Plasma prolactin responses to thyrotropin-releasing hormone in patients with breast cancer

The forgotten effects of thyrotropin-releasing hormone: Metabolic functions and medical applications

Thyrotropin-releasing hormone (TRH) causes a variety of thyroidal and non-thyroidal effects, the best known being the feedback regulation of thyroid hormone levels. This was employed in the TRH stimulation test, which is currently little used. The role of TRH as a cancer biomarker is minor, but exaggerated responses to TSH and prolactin levels in breast cancer led to the hypothesis of a potential role for TRH in the pathogenesis of this disease. TRH is a rapidly degraded peptide with multiple targets, limiting its suitability as a biomarker and drug candidate. Although some studies reported efficacy in neural diseases (depression, spinal cord injury, amyotrophic lateral sclerosis, etc.), therapeutic use of TRH is presently restricted to spinocerebellar degenerative disease. Regulation of TRH production in the hypothalamus, patterns of expression of TRH and its receptor in the body, its role in energy metabolism and in prolactin secretion are addressed in this review.

Breast cancer in a male patient with prolactinoma

A 68-year-old man was diagnosed as having left primary breast cancer. Systemic bone roentgenography showed no evident metastasis, however, skull roentgenography revealed ballooning of the sella turcica, suggesting a pituitary tumor, which was subsequently confirmed by computed tomography. Because there was a high serum prolactin level, the pituitary tumor was diagnosed as a prolactinoma. A modified radical mastectomy was performed for the breast cancer, and bromocriptine therapy given for the prolactinoma. Prolactin is known to initiate and promote breast cancer in mice and rats but little is known about its role in human breast cancer. If hyperprolactinemia plays an important role in the tumorigenesis of human breast cancer as it does in mice and rats, the incidence of breast cancer in patients with hyperprolactinemia may be high. To our knowledge, however, only four such cases have been reported. The present rare case of male breast cancer with prolactinoma is discussed with reference to the literature.

Prolactin and total lactogenic hormone measured by microbioassay and immunoassay in breast cancer

Basal prolactin (PRL) and total lactogenic hormone (TLH) levels were measured using a new microbioassay (BA) and conventional immunoradiometric assay (IRMA) in patients with breast cancer and compared to an age-matched control group. No significant differences were found using the IRMA, but BA lactogenic levels were significantly elevated in breast cancer patients compared controls, leading to a markedly elevated BA/IRMA ratio for both PRL (2.7 vs 1.4, P less than 0.0001) and TLH (2.8 vs 1.4, P less than 0.0001) which was greatest for postmenopausal women. Using the mean +2 standard deviations as the upper limit of normal, there was no significant difference between breast cancer patients and controls for IRMA, but BA and BA/IRMA PRL levels were elevated in 42% and 61% of the patients, respectively. There was a weak negative correlation of BA and IRMA PRL with age for normals (r = -0.53 for both) but no correlation was evident for breast cancer patients (r = 0.06 and -0.13, respectively) implying a sustained absolute and relative bioactive hyperprolactinaemia at all ages. These results show increased lactogenic bioactivity in breast cancer and suggest that different forms of bioactive prolactin undetected by IRMA (or enhancing serum factors) are present in the sera of these patients.

Diet and breast cancer in causation and therapy

The major macronutrient associated with increased breast cancer risk is dietary fat. Evidence for this association is based on epidemiologic, clinical, and laboratory animal studies. In addition, there is suggestive epidemiologic evidence that differences in postmastectomy survival rates in Japan and the United States may be attributable to differences in dietary fat intake. The importance of the type of fat consumed, as well as its amount, has emerged as an issue of major importance. Some oils, including those rich in monounsaturates, medium chain fatty acids, or omega-3 (n-3) fatty acids appear to lack tumor-promoting effects despite their presence in the diet at high levels. Possible mechanisms by which dietary fat may exert its effects could be either direct or indirect. Direct mechanisms involve dietary modification of membrane structure and function; indirect mechanisms involve alterations in the endocrine system, and/or the metabolism of essential fatty acids to biologically active eicosanoids such as prostaglandins, and suppression of immune responses. Dietary guidelines and dietary intervention trials for the primary and secondary prevention of breast cancer are discussed.

Plasma lipids and prolactin in patients with breast cancer

In a comparative study of pre- and postmenopausal women with benign and malignant breast disease, a number of differences were observed in circulating plasma prolactin and lipid concentrations. Plasma lipids, phospholipids, triglycerides, cholesterol and free fatty acids were all higher in blood obtained from breast cancer patients prior to surgery. HDL-Cholesterol levels were significantly lower in these patients. These differences remained when the patient groups were sub-divided according to menopausal status. Plasma prolactin concentrations were also found to be higher in cancer compared with non-cancer patients, this effect being more marked in premenopausal than in postmenopausal patients. Premenopausal patients with invasive or poorly differentiated disease had significantly higher prolactin levels than those with non-invasive disease. No correlations were found between plasma prolactin and any of the lipid fractions.

Serum and breast duct fluid prolactin and estrogen levels in healthy Finnish and American women and patients with fibrocystic disease

Nipple aspiration yielded measurable amounts of breast duct fluid for 27 of 42 (64%) healthy premenopausal Finnish women, 93 of 218 (43%) premenopausal American patients with fibrocystic disease, but only 24 of 92 (26%) healthy American premenopausal controls. When aspiration was successful, the average volumes obtained were larger for the normal Finnish women and, particularly, for the American fibrocystic disease patients compared with the American controls. The difference in secretion between the healthy Finnish and American women appeared to be related to a history of breast feeding, and its duration. While serum estrogen and prolactin concentrations were similar in the three groups, prolactin levels in breast fluids from the Finnish women were frequently higher than those in the American controls. A similar trend, which did not reach statistical significance, was observed in the 43 of 93 (46%) secretors with fibrocystic disease and cyclical mastalgia.

Prolactin receptors in human breast cancer

Prolactin receptors have been measured in 92 human breast carcinomas. Both free and total receptors (after desaturation by MgCl2) have been looked for. Free receptors have been found in 46% of the cases, total receptors in 72%. Specific binding ranges from 0.8 to 8.0%. No correlation could be found between prolactin receptors and age, weight, menopausal status and pathological features (differentiation, histoprognostic grading, cellular density). A highly significant correlation has been found between prolactin receptors on the one hand and estradiol and progesterone receptors on the other.

Plasma prolactin levels in patients with breast cancer

The plasma prolactin levels of 98 healthy women 22 to 65 years old showed a strong inverse correlation with age. This relationship persisted for older premenopausal and postmenopausal women (aged 30 to 65 years) whose results were compared with those of 34 premastectomy early breast cancer patients, another 38 studied four to six weeks after mastectomy, and 38 with advanced disease (age range, 30 to 77 years). There was no correlation between age and plasma prolactin in any of the breast cancer groups. When patients and controls were classified according to their menopausal status, the premastectomy and postmastectomy early breast cancer groups both showed significantly higher prolactin concentrations than the corresponding controls (P less than 0.001) in all cases). These abnormalities were particularly prominent in the patients studied after surgery, although the difference was significant only for the postmenopausal groups (P less than 0.05). Plasma cortisol and urinary free cortisol levels were normal in postmastectomy patients, suggesting that stress was not the cause of elevated prolactin levels. In advanced breast cancer, elevated plasma prolactin concentrations were found only in the postmenopausal patients.

Androgen substitution with testosterone containing nasal drops

Testosterone proprionate in form of eye drops will not be absorbed. A good absorption takes place following the administration of testosterone containing nasal drops in the form of an emulsion of pure testosterone. A quick, significant testosterone increase but of only short duration takes place. Unpleasant side effects were not observed. This treatment may be clinically applicable to male patients in the climacteric period.

Pituitary gonadotrophins and prolactin in patients with endometrial cancer, fibroids or ovarian tumours

The serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH) and, prolactin (PRL) were measured before and after gonadotrophin releasing hormone (GnRH) and thyrotrophin releasing hormone (TRH) stimulation in 17 patients with endometrial cancer, in 15 patients with uterine fibroids, in 11 patients with ovarian cystadenomas or cancer and in 14 age-matched controls. The women with fibroids had a low FSH level and a diminished FSH response to GnRH but an excessive PRL response to TRH while the other patient groups did not differ from the controls. The results indicate no relation between pituitary function and endometrial or ovarian tumor.

Treatment of benign breast disease with bromocriptine

23 women with benign breast disease (fibrocystic disease or fibroadenosis) were treated for three months consecutively with a prolactin inhibitor drug, bromocriptine, at the dose of 2.5 mg every eight hours. Serum prolactin levels were normal before treatment; during treatment prolactin concentrations were significantly suppressed all the day long. 21 out of 23 patients receiving bromocriptine showed marked relief to pain and mammary tension after a few days of treatment; adenomatous of cystic nodules became smaller and softer, often with disappearance of the smaller ones. Two patients failed to respond to treatment. In all positive cases the improvement persisted for at least six months after the end of treatment. No important side effects were observed during the therapy. Our results do not allow any conclusion on the real mechanism of action of bromocriptine in benign breast disease, nevertheless they indicate the possible usefulness of this drug in treating patients with benign breast disease.

Pituitary-ovarian function in breast cancer patients on adjuvant chemoimmunotherapy

One hundred thirty-one patients with operable breast cancer were treated with adjuvant chemoimmunotherapy consisting of 5-fluorouracil, adriamycin, cyclophosphamide, and BCG (FAC-BCG). Fifty-five of 131 patients were premenopausal of which 71% (38/55) became amenorrheic. To determine the mechanism of amenorrhea, we measured the immunoreactive serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and plasma estradiol (E2) before and after intravenous administration of luteinizing hormone-releasing hormone (LH-RH) in 11 unselected premenopausal patients who developed amenorrhea and 11 unselected patients who did not. Serum prolactin (PRL) levels were also measured before and after iv administration of thyrotropin-releasing hormone (TRH). Our results showed that patients who developed amenorrhea had abnormally high serum LH and FSH levels at basal and after LH-RH stimulation and low plasma estradiol. Serum PRL levels were normal. Patients who developed amenorrhea were older than those who did not, but their serum LH and FSH levels were also significantly higher and plasma estrogens were significantly lower than that found in 11 normal women with regular menses of the same age range. These results indicate that amenorrhea that develops in some patients with breast cancer after FAC-BCG therapy is a result of primary ovarian failure.

A quantitative approach to determining disease response during therapy using multiple biologic markers: application to carcinoma of the breast

This analytical study was undertaken in an effort to develop a model for a quantitative approach to the evaluation of multiple biological marker levels in blood and urine as a means for determining tumor changes during treatment of patients with malignant disease. The potential biologic markers measured in patients with carcinoma of the breast consist of three urinary polyamines (putrescine, spermidine and spermine), three urinary nucleosides (pseudouridine, N2, N2-dimethylguanosine and 1-methylinosine), and plasma carcinoembryonic antigen (CEA). The distribution patterns of the seven markers measured pretreatment and five weeks after initiating therapy were examined by grouping the patients into the three categories of progression, stable, or regression based on their clinical response to treatment. In addition to the individual marker measurements, the pretreatment and posttreatment values of the ratios of the polyamine levels (spermine/putrescine, spermine/spermidine, and spermidine/putrescine) and the nucleoside levels (N2, N2-dimethylguanosine/pseudouridine, 1-methylinosine/pseudouridine, and 1-methylinosine/N2, N2-dimethylguanosine) were also evaluated. In the pretreatment measurements, CEA levels were elevated for 76% of the patients and the three nucleosides were elevated for 36% of the patients and the three nucleosides were elevated for 36% to 37% of the patients. Urinary spermidine and spermine levels were abnormal for 27% and 24%, respectively, while putrescine levels were elevated for 7% of the patients. When all 14 marker measurements and the 12 ratios of these measurements were considered, the multiple regression equation evaluated the treatment results with a multiple correlation coefficient (R = 0.891; P less than 0.100) about 2.4 times higher than with the most sensitive single marker variable, N2, N2-dimethylguanosine/pseudouridine (R = 0.377; P less than 0.05), alone. Stepwise regression analysis revealed that the minimum number of multiple marker measurements and their ratios required to achieve the maximum value of the multiple correlation coefficient (R = 0.653; p = 0.010) was fifteen. These include the pre and posttreatment measurements of CEA, spermine, N2, N2-dimethylguanosine and 1-methylinosine, as well as two ratios of the polyamines and three ratios of the nucleosides in the post-treatment of the polyamines and three ratios of the nucleosides in the post-treatment measurements. These data suggest that the utilization of regression analysis to evaluate the monitoring utility of multiple marker measurements may be of clinical value.

Recurrent breast cancer treated with the antioestrogen tamoxifen: correlation between hormonal changes and clinical course

Forty-five post-menopausal women with recurrent breast cancer were treated with the antioestrogen, tamoxifen, 20 mg twice daily. Clinical assessment after 12 weeks indicated that 18 (40%) showed some remission. Gonadotrophins were suppressed within two weeks to relatively constant concentrations within the post-menopausal range, responses to luteinising hormone-releasing hormone (LH-RH) did not change, and androgen concentrations remained within the normal range in all patients. Oestradiol concentrations rose steadily only in women in whom treatment failed. Serum prolactin concentrations were raised in 18 out of the 44 (41%) patients in whom they were measured; 13 of these did not respond to treatment. Treatment did not change the average prolactin concentration when this was within the normal range, but it significantly reduced prolactin concentrations in hyperprolactinaemic patients--within two weeks (P less than 0-01) in those who responded well and by six weeks (P less than 0-05) in those who showed no remission. Among patients with normal prolactin values the release of prolactin after thyrotrophin-releasing hormone was significantly greater in those with no remission than in those who responded to tamoxifen. Responses in those with hyperprolactinaemia were reduced to about half the control values, and again this change occurred faster in those who were successfully treated. Patients therefore seem to have a better chance of responding to anti-oestrogen treatment if prolactin secretion is low.