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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Annexins are a family of structurally related, water-soluble proteins that have calcium- and phospholipid-binding domains. Annexin I is thought to be involved in cell proliferation and differentiation and has recently been shown to be expressed on the surfaces of lymphoma cells where it acts as an endothelial cell adhesion molecule. To evaluate the expression of annexin I in relation to human breast cancer development and progression we used breast biopsy tissues. Immunohistochemical analysis of annexin I in paraffin-embedded ductal epithelial cells of various human breast tissues indicated that this annexin was not demonstrable in the ductal luminal cells of normal breast tissues (n = 11) and benign tumors (n = 10) (except for one ductal adenoma) but was generally expressed in various types of breast cancers, including noninvasive ductal carcinoma in situ (DCIS), invasive and metastatic breast tumors (n = 33). The results suggest that annexin I expression might correlate with malignant breast cancer progression but it is most likely involved at an early stage of human breast cancer development.
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PMID:Differential expression of annexin I in human mammary ductal epithelial cells in normal and benign and malignant breast tissues. 906 91

The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage and administration of gemcitabine are reviewed. Gemcitabine is a deoxycytidine-analogue antimetabolite with activity against some solid tumors. Gemcitabine is phosphorylated intracellularly to difluorodeoxycytidine triphosphate, which terminates DNA-chain elongation and competitively inhibits DNA polymerase and ribonucleotide reductase. After i.v. administration, gemcitabine is rapidly distributed into total body water. The drug is deaminated in the plasma to inactive difluorodeoxyuridine; both gemcitabine and difluorodeoxyuridine are primarily renally eliminated. In clinical studies, gemcitabine reduced pain and improved function in patients with advanced pancreatic cancer. Gemcitabine has shown some activity against non-small-cell lung cancer, particularly when combined with cisplatin or ifosfamide. The agent has also shown modest activity against advanced ovarian and breast cancer. Adverse effects include dose-limiting myelosuppression, flu-like symptoms, nausea, vomiting, and rash. Gemcitabine has FDA-approved labeling for use in the treatment of locally advanced and metastatic pancreatic cancer. The recommended dosage for this indication is 1000 mg/m2 (as the hydrochloride salt) i.v. given over 30 minutes weekly for seven weeks, followed after one week of rest by 1000 mg/ m2 i.v. given over 30 minutes weekly for three weeks every four weeks. Gemcitabine palliates symptoms in patients with advanced or metastatic pancreatic cancer. More study is needed to determine gemcitabine's role in the treatment of non-small-cell lung cancer, ovarian cancer, and breast cancer.
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PMID:Gemcitabine: a cytidine analogue active against solid tumors. 911 4

Diffusion NMR spectroscopy was used to study intracellular volume and apparent water diffusion constants in different cell lines (DU145, human prostate cancer; AT3, rat prostate cancer; MCF-7, human breast cancer; RIF-1, mouse fibrosacroma). The cells were grown on various matrices (collagen sponge, collagen beads, polystyrene beads) which enabled continuous growth in perfused high density cell culture suitable for NMR studies. In perfused cell systems, the attenuation of the water signal versus the squared gradient strength was fitted by the sum of two decaying exponentials. For the slowly decaying component the apparent water diffusion constant at 37 degrees C was 0.22 (+/-0.02) x 10(-9) s/m2 for all cell lines at diffusion times > 100 ms. It continuously increased up to 0.47 (+/-0.05) x 10(-9) s/m2 when the diffusion time was decreased to 8 ms, indicating restricted diffusion. No significant effect of the matrices was observed. The fractional volume of the slow component as determined from the biexponential diffusion curve correlated with the relative intracellular volume, as obtained from the cell density in the sample and the cell size as measured by light microscopy. Therefore, this simple NMR approach can be used to determine intracellular volume in perfused cell cultures suitable for NMR studies. Using this information in combination with spectroscopic data, changes in intracellular metabolite concentration can be detected even when the cellular volume is changing during the experiment. The apparent diffusion constant for the fast diffusing component varied with growth matrix, cell density and cell type and also showed the typical characteristics of restricted diffusion (increase of apparent diffusion constant with time).
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PMID:Intracellular volume and apparent diffusion constants of perfused cancer cell cultures, as measured by NMR. 917 32

Paclitaxel, a novel antitumour agent, is active clinically against advanced ovarian and breast cancer and under investigation for various other cancers. One of the problems associated with the intravenous administration of paclitaxel is its low solubility in water. The current pharmaceutical formulation consists of a 1:1 (v/v) mixture of ethanol and Cremophor EL. This formulation, however, has been demonstrated to cause some severe hypersensitivity reactions. Therefore the development of a safer intravenous formulation devoid of Cremophor EL is an important investigational issue. This review deals with some of the most promising formulation alternatives.
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PMID:Alternative formulations of paclitaxel. 922 60

The detection of breast cancer in women using magnetic resonance imaging (MRI) is increasingly used as a supplement to X-ray mammography. Furthermore, proton MR spectroscopy (1H MRS) has detected alterations in lipid profiles that are linked with tumor development and progression in human biopsy tissue. Because normal "resting" breast is highly active, it is necessary to consider that any alterations observed in lipid profiles may not be indicative of breast tumor development. The purpose of this study was to assess the changes in lipid composition in the breast throughout the menstrual cycle in "normals" using MRS at 4.0 T. Five women with no known history of breast disease were subject to biweekly MRS breast examinations. MRS results showing water and fat resonances revealed cyclic changes in the lipid content throughout the duration of the menstrual cycle. In particular, intensity changes were seen in methylene (-CH2-) and allylic methylene (CH2CH2*CH=) resonances at 2.1 ppm and 1.3 ppm, respectively. These intensity changes assumed a similar cyclic trend for each subject over the 28 days that correlate with the follicular, ovulatory, and luteal phases of the menstrual cycle. The results obtained may indicate cell synthesis or metabolic activity in the breast during the menstrual cycle and provide valuable information pertinent to lipid responses associated with breast disease.
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PMID:Lipid composition changes in normal breast throughout the menstrual cycle. 926 73

Symptomatic malignant pleural effusions should be treated systemic chemotherapy in chemo-sensitive tumors such as small cell lung cancer, breast cancer, lymphoma, or ovarian cancer. In other non-chemo-sensitive malignancies including non-small cell lung cancer, water-sealed tube drainage and pleurodesis is the standard treatment of choice in most of the cases. Drugs for instillation should be blomycin or OK-432 if commercially available. Instead of the former standard drug tetracycline, doxycycline has been frequently used. As we have no randomized trials, this drug awaits phase III trials. Talc slurry has been accepted and counted as one of the standard choices in the western countries, however, it usually needs general anesthesia and adverse effects are not negligible. As we have little experience on this modality, it should not be considered as a standard treatment. Other antitumor drugs instillation, thoraco-abdominal shunting, and pleuro-pneumonectomy should be considered experimental because of the lack of randomized trials. Symptomatic pericardial malignant effusion or cardiac tamponade is an oncologic emergency. We had better to treat the patient immediately by pericardiocentesis under the cardiac echographic guidance. It should be reserved to solve in randomized trials that the best method would be pericardiocentesis alone, percutaneous continuous drainage, pericardial fenestration, or pericardio-thoraco fenestration. Instillation of drug like doxycycline, OK-432, or bleomycin, lacks phase III comparison and it should be categorized as experimental.
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PMID:[State of the art: treatment of malignant pleural and pericardial effusions]. 936 17

The incidence of breast cancer in the United States has steadily increased for the past three decades. Exposure to excess estrogen, in both natural and synthetic forms, has been implicated as a risk factor for the development of this disease. Considerable interest has been focused on organochlorines, such as the triazine herbicides, and their possible role in the initiation or promotion of human breast cancer. To explore this relationship, an ecologic study of Kentucky counties was designed. Exposure to triazines was estimated by use of water contamination data, corn crop production, and pesticide use data. A summary index of triazine herbicide exposure was developed to classify counties into low, medium, or high exposure levels. Data on county breast cancer rates were obtained from the state registry. A Poisson regression analysis was performed, controlling for age, race, age at first live birth, income, and level of education. Results revealed a statistically significant increase in breast cancer risk with medium and high levels of triazine exposure [odds ratio (OR) = 1.14,p<0.0001 and OR = 1.2, p<0.0001, respectively]. The results suggest a relationship between exposure to triazine herbicides and increased breast cancer risk, but conclusions concerning causality cannot be drawn, due to the limitations inherent in ecologic study design.
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PMID:Triazine herbicide exposure and breast cancer incidence: an ecologic study of Kentucky counties. 937 May 19

The possibilities of using simultaneous fluence and energy modulation techniques in electron beam therapy to shape the dose distribution and almost eliminate the influences of tissue inhomogeneities have been investigated. By using a radiobiologically based optimization algorithm the radiobiological properties of the tissues can be taken into account when trying to find the best possible dose delivery. First water phantoms with differently shaped surfaces were used to study the effect of surface irregularities. We also studied water phantoms with internal inhomogeneities consisting of air or cortical bone. It was possible to improve substantially the dose distribution by fluence modulation in these cases. In addition to the fluence modulation the most suitable single electron energy in each case was also determined. Finally, the simultaneous use of several preselected electron beam energies was also tested, each with an individually optimized fluence profile. One to six electron energies were used, resulting in a slow improvement in complication-free cure with increasing number of beam energies. To apply these techniques to a more clinically relevant situation a post-operative breast cancer patient was studied. For simplicity this patient was treated with only one anterior beam portal to clearly illustrate the effect of inhomogeneities like bone and lung on the dose distribution. It is shown that by using fluence modulation the influence of dose inhomogeneities can be significantly reduced. When two or more electron beam energies with individually optimized fluence profiles are used the dose conformality to the internal target volume is further increased, particularly for targets with complex shapes.
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PMID:Optimization of 3D conformal electron beam therapy in inhomogeneous media by concomitant fluence and energy modulation. 939 99

An electronic portal imaging device has been designed and constructed. It consists of an array of 128 CsI scintillation crystals coupled to photodiodes which is scanned across the field in 4 seconds. The linac is operated at a dose rate of 400 cGy min-1 and the dose delivered for image acquisition is approximately 27 cGy. The data acquisition controller is a stand-alone STE computer located within the scan arm. Sample images are presented showing contrast and spatial resolution of the system together with a humanoid phantom image and a clinical image of a breast cancer patient. The phantom images show the detector has a contrast resolution of 0.3% (at 15 mm diameter) and a spatial resolution of 2.5-3.2 mm. Images of uniform Perspex blocks have also been calibrated for thickness, indicating the system can measure radiological thickness to an accuracy of 2-3 mm of water. These results indicate the detector may be used for transit dosimetry applications including compensator design.
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PMID:An electronic portal imaging device for transit dosimetry. 939 12

Improvements in 99Tcm-sestamibi breast lesion visualization using single photon emission tomography (SPET) may help define the clinical role of this technique alongside X-ray mammography in the diagnosis and management of breast cancer. Pinhole SPET offers the advantages of high resolution and sensitivity when compared to conventional parallel-beam collimation for sources located near the pinhole aperture. In this work, the potential of incomplete (180 degrees) circular orbit (ICO) SPET with pinhole collimation is investigated as a means to visualize small (6.4 and 9.6 mm diameter) spherical simulated tumours, at clinical count densities and tumour-to-background ratios, in a breast phantom. ICO pinhole SPET is compared to complete circular orbit (CCO) pinhole SPET for reference, and planar breast imaging (scintimammography) using parallel-beam and pinhole collimators. A prototype box-shaped pinhole collimator with a 4 mm diameter circular aperture was used to acquire projections of an 890 ml breast phantom both in isolation and mounted on a cylinder filled with a mixture of 99Tcm-pertechnetate and water. A heart phantom containing 99Tcm activity in the myocardium was placed in the cylinder. Simulated tumours containing 99Tcm were placed in the breast phantom and scanned at clinically relevant count densities and scan times with tumour-to-normal tissue concentration ratios of 5.0:1 (9.6 mm sphere) and 7.7:1 (6.4 mm sphere). Phantom data were reconstructed using pinhole filtered backprojection (FBP) and maximum likelihood-expectation maximization (ML-EM). The tumours were not visualized with scintimammography, in which lesion contrast and signal-to-noise were estimated from region of interest analysis to be < 2% and 0.01, respectively. Average (over lesion size and scan time) contrast and signal-to-noise in the ICO (CCO) SPET images were 33% and 1.72 (34% and 1.3), respectively. These values indicate that ICO pinhole SPET has the potential to improve visualization of small (< 10 mm) breast tumours when compared with scintimammography, which may be beneficial for the early classification of cancers of the breast.
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PMID:Breast tumour imaging using incomplete circular orbit pinhole SPET: a phantom study. 942 9


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