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

The association of dual steroidal disorders with breast cancer, as proposed on the basis of a case-control study in a high risk area of Japan, was tested for its validity in breast cancer patients from a low risk area of Japan. A state of glucocorticoid excess, the first hormonal trait of a breast cancer patient, was assessed using a urinary steroid parameter (a reduction of the androsterone to tetrahydrocortisol ratio by definition), and/or using a physical parameter (an elevation of the waist to hip circumference ratio by definition). Inclination to ovulation failure, the second hormonal trait, was tested using another urinary steroid parameter (a specified disorder of progestin metabolism by definition), and/or a demographic parameter (a reduction in the number of live births by definition). Results obtained are as follows: 1) premenopausal breast cancer patients from a low risk area were found to have the second trait but not the first trait, as tested using 2 parameters for each trait. 2) Postmenopausal cancer patients from a low risk area as well as pre- and post-menopausal cancer patients from a high risk area had both the 2 hormonal traits. 3) There was no discrepancy of results between any 2 test systems with the identification of 2 hormonal traits in 4 cancer patient groups. The significance of the dissociation of 2 hormonal traits, as observed in premenopausal cancer patients from a low risk area, is discussed in favor of the two-step carcinogenesis theory. Possible interaction of heredity and environment in the genesis of breast cancer is also taken into consideration.
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PMID:The genesis of breast cancer is a two-step phenomenon. II. Dissociation of two biomarkers in cancer patients from a low risk area of Japan. 156 62

The bcl-1 gene maps to chromosome 11q13 and has recently been shown to be a member of the cyclin gene family. Amplification of the chromosome region containing bcl-1 occurs frequently in breast cancer, squamous cell cancer, and other tumor types. We have hypothesized that amplification results in altered expression of the bcl-1 gene, contributing to carcinogenesis. In this work, we studied bcl-1 gene amplification and expression in a panel of human cell line. bcl-1 is expressed in all cell lines studied. The level of expression tends to be higher in amplified cell lines. We also screened these cell lines for int-2 and hst-1 expression, genes which are frequently coamplified with bcl-1. No int-2 expression was detected, and the two cell lines expressing hst-1 were unamplified. Our data provide support for the importance of bcl-1 in carcinogenesis.
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PMID:Amplification and expression of the bcl-1 gene in human solid tumor cell lines. 156 16

Earlier physical maturity in girls, involving an earlier and more marked growth hormone spurt and also an earlier menarche, is a marker of subsequent higher risk to breast cancer. Based on the results of recent research, it is postulated that interaction between growth hormone, insulin-like growth factor and sex steroids at an earlier age, has a major role in stimulating not only linear growth but also precocious proliferative activity in the breasts of adolescent girls. This may promote carcinogenesis in a susceptible mammary epithelium and could partly account for the rising breast cancer mortality rate among both Japanese and Western women.
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PMID:Breast cancer risk in Japanese women with special reference to the growth hormone-insulin-like growth factor axis. 157 84

The phospholipid (PL) content was 4-fold higher while the triacylglycerol (TG) content tended to be 65% lower in human breast cancer tissues as compared with non-cancerous reference parts from excised breast tissues. The variation in TG content among breast tissues was very large while that of PL was relatively small. The fatty acid compositions of PL were significantly different between the cancer and reference tissues; the proportions of octadecenoate (18:1), docosahexaenoate (22:6n-3), the total n-3 fatty acids and the n-3/n-6 ratio, but not the proportion of arachidonate (20:4n-6), were significantly higher in the major PL of cancer tissues as compared with those of the reference tissues. No significant differences were observed in the proportion of the major fatty acids of TG in these tissues. The turnover of lipids was faster in the cancer tissues than in the reference tissues. The turnover of TG was faster than that of PL in the cancer tissues, whereas the opposite was true in the reference tissues, indicating significant differences in lipid metabolism between these tissues. A striking difference in the n-3 and n-6 fatty acids of the reference tissues noted for Japanese and Finnish women is discussed in relation to the roles of eicosanoids and eicosanoid precursors in mammary carcinogenesis.
Carcinogenesis 1992 Apr
PMID:Composition and turnover of phospholipids and neutral lipids in human breast cancer and reference tissues. 157 10

As part of a search for an effective and safe antiestrogen to be used as adjunct therapy in the treatment of breast cancer, we examined the potential of RU 39,411 and keoxifene to inhibit the incidence of estradiol-induced kidney tumors in Syrian hamsters. Groups of 10 hamsters were chronically treated with implants of either keoxifene, RU 39,411, estradiol plus keoxifene, or estradiol plus RU 39,411 for 8 months. Five hamsters received only estradiol and 5 control animals remained untreated. There was a 100% kidney tumor incidence in estradiol-treated hamsters, which was not statistically different from that in animals co-treated with estradiol plus keoxifene (3 of 4 hamsters with tumors) or estradiol plus RU 39,411 (7 of 8 hamsters with tumors). Rodents treated only with antiestrogen remained tumor free. In addition to kidney tumors, testicular cancer was also found in animals cotreated with either estradiol plus keoxifene (2 of 4 hamsters with tumors) or estradiol plus RU 39,411 (3 of 8 hamsters with tumors). Two animals of this latter group also developed liver tumors. Testicular or liver neoplasms were not observed in hamsters implanted only with estradiol or only with antiestrogen. The lack of inhibition of estrogen-induced carcinogenesis in hamsters by RU 39,411 or keoxifene suggests that these two antiestrogens are not as effective as previously tested substances in inhibiting the appearance of this cancer. However, their concentrations were sufficient to induce, in combination with estradiol, the development of testicular tumors in these hamsters.
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PMID:Lack of effectiveness of antiestrogens RU 39,411 or keoxifene in the prevention of estrogen-induced tumors in Syrian hamsters. 159 73

Earlier research suggested an appreciable latent period between the time of exposure to indoor tobacco smoke and the detection of breast cancer. A close relationship was found in the U.S. between state breast cancer mortality from 1978 through 1981 and state cigarette sales from 1950 through 1954 (R = 0.64, p less than 0.001). The correlation declined for sales in subsequent years but remained highly significant until 1970, but not thereafter. Thus, it appears that the role of indoor tobacco smoke in breast carcinogenesis is that of an initiator and/or an early-stage promoter in the process that leads after 15 to 30+ years to cancer. Trends in cigarette consumption from 1915 to 1965 paralleled breast cancer incidence in Connecticut women from 1935 to 1989. The 1953 and 1975 peaks in incidence were related to 1930 and 1953 peaks in cigarette consumption, respectively, showing a 22.5-year latent period. The drop in cigarette sales in the mid-1950s was followed by a surge to new highs in sales in the early 1960s in the great majority of the states. Approximately 23 years later, breast cancer incidence rates in the mid-1980s in all nine SEER populations are reflecting that surge in cigarette sales, rising to an all-time high in 1985. The earliest declines in breast cancer incidence should occur in New York and Connecticut, where cigarette sales have fallen most dramatically. By the year 2015, white women in the South, currently living with the men with the highest lung cancer rates in the U.S., are expected to show the highest breast cancer rates in the country.
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PMID:Epidemiologic evidence for the role of indoor tobacco smoke as an initiator of human breast carcinogenesis. 160 May 21

A prospective, longitudinal study was performed to test the hypothesis that environmental factors (e.g., diet or cigarette smoking) modulate genetic damage caused by treatment for breast cancer and render these women more susceptible to developing second malignancies. A total of 107 women (49 with breast cancer, 52 with benign breast masses, and 6 normal women) were enrolled. This report describes initial studies at the time of enrollment and disease presentation. Mutant frequency at the hprt locus and cloning efficiency of peripheral blood lymphocytes did not differ significantly among the 3 groups. Mutant frequency increased with age, with a history of cigarette smoking, and with the number of years that current smokers used cigarettes. There was no correlation in women with benign masses between mutant frequency and the incidence of chromosome aberrations (28 women) or sister chromatid exchanges (23 women). A maternal history of breast cancer did not influence mutant frequency. There was no significant relationship between dietary intake of vitamins A, B12, C and E, folacin, selenium, calcium, caffeine, or multivitamin pills, and mutant frequency. Serum folate levels in the deficient range were associated (P = 0.02) with elevated mutant frequencies, whereas SCE rates inversely correlated with serum vitamin B12 levels. These results confirm the importance of age and, less so, cigarette smoking as factors that influence mutant frequency and suggest that a micronutrient, folic acid, may modify genetic damage at the hprt locus. To the extent that somatic mutation contributes to carcinogenesis, these environmental factors may enhance the risk of developing malignant transformation.
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PMID:Factors influencing mutation at the hprt locus in T-lymphocytes: studies in normal women and women with benign and malignant breast masses. 160 Sep 53

We developed a new approach for detecting the gene amplification of cancer DNAs with restriction landmark genomic scanning (RLGS). In cancer research, much effort has been made to find the amplified loci of cancer DNAs, because many lines of evidence indicate association between oncogene amplification and carcinogenesis. Conventionally, such gene amplification has been detected by using Southern hybridization with DNA probes. However, only the information of one locus can be obtained by one hybridization procedure, and analysis of many loci throughout the genome is too laborious and time consuming, even if only several candidate genes are investigated. On the other hand, the "in-gel renaturation method" was reported as another alternative for detection of amplified regions. However, even though this method is much improved, it is difficult to detect less than 7-fold amplification, which is often higher than the amplification of many cancer cases. To overcome these limitations and, in addition, to locate the amplified DNA two dimensionally, we applied RLGS for analysis of DNA amplification in cancer tissues, such as breast cancer (infiltrative tubuloadenocarcinoma), neuroblastoma, meningioma (endotheliomatous meningioma), and thyroid cancer (papillary adenocarcinoma). In some cases of breast cancer, several amplified spots located on the same amplicon were detected. In thyroid cancer, in which no amplification has yet been reported, low-grade amplification was also detected. In this report, we demonstrated that RLGS allows us to screen 2000-3000 restriction landmarks distributed on the genome simultaneously, and even low-grade amplification could be detected effectively. Thus, RLGS has proven to be a very useful method in detecting DNA amplification.
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PMID:New approach for detection of amplification in cancer DNA using restriction landmark genomic scanning. 161 37

This review of the action of estrogens and progestagens, the steroids in oral contraceptives, on cells in the endometrium, breast, ovary, cervix and other tissues, regarding possible causative role in cancer development focuses on the level of steroid receptors and observed actions of these hormones on the cellular level. The steroid hormones are thought to interact with cells by binding to a specific receptor on the cell surface, especially estrogen receptors, while progestagen receptors overlap with glucocorticoids and androgens. Oral contraceptives typically have progestin dosages at the plateau of the dose-response curve, but lower estrogen doses may possible improve the cancer risk. Plasma levels are not reliable estimates of estrogen influence; moreover, estrogens are synthesized locally. Carcinogenesis is a multi-stage process requiring cell proliferation, involving an initiating event, and probably promotion agents, resulting in tumor growth. Estrogens increase cell replication in endometrium, and progestins counter it. Breast cancer evolves in several cell types in the epithelium of the terminal ductal lobular unit, with a 20-year latency. Estrogens stimulate ductal growth and progestins its development, and both are required for full stimulation, as in pregnancy. Estrogens usually stimulate cancer growth, but the precise sensitivity to steroids depends on the timing in the life cycle of the tumor. Ovarian cancer is unique in that neoplasms arise from the epithelium, not the hormone-sensitive tissue. Therefore the suppressive effect of steroids on ovarian neoplasia is thought to be via down- regulation of the gonadotropins, prevention of follicular rupture and consequent cell division of the epithelium, or some effect on growth regulating factors. The effect of steroids on the cervix is unclear, since cervical cancers are hormone-resistant, but there may be a step in transformation by human papilloma virus that involves a glucocorticoid- or progesterone receptor. Steroid receptors are also known to exist in tumors of liver, skin, colon, kidney and anterior pituitary, but their function is neoplasia is unknown.
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PMID:Biology of female sex hormone action in relation to contraceptive agents and neoplasia. 165 Dec 4

Several recent studies based on restriction fragment length polymorphism analysis have supported the concept that the accumulation of multiple genetic alterations converts a normal cell to a malignant cell. Activation of oncogenes and/or inactivation of tumor suppressor genes have been observed during tumor progression in colorectal cancer, lung cancer, and breast cancer. To investigate the possibility that multiple genes are altered during the progression of renal cell carcinoma, we have used restriction fragment length polymorphism markers throughout the genome to test for loss of heterozygosity in 38 renal cell carcinomas. Nearly 64% of the tumors had lost heterozygosity on the short arm of chromosome 3. We also observed loss of heterozygosity averaging about 30% at informative loci on six other chromosomal arms (chromosomes 5q, 6q, 10q, 11q, 17p, and 19p). These results lead us to suspect the existence of several tumor suppressor genes associated with carcinogenesis of renal cell carcinoma.
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PMID:Allelotype of renal cell carcinoma. 167 Sep 99


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