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Three hundred eleven patients with node-positive breast cancer were randomized to one of three adjuvant treatments: cyclophosphamide (Cytoxan), methotrexate, and 5-fluorouracil; all of the above with tamoxifen citrate; or all of the above with tamoxifen and bacillus Calmette-Guerin vaccination. Local therapy for all patients was a modified radical mastectomy. Estrogen receptors were measured on all primary tumors. Patients were stratified by the number of positive nodes (one to three nodes and more than three nodes) and estrogen-receptor value (less than 3 femtomole/mg and greater than or equal to 3 femtomole/mg). Follow-up is available, with a mean of 9.1 and maximum of 14.2 years. In this study the efficacy of short-term tamoxifen is apparent over that of chemoimmunotherapy alone and continues to be significant with prolonged follow-up. The addition of tamoxifen to chemoimmunotherapy significantly prolonged disease-free survival among patients with estrogen receptor-positive tumors who were postmenopausal, who had larger tumors (greater than 3 cm), or who had more extensive axillary node involvement (more than three nodes). Tamoxifen improved overall survival for patients with estrogen receptor-positive tumors larger than 3 cm. The addition of bacillus Calmette-Guerin Cytoxan, methotrexate, 5-fluorouracil, and tamoxifen did not significantly alter disease-free or overall survival.

Forty-eight of 81 (59%) of N-nitrosomethylurea-induced rat mammary tumors regressed in average to almost one-half of the original size 10 days after ovariectomy (ovax) (hormone responsive), while 33 remained essentially unchanged (hormone resistant). AT 20 days after ovax, further decline in hormone-responsive tumors was observed when the rats were treated daily with 0.9% NaCl solution on the tenth day after ovax. Treatment for the same length of time with estrogen either alone or in combination with bromocryptine (to effectively suppress serum prolactin level) prevented tumor regression in hormone-responsive tumors. A similar effect was observed when rats were treated with perphenazine (to stimulate endogenous prolactin secretion) either alone or in combination with the antiestrogen tamoxifen. Estrogen receptors (ERs) significantly declined after ovax. Treatment with estrogen or perphenazine did not have any significant effect on ER level. Progesterone receptors (PGRs) became virtually undetectable after ovax. Treatments with estrogen, estrogen plus bromocryptine, and perphenazine plus tamoxifen but not perphenazine alone were able to partially restore PGRs although this effect was of borderline statistical significance. ER and PGR levels were not significantly different between hormone-responsive and -resistant tumors within each group. We conclude that both estrogen and prolactin play a role in the growth of the N-nitrosomethylurea-induced rat mammary tumor. Changes in ER and PGR levels did not correlate with tumor growth under the present experimental conditions.

The presence of estrogen receptors in breast cancers is now accepted as a predictor of extended disease-free survival, but the relative value of progesterone receptors for this purpose has not been established. We have examined both receptors along with other risk factors in 189 patients receiving adjuvant therapy for Stage II breast cancer. The presence of either estrogen receptors or progesterone receptors was positively correlated with disease-free survival when analyzed separately, whether or not the adjuvant regimen included an endocrine component. However, when estrogen receptors and progesterone receptors were analyzed together in multivariate models, the presence of progesterone receptors was more significant than that of estrogen receptors for predicting time to recurrence, regardless of what other variables were included in the model. These data suggest that determination of the progesterone-receptor concentration is of equal or greater value than determination of the estrogen-receptor concentration for predicting the disease-free survival of patients with breast cancer. Future trials should include measurement of progesterone receptors.

Recent reports of patients with Cushing's disease who have been explored via the transsphenoidal route indicate that the great majority has pituitary adenomas. We report a patient with biochemically documented pituitary-based hypercortisolism who had a clinical and biochemical remission following hypophysectomy. Serial sections of the pituitary tissue removed showed hyperplasia of corticotroph cells but no adenoma. Hypophysectomy was complete as documented by serum levels of FSH, LH, TSH, prolactin, hGH and ACTH at the lower limits of the respective assays, with no response to appropriate stimuli. This case demonstrates that a minority of patients with Cushing's disease has corticotroph cell hyperplasia without a pituitary adenoma.

The majority (87%) of N-nitrosomethylurea-induced rat mammary tumors regressed within 1 week after hypophysectomy (hypox). After a hypox-induced tumor regression, ovine PRL (oPRL), and 17 beta-estradiol (E2) were administered separately or in combination in order to define the individual role of these hormones in regulating tumor growth and influencing estrogen (E), progesterone (Pg), and PRL receptor (R) levels. Administration of E2 (2.5 micrograms twice daily) or oPRL (20 IU daily, started 5 days after hypox and continued for 10 days, resulted in stabilization of tumor growth. Simultaneous administration of E2 and oPRL resulted in a synergistic effect and reactivation of tumor growth. ER levels in mammary tumors were significantly lower than those in the control 15 days after hypox (P less than 0.01). Treatment with E2, oPRL, or both simultaneously had no significant effect on ER levels. A significant decline in PgR levels was noted at both 5 and 15 days after hypox. Whereas treatment with oPRL had no significant effect on PgR levels, E2 administration either alone or in combination with oPRL restored PgR levels to control values. PRLR levels were unchanged from control values at 5 days, but significantly declined (P less than 0.005) 15 days after hypox. Treatment with E2, oPRL, or both hormones simultaneously partially maintained PRLR and prevented the decline to the extremely low level noted in the untreated group. We conclude that the growth of nitrosomethylurea-induced rat mammary tumors is dependent on both E2 and PRL. There was a synergistic effect between E2 and PRL on tumor growth but not on ER, PgR, or PRLR. Neither E2 nor PRL had any significant effect on ER after hypox. PgR is under E2 control. Either E2 or PRL or both hormones were able to maintain PRLR in mammary tumors after hypox.

A prospective, randomized clinical trial of adjuvant treatment of 312 stage II breast cancer patients with use of chemotherapy, antiestrogen therapy, and immunotherapy is reported after 72 months of follow-up. The stratification of patients was based on nodal involvement and estrogen receptor (ER) assay of the primary tumors. Findings at 72 months indicate that antiestrogen therapy (tamoxifen, Nolvadex) added to chemotherapy with cyclophosphamide (Cytoxan), methotrexate, and fluorouracil (5-Fluorouracil) (CMF) resulted in significant delayed recurrence in ER-positive postmenopausal patients, ER-positive patients with four or more positive nodes, and ER-positive patients with tumors greater than 3 cm in diameter. The addition of nonspecific immunotherapy with bacillus Calmette-Guerin had no effect on disease-free survival. ER and progesterone receptor measurements in patients with primary breast cancer provide valuable prognostic information on subsequent recurrence and overall survival and should be documented in future clinical trials.

A prospective, randomized clinical trial of three treatment regimens: (1) Cytoxan, methotrexate, and 5-fluorouracil (CMF), (2) CMF plus the antiestrogen drug, tamoxifen (CMFT), and (3) CMFT plus bacillus Calmette-Guerin (BCG) vaccinations in women with stage 22 breast cancer is reported. All patients underwent mastectomy and estrogen receptor (ER) analysis was performed. The results of this study show that patients with ER- tumors have recurrences more rapidly and have a higher mortality rate than patients with ER+ tumors (P less than 0.0001). In ER+ patients CMFT treatment is more effective in delaying recurrence than CMF alone at 33 months (P = 0.0176). This effect appears to be occurring in both premenopausal and postmenopausal women. In ER- patients the recurrence rate is high, and there is no significant difference among the three treatment groups. In premenopausal patients treated with CMF alone, however, ER- patients recur more rapidly than ER+ patients (P = 0.0313) and suggests that the effect of CMF may be related to the suppression of ovarian function. These findings have demonstrated a significant role for the use of antiestrogen therapy in patients with state II, ER+ breast cancer.

Follow-up data of 113 patients with stage IV breast cancer treated with the antiestrogen tamoxifen show that the duration of remission is in average in excess of 21 months with a median of 16 months. Survival from start of antiestrogen therapy was significantly longer in patients who responded to tamoxifen, in those with dominant site of disease in the soft tissue, and in those with less extensive metastatic involvement. Overall survival from onset of metastasis was also much longer in patients who had responded to tamoxifen than in those who had failed (median of 52 and a half months vs 23 months). Hypophysectomy and androgen therapy used sequentially after antiestrogen each induced further remissions in almost half of the patients with a median duration of 16 months and 10 months respectively. Five drug chemotherapy used in most patients after maximum benefit had been obtained with endocrine therapy induced remissions in two-thirds of the patients with a median duration of 8 months. Adriamycin used sequentially as a single agent induced significant further palliation in almost half of the patients with a median duration of 4 and a half months. We conclude that sequential endocrine therapy and chemotherapy is highly effective in the treatment of stage IV breast cancer and offers prolonged survival to patients with hormone responsive tumors.

The prognostic value of estrogen receptor determination was studied for 510 stage I (axillary node negative) breast cancer patients treated by mastectomy alone. Results at 60 months after mastectomy indicate that stage I patients whose tumors lack estrogen receptors fall into a significantly poorer prognostic group for both recurrence and survival than those whose tumors contain estrogen receptors. Within the postmenopausal group, estrogen receptor negative (ER -) patients are recurring more rapidly than estrogen receptor positive (ER +) patients. Within the premenopausal group, ER + patients have a recurrence rate identical to ER - patients, which is apparent only after prolonged follow-up. In contrast to postmenopausal ER + patients, premenopausal ER + patients appear to have no prognostic advantage over the ER - patients, and thus constitute a high risk group for which adjuvant endocrine therapy might prove beneficial.

Fluoxymesterone (Halotestin), 10 mg p.o. BID, was given to 33 women with Stage IV breast cancer who had previously been treated wih the antiestrogen tamoxifen (Nolvadex) and of whom 17 had also undergone hypophysectomy. Objective remissions were obtained in 13 patients (39%) with an average duration of 11+ months. Response rate to fluoxymesterone was similar in patients who had previously responded to tamoxifen and in those who had failed. Duration of response was longer in the former group (12+ vs. 8 months), but this difference was not statistically significant. Of 17 patients who had been previously treated with tamoxifen and hypophysectomy, seven obtained further remission from fluoxymesterone for an average duration of ten months. Two patients with remissions from fluoxymesterone had previously failed to respond both to antiestrogen therapy and to the removal of the pituitary gland. Androgens appear to be an effective sequential endocrine treatment of Stage IV breast cancer after tamoxifen and hypophysectomy. The mechanism by which androgens induce tumor regression in some patients is probably not an antiestrogenic effect or an indirect effect mediated through the pituitary gland, but perhaps a direct action at the tumor level.

Results of a prospective, randomized clinical trial of three treatment regimens--cyclophosphamide, methotrexate, and 5-fluorouracil (C); C plus the antiestrogen, tamoxifen citrate (CT); and CT plus bacillus Calmette-Guerin (CTBCG)--in 311 women with stage II breast cancer are reported. The data were analyzed by univariate (product limit and log rank) analysis and by multivariate analysis. Estrogen receptors were measured in all primary tumors. The mean follow-up period was 78.2 months. The regimens containing tamoxifen citrate significantly decreased the risk of recurrence in patients with positive estrogen receptors. The addition of tamoxifen does not, however, appear to provide an advantage in overall survival. No benefit in disease-free or overall survival was observed resulting from the addition of BCG to the treatment regimen. The design of the study did not permit an evaluation of the efficacy of the chemotherapy used inasmuch as all patients received it.

An estrogen binding protein for estradiol-17beta is present in the liver cytosol of female intact and one day oophorectomized rats. The dissociation constant reveals high affinity binding (Kd: 0.69 +/- 0.14 times 10(-10) M). Quantitation of EBP using a dextran-coated charcoal method shows that this specific macromolecular binding is much less than in the rat uterus, but similar to that in DMBA-induced mammary tumors. Sucrose density gradient analysis shows sedimentation at 8-9 S and 4-5 S when compared to bovine serum albumin.

Transsphenoidal hypophysectomy was performed in 212 consecutive patients with metastatic breast cancer: 11 died within 30 days, two of surgical complications and nine of advanced metastatic disease. Two patients were unevaluable because of inadequate follow-up in one and simultaneous radiation treatment in the other. Of 199 evaluable patients 42% had an objective remission. Duration of remission averaged 18+ months with 10 out of 84 patients still in remission. Presence of estrogen receptors in the tumor significantly predicted response to hypophysectomy. Of 156 patients in whom completeness of hypophysectomy was assessed, 128 were thought to have a complete removal as shown by the fact that their growth hormone and prolactin were undetectable after stimulation with arginine or chlorpromazine, respectively. Of 26 patients in whom TRH test was performed, TSH and prolactin were undetectable in 20. Of 23 patients where autopsy was performed only six had microscopic pituitary tissue remaining. Hypophysectomy induced remission in eight of 15 patients who had previously responded and then relapsed to the antiestrogen Tamoxifen and in four of 17 who had failed. Conversely, antiestrogen therapy induced remission in six of 26 patients who had previously responded to hypophysectomy and in whom serum estrogens were present in small amount. These data indicate that both gonadal and pituitary hormones play a role in the growth of some human breast cancers.

Six-year results of a prospective, randomized clinical trial of three treatment regimens [(1) cytoxan, methotrexate and 5-fluorouracil (CMF); (2) CMF plus the antiestrogen drug, tamoxifen (CMFT); (3) CMFT plus Bacillus Calmette-Guerin (BCG) vaccinations] in 312 women with stage II breast cancer are reported. Addition of tamoxifen to CMF therapy significantly decreased the number of recurrences at 6 years in ER + patients with greater than or equal to 4 positive axillary lymph nodes, and in those with tumor diameter in excess of 3 cm. The beneficial effect of tamoxifen appeared to be independent of the menopausal status. Addition of tamoxifen to CMF had no effect on disease-free survival in ER + patients with 1-3 positive axillary lymph nodes or in patients with ER--tumors. Addition of BCG vaccinations had no discernible effect on disease-free survival. ER measurements in the primary tumor provide important prognostic information regardless of treatment, with ER + patients having increased overall survival after 6 years. Further follow-up is needed to determine whether tamoxifen is delaying recurrence or preventing it in a subset of these patients.

Estrogen receptor(s) (ER), progesterone receptor(s) (PGR), androgen receptor(s) (ANR), and prolactin receptor(s) (PRLR) were measured in N-nitrosomethylurea-induced mammary tumors in intact female Sprague-Dawley rats and in rats 9 days after ovariectomy. Following ovariectomy, 12 of 15 tumors regressed to 47.7 +/- 5.5% of the original size (hormone-dependent tumors), while the remaining three had arrest of growth reaching 88.8 +/- 7.3% of their original sizes. Cytosol ER level was 50.3 +/- 6.6 fmol/mg protein in tumors of intact rats and was significantly lower (25.6 +/- 8.3 fmol/mg, p < 0.025) in the ovariectomized group. PGR was abundantly present in ten of 13 tumors of intact rats (mean, 144.5 +/- 46.8) but was undetectable in five of six hormone-dependent tumors after ovariectomy (p < 0.01). ANR ws detectable at low levels in only four of 13 tumors of intact rats but in none of six hormone-dependent tumors after ovariectomy. PRLR was not significantly different in tumors of intact and ovariectomized rats (20.6 +/- 2.4 and 15.6 +/- 1.8 fmol/mg, respectively). In three tumors that had arrest of growth after ovariectomy, the levels of ER, PGR, ANR, and PRLR were not significantly different from those of the hormone-dependent tumors. We conclude that the majority of N-nitrosomethylurea-induced rat mammary tumors are hormone dependent. ER, PGR, and PRLR were abundantly present in the majority of these tumors, while ANR was present in only four of 13 tumors. The levels of ER and PGR were significantly lower following ovariectomy, while PRLR was not significantly changed.

Twenty-five patients with acromegaly and 3 patients with gigantism underwent transsphenoidal microsurgery in an attempt to remove the tumor and preserve normal pituitary function whenever possible. An adenoma was identified and removed in 27 of 28 patients. Evaluation 3--6 months postoperatively revealed a GH level less than 5 ng/ml in 29 patients, 5--10 ng/ml in 4 patients and 11--29 ng/ml in 4 other patients. Dynamics of GH secretion were normal in 11 patients who had normal pituitary function and are considered cured. Two patients with low or undetectable GH levels are also considered cured at the expense of being hypopituitary. Three of 7 patients with normal basal GH levels but abnormal dynamics of GH secretion relapsed within 1 yr. Eleven of the 13 patients considered cured did not have extrasellar extension, while 14 of the 15 patients not cured had extrasellar extension. Five patients who were not cured with surgery received radiation therapy. Three patients were treated with an ergot derivative, Lergotrile mesylate, after surgery and radiation therapy failed to normalize GH levels. Transsphenoidal microsurgery is an optimal form of therapy for patients with acromegaly or gigantism, especially those with no extrasellar extension. Dynamics of GH secretion are very useful in evaluating the completeness of adenoma removal.

Prolactin-secreting pituitary adenomas were selectively removed through a transsphenoidal approach from 120 women. Basal serum PRL levels (measured one to six months after surgery) were normal in 96 patients and decreased appreciably but not to normal in the remaining 24 patients. Dynamics of PRL secretion were studied at three to four months in 81 patients who had normal basal PRL level. Two different patterns of response to provocative stimuli were noted in these patients. In one group (group I, n = 65), patients had greater than 100% rise in serum PRL following TRH or perphenazine (Pz) administration. However, when analyzed as a group, the mean +/- SEM incremental responses (delta PRL) to TRH and Pz in these patients (29.9 +/- 1.9, 20.4 +/- 1.5 ng/mL) were significantly less (P less than 0.005 and P less than 0.001) than those of normal women (38.8 +/- 5, 33 +/- 5 ng/mL, respectively). Nineteen of these patients were restudied 12 to 72 months after surgery. The responses to provocative stimulation at that time were improved and similar to normal women. In contrast, in the second group (n = 16) of patients (group II), the responses to stimulation with the same agents were blunted or absent and remained so during subsequent studies. Recurrence of the hyperprolactinemia was noted in 11 of the 16 patients in group II and in only two of 65 patients in group I. The daily serum PRL levels in the immediate postoperative period were higher in patients from group II than those from group I. We conclude that transsphenoidal surgery is an optimal form of therapy for patients with PRL-secreting adenomas.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of various ergot alkaloids on prolactin (Pr) secretion in adult female rats was determined by radioimmunoassay. Ergocorine (ECO) and ergocristine (ECR) in doses of 0.25 to 1.0 mg lowered serum Pr markedly by 1 h with the effect persisting for 24 h at the larger doses. Several other ergots had similar effects while the dihydro derivatives had diverse responses. The pro-oestrous surge of Pr could be blocked by ECR or ECO without interfering with the oestrous cycle. ECO or ECR could suppress the rise in serum Pr induced by oestradiol benzoate (OeB) (5-50 mug) in oophorectomized rats. Perphenazine (PE) stimulation of Pr could be partially antagonized by ECO depending on dose and timing of injections. ECO 2 mg produced an abrupt cessation of lactation with concomitant fall in serum Pr, and ovine prolactin restored this function. Evaluation of pituitary Pr concentration in lactating and intact rats receiving ECO leads to the conclusion that release of Pr from the pituitary is affected. ECO 1 or 2 mg produced a regression of dimethyl-benz(a)anthracene (DMBA) induced rat mammary tumours which could not be reversed by OeB 5 mug, with persisting low serum Pr. PE 1 mg was able to raise serum Pr and stimulated tumour growth. Several of the ergot alkaloids have a profound inhibiting effect on Pr secretion and may be used for studies on Pr action, as well as in medical therapeutics.

The effect was studied of repeated injections of oestradiol-17 beta (5, 10, 25, 50 micrograms) given for various lengths of time (3, 5, 9 days) on total cell content of oestrogen receptors and cytosol progesterone receptors in the uteri of ovariectomized rats. An additional group of rats was injected daily with 50 micrograms oestradiol benzoate (OB) for 9 days in order to achieve a more sustained concentration of oestradiol in the blood. Injections were begun 24h after ovariectomy and the rats were killed 24h after the last injection. Daily administration of 5 micrograms oestradiol prevented the initial transient rise in oestrogen receptors which was observed in the uteri of untreated rats after ovariectomy. Repeated injections of 10 micrograms oestrogen produced an initial lowering in oestrogen receptors after 3 days of treatment which was followed by a prompt rise at 5 and 9 days when treatment was continued. A significant reduction in oestrogen receptors occurred at all times studied when rats were injected daily with 25 and 50 micrograms oestradiol. A more profound reduction in oestrogen receptors was observed in the group of rats treated for 9 days with 50 micrograms OB. Synthesis of progesterone receptors was stimulated by all doses of oestrogen studied. Concentrations of progesterone receptors were significantly higher after 3 and 5 days of treatment with 25 and 50 micrograms oestrogen. After 9 days of treatment, however, concentrations of progesterone receptors were virtually identical in all treated groups, including the group treated with OB. We have concluded that large doses of oestrogen significantly decrease oestrogen receptor content in the rat uterus, especially when OB is used. The degree of reduction, however, is only moderate under these experimental conditions and is insufficient to inhibit synthesis of progesterone receptors.

Local-regional versus distant recurrence patterns were investigated for 311 patients with stage II node-positive breast cancer who were part of an endocrine-chemotherapy adjuvant breast cancer trial. After mastectomy patients were randomized to receive either cytoxan, methotrexate, and 5-fluorouracil (CMF) (1 year) or CMF with tamoxifen (1 year) with or without bacillus Calmette-Guérin (BCG). With a median follow-up of 92.1 months, 55.3% of the patients had recurrences. The first site of recurrence was local-regional for 31.4% of patients and distant for 68.6%. This pattern of first recurrence was not associated with treatment groups, menopausal status, race, estrogen receptor value, number of positive lymph nodes, or tumour diameter. Although patients with a first local-regional recurrence had a better overall prognosis compared with those with a first distant recurrence, 52.2% of those patients with an initial local-regional recurrence developed a distant recurrence within 12 months. Among patients who had a recurrence, 48.3% had a local-regional recurrence at some time during their follow-up. Conclusions from this study are (1) patterns of recurrence were not affected by the addition of antiestrogen therapy to chemotherapy; (2) for the variables tested, including number of positive nodes and tumor diameter, no association with recurrence patterns was found; and (3) most patients (52.2%) with a first local-regional recurrence will develop a distant recurrence within 1 year.

A prospective, randomized clinical trial of adjuvant treatment of 318 stage II breast cancer patients, using chemotherapy, the antiestrogen tamoxifen, and immunotherapy is reported at 48 months follow-up. Women whose primary tumors have no estrogen receptors fall into a significantly poorer prognostic group than those whose tumors contain estrogen receptors. None of the adjuvant regimens appeared to offer any clear-cut advantage for the estrogen receptor negative patients. Those women whose primary tumor contains estrogen receptors appear to be in a prognostically favorable group, when their treatment regimen included the antiestrogen, tamoxifen. The adjuvant use of BCG immunotherapy does not appear to offer additional benefit, but the follow-up period of these treated patients is too brief to be conclusive. A longer period of observation is needed to determine whether this systemic treatment in estrogen receptor positive patients is preventing recurrence or merely delaying it.

Tamoxifen (NSC-180973, ICI-46474), an antiestrogen, was administered to 39 women with stage IV breast cancer at a dose of 20 mg orally every 12 hours. Patients were selected as eligible for endocrine ablative treatment and with disease not so aggressive as to jeopardize further treatment in case the experimental drug failed. Objective remission was obtained in 19 patients (49%) with a mean duration of 11+ months and ten patients are still in remission. No progression was seen in seven patients (18%) lasting 13+ months with only one patient in relapse. Thirteen patients (33%) have failed. Objective remission was obtained in two premenopausal women even though menstrual cycles were not suppressed; bilateral oophorectomy in one of these patients induced a second remission after relapse from tamoxifen. Objective remissions were obtained in two women with proven complete hypophysectomy a direct action of antiestrogens at the tumor level. Positive estrogen receptors were suggestive of being a good predictor of response. Menopausal status and dominant site of metastasis did not affect the response to tamoxifen in this small series. Tamoxifen did not alter prolactin secretion, and side effects from the drug were usually mild and transient in nature. We conclude that tamoxifen is an effective antitumor agent in patients with stage IV breast cancer; further studies are necessary to determine whether it will equal the therapeutic effect of oophorectomy, adrenalectomy, and hypophysectomy.

N-Nitrosomethylurea-induced rat mammary tumors were grown in vitro using the clonogenic soft agar technique. Cells from all tumors (n = 46) formed colonies in vitro. Tamoxifen (10(-7), 10(-6) M) inhibited colony formation to 72 and 53% of control values, respectively. The inhibitory effect of tamoxifen could be reversed with the addition of estradiol (10(-10) to 10(-8) M) to the medium. Estradiol (10(-10) to 10(-8) M), on the other hand, added alone to serum-containing medium did not influence the number of colonies formed in vitro. We conclude that the soft agar clonogenic assay is a feasible technique to study the influence of hormones and antihormones in vitro. The effects of tamoxifen and estradiol noted in vitro were similar to the known in vivo effects of these agents.

Attempts to restore PRL receptors (PRL-R) in liver membranes of hypophysectomized rats with injections of PRL have so far been only partly successful. In the present study, bovine PRL (bPRL) was mixed with polyvinylpyrrolidone (PVP) in order to sustain PRL blood levels with a single injection a day. PRL-R were measured by displacement of the binding of [125I]ovine PRL (lactoperoxidase oxidation) to a 5000 x g particulate fraction of liver by unlabeled ovine PRL. The number of binding sites was calculated by Scatchard analysis and expressed as femtomoles per mg protein. PRL-R were 85 +/- 12 fmol/mg in normal intact female rats. Seven days posthypophysectomy, PRL-R were undetectable. Daily injections of bPRL with PVP for 10 days fully restored PRL-R (117 +/- 32 fmol/mg). No significant change in PRL-R was noted when bPRL was injected with bovine GH (bGH; 120 +/- 23 fmol/mg), bovine LH (bLH; 84 +/- 14 fmol/mg), bGH plus bLH (90 +/- 12 fmol/mg), or estrogens (79 +/- 12 fmol/mg). Daily injections of bGH or bLH, alone or in combination, or estrogens with PVP failed to restore PRL-R. These results demonstrate a direct role of PRL in stimulating the production of its own receptors when a sustained blood level of the hormone is achieved.

Cells obtained from N-nitrosomethylurea-induced rat mammary tumors were grown in vitro using the soft-agar clonogenic assay technique. Their growth was studied in regular media containing serum as well as in media lacking serum, but to which insulin was added. Deletion of serum from the media resulted in a mean decrease of 49% in the number of colonies formed in vitro in 13 of 18 tumors and was without effect in the remaining 5 tumors. The addition of either 17 beta-estradiol (10(-8) M) or ovine prolactin (OPRL, 100 ng/ml) to the defined media resulted in an increase in the number of colonies formed in 12 of 18 tumors. The mean numbers of colonies per Petri dish in 17 beta-estradiol- and OPRL-treated Petri dishes were 95 +/- 5.4 (S.E.) and 92 +/- 6.2% of the values seen in serum-containing media. Simultaneous addition of both hormones to the defined media resulted in a significant increase in the number of colonies formed which was greater than that seen when either hormone was added separately. Of four tumors where neither hormone influenced colony formation, the addition of both 17 beta-estradiol and OPRL resulted in an increase in the number of colonies formed in three tumors. We conclude that the N-nitrosomethylurea-induced mammary tumors can be grown in soft agar using defined media and that their growth can be enhanced by either 17 beta-estradiol or OPRL. These hormones have a synergistic effect on the growth of some of these tumors in vitro. These data are consistent with the known in vivo effects of these hormones on the N-nitrosomethylurea-induced rat mammary tumors.

Breast cancer is often hormone responsive, since growth or regression of tumors can often be modulated by appropriate endocrine manipulations. Estrogen and progesterone appear to be major hormones involved in regulation of breast tumor growth. It has been recently argued that a more accurate marker of hormonal responsiveness might result if an end product of an intact estrogen response system were measured instead of the initial hormone binding step. Progesterone receptor (PgR) has been investigated in this regard since it can be readily measured in human breast tumors and there is clear evidence in experimental breast tumor model systems that PgR is under acute estrogen control. PgR is rarely found in ER- metastatic breast tumors but is present in approximately 59% of ER+ metastatic tumors, especially in those tumors with high levels of ER. Preliminary clinical correlation of ER, PgR and response to endocrine therapy is encouraging. The response rate is significantly higher if the tumor contains both ER and PgR than if the tumor contains ER alone.

Cells obtained from freshly resected human breast cancer were grown in vitro utilizing the soft agar technique. The effects of adding an antiestrogen (tamoxifen, TAM) and 17 beta-estradiol alone or simultaneously on cell growth were assessed. The addition of TAM (10(-6) M) to the medium resulted in a significant decrease in cell growth in 26 of 36 (72%) estrogen receptor (ER)-positive tumors and in one of 5 ER-negative tumors (20%). The degree of inhibition caused by TAM was significantly higher in the ER-positive tumors that also contain the progesterone receptor (PgR) as compared to those that lacked that receptor (i.e., PgR negative) (46.2 +/- 2% versus 36.2 +/- 1.2% inhibition, P less than 0.01). The simultaneous addition of 17 beta-estradiol (10(-8) M) neutralized the inhibitory effect of TAM (10(-6) M) in the majority of tumors. With the presence of serum in the medium, the addition of 17 beta-estradiol alone resulted in an enhancement of cell growth in 6 of 17 tumors. However, because of the confounding effects of serum in the medium, we studied the individual effect of 17 beta-estradiol (10(-8) M) when added alone under serum-free conditions. Of 20 tumors studied, 17 beta-estradiol significantly enhanced cell growth in 12. There was a 67.8 +/- 12.6% increase in the number of colonies formed in these 12 responding tumors. One of these 12 responding tumors was ER negative as well as PgR negative, while the rest were all ER positive. These in vitro studies demonstrate that this approach can provide valuable information on endocrine mechanisms controlling the growth of human breast cancer.

Tamoxifen (T) was given in doses of 40-120 mg/day to 11 premenopausal women with stage IV breast cancer. Objective remission occurred in five, the disease did not progress in one, and five failed to respond. Duration of remission is 19+ months. Five patients underwent ovariectomy after receiving T: of two who responded to T and then relapsed, one responded to ovariectomy; three who failed to benefit from T also failed to improve after ovariectomy. The effect of T on the menstrual cycle ranged from no effect to complete cessation of menses, usually observed in patients who received larger doses. T induced a marked rise in serum estrone and estradiol, reaching levels up to 2500 pg/ml; serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels remained in the normal premenopausal range or were slightly elevated. In two patients in whom amenorrhea was induced with larger doses of T, both serum estrogen and gonadotropin levels were elevated. We conclude that T is effective in treating premenopausal patients with stage IV breast cancer. Because of the stimulating effect of T on ovarian function. escalated doses of T or castration plus T may be necessary in those patients who respond to T.

The nonsteroidal antiestrogen tamoxifen has emerged as a highly effective, nontoxic endocrine therapy for women with Stage IV and II estrogen receptor-positive breast cancer. Tamoxifen appears to act by blocking endogenous estrogen action at the target tissue level rather than by suppression of circulating estrogen levels. In a series of 113 consecutive, selected patients with Stage IV breast cancer, tamoxifen induced objective remissions in 50% lasting an average period of 21 + months and a median period of 16 months. These results are comparable to previous results with surgical hypophysectomy. Recent randomized studies comparing pharmacological doses of estrogen versus tamoxifen in postmenopausal women with Stage IV breast cancer have shown comparable results with these two treatment modalities. Antiestrogen therapy has been shown to be effective in some patients after prior endocrine additive therapy and, in particularly, after ablative procedures, such as ovariectomy, adrenalectomy, and hypophysectomy. It has been shown that circulating estrogens are not completely eliminated following ablation of these endocrine glands, which may account for the effectiveness of antiestrogen in this setting. Other endocrine therapies have been shown to be effective after prior treatment with antiestrogen. Hypophysectomy can induced remissions in 60% of patients who initially responded to tamoxifen and in 25% of patients who failed to benefit from tamoxifen. Recent studies have shown that aminoglutethimide plus hydrocortisone may also induce remissions in some patients after prior treatment with tamoxifen. This latter finding is of particular interest since aminoglutethimide is thought to work by blocking estrogen production, and the finding suggests that tamoxifen does not completely block all endogenous estrogen activity. Fluoxymesterone has been shown to induce remissions after tamoxifen or after tamoxifen plus hypophysectomy, and there was no correlation between the response to antiestrogen abd subsequent response to androgen. Because of its effectiveness and minimal side effects, tamoxifen is considered to be an initial endocrine therapy of choice in women with breast cancer. However, it has its limitations, as demonstrated by the results of secondary endocrine therapies such as hypophysectomy, medical adrenalectomy, and androgen therapy.

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.

Five-year results of a prospective, randomized clinical trial of three treatment regimes--(a) cytoxan, methotrexate, and 5-fluorouracil (CMF); (b) CMF plus the antiestrogen drug, tamoxifen (CMFT); and (c) CMFT plus bacillus Calmette-Guerin (BCG) vaccinations--in 312 women with stage-II breast cancer are reported. Estrogen receptors (ER) were measured in all of the primary tumors. Addition of tamoxifen to CMF therapy significantly decreased the number of recurrences at five years in ER positive patients with four or more positive axillary lymph nodes. Addition of tamoxifen to CMF had no effect on disease-free survival in ER-positive patients with 1-3 positive axillary lymph nodes or in patients with ER-negative tumors. Addition of BCG vaccinations had no discernible effect on disease-free survival. ER measurements in the primary tumor provide important prognostic information regardless of treatment, with ER-positive patients having lower recurrence rates and mortality after five years. ER measurements also have predictive value for response to endocrine therapy. Further follow-up is needed to determine whether tamoxifen is delaying recurrence or preventing it in a subset of these patients.

Tamoxifen (ICI 46474), an antiestrogen, was given to 89 selected patients with stage IV breast cancer at a dose of 20 mg orally every 12 hours. Forty-seven percent of the patients had objective tumor regression averaging 11+ months with 25 of 42 women still in remission. In the first 39 patients where the minimum follow-up period is 16 months the average duration of remission is more than 15 months with 8 of 19 patients still in remission. These results are approaching those of surgical hypophysectomy, where, in our experience the average remission lasts about 18 months. Thus, Tamoxifen is a highly effective antitumor agent and is probably the initial treatment of choice for women with hormone responsive breast cancer. Antiestrogen induced objective remissions in 5 of 19 patients who had previously responded to surgical hypophysectomy, and 5 additional patients showed no progression of disease lasting 15+ months. Estradiol and estrone were detectable in the serum of these patients whereas, prolactin and growth hormone were not detectable. Thus, antiestrogen can induce remissions in some patients in the absence of the pituitary gland, and this constitutes additional palliation and provides evidence that estrogens can directly stimulate tumor growth. Four of 7 patients who obtained remissions from Tamoxifen obtained further improvement from hypophysectomy, and 1 of 8 patients who failed to benefit from antiestrogen improved after hypophysectomy. These results suggest that prolactin and growth hormone may also play a role in stimulating tumor growth in some patients.

We report an incidence of thrombosis of 17.6% in 159 patients treated with a five-drug chemotherapy regimen (cyclophosphamide, methotrexate, 5-fluorouracil, vincristine, and prednisone) for Stage IV breast carcinoma. Chi-squared analysis of risk factors for thrombosis (ambulatory status, obesity, family history, smoking, diabetes mellitus, hypertension, liver dysfunction, thrombocytosis, and previous endocrine therapy) showed no difference between the patients who had a thromboembolic event and those who did not. Statistical analysis revealed that a significantly higher incidence of thrombosis occurred during the chemotherapy regimen than when off this regimen (P less than 0.05). Detailed coagulation studies done prospectively on 10 patients receiving the five-drug chemotherapy regimen compared with 10 control patients showed a significantly elevated Factor VIII antigen:activity ratio in the group receiving the chemotherapy regimen compared with the control group and normals. These results implicate the chemotherapeutic regimen in the pathogenesis of the increased incidence of thrombosis. The pathophysiology of thrombosis in settings such as this awaits better in vitro tests defining the "hypercoagulable state."

Human pituitary tumors were studied in vitro using the clonogenic stem cell assay. Mechanical dispersion was used to prepare single cell suspensions for plating. Colony formation occurred in 21 of 24 tumors plated. Bromocriptine (Brc; 10 nM) added to the medium resulted in a significant decrease in the number of colonies formed in 5 of 10 prolactinomas and in 1 tumor secreting both PRL and GH. However, PRL secretion was decreased in 8 of 9 tumors tested. Brc had no effect on either colony formation or hormone secretion in other tumors secreting GH (n = 2), ACTH (n = 2), or FSH (n = 1) or in nonsecreting tumors (n = 4). Tamoxifen (Tam; 10(-7) M) inhibited colony formation in 6 of 10 prolactinomas and in 1 tumor secreting GH and PRL. PRL secretion into the medium correlated with the changes in the number of colonies. Tam was not effective in any other tumor tested. In only 1 instance was there a synergistic action between Brc and Tam on inhibition of colony formation. Brc, but not Tam, caused a significant decrease in the size of the colonies formed from cells of PRL-secreting tumors. The least numbers of colonies per plate were found in 3 prolactinomas from patients treated preoperatively with Brc. We conclude that the soft agar clonogenic assay technique is a feasible method to study human pituitary tumors in vitro. Both Brc and Tam inhibited colony formation in this system in a significant proportion of tumors. The potential antiproliferative action of Tam in vivo needs to be studied in view of these results.

The effect of prolactin in supporting the growth of 7, 12-dimethylbenz(a)anthracene-induced mammary tumor in adult female Sprague-Dawley rats was investigated when estrogen receptors were blocked by the nonsteroidal antiestrogen, Tamoxifen, ICI 46,474. Following an oophorectomy-induced remission, perphenazine, which stimulates endogenous prolactin release, was able to restore tumor growth whether or not Tamoxifen was added. A second course of perphenazine treatment, instituted after the tumors were allowed to shrink, was again effective in stimulating tumor growth. After a regression in tumor size induced by oophorectomy and daily administration of Tamoxifen, perphenazine was able to restore original tumor size despite continued treatment with Tamoxifen. In intact rats, after regression was obtained by daily administration of Tamoxifen and the prolactin inhibitor, lergotrile mesylate, perphenazine induced tumor growth when the latter was discontinued, even though Tamoxifen was continued for 50 days. Estrogen receptors measured at the time of maximum stimulation by perphenazine were undetectable. On the other hand, estradiol did not stimulate tumor growth when serum prolactin was depressed to undetectable levels by lergotrile. These results indicate that prolactin supports the growth of 7, 12-dimethylbenz(a)anthracene-induced rat mammary tumor and that estrogen receptors are not required under these conditions.

The antiestrogen Tamoxifen (T), given orally to 113 patients with stage IV breast cancer, induced objective remission in 50%. Duration of remission in the first 39 patients, with minimum 27 months follow up, is 18 + months; these results are equal to those of surgical hypophysectomy. T prolonged survival in responders. Older age, previous response to endocrine therapy and positive estrogen receptors predicted response to T. T was effective in hypophysectomized patients in whom serum growth hormone and prolactin were undetectable, but serum ostrogens were present in low amount, suggesting a direct stimulatory effect of estrogens at the tumor level. Hypophysectomy induced further palliation after treatment with T, indicating that pituitary hormones may also play a role in the growth of some human breast cancers. Side effects from T were minimal. T is the initial treatment of choice for postmenopausal women with hormone responsive stage IV breast cancer.