SERMs, biphosphonates, calcitonin) may have serious side effects or contraindications. In an attempt to find food components potentially acting as SERMs, we submitted four plant aqueous extracts derived from Greek flora (Sideritis euboea, Sideritis clandestina, Marticaria chamomilla, and Pimpinella anisum) in a series of in vitro biological assays reflective of SERM profile. We examined their ability (a) to stimulate the differentiation and mineralization of osteoblastic cell culture by histochemical staining for alkaline phosphatase and Alizarin Red-S staining, (b) to induce, like antiestrogens, the insulin growth factor binding protein 3 (IGFBP3) in MCF-7 breast cancer cells, and (c) to proliferate cervical adenocarcinoma (HeLa) cells by use of MTT assay. Our data reveal that all the plant extracts studied at a concentration range 10-100 microg/mL stimulate osteoblastic cell differentiation and exhibit antiestrogenic effect on breast cancer cells without proliferative effects on cervical adenocarcinoma cells. The presence of estradiol inhibited the antiestrogenic effect induced by the extracts on MCF-7 cells, suggesting an estrogen receptor-related mechanism. In conclusion, the aqueous extracts derived from Sideritis euboea, Sideritis clandestina, Marticaria chamomilla, and Pimpinella anisum may form the basis to design "functional foods" for the prevention of osteoporosis.
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PMID:Greek plant extracts exhibit selective estrogen receptor modulator (SERM)-like properties. 1553 3

The effects of Keishi-bukuryo-gan on calcitonin gene-related peptide (CGRP)-induced elevation of skin temperature were investigated in gonadotropin-releasing hormone (GnRH) analogue-treated female rats. Leupline (1.0 mg/kg) as the GnRH analogue was subcutaneously (s.c.) injected into female rats. After Keishi-bukuryo-gan (100-1,000 mg/kg, p.o.) or 17beta-estradiol (0.010 mg/kg, s.c.) was administered to GnRH analogue-treated rats for 14 days, CGRP-induced skin temperature elevation, concentration of plasma 17beta-estradiol and pituitary gonadotropin (luteinizing hormone; LH, and follicle stimulating hormone; FSH) were measured. In addition, effects of 17beta-estradiol and Keishi-bukuryo-gan on the proliferation of estrogen-dependent human breast cancer (MCF-7) cells were investigated under in vitro conditions. GnRH analogue significantly lowered the concentrations of plasma 17beta-estradiol and pituitary gonadotropins. Tissue weights of the ovaries and uterus were also decreased by the analogue. Under the condition of estrogen deficiency, intravenous (i.v.) injection of exogenous CGRP (10 microg/kg) elevated the skin temperature of the hind paws more significantly than it did in sham-treated control rats. Estrogen supplementation inhibited this elevation of skin temperature with restoration of both the lowered plasma estrogen level and the decreased uterine weight in GnRH analogue-treated rats. On the other hand, Keishi-bukuryo-gan inhibited the elevation of skin temperature in a dose-dependent manner without restoring the plasma estrogen level and uterine weight. In addition, in an in vitro study, MCF-7 cells proliferated in a dose-dependent manner by the addition of 17beta-estradiol (10(-13)-10(-8) M) to the medium. However, Keishi-bukuryo-gan (10(-6)-10(-4) mg/ml) did not activate the MCF-7 cell proliferation. These results suggest that Keishi-bukuryo-gan, which does not exhibit estrogen activity, may be useful for the treatment of hot flashes in women who are undergoing medical ovariectomy with a GnRH analogue.
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PMID:Skin temperature rise induced by calcitonin gene-related peptide in gonadotropin-releasing hormone analogue-treated female rats and alleviation by Keishi-bukuryo-gan, a Japanese herbal medicine. 1582 75

The most devastating consequence of osteoporosis is bone fracture, particularly at the vertebral or femoral level. As defined by the WHO, patients with osteoporosis who have had one or more fragility fractures have severe osteoporosis. Those who sustain a vertebral fracture represent a particularly vulnerable group whose risk of another vertebral fracture within the following year is increased by a factor of 3-5. In addition, the presence of a vertebral fracture is associated with an increased risk of hip fracture. In light of these data, treatment of established osteoporosis is extremely important to prevent other fragility fractures. This review examines the therapies approved by the US FDA for the treatment of osteoporosis that have been shown to reduce the incidence of new fractures in patients with established osteoporosis. We evaluated the mechanisms of action, available formulations, efficacy in preventing fractures and increasing bone mineral density (BMD), duration of treatment, adverse effects and contraindications to use of alendronic acid (alendronate), risedronic acid (risedronate), calcitonin, raloxifene and teriparatide. All these drugs are able to prevent new vertebral fractures in patients with established osteoporosis. Only alendronic acid and risedronic acid have also been shown to reduce the risk of fracture at the femoral level, but they are contraindicated in patients with upper gastrointestinal diseases. Calcitonin is a good option in subjects with back pain because of its analgesic effect. Raloxifene is useful when patients have high plasma lipid levels or a family history of breast cancer. Teriparatide is indicated in subjects with very low BMD and multiple vertebral fractures. Patient characteristics should determine selection of therapy but the decision is always difficult and fraught with uncertainty.
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PMID:Pharmacological management of severe postmenopausal osteoporosis. 1590 53

Calcitonin is currently used to treat hypercalcemia of many clinical types. However, we encountered a woman who suffered severe hypercalcemia and status epilepticus, both of which developed 8 days after the administration of salmon calcitonin for the treatment of breast cancer. When the patient first presented her serum calcium level was 15.5mg/dl, intact parathyroid hormone level 118 pg/ml, calcitonin <2 pg/ml, magnesium 1.2mg/dl, and phosphate 1mg/dl. Her serum calcium level returned to the reference range within 48 h after correction. At follow-up no hypercalcemia had developed, although the patient had received no further treatment for her breast cancer and multiple metastases were subsequently detected. Her hypercalcemia is ascribed to exogenous calcitonin supplementation. These conflicting events may be due to functionally heterogeneous calcitonin receptors or to activation of 1 alpha-hydroxylase by exogenous calcitonin.
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PMID:Hypercalcemia and status epilepticus relates to salmon calcitonin administration in breast cancer. 1614 33

There is a growing body of evidence indicating that calcitonin (CT) and calcitonin receptor (CTR) are involved in the regulation of cell growth, differentiation, and survival and in tissue development. However, the precise functional role of CT/CTR in breast cancer is still unknown. It is well established that the urokinase plasminogen activator (uPA) system plays an important role in breast cancer invasion and metastasis. The goal of this study was to investigate the effects of CT on regulation of the uPA system and invasive capacity of breast cancer cells. In the highly invasive MDA-MB-231 cell line, 10(-8) M CT decreased both uPA and uPAR mRNA and protein expression which was associated with inhibition of the extracellular signal-regulated kinase (ERK) 1/2 pathway. Furthermore, two weeks of CT administration to nude mice inhibited the expression of uPA mRNA in primary tumors by 25% (P<0.05), as compared to control, untreated animals. CT also inhibited the invasiveness of MDA-MB-231 cells by 37% (10(-8) M CT, P<0.05), as determined by a Matrigel invasion assay. To the best of our knowledge, this is the first report describing a direct effect of CT on breast cancer cell invasion. Our data might suggest a close link between CT signaling, the uPA-mediated pathway, and breast cancer invasion.
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PMID:Calcitonin inhibits invasion of breast cancer cells: involvement of urokinase-type plasminogen activator (uPA) and uPA receptor. 1652 28

Osteoporosis, breast cancer and cardiovascular diseases are major health problems among postmenopausal women. Several pharmacologic options for treatment of osteoporosis are available, including hormone replacement therapy (HRT), bisphosphonates, calcitonin and selective estrogen receptor modulators. However, longterm HRT is associated with unwanted side effects such as vaginal bleeding and breast cancer and bisphosphonates, besides bone, have no other benefits. Therefore, raloxifene, the first of the second-generation of SERMs represents a significant improvement in the treatment of postmenopausal women. It could have either estrogen agonist (bone) or antagonist (breast) activity according to the type of estrogen-responsive tissue. Raloxifene prevents bone loss, reduces the number of vertebral fractures in women with and without prevalent vertebral fractures, induces reduction of estrogen-receptor positive invasive breast cancer and has potential beneficial effect on cardiovascular diseases in women with high risk. CORE study, that was recently published, confirmed previously observed reduction of invasive breast cancer in women treated with raloxifene (MORE study), while the data on skeletal effects after 8-years treatment with raloxifene will be published in the near future. Further studies (RUTH, STAR) will provide additional information on efficacy and safety of raloxifene.
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PMID:[Raloxifene (Evista) in the treatment of postmenopausal osteoporosis--the profile of the patient]. 1668 33

Drugs for treating primary hyperparathyroidism can be divided into two main groups: (i) antiresorptive drugs that inhibit the increased bone turnover, which can be divided into estrogen-like compounds (estrogen, oral contraceptives and selective estrogen receptor modulators [SERMs]), bisphosphonates and calcitonin; and (ii) drugs that interfere with parathyroid hormone (PTH) secretion (currently only cinacalcet is available). No drugs that interfere with PTH action are currently available. Available studies suggest that all classes of drugs are able to lower serum calcium levels. However, calcitonin does so only temporarily. Estrogen-containing compounds (hormone replacement therapy) may be less attractive because of the potential risk of breast cancer, cardiovascular disease and deep vein thromboembolism. Oral contraceptives have not been shown to be able to prevent fractures in the general population, and no data are available on their effect in women with primary hyperparathyroidism. The only SERM marketed for hyperparathyroidism is raloxifene and this has not been associated with an increased risk of breast cancer and cardiovascular diseases, and has been shown to be able to prevent vertebral fractures in postmenopausal women with osteoporosis. Two small trials suggest that raloxifene may increase bone mineral density (BMD) and decrease serum calcium levels in patients with primary hyperparathyroidism. Bisphosphonates have been shown to decrease serum calcium and increase BMD in patients with primary hyperparathyroidism, but PTH levels may increase. Cinacalcet effectively induces a sustained decrease in serum calcium and PTH for up to 1 year. However, BMD does not seem to increase. No data on hard endpoints such as fractures, kidney stones, cardiovascular disease etc. are available for any of the drugs available for the treatment of primary hyperparathyroidism.
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PMID:Current pharmacological options for the management of primary hyperparathyroidism. 1713 3


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