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

Specific iodine-125-labeled prolactin binding was measured in membrane particles prepared from R3230AC mammary carcinoma and liver of tumor-bearing Fischer rats after either prolactin, estrogen, or lergotrile mesylate treatment, or after the induction of diabetes by streptozotocin. Hormone binding to tumors was decreased by treatment with prolactin (.5 or 1 mg/day) or estradiol valerate (7.5 mg/kg/week). In contrast, prolactin treatment was without affect on prolactin binding to liver membrane particles, but estradiol valerate treatment resulted in a 4-fold increase in prolactin binding to this tissue. Lergotrile mesylate, which lowers plasma prolactin levels, had no affect on tumor growth or prolactin binding to either tumor or liver. Prolactin binding to both tumor and liver was significantly reduced in diabetic rats, suggesting that insulin may play an important role in controlling tissue sensitivity to prolactin. Specific binding of iodine-labeled prolactin to enzymatically dissociated cells from R3230AC tumors was demonstrated in vitro. The binding capacity of the cells was found to be of the same order of magnitude as the binding capacity in membrane preparations when appropriate corrections were applied for yields of cells and membranes. R3230AC tumor, which is responsive to prolactin, appears therefore to be a useful model system for further study aimed at elucidation of growth and metabolic response to the hormone prolactin in breast cancer.
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PMID:Prolactin binding to R3230AC mammary carcinoma and liver in hormone-treated and diabetic rats. 18 51

Hypophysectomy was performed in 28 women with Stage IV breast cancer who were treated initially with antiestrogens. Six of 13 patients who responded to tamoxifen and 2 of 12 who failed to benefit from tamoxifen obtained remissions from hypophysectomy. The remissions average 11+ months. Three of 8 patients treated initially with antiestrogens have responded to androgen therapy. The results suggest that hormones other than estrogen, which appears to play a major role, may be involved in stimulating the growth of some human breast cancers. Prolactin receptors were detectable in 51% of human breast cancers and were detected in both estrogen receptor-positive and -negative tumors. Preliminary clinical correlations suggest that prolactin receptors will not be useful in predicting response to antiestrogen therapy.
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PMID:Role of pituitary hormones in the growth of human breast cancer. 21 92

Prolactin receptors have been identified for the first time in a number of human breast cancer cell lines and a normal human breast cell line maintained in long-term tissue culture. Optimal conditions for determining the binding of 125I-labeled human prolactin to these cells were established. Five different tumor cell lines have different content of prolactin receptors ranging from 2,300 to 26,000 sites/cell. All tumor cell lines contained more prolactin receptors than does one normal breast cell line (1700 sites/cell). The prolactin receptors in these human mammary tumor cells not only bind human prolactin but also recognize other lactogenic hormones such as human growth hormone, human placental lactogen, and sheep prolactin, but not animal growth hormone, which are not lactogenic. The affinity (Ka) of binding of human prolactin to these cells is 4 x 10(9) M-1 (Kd = 2.5 x 10(-10)M). The hormone specificity and affinity for hormone of these human mammary tumor cells are very similar to that found for the rabbit mammary gland. These human mammary tumor cell lines in long-term culture should prove very useful to study the biology of prolactin receptors in living human cells and the role of prolactin in the tumorigenesis of the human breast.
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PMID:Prolactin receptors in human breast cancer cells in long-term tissue culture. 22 85

Cancer of the human breast is probably a group of diseases which have different causes. Changes in hormonal status that increase breast cancer risk probably do so by 'promoting' tumour development rather than by 'initiating' it. Exogenous oestrogens seem to act as tumour promoters in this context, but there is to date no evidence that oral contraceptives, some of which contain oestrogens in low dosage, increase breast cancer risk. On the contrary, they appear to reduce the incidence of benign breast tumours. Prolactin-release is associated with increased mammary tumour incidence in rats but not in humans. There is no evidence that viruses or exposure to hair-dyes increase breast cancer risk. The fact that slight dietary restriction can dramatically reduce mammary tumour incidence in rats, suggests that dietary factors should be looked at more closely in the search for aetiological factors in man.
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PMID:Aetiology of breast cancer: a brief review. 22 89

A controversy exists in regard to thyroid function and breast cancer. Hypothyroidism has been suggested as being either protective from breast cancer or predisposing to the disease. It has been hypothesized that a deficiency in circulating thyroid hormones may hypersensitize the mammary glandular epithelium toward prolactin and estrogens, thus aiding the development of breast neoplasia. On the other hand, thyroid hormone replacement therapy has been connected with an increased risk of breast cancer, but this has been contested. At this time the American Thyroid Association recommends that, if indicated, hypothyroid patients should take their thyroid hormone medication. Hyperthyroidism has been associated with a decreased risk of breast cancer. Also, in hyperthyroid patients with inoperable breast cancer, the malignant growth is thought to be slowed. However, this, too has been disputed. Moreover, hyperthyroidism has been connected with the development of breast cancer in premenopausal women. At present no role of thyroid hormone in the pathobiology of breast cancer can be defined. It seems that the "thyroid-breast cancer controversy" can only be resolved by a prospective study preferably on postmenopausal women correlating thyroid (T3, T4, PBI), pituitary (TSH, TRH, Prolactin), and adrenocortical (androgens) function tests with the clinical examination of thyroid, breast, and genital apparatus and determination of the estrogen status (vaginal smear, plasma estrogens) as well.
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PMID:Thyroid disease in relation to breast cancer. 36 55

1 Low doses of carbidopa/levodopa (12.5 mg 1-alpha-methyl-dopahydrazine, 125 mg levodopa) were administered orally to 29 patients with tumours of the breast (16 with breast cancer, 13 with benign breast disease). 2 Plasma dopa response curves were similar in all the patients studied. 3 Prolactin and growth hormone showed similar responses to carbidopa/levodopa irrespective of age or diagnosis. 4 Prolactin showed an unusual reponse in four patients which has not previously been recorded.
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PMID:The effect of low dose carbidopa/levodopa on prolactin and growth hormone concentrations in patients with breast cancer and in benign breast tumours. 65 81

Transnasal, transsphenoidal microsurgical hypophysectomy is a useful therapeutic procedure for patients with Stage IV breast cancer which can be peformed in selected patients with minimal morbidity and mortality. Functionally complete hypophysectomy can be accomplished with regularity, and anything less than this is considered to be a technical failure despite the fact that remissions may occur after incomplete hypophysectomy. In view of the recent outstanding results with antiestrogen therapy in patients with breast cancer, we recommend this as the initial treatment in those patients who are good candidates for endocrine therapy. Hypophysectomy has been shown to induce improvement after antiestrogen treatment, particularly in those patients who have had an initial response to antiestrogens as well as in a few patients who failed to benefit. Estrogen receptor measurements in the tumor tissue have been shown to be useful in selecting patients for hypophysectomy as well as for antiestrogen therapy. Prolactin receptors have been found in about 50 per cent of human breast cancers, and their potential usefulness in selecting patients for hypophysectomy is being explored. Hypophysectomy is a definitive therapeutic procedure that should not be used as a last resort in the terminally ill patient.
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PMID:Hypophysectomy for stage IV breast cancer. 68 62

Mean 24-hr prolactin concentrations were determined in 25 female control subjects, 16 women with benign breast masses, and 23 subjects with breast cancer. This evaluation performed before breast surgery revealed significantly decreased (p less than 0.02) nocturnal (12 a.m. to 7 a.m.) prolactin concentrations in 12 postmenopausal breast cancer subjects that contrasted with significantly increased (p less than 0.05) nocturnal prolactin levels in five luteal-phase premenopausal women with breast cancers. Prolactin concentrations in patients with benign breast disease were not significantly different from control subjects. Two of the premenopausal breast cancer patients had marked preoperative elevations in their mean 24-hr prolactin levels, and they were two of the three subjects who have since expired. Nocturnal prolactin secretion was significantly decreased (p less than 0.03) in four premenopausal breast cancer patients when they were studied 1 year after surgery; however, it remained the same in the eight postmenopausal breast cancer patients similarly evaluated. Although disordered prolactin regulation has been found in these women with breast cancer, its role in the etiology and progression of human cancer is still uncertain.
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PMID:Disordered nocturnal prolactin regulation in women with breast cancer. 92 45

The recent findings regarding the possible relation of prolactin to human breast cancer are reviewed. Prolactin is a single-chain polypeptide hormone secreted by the anterior pituitary; it appears important to the development and growth of mammary tumors in mice and rats. Certain drugs (L-dopa, the ergot derivatives) inhibit the release of prolactin from the anterior pituitary and lower its serum concentration. Chlorpromazine and other phenothiazines block the synthesis, release, or action of prolactin-inhibiting factors leading to increased prolactin secretion. The midcycle serum estrogen elevation does not increase serum prolactin but often high doses of estrogen will. Mammary tumors in mice and rats appear different from those in human, being of alveolar origin while human tumors are thought to be ductal. Also, rodent cancers do not usually metastasize, even when large. About 40% of human breast cancers respond to endocrine therapy while in Sprague-Dawley rats induced mammary tumors are 80% hormone responsive. In mice hyperplastic nodules but not mammary cancers respond to horomone deprivation. Prolactin is a key hormone in the stimulation of hyperplastic nodules in mice and mammary tumors in rats. The effects of progesterone on these growths is not clear. Serum prolactin levels normally vary throughout the day. Levels are not different in cancer patients but certain families with high cancer rates have been shown to have higher than normal serum levels. Although prolactin receptors have been identified in mouse and rat mammary tissue and tumors and prolactin responsiveness of the tumors correlated with the number of such receptors, these receptors have not been identified in human breast cancer cells. Patients have responded to L-dopa with relief of bone pain and a 50% decrease in serum prolactin. Suppressing atypical precancerous lesions by depriving them of their hormonal support offers the best chance for preventing eventual development of breast cancer. In vitro determination of the presence of prolactin receptors in human breast tumor tissue may allow accurate prediction of response to endocrine ablation. Variations in prolactin receptors may account for response differences of breast tumors to different doses of estrogen. Near-zero prolactin levels following hypophysectomy in some patients have been correlated with clinical remissions. Combinations of drugs to reduce serum prolactin levels or antagonize the hormones's effect on the breast may be needed to obtain results.
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PMID:Prolactin and breast carcinoma. 108 86

The comparison of blood levels of oestradiol, testosterone, prolactin, and sex-hormone binding globulin (SHBG) was made of 3250 rural Chinese and 300 British women, aged 35 to 64. To reduce the number of assays performed the blood samples were combined so as to form 390 and 30 pools, respectively. The Chinese had significantly less oestradiol and testosterone. Prolactin levels were similar in both races. SHBG was significantly lower in postmenopausal British women. In the Chinese women, testosterone was positively and prolactin negatively correlated with breast cancer mortality.
Breast Cancer Res Treat 1991 May
PMID:Serum hormone levels in British and rural Chinese females. 187 56


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