Low-dose aminoglutethimide with and without hydrocortisone replacement as a first-line endocrine treatment in advanced breast cancer: a prospective randomized trial of the Italian Oncology Group for Clinical Research

Effect of glucocorticoid use on survival in patients with stage I-III breast cancer

PURPOSE

Glucocorticoids (GCs) are commonly used in breast cancer patients to ameliorate emesis induced by chemotherapy. Some preclinical studies have suggested that systemic GCs might promote survival of estrogen receptor (ER)-negative breast cancer cells. This study aims to clarify their clinical effect on patient survival.

METHODS

A total of 18,596 women with newly diagnosed stage I-III breast cancer in 2002-2006 were identified from the Taiwan Cancer Database and drug treatment was examined from the Taiwan National Health Insurance Claims Database. Of these, 3989 who did not receive adjuvant chemotherapy (non-chemotherapy cohort) and 3237 patients who received six cycles of adjuvant anthracycline-based chemotherapy (anthracycline cohort) were included. The impact of GC use on survival was analyzed separately in these two cohorts using Cox proportional hazards models.

RESULTS

In the non-chemotherapy cohort, GC use was associated with aggressive clinicopathological features of breast cancer. High-dose GC was associated with shorter overall survival in univariate analysis but not in multivariate analysis. In the anthracycline cohort, multivariate analysis showed that GC use at each dose level was significantly associated with longer breast cancer-specific survival (HR 0.65, 0.70, and 0.70 for low-dose, median-dose, and high-dose GC, respectively) and overall survival (HR 0.72, 0.76, and 0.73, respectively) when compared with those receiving no GC. The associations were significant in both ER-positive and ER-negative subgroups for breast cancer-specific survival, and in ER-negative subgroup for overall survival.

CONCLUSION

Concomitant use of GC improved survival in patients receiving adjuvant anthracycline-based chemotherapy for stage I-III breast cancer.

Systematic review of the clinical effect of glucocorticoids on nonhematologic malignancy

BACKGROUND

Glucocorticoids are often used in the treatment of nonhematologic malignancy. This review summarizes the clinical evidence of the effect of glucocorticoid therapy on nonhematologic malignancy.

METHODS

A systematic review of clinical studies of glucocorticoid therapy in patients with nonhematologic malignancy was undertaken. Only studies having endpoints of tumor response or tumor control or survival were included. PubMed, EMBASE, the Cochrane Register/Databases, conference proceedings (ASCO, AACR, ASTRO/ASTR, ESMO, ECCO) and other resources were used. Data was extracted using a standard form. There was quality assessment of each study. There was a narrative synthesis of information, with presentation of results in tables. Where appropriate, meta-analyses were performed using data from published reports and a fixed effect model.

RESULTS

Fifty four randomized controlled trials (RCTs), one meta-analysis, four phase l/ll trials and four case series met the eligibility criteria. Clinical trials of glucocorticoid monotherapy in breast and prostate cancer showed modest response rates. In advanced breast cancer meta-analyses, the addition of glucocorticoids to either chemotherapy or other endocrine therapy resulted in increased response rate, but not increased survival. In GI cancer, there was one RCT each of glucocorticoids vs. supportive care and chemotherapy +/- glucocorticoids; glucocorticoid effect was neutral. The only RCT found of chemotherapy +/- glucocorticoids, in which the glucocorticoid arm did worse, was in lung cancer. In glucocorticoid monotherapy, meta-analysis found that continuous high dose glucocorticoids had a detrimental effect on survival. The only other evidence, for a detrimental effect of glucocorticoid monotherapy, was in one of the two trials in lung cancer.

CONCLUSION

Glucocorticoid monotherapy has some benefit in breast and prostate cancer. In advanced breast cancer, the addition of glucocorticoids to other therapy does not change the long term outcome. In GI cancer, glucocorticoids most likely have a neutral effect. High dose continuous glucocorticoids have a detrimental effect in nonhematologic malignancy. Glucocorticoid therapy might have a deleterious impact in lung cancer.

Randomized trial of tamoxifen versus tamoxifen plus aminoglutethimide as adjuvant treatment in postmenopausal breast cancer patients with hormone receptor-positive disease: Austrian breast and colorectal cancer study group trial 6

PURPOSE

To determine whether the addition of aminoglutethimide to tamoxifen is able to improve the outcome in postmenopausal patients with hormone receptor-positive, early-stage breast cancer.

PATIENTS AND METHODS

A total of 2,021 postmenopausal women were randomly assigned to receive either tamoxifen for 5 years alone or tamoxifen in combination with aminoglutethimide (500 mg/d) for the first 2 years of treatment. Tamoxifen was administered at 40 mg/d for the first 2 years and at 20 mg/d for 3 years.

RESULTS

All randomized and eligible patients were included in the analysis according to the intention-to-treat principle. After a median follow-up of 5.3 years, the 5-year disease-free survival in the aminoglutethimide plus tamoxifen group was 83.6% versus 83.7% in the monotherapy group (P =.89). The corresponding data for overall survival at 5 years were 91.4% and 91.2%, respectively (P =.74). More patients failed to complete combination treatment (13.7%) because of side effects as compared to tamoxifen alone (5.2%; P =.0001).

CONCLUSION

Aminoglutethimide given for 2 years in addition to tamoxifen for 5 years does not improve the prognosis of postmenopausal patients with receptor-positive, lymph node-negative or lymph node-positive breast cancer.

A randomised trial comparing two doses of the new selective aromatase inhibitor anastrozole (Arimidex) with megestrol acetate in postmenopausal patients with advanced breast cancer

The aim of this study was to compare the efficacy and tolerability of the new aromatase inhibitor 'ARIMIDEX' (anastrozole) with megestrol acetate in the treatment of advanced breast cancer in postmenopausal women. Anastrozole is a new potent and highly selective non-steroidal aromatase inhibitor. We conducted a prospective randomised trial comparing two doses of anastrozole (1 and 10 mg orally once daily) with megestrol acetate (40 mg orally four times daily) in postmenopausal patients with advanced breast cancer who progressed after prior tamoxifen therapy. All patients were analysed for efficacy as randomised (intention to treat) and for tolerability as per treatment received. Of the 378 patients who entered the study, 135 were randomised to anastrozole 1 mg, 118 to anastrozole 10 mg, and 125 patients to megestrol acetate. After a median follow-up of 192 days, response rate which included complete response, partial response and patients who had disease stabilisation for 6 months or more was 34% for anastrozole 1 mg, 33.9% for anastrozole 10 mg and 32.8% for megestrol acetate. There were no statistically significant differences between either dose of anastrozole and megestrol acetate in terms of objective response rate, time to objective progression of disease or time to treatment failure. The three treatments were generally well tolerated, but more patients on megestrol acetate reported weight gain, oedema and dyspnoea as adverse events while more patients on anastrozole reported gastro-intestinal disorders, usually in the form of mild transient nausea. Patients on anastrozole did not report higher incidences of oestrogen withdrawal symptoms. Anastrozole is an effective and well tolerated treatment for postmenopausal patients with advanced breast cancer. The higher 10 mg dose did not result in additional clinical benefit, but was well tolerated reflecting the good therapeutic margin with anastrozole. Based on this data, anastrozole 1 mg should be the recommended therapeutic dose.

First generation aromatase inhibitors--aminoglutethimide and testololactone

Aminoglutethimide and testololactone may be considered the first generation aromatase inhibitors for the endocrine treatment of breast carcinoma. Initially, both of these agents were designed and used clinically based on different concepts of their mechanisms of action. Only later were they both demonstrated to inhibit aromatase. Curiously, testololactone was earlier and more widely used than aminoglutethimide in treating advanced breast carcinoma. The discovery of the peripheral aromatase inhibition as the proper mechanism of action was delayed for both the agents but was relatively more timely for aminoglutethimide. Paradoxically, the clinical use of testololactone has become already obsolete since its true mechanism of action was discovered. Aminoglutethimide is still the most widely used aromatase inhibitor in treating advanced breast carcinoma. Due to the initial misinterpretation of its mechanism of action, aminoglutethimide was used for a long time at a relative high daily dose, always combined with hydrocortisone. Subsequent phase II and then randomized phase III studies demonstrated an equivalent efficacy using half (500 mg) of the previous conventional daily dose (1000 mg), with hydrocortisone. Very recently, a randomized clinical trial demonstrated that administering this lower dose without hydrocortisone did not significantly decrease the clinical efficacy. By decreasing the dose of aminoglutethimide, the incidence of side effects has been reduced. So, the last paradoxical aspect of the aminoglutethimide story is that this agent seemed initially very toxic but finally, with the new schedules, shows a very low toxicity profile, especially after the first few weeks of treatment.

Efficacy and tolerability of 4-hydroxyandrostenedione (4-OHA) as first-line treatment in postmenopausal patients with breast cancer after adjuvant therapy

Aromatase inhibitors are known to be effective in the treatment of advanced postmenopausal breast cancer. To assess the efficacy of the aromatase inhibitor 4-hydroxyandrostenedione (4-OHA) as first-line treatment in patients who were either resistant to or had relapsed after adjuvant therapy, 50 eligible patients received intramuscular 4-OHA either 250 mg or 500 mg fortnightly until disease progression or severe adverse events. Of the 43 patients evaluable for clinical response (UICC criteria), 15 (36%) showed objective response (CR+PR), 6 (14%) stable disease (SD). In relation to disease site, objective responses were obtained in 55% of cases with soft tissue metastases (16/29); in 33% with visceral metastases (8/24), and in 24% with bone involvement (5/21). In relation to previous adjuvant treatment, there were eight objective responses among the 17 patients treated with chemotherapy (47%), and seven objective responses among the 24 treated with tamoxifen (29%). The treatment was well tolerated. These results support the hypothesis that adjuvant therapy, whether hormonal or chemotherapy, may make patients less responsive to subsequent treatment.

Hormone treatments in the common 'hormone-dependent' carcinomas

Current understanding of the mechanisms of action of hormonal therapies in carcinomas of the breast, prostate, endometrium and ovary is briefly reviewed. The range of available hormonal therapies for each disease is considered together with response rates, toxicity and any evidence for survival benefit. Practical guidelines for the palliative use of hormonal therapies are suggested.

Clinical use of aromatase inhibitors in the treatment of breast cancers

Estrogens are the major hormones supporting the growth of human breast cancer. Aromatization of androgen precursors in peripheral tissues, including the breast cancer itself, is the major source of estrogens in postmenopausal women. Therefore, inhibition of the aromatase enzyme offers an effective means of inducing regression of hormone-responsive breast cancer. Aminoglutethimide, the first and most widely tested aromatase inhibitor, suppresses estrogen production to the level of adrenalectomy and exerts an anti-tumor action comparable to other standard endocrine therapies such as tamoxifen. However, conventional doses of the drug (1000 mg daily) cause moderate toxicity and inhibit other critical cytochrome P-450 steroidogenic enzymes, thus requiring concomitant glucocorticoid administration. New non-steroidal, competitive aromatase inhibitors with greater selectivity and less toxicity are being developed. The second generation compound, fadrazole (CGS 16949), lowers estrogen production to a degree similar to aminoglutethimide (50-80%), but at much lower doses (approximately 2 mg daily) and is associated with minimal toxicity. Although not totally specific, this drug is sufficiently selective not to require simultaneous cortisol replacement. CGS 16949 has been shown to possess significant anti-tumor action in pilot studies and is currently being tested in Phase III trials. Recently, a third generation inhibitor, CGS 20267, has been found to have virtually complete selectivity for the aromatase enzyme. Furthermore, this drug suppresses estrogen biosynthesis to a greater extent (approximately 90%) than previously observed with other aromatase inhibitors. Such enhanced activity may lead to a superior anti-tumor action, and may extend the use of this drug to a variety of other conditions where optimal suppression of estrogen biosynthesis is desired.