Medical Castration with Zoladex: A Conservative Approach to Premenopausal Breast Cancer

Ovarian Function Suppression with the Gonadotrophin-Releasing Hormone (GnRH) Analogue Goserelin in Premenopausal Advanced Breast Cancer

Aims and background

Goserelin is a gonadotrophin-releasing hormone (GnRH) analogue that induces the suppression of gonadal steroidogenesis, and it could therefore be a medical alternative to irreversible surgical castration. We report the clinical and endocrine results from 40 goserelin-treated premenopausal patients with advanced breast cancer.

Methods

A depot formulation of the drug (3.6 mg s.c.) was administered fortnightly for the first 4 doses, and monthly thereafter. Gonadotrophins and estradiol (E2) levels were measured before and at specific times during the treatment.

Results

Objective responses were observed in 17 of the 38 evaluable patients (45%), six of whom achieved complete remission. The best responses were observed on soft tissues (65%). Castration E2 levels were achieved in all of the patients.

Conclusions

Our results confirm that goserelin is as effective as surgical oophorectomy in premenopausal advanced breast cancer.

Adjuvant cytotoxic and endocrine therapy in pre- and postmenopausal patients with breast cancer and one to nine infiltrated nodes: five-year results of the Hellenic Cooperative Oncology Group randomized HE 10/92 study

SUMMARY

The present randomized phase III trial was designed to detect a 15% benefit in relapse-free survival (RFS) or overall survival (OS) from the incorporation of adjuvant tamoxifen to the combination of CNF [cyclophosphamide, 500 mg/m2; mitoxantrone (Novantrone), 10 mg/m2; fluorouracil, 500 mg/m2 chemotherapy and ovarian ablation in premenopausal patients with node-positive breast cancer and conversely from the incorporation of CNF chemotherapy to adjuvant tamoxifen in node-positive postmenopausal patients. From April 1992 until March 1998, 456 patients with operable breast cancer and one to nine infiltrated axillary nodes entered the study. Premenopausal patients were treated with six cycles of CNF chemotherapy followed by ovarian ablation with monthly injections of triptoreline 3.75 mg for 1 year (Group A, 84 patients) or the same treatment followed by 5 years of tamoxifen (Group B, 92 patients). Postmenopausal patients received 5 years of tamoxifen (Group C, 145 patients) or 6 cycles of CNF followed by 5 years of tamoxifen (Group D, 135 patients). Adjuvant radiation was administered to all patients with partial mastectomy. After a median follow-up period of 5 years, 125 patients (27%) relapsed and 79 (17%) died. The 5-year actuarial RFS for premenopausal patients was 65% in Group A and 68% in Group B (p = 0.86) and for postmenopausal patients 70% in Group C and 67% in Group D (p = 0.36). Also, the respective OS rates were 77% and 80% (p = 0.68) for premenopausal and 84% and 78% (p = 0.10) for postmenopausal patients. Severe toxicities were infrequently seen, with the exception of leukopenia (18%), among the 311 patients treated with CNF. In conclusion, the present study failed to demonstrate a 15% difference in RFS in favor of node-positive premenopausal patients treated with an additional 5 years of tamoxifen after CNF adjuvant chemotherapy and ovarian ablation. Similarly, six cycles of CNF preceding 5 years of tamoxifen did not translate to a 15% RFS benefit in node-positive postmenopausal patients.

Successful co-treatment with LHRH-agonist for ovarian over-stimulation and cystic formation in premenopausal tamoxifen exposure

The present study evaluates the potential beneficial effect of co-treatment with LHRH-agonist in resolving premenopausal tamoxifen's induced supraphysiological serum 17beta estradiol levels and persistent ovarian cysts. Ultrasonographic and serum hormonal evaluations were performed before, during, and following three consecutive injections of long acting LHRH-agonist administered to 14 premenopausal breast cancer patients treated with tamoxifen, who had supraphysiological serum 17beta estradiol levels and simultaneous persistent ovarian cysts. Within 3 weeks of the first LHRH-agonist injection, all patients had menopausal serum estradiol levels. Ovarian cysts completely disappeared within 2 months following the first injection. Following the discontinuation of LHRH-agonist co-treatment, serum estradiol levels remained in physiological levels and the ovaries remained a normal size in 64.3% of the patients for 13.3 +/- 11.5 months. 28.6% of the patients had a gradual reappearance of high serum estradiol levels and of ovarian cysts, and were, therefore, treated with a second course of LHRH-agonist. Following the second course, serum estradiol levels remained in physiological levels and the ovaries remained a normal size for 8-15 months. It is concluded that short duration of co-treatment with long acting LHRH-agonist administered to premenopausal breast cancer patients treated with tamoxifen, successfully resolved the tamoxifen-induced supraphysiological serum 17beta estradiol levels and the ovarian cysts.

Laparoscopic oophorectomy: a prospective evaluation in pre-menopausal breast cancer with particular reference to incidence and severity of menopausal symptoms

Laparoscopic oophorectomy offers potential advantages over other methods of ovarian ablation. In this prospective study the technique, complications and side-effects have been assessed in 69 consecutive patients. Menopausal symptoms were assessed using two scoring systems - the Kupperman index and the Women's Health Questionnaire. The serum beta oestradiol levels fell rapidly post-operatively (from 540 pmol/l to 25 pmol/l within 1 month). Menopausal symptoms were mild in 75% of patients and severe in none. Complications occurred in three patients. Laparoscopic oophorectomy has an important role to play in the management of pre-menopausal breast cancer and this study confirms that is well tolerated and gives good short-term results.

Ovarian ablation versus goserelin with or without tamoxifen in pre-perimenopausal patients with advanced breast cancer: results of a multicentric Italian study

BACKGROUND

Oophorectomy is one of the treatments of choice for premenopausal women with advanced breast cancer. However, in recent years LH-RH analogs have replaced surgical castration (or ovarian irradiation) on the basis of the comparable therapeutic activity shown by these drugs in phase II studies. Moreover, the combination of tamoxifen and LH-RH analogs has gained popularity among clinicians attempting to obtain a 'total estrogen blockade' according to the same rationale previously proposed for advanced prostatic cancer. However, it has thus far not been proven that medical castration is as effective as oophorectomy or ovarian irradiation, nor is there enough evidence that tamoxifen could improve the efficacy of ovarian ablation.

PATIENTS AND METHODS

Eighty-five perimenopausal patients with estrogen receptor or unknown positive metastatic breast cancer were randomly allocated to receive one of the following treatments: surgical castration (or ovarian irradiation); goserelin; surgical castration (or ovarian irradiation) plus tamoxifen; goserelin plus tamoxifen. The study was performed according to a 2 x 2 factorial randomised design.

RESULTS

While overall there was no significant difference in the response rates observed after two by two grouping, a trend did favour oophorectomy (or ovarian ablation) with respect to treatment activity. In fact, the best response rate was observed in patients allocated to this treatment (46.6% OR -95% CL: 21.2-72.9) while the lowest rate was observed in patients treated with oophorectomy plus tamoxifen (11.1% OR: CL: -3.4-25.6). Response to goserelin and goserelin plus tamoxifen was 27.2% (+/- 18.6) and 45% (+/- 21.8), respectively. Logistical regression analysis suggested that there might be a different interaction between tamoxifen and goserelin or oophorectomy (ovarian irradiation), respectively. Nevertheless, patient survivals were comparable, irrespective of allocated treatment. This indicates that two by two grouping has some value with respect to treatment efficacy and shows that oophorectomy (or ovarian irradiation) and goserelin have comparable efficacies. Tamoxifen did not improve the efficacy of gonadal ablation, although it did enhance the activity of goserelin treatment.

CONCLUSIONS

The results of the present study confirm prospectively that the efficacy of chemical castration is comparable to that of oophorectomy (or ovarian irradiation). The concurrent use of tamoxifen can probably enhance the activity of goserelin, but it also induces more side effects. However, it doesn't appear that 'total estrogen blockade' is more effective than gonadal ablation alone. Indeed, the question of whether chemical and surgical castration have the same effect in breast cancer is still open as is the one concerning the interaction between tamoxifen and gonadal ablation. Both questions should be addressed by prospective studies.

Management of metastatic breast cancer

Systemic treatment almost certainly prolongs the median survival of women with metastatic breast cancer, and it may prolong the survival of a small number of patients substantially. Even with conventional therapy, 10% or more patients may live into the second decade after recurrence. However, the disease cannot be eradicated, and the primary goal of treatment remains palliation and improvement of the quality of life. Because of the great variability in the pattern and course of the disease from one patient to another, therapy should be selected judiciously to maximize response and minimize toxicity. In some clinical situations, such as pathologic fractures and brain metastases, local therapies alone, such as surgery or irradiation, are the treatments of choice. Patients who will respond to endocrine therapy are well defined, and all patients with the characteristics of an endocrine responder deserve a chance at palliation with this modality alone because of its limited toxicity. A number of new forms of endocrine therapy with more specific targets at estrogen and progesterone receptor sites are now in clinical trials. When used appropriately, chemotherapy significantly improves patient quality of life despite its toxicity. No drug combinations, schedules, or doses have been shown to prolong survival or provide better net palliation than classic CMF (oral cyclophosphamide with intravenous methotrexate and 5-fluorouracil) or CAF (intravenous cyclophosphamide, doxorubicin, and 5-fluorouracil). Treatment with these combinations in excess of 6 to 9 months provides only marginal additional benefits and no survival advantage. The role of high dose chemotherapy with autologous bone marrow transplantation remains a promising area of investigation, but the available survival data are entirely compatible with the possibility that this modality will eventually prove inferior to conventional therapy. Many new cytotoxic agents with unique mechanisms of action are currently under investigation, including taxol, taxotere, Topotecan, and amonafide. Taxol may be the most promising therapy now available for patients whose disease has become refractory to doxorubicin. Biologic therapies using monoclonal antibodies against a specific oncogene or its product have entered clinical trials, and novel drug delivery systems using liposomes are under evaluation.