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

Our studies of human neoplastic tissues had revealed that the T1 values of many malignant tissues had a tendency to be longer than those of normal ones. But the T1 values did not always reflect the grade of malignancy on account of the variety of their histologies. Therefore, by using DMBA-induced rat breast cancer, we investigated the relation between the degree of malignancy and the T1 values, and the following results were obtained. 1) The growth rate of the cancers had a correlation with their T1 values, and 2) the water content of the cancers correlated with their T1 values, but 3) there was no correlation between their growth rate and their water content.
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PMID:[Nuclear magnetic resonance investigations of DMBA-induced rat breast cancers--the relationship between tumor doubling times and water proton spin-lattice relaxation times]. 298 80

Irradiation for breast cancer in the presence of a silicone gel breast prosthesis is sometimes necessary. There is a concern among radiation and other oncologists as to whether the presence of the prosthetic implant would interfere with delivery of the needed irradiation doses. Electron beams, with their finite penetration and rapid fall-off, offer a mode of adequately treating the recurrence and minimizing the radiation to the underlying normal structures, such as the lung and the heart. The dose distribution using 9-20 MeV electrons in the presence of a breast prosthesis is compared to the dose distribution without the implant in a tissue equivalent water phantom. The results reveal no significant difference in the dose delivered due to the presence of the prosthesis. Clinical verification of the dosimetry in the presence of the prosthesis confirmed that the presence of the silicone gel implant does not compromise treatment by irradiation in the management of breast cancer.
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PMID:Electron beam irradiation after reconstruction with silicone gel implant in breast cancer. 308 76

The accuracy of two different pencil beam models for electron beam dose planning is shown by comparisons with measured dose distributions. The investigation is restricted to two-dimensional geometries. In one model the multiple scattering of the electrons is considered by the small angle Gaussian approximation of Fermi and Eyges. In the other, the generalized Gaussian model, the large angle single scattering events are also considered. The parallel slab approximation is used in both models. The comparisons have been made for two different anatomical phantoms. One phantom was constructed to simulate a transversal cross-section through the chest wall and lung in radiotherapy of breast cancer. The other phantom was made to simulate the head at the level of the nose. The measurements in these phantoms were made with thermoluminescence dosimetry, LiF rods. The accuracy of the oblique incidence case was investigated in a homogenous water phantom. The results show that for oblique incidence and geometries where the semi-infinite slab approximation is reasonably good, the generalized Gaussian model is more accurate. Within and behind low density cavities, in the phantom, the Gaussian model often gives a better agreement to experimental data. This is shown to be due to mutually balancing errors from the semi-infinite slab approximation and the Gaussian approximation.
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PMID:Accuracy in clinical electron beam dose planning using pencil beam algorithms. 312 62

We have provided evidence for a critical role of polyamines in the growth of the hormone-responsive N-nitrosomethyl-urea (NMU)-induced rat mammary tumor in vitro. The present experiments were designed to test whether polyamines are involved in the growth of this experimental tumor in vivo. To test this hypothesis, groups of rats bearing NMU-induced mammary cancers were randomly allocated to receive no treatment or escalating doses of the polyamine biosynthesis inhibitor alpha-difluoromethyl-ornithine (DFMO) (0.5%, 1%, 2%, 3% in drinking water). DFMO inhibited tumor growth in a dose-dependent fashion and consistently reduced tumor putrescine level. To evaluate the time dependency of this effect, additional groups of rats received either no treatment or 2% DFMO for 3, 7, 14, and 21 days. At all times DFMO suppressed tumor putrescine level as well as spermidine to spermine ratio. Finally, exogenous administration of putrescine (200 mg/kg/i.p./day x 21 days) given concomitantly with DFMO restored tumor growth, partially repleted tumor putrescine level, and raised the spermidine to spermine ratio to control levels. Putrescine, given alone, had no significant effect on either tumor polyamine levels or tumor growth. Except for modest weight loss, no major toxicity was encountered. These results indicate that polyamines play an important role in the growth of the NMU rat mammary tumor in vivo. The interaction between polyamines and hormones in supporting NMU mammary tumor growth in vivo remains to be elucidated.
Breast Cancer Res Treat 1988 Jul
PMID:Role of polyamines in the growth of hormone-responsive experimental breast cancer in vivo. 313 11

Iproplatin [cis-dichlor-trans-dihydroxy-bis-isopropylamine platinum (CHIP, JM9)] is a new antineoplastic platinum analogue with an octahedral conformation. It has more water solubility than does cisplatin and was found to have less neurotoxicity and nephrotoxicity in experimental animals than cisplatin. Like cisplatin, it has been demonstrated to have a broad spectrum of activity in experimental tumor systems. A phase I study of iproplatin was conducted in 28 patients (12 with melanoma, 8 with sarcoma, 6 with breast cancer, and 2 with colon cancer). All patients had failed prior chemotherapy. Four consecutive doses of iproplatin were administered at weekly intervals followed by a rest period of two weeks for hematologic recovery (one course). One hundred forty-two weekly doses were administered with all patients except three receiving at least one full course. The weekly starting dose of 40 mg/m2 was increased to 120 mg/m2 given over 30 minutes without hydration. Myelosuppression predominantly thrombocytopenia, was the dose-limiting toxicity at weekly doses of greater than or equal to 95 mg/m2 per course. With iproplatin doses 75 mg/m2, 95 mg/m2, and 120 mg/m2, the lowest median granulocyte counts were 2.6 x 10(3)/mm3, 2.2 x 10(3)/mm3, and 1.8 x 10(3)/mm3, respectively. Similarly, at iproplatin doses of 75 mg/m2, 95 mg/m2, and 120 mg/m2, the lowest median platelet counts were 144 x 10(3)/mm3, 99 x 10(3)/mm3, and 31 x 10(3)/mm3, respectively. Mild to moderate nausea and vomiting were observed in the majority of patients. No significant neurotoxicity, nephrotoxicity, or ototoxicity was observed. Objective tumor regression was not observed in this study.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Phase I study of weekly-administered iproplatin [cis-dichloro-trans-dihydroxy-bis-isopropylamine platin (chip, JM9)]. 322 43

Proton magnetic resonance (PMR) relaxation times were measured for dissected malignant and normal tissue derived from breast cancer patients. Relaxation time measurements (T1, T2) were carried out at a RF frequency of 20 MHz and at a temperature of 27 degrees C with a Brucker PC 120 NMR Process analyser. The tissue types were confirmed by histopathological examination. In general T1 values were found to be longer for malignant tissues as compared to normal tissues which is in agreement with the earlier observations. The measured T2 values do not exhibit the malignant tissues above. The percentage of water content was also measured in both normal and malignant tissue and was found to be considerably larger in tumour tissue as compared to normal tissue. These results are discussed on the basis of two fraction fast exchange models of water molecules and confirm that PMR relaxation time measurement plays an important role in the differentiation of cancerous tissues from that of normal.
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PMID:Proton magnetic relaxation studies in normal and cancerous breast tissues. 325 42

Available data on cancer incidence for 1969-1971 showed statistically elevated rates for breast cancer in St. Louis Park, Minnesota, a community with creosote contamination of the water supply, when compared with the rest of the Minneapolis-St. Paul area taken as the reference population. In order to assess the effect of other known risk factors for breast cancer, 75 persons with breast cancer in each of the two populations were interviewed to obtain frequencies of known risk factors. An adjusted morbidity ratio in the two populations and an expected case rate in the exposed community were calculated from these frequencies, using relative risk values from the medical literature. The adjusted morbidity ratio was less than 1.0, and the observed rate was almost identical to the new expectation, although the age-adjusted rates alone had suggested a significant difference in incidence. This method makes use of relative risks from published studies rather than those associated with local cases and controls. It allows more refined evaluation of differences in cancer rates between communities than can be provided by age- and sex-specific calculations alone, and may allow use of available statistics in situations where cost, temporal considerations, or population size do not favor large new studies.
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PMID:Adjusting morbidity ratios in two communities using risk factor prevalence in cases. 334 65

The nutritional status of three groups of postmenopausal women (age 41-80 yrs) with advanced breast cancer was investigated with special reference to vitamin B6. The interference of hormonal treatment was studied with respect to the progestin megestrol acetate (Group MA, n = 14) and the antiestrogen tamoxifen (Group TAM, n = 15) compared with untreated patients (Group U, n = 11). Healthy postmenopausal women served as controls (Group C, n = 16). Nutritional status was judged from body mass index (BMI), vitamin and trace element status, hematology, and clinico-chemical parameters. Intake of nutrients was calculated from a food record. Hormonal status was studied by analysis of LH, FSH, and prolactin in plasma and of steroids and catecholamines and their metabolites in 24-hour urine. Compared with values for Group C, nutrient intake, hematology, clinico-chemical parameters, and 24-hour urinary excretion of catecholamines and their metabolites of patient groups (U, TAM, and MA) were not significantly different. The BMI of patients was significantly higher (by about 10%; 60% showed an overweight) than that of controls. With respect to fat-soluble vitamin status, significantly lower plasma levels of vitamin A (at least 40% lower, with deficient levels in more than 50% of the patients), D (40% lower), and E (20% lower) were found for Group U. However, water-soluble vitamin status of the four groups was fairly similar. A significantly higher excretion of xanthurenic acid in 24-hour urine, after an oral tryptophan load, was observed for Groups TAM and MA. This is most probably the result of hormonal treatment without affecting vitamin B6 status. Small, but significant, differences between groups were found for trace element status, especially with respect to lower plasma selenium of Group U (25% lower). LH, FSH, and prolactin in plasma and excretion of steroids in 24-hour urine showed levels that could be expected for controls and for untreated and hormonally treated patients. We concluded that the nutritional status of all patients is reasonably adequate. Hormonal treatment did not influence vitamin B6 status, although levels of vitamins A, D, and E and of selenium seem to be elevated.
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PMID:Investigations on the nutritional status of advanced breast cancer patients. The influence of long-term treatment with megestrol acetate or tamoxifen. 343 93

Estradiol (ER), progesterone (PR), androgen (AR) and glucocorticoid receptor (GR) levels were assayed in 25 breast cancer tumors. The tissue was pulverized and homogenized in buffer, then divided into two parts: one was assayed by the standard dextran-coated charcoal method (DCC), with Scatchard plot analysis, the other was assayed by a micromethod developed in our laboratory, as described below: --incubation of the cytosol with several ligands (labelled and unlabelled) selected to avoid unwanted cross-reactions --DCC separation, followed by extraction of all receptor-bound steroids by precipitation of proteins with methanol/TCA --separation of these steroids on a high pressure liquid chromatography (HPLC) column using a methanol/water solvent --collection of the fractions of the column outlet and counting. Use of three labelled ligands and appropriate unlabelled ligands allowed assays of the four receptors. This micromethod was highly correlated with the standard method: ER = 0.985 (P less than 0.001); PR = 0.999 (P greater than 0.001); AR = 0.989 (P less than 0.001); GR = 0.867 (P less than 0.001). Thresholds of positivity were not modified. This micromethod allowed simultaneous measurement of several receptors in 40 mg biopsy specimens and can be applied to other hormone-dependent tissues.
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PMID:HPLC micromethod for simultaneous measurement of estradiol, progesterone, androgen and glucocorticoid receptor levels. Application to breast cancer biopsies. 350 49

Comparative studies of the toxicity, stability, and retention of the water-soluble porphyrin, tetraphenylporphyrin sulfonate (TPPS), and its complex with Mn(III), have been made with the human breast cancer cell line MCF-7 wild type, and an adriamycin-resistant line derived from it, termed AdrR. Based on growth inhibition, we determined the maximum non-toxic concentration of MnTPPS tolerated by these cells. The integrity of MnTPPS in vitro was investigated by fluorescence microscopy, and we found that there is very little dissociation of MnTPPS within these cells within 4 days. We report novel proton magnetic resonance relaxation measurements of the bulk water of cells in a gel matrix undergoing perfusion. A slightly greater net uptake of MnTPPS in the wild-type cells was observed compared to AdrR; however, there was no significant difference in retention of MnTPPS. These results indicate that over a period of several hours the mechanism of selective retention of these compounds in tumour cells is not due to specific interaction with heme-binding protein, of which there is enhanced expression in the resistant cells. The fact that the net rate of washout of MnTPPS is approximately the same as the net rate of uptake also appears to eliminate compartmentalization or enzymatic modification of MnTPPS within these cells.
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PMID:Studies on the mechanism of selective retention of porphyrins and metalloporphyrins by cancer cells. 359 79


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