The clinical relevance of static disease (no change) category for 6 months on endocrine therapy in patients with breast cancer

A meta-analysis of clinical benefit rates for fulvestrant 500 mg vs. alternative endocrine therapies for hormone receptor-positive advanced breast cancer

BACKGROUND

Fulvestrant, a selective estrogen receptor degrader, is approved for first- and second-line treatment of postmenopausal women with hormone receptor-positive advanced breast cancer (ABC).

METHODS

Meta-analysis of randomized controlled trials (RCTs) evaluating fulvestrant 500 mg in postmenopausal hormone receptor-positive ABC, to evaluate differences in clinical benefit rate (CBR; proportion of patients experiencing best overall response of complete response, partial response, or stable disease for ≥ 24 weeks) between fulvestrant 500 mg and comparator endocrine therapies. Odds ratios (OR) and 95% confidence intervals (CI) for CBR were calculated; fixed effects (FE) models were constructed (first- and second-line data, alone and combined).

RESULTS

Six RCTs were included. Four studies evaluated fulvestrant 500 mg vs. fulvestrant 250 mg; two evaluated fulvestrant 500 mg vs. anastrozole 1 mg. In total, 1054 and 534 patients were included (first- and second-line treatment, respectively). Analysis of OR and 95% CI of CBR by therapy line favored fulvestrant 500 mg vs. comparator therapy. Assessing all results combined in the FE model indicated significant improvement in CBR with fulvestrant 500 mg vs. comparator treatments (OR 1.33; 95% CI 1.13-1.57; p = 0.001). Restricting the FE model to therapy line demonstrated significant improvement in CBR vs. comparator treatments (OR 1.33; 95% CI 1.02-1.73; p = 0.035) for first-line, and a trend to improvement vs. comparator treatments (OR 1.27; 95% CI 0.90-1.79; p = 0.174) for second-line.

CONCLUSIONS

In postmenopausal patients with hormone receptor-positive ABC, fulvestrant 500 mg first-line was associated with significantly greater CBR (more patients benefiting from treatment) vs. comparator endocrine therapy.

Endocrine Therapy for Breast Cancer: A Model of Hormonal Manipulation

Oestrogen receptor (ER) is the driving transcription factor in 70% of breast cancer. Endocrine therapies targeting the ER represent one of the most successful anticancer strategies to date. In the clinic, novel targeted agents are now being exploited in combination with established endocrine therapies to maximise efficacy. However, clinicians must balance this gain against the risk to patients of increased side effects with combination therapies. This article provides a succinct outline of the principles of hormonal manipulation in breast cancer, alongside the key evidence that underpins current clinical practice. As the role of endocrine therapy in breast cancer continues to expand, the challenge is to interpret the data and select the optimal strategy for a given clinical scenario.

The Role of Blood Tumor Marker Measurement (Using a Biochemical Index Score and C-Erbb2) in Directing Chemotherapy in Metastatic Breast Cancer

The role of blood tumor markers in monitoring response in advanced breast cancer is established in endocrine therapy and standard chemotherapy. This study examines marker levels in patients receiving new chemotherapy regimens. Thirty patients were recruited into two multicenter trials in which docetaxel-based regimens were used in 15 patients. The other 15 received doxorubicin-based regimens. Biochemical response calculated from a score using CA15.3, CEA and ESR was compared with UICC response. Marker changes at 2, 4 and 5 months correlated with UICC response at 3, 41/2 and 6 months, respectively (p < 0.03). Eleven patients achieved both clinical/radiological and biochemical response at the end of treatment; markers had not yet returned to below cutoffs in seven, suggesting a possible advantage to continue chemotherapy. No patient showed a biochemical response whilst judged clinically/radiologically progressive. Nineteen patients had progressed either clinically/radiologically or biochemically at six months; of these, eight showed progression assessed earlier by markers so that a median of four cycles of chemotherapy could have been saved. Measurements of serum c-erbB2 showed a correlation with tissue c-erbB2 staining in the primary tumor (p < 0.003). Among the patients with positive tissue staining, sequential changes in serum c-erbB2 completely paralleled initial response.

Oestrogen receptor negative early operable primary breast cancer in older women-Biological characteristics and long-term clinical outcome

Background

Older women are at the greatest risk of breast cancer development and a considerable number present with comorbidities. Although the majority of breast cancers in this age group express oestrogen receptor (ER), which makes endocrine therapy (primary or adjuvant) feasible, given the huge size of the elderly population, there remains a significant number of patients, in absolute term, whose tumours do not express ER and their management is challenging.

Methods

Of a consecutive series of 1,758 older (≥70 years) women with early operable primary breast cancer managed in a dedicated service from 1973–2010, 252(14.3%) had ER-negative (histochemical (H) score ≤50) tumours. Their clinical outcome was retrospectively reviewed and tumour samples collected from diagnostic core biopsies were analysed for progesterone receptor (PgR), HER2 and Ki67 using immunohistochemistry.

Results

The commonest primary treatment was surgery (N = 194, 77%) followed by primary endocrine therapy (14.3%), primary radiotherapy (5.6%) and supportive treatment only (3.1%). Among the patients undergoing surgery, most of them had grade 3 (78.1%) and node-negative disease (62.2%). Some of them (21.1%) received postoperative radiotherapy. At a median follow-up of 37.5 months, 117 patients had died, out of which 48.6% were due to breast cancer. For those who underwent surgery, the regional and local recurrence rates were 2% and 1.1% per annum respectively. For those who received primary endocrine therapy, 38% progressed at 6 months, however all patients who had primary radiotherapy achieved clinical benefit at 6 months. Regardless of treatment given, the 5-year breast cancer specific and overall survival rates were 70% and 50% respectively. Biological analysis based on good quality needle core biopsy specimensfrom181 patients showed that 26.8% (N = 49), 16.9% (N = 31) and 70.7% (N = 70)expressed positivity for PgR, HER2 and Ki67 respectively. No correlation between these biomarkers and breast cancer specific survival was demonstrated.

Conclusion

Oestrogen receptor negative early operable primary breast cancer in older women is associated with poor prognostic features in terms of biology and clinical outcome. Surgery appears to produce the best outcome as a primary treatment, however for those where neither surgery nor chemotherapy is appropriate, primary radiotherapy can be beneficial.

Management of operable primary breast cancer in older women

A considerable number of breast cancer diagnoses are made in older women. Differing physiological needs of older patients and biology of tumors compared with younger patients may alter treatment options between surgery and nonsurgical primary approaches. Adjuvant therapies may benefit these patients; however, concerns about toxicity and physical demands of treatment may affect patient choice regarding treatment. Furthermore, quality of life may be more important to the older individual than curative treatment alone. Growing evidence is emerging for employing Comprehensive Geriatric Assessment to determine other factors that may contribute to treatment decision-making in the older population. The way geriatric oncology is delivered varies, bringing the importance of the multidisciplinary team to the forefront of care delivery in this age group. Future research in this area should include combined consideration of tumor biology and geriatric needs.

A randomized trial of combination anastrozole plus gefitinib and of combination fulvestrant plus gefitinib in the treatment of postmenopausal women with hormone receptor positive metastatic breast cancer

EGFR signalling pathways appear involved in endocrine therapy resistance in breast cancer. This trial estimates the antitumor efficacy and toxicity of the EGFR tyrosine kinase inhibitor gefitinib in combination with anastrozole or fulvestrant in postmenopausal hormone receptor positive breast cancer. Subjects with estrogen receptor and/or PgR positive, metastatic breast cancer were randomized into this phase II study of gefitinib (initial dose was 500 mg orally daily, due to high rate of diarrhea, starting dose was reduced to 250 mg orally daily) with either anastrozole 1 mg daily or fulvestrant 250 mg every 4 weeks. The primary endpoint was clinical benefit (complete responses plus partial responses plus stable disease for 6 months or longer). 141 eligible subjects were enrolled, 72 in the anastrozole plus gefitinib arm, and 69 in the fulvestrant plus gefitinib arm. Anastrozole plus gefitinib had a clinical benefit rate of 44% [95% confidence interval (CI) 33-57%] and fulvestrant plus gefitinib 41% (95% CI 29-53%). Median progression-free survival was 5.3 months (95% CI 3.1-10.4) versus 5.2 months (95% CI 2.9-8.2) for anastrozole plus gefitinib versus fulvestrant plus gefitinib, respectively. Median survival was 30.3 months (95% CI 21.2-38.9+) versus 23.9 months (95% CI 15.4-33.5) for anastrozole plus gefitinib versus fulvestrant plus gefitinib, respectively. In general, the toxicity is greater than expected for single agent endocrine therapy alone. Anastrozole plus gefitinib and fulvestrant plus gefitinib have similar clinical benefit rates in the treatment of estrogen and/or PgR positive metastatic breast cancer, and the rates of response are not clearly superior to gefitinib or endocrine therapy alone. Further studies of EGFR inhibition plus endocrine therapy do not appear warranted, but if performed should include attempts to identify biomarkers predictive of antitumor activity.

C-myc as a predictive marker for chemotherapy in metastatic breast cancer

C-myc is considered to have an important role in cancerogenesis and tumor progression. The aim of this study was to evaluate a possible significance of c-myc amplification as a clinically useful prognostic/predictive parameter in metastatic breast cancer (MBC). Eighty-seven MBC patients with known clinicopathological parameters were included in the study, at the time of diagnosis of metastatic disease. In metastatic setting, 52% of patients received CMF, 34% received FAC, and 32% received hormonal therapy (tamoxifen). C-myc amplification was analyzed by chromogenic in situ hybridization, according to the manufacturer's instructions. C-myc amplification was detected in 26% cases and showed a strong correlation with ER status, stage of disease (initial) and existence of distance metastasis. There was no statistically significant difference in MBC (post-relapse) survival between c-myc-nonamplified and c-myc-amplified subgroups regardless of or regarding the treatment. However, correlation was found between c-myc status and individual patient's outcomes. Patients with c-myc amplification treated with chemotherapy (CMF and FAC) had clinical benefit (complete remission, partial remission or stable disease) in contrast to patients without amplification. Lack of significant difference in MBC (post-relapse) survival according to c-myc status could be due to a better response of patients to appropriate treatment (chemotherapy). It is possible that negative prognostic impact of c-myc amplification is masked with increased responsiveness to chemotherapy.

Fulvestrant in the management of postmenopausal women with advanced, endocrine-responsive breast cancer

Fulvestrant is a pure estrogen antagonist that binds, blocks and downgrades the estrogen receptor (ER). Its unique mechanism of action is its antitumor activity after progression on prior endocrine therapy. Fulvestrant has shown activity in ER-dependent cells that are ligand independent. Fulvestrant has been approved at 250 mg/month for postmenopausal women with hormone-sensitive advanced breast cancer after progression or recurrence on antiestrogen therapy. The fulvestrant 500 mg regimen has just received approval by the EMA and the US FDA, supported by dose-dependent ER downregulation and the recent results of the clinical trial CONFIRM. Fulvestrant in combination with systemic lowering of estrogen has shown no improvement over fulvestrant alone. Combination therapy with inhibitors of growth factor signaling may have greater efficacy and is under exploration. To enhance the benefit of fulvestrant and improve outcomes for individuals with ER-positive breast cancer, greater understanding of resistance mechanisms is required. A key issue is identification of patients with ER-positive disease who retain sensitivity to antiestrogen therapy after progression on tamoxifen and/or aromatase inhibitors.

Long-term clinical outcome of oestrogen receptor-positive operable primary breast cancer in older women: a large series from a single centre

INTRODUCTION

A Cochrane review of seven randomised trials (N=1571) comparing surgery and primary endocrine therapy (PET) (oestrogen receptor (ER) unselected) shows no difference in overall survival (OS). We report outcome of a large series with ER-positive (ER+) early invasive primary breast cancer.

METHODS

Between 1973 and 2009, 1065 older (≥ 70 years) women (median age 78 years (70-99)) had either surgery (N=449) or PET (N=616) as initial treatment.

RESULTS

At 49-month median follow-up (longest 230 months), the 5-year breast cancer-specific survival (BCSS) and OS were 90 and 62%, respectively. Majority (74.2%) died from causes other than breast cancer. The rates (per annum) of local/regional recurrence (<1%) (following surgery), contralateral tumour (<1%) and metastases (<3%) were low. For patients on PET, 97.9% achieved clinical benefit (CB) at 6 months, with median time to progression of 49 months (longest 132 months) and significantly longer BCSS when compared with those who progressed (P<0.001). All patients with strongly ER+ (H-score >250) tumours achieved CB and had better BCSS (P<0.01). Patients with tumours having an H-score >250 were found to have equivalent BCSS regardless of treatment (surgery or PET; P=0.175), whereas for those with H-score ≤ 250, surgery produced better outcome (P<0.001).

CONCLUSION

Older women with ER+ breast cancer appear to have excellent long-term outcome regardless of initial treatment. Majority also die from non-breast cancer causes. Although surgery remains the treatment of choice, patients with ER-rich (H-score >250) tumours tend to do equally well when treated by PET. This should be taken into account when therapies are considered.

Clinical Evaluation of the Use of Exemestane as Further Hormonal Therapy after Nonsteroidal Aromatase Inhibitors in Postmenopausal Metastatic Breast Cancer Patients

OBJECTIVES

The aromatase inhibitors Anastrozole, Letrozole (type 2 nonsteroidal aromatase inhibitors: n-SAI) and Exemestane (type 1 steroidal aromatase inactivator) are used respectively as first- and second-line hormonal therapy in postmenopausal metastatic breast cancer women. Few clinical data are published on the sequential use of different classes of aromatase inhibitors.

METHODS

We report an analysis on 30 postmenopausal metastatic breast cancer women treated between January 2000 and May 2002 in 2 Italian Oncology Institutions with the hormonal sequence n-SAI (Anastrozole, Letrozole) --> Exemestane.

RESULTS

When receiving n-SAI (Anastrozole 8 patients and Letrozole 22 patients), 1 out of 30 women achieved a partial response, 20 of 30 patients no change (NC) > or =6 months. The analysis of the entire population treated with Exemestane showed an overall clinical benefit (CB) of 46.6 percent (14/30) with a median duration of 12 months (95%CI 6-25) and a median time to progression (TTP) of 4 months (95%CI 1-25).

CONCLUSIONS

These data confirm a partial lack of cross-resistance between n-SAI --> Exemestane given in sequence.

Endocrine therapy of metastatic breast cancer

Breast cancer growth and dissemination is regulated by estrogen and different growth factor receptor signalling pathways. The increasing knowledge of the biology of breast cancer regarding the interaction of these signalling pathways provides a tool to understand endocrine therapies response and resistance mechanisms. In patients with slowly progressive disease, no visceral involvement, and minimal symptoms, endocrine therapy could be the strategy of choice, even if the tumor has low estrogen receptor expression. Ovarian suppression and tamoxifen are recommended for premenopausal patients whether aromatase inhibitors are the option for postmenopausal ones. Chemotherapy still remains as the right alternative for hormone unresponsive or resistant patients. This is a review focused on the different strategies and combinations of endocrine therapies for metastatic breast cancer patients considering the potential strategies clinically tested to overcome resistance and the different treatments of choice available for each scenario of disseminated disease.

Two-stage designs for phase II cancer trials with ordinal responses

A common approach to the design of phase II clinical trials in oncology is to conduct a two-stage trial so as to control type I and type II error rates. A number of researchers have proposed methods for the design of such trials when the response can take one of a number of ordered values such as tumor response, stable disease or progressive disease. In this case, the problem may be formulated as that of testing a complex null hypothesis. Control of the type I error rate thus requires specification of the null region and construction of a test that limits the maximum error rate over this region. In this paper we propose that the null region should be bounded by a line in the two-dimensional parameter space for the setting with a response with three levels and more generally by a plane or hyperplane. We then propose a test based on the likelihood ratio statistic and show how this may be calculated in this case for a three-level response. The method is illustrated using an example of a clinical trial to evaluate a new treatment for breast cancer.

Fulvestrant (Faslodex) -- how to make a good drug better

Fulvestrant (Faslodex); AstraZeneca Pharmaceuticals, Wilmington, DE) is an estrogen receptor (ER) antagonist with a novel mode of action; it binds, blocks, and increases degradation of ER. Fulvestrant (at the approved dose [250 mg/month]) is at least as effective as anastrozole (1 mg/day) in the treatment of postmenopausal women with hormone receptor-positive advanced breast cancer (HR(+) ABC) progressing or recurring on antiestrogen therapy, and is also an active first-line treatment. Although fulvestrant (250 mg/month) is clearly effective, it takes 3-6 months to achieve steady-state plasma levels. Steady-state concentrations are approximately twofold higher than those achieved with a single dose; reaching this earlier, for example, via a loading-dose (LD) regimen (250 mg/month plus 500 mg on day 0 and 250 mg on day 14 of month 1), may allow responses to be achieved more quickly and limit the possibility of early relapse. Fulvestrant high-dose (HD) regimens (500 mg/month) offer the possibility of greater antitumor activity, because (a) ER downregulation is a dose-dependent process (an approximately 70% reduction is observed with a single 250 mg dose of fulvestrant) and (b) evidence correlates greater ER downregulation with superior efficacy. A fulvestrant HD regimen offers the potential of achieving near 100% ER downregulation. There is also potential to increase fulvestrant-ER binding by reducing plasma estrogen levels, for example, with concomitant aromatase inhibitor treatment. Several ongoing trials use LD, HD, and combination regimens; results from these studies are awaited with interest. Meanwhile, fulvestrant (250 mg/month) remains a valuable additional endocrine treatment for postmenopausal women with HR(+) ABC recurring or progressing on antiestrogen therapy.

Primary endocrine therapy in locally advanced breast cancers--the Nottingham experience

INTRODUCTION

There are trials comparing different neoadjuvant chemotherapy regimens for locally advanced primary breast cancer (LAPC). Few studies have evaluated alternative therapeutic approaches towards LAPC. A previous trial from our institute in LAPC patients unselected for oestrogen receptor (ER) status, comparing primary endocrine therapy versus multimodal treatment, showed no difference in breast cancer related deaths or overall survival. We report our experience of primary endocrine therapy in ER+ LAPC.

METHODS

Between 1988 and 2007, 195 ER+, non-inflammatory LAPC patients were treated with primary endocrine agents in our institute, due to patient choice, being unfit for chemotherapy, or recruitment into the above mentioned trial. All patients had disease assessable by UICC criteria.

RESULTS

Median age was 69 years. The median follow-up was 61 months. 154 patients (79%) received endocrine treatment alone. 185 patients (95%) derived clinical benefit (complete response/ partial response/ stable disease) for > or =6 months from primary endocrine therapy. Overall 5-year survival was 76% and 5-year breast cancer specific survival was 86%.

CONCLUSION

In selected group of ER+ LAPC patients, primary endocrine treatment achieves excellent survival outcome and is a viable alternative to other modalities of treatment.

Hormonal therapy for advanced breast cancer

Hormonal therapy for advanced breast cancer has evolved significantly in the more than 100 years since the first publications documenting the effect of ovarian ablation on advanced breast cancer in premenopausal women. Since that time, not only have we developed the methods to measure estrogen and progesterone receptors in cancer cells, but more recently we have understood that expression of these receptors determines response to hormone therapy. The availability of more selective antiestrogen therapies has changed and significantly improved the treatment options for women who have advanced hormone-responsive breast cancer. Current research is focusing on reversing resistance to hormone therapy with the addition of targeted biologic agents to standard hormonal treatment.

Efficacy and tolerability of high dose "ethinylestradiol" in post-menopausal advanced breast cancer patients heavily pre-treated with endocrine agents

Background

High dose estrogens (HDEs) were frequently used as endocrine agents prior to the introduction of tamoxifen which carries fewer side effects. Due to the development of resistance to available endocrine agents in almost all women with metastatic breast cancer, interest has renewed in the use of HDEs as yet another endocrine option that may have activity. We report our experience with one of the HDEs ("ethinylestradiol" 1 mg daily) in advanced breast cancer (locally advanced and metastatic) in post-menopausal women who had progressed on multiple endocrine agents.

Patients and methods

According to a database of advanced breast cancer patients seen in our Unit since 1998, those who had complete set of information and fulfilled the following criteria were studied: (1) patients in whom further endocrine therapy was deemed appropriate i.e., patients who have had clinical benefit with previous endocrine agents or were not fit or unwilling to receive chemotherapy in the presence of potentially life-threatening visceral metastases; (2) disease was assessable by UICC criteria; (3) were treated with "ethinylestradiol" until they were withdrawn from treatment due to adverse events or disease progression.

Results

Twelve patients with a median age of 75.1 years (49.1 – 85 years) were identified. Majority (N = 8) had bony disease. They had ethinylestradiol as 3^rd to 7^th line endocrine therapy. One patient (8%) came off treatment early due to hepato-renal syndrome. Clinical benefit (objective response or durable stable disease for ≥ 6 months) was seen in 4 patients (33.3%) with a median duration of response of 10+ (7–36) months. The time to treatment failure was 4 (0.5–36) months.

Conclusion

Yet unreported, high dose "ethinylestradiol" is another viable therapeutic strategy in heavily pre-treated patients when further endocrine therapy is deemed appropriate. Although it tends to carry more side effects, they may not be comparable to those of other HDEs (such as diethylstilbestrol) or chemotherapy.

"Resurrection of clinical efficacy" after resistance to endocrine therapy in metastatic breast cancer

Background

In a significant proportion of metastatic breast cancer (MBC) patients whose tumour has progressed within 6 months of endocrine therapy (de novo resistance), it is generally believed that the chance of achieving clinical benefit (CB) with further endocrine therapy is minimal.

Methods

Data was retrieved from a prospectively updated database of metastatic breast cancer. Relevant data was exported to SPSS™ software for statistical analysis.

Results

In oestrogen receptor (ER) positive MBC patients with assessable disease, CB was achieved in 159 (71.3%) (1^st line) patients. When these patients were put on further endocrine therapy, the CB rates were 63.2% (on 2^nd line), 46.1% (on 3^rd line) and 20% (on 4^th line) with a median duration of response (DOR) in those with CB of 22, 12, 11 and 15 months respectively. The remaining 64(28.7%) patients had de novo resistance on 1^st line endocrine therapy. Seventeen of these patients were treated with further endocrine therapy. The CB rates were 29.4% (on 2^nd line) and 22.2% (on 3^rd line) with a median DOR in those with CB of 22.7 months and 14 months respectively.

Conclusion

The chance of further endocrine response continues to decrease with each line of therapy, yet CB is still seen with reasonable duration even with a 4^th line agent. In addition, further endocrine response, with long duration, can be seen in a significant proportion of patients who have developed de novo resistance to 1^st line endocrine therapy. The use of further endocrine therapy should not be excluded under these circumstances.

How ADAM-9 and ADAM-11 differentially from estrogen receptor predict response to tamoxifen treatment in patients with recurrent breast cancer: a retrospective study

PURPOSE

To evaluate the predictive value of the disintegrin and metalloproteinases, ADAM-9, ADAM-10, ADAM-11, and ADAM-12, and of the matrix metalloproteinases, MMP-2 and MMP-9, in patients with recurrent breast cancer treated with tamoxifen.

EXPERIMENTAL DESIGN

A retrospective study was done on 259 frozen specimens of estrogen receptor-positive primary breast carcinomas from patients who developed recurrent disease and were treated with tamoxifen as the first line of therapy. The expression levels of the biological factors were assessed by real-time quantitative reverse transcriptase PCR.

RESULTS

Using log-transformed continuous variables, increasing levels of ADAM-9 [odds ratio (OR) = 1.41; P = 0.015] and decreasing levels of MMP-9 (OR, 0.81; P = 0.035) predicted favorable disease control independent from the traditional predictive factors. Furthermore, when tumors were dichotomized at the median level of 70% tumor cell nuclei, our univariate analysis showed particularly strong results for the group of 153 patients with primary tumors containing 30% or more stromal cells. Although estrogen receptor levels lost their predictive power for this group of patients, high levels of ADAM-9 (OR, 1.59; P = 0.007) and ADAM-11 (OR, 1.65; P = 0.001) were significantly associated with a higher efficacy of tamoxifen therapy.

CONCLUSIONS

Our results show that especially for primary tumors containing stromal elements, the assessment of mRNA expression levels of ADAM-9 and ADAM-11 could be useful to identify patients with recurrent breast cancer who are likely to benefit or fail from tamoxifen therapy.

A meta-analysis on the interaction between HER-2 expression and response to endocrine treatment in advanced breast cancer

PURPOSE

Experimental data suggest a complex cross-talk between HER-2 and estrogen receptor, and it has been hypothesized that HER-2-positive tumors may be less responsive to certain endocrine treatments. Clinical data, however, have been conflicting. We have conducted a meta-analysis on the interaction between the response to endocrine treatment and the overexpression of HER-2 in metastatic breast cancer.

EXPERIMENTAL DESIGN

Studies have been identified by searching the Medline, Embase, and American Society of Clinical Oncology abstract databases. Selection criteria were (a) metastatic breast cancer, (b) endocrine therapy (any line of treatment), and (c) evaluation of HER-2 expression (any method). For each study, the relative risk for treatment failure for HER-2-positive over HER-2-negative patients with 95% confidence interval was calculated as an estimate of the predictive effect of HER-2. Pooled estimates of the relative risk were computed by the Mantel-Haenszel method.

RESULTS

Twelve studies (n = 2,379 patients) were included in the meta-analysis. The overall relative risk was 1.42 (95% confidence interval, 1.32-1.52; P < 0.00001; test for heterogeneity = 0.380). For studies involving tamoxifen, the pooled relative risk was 1.33 (95% confidence interval, 1.20-1.48; P < 0.00001; test for heterogeneity = 0.97); for studies involving other hormonal drugs, a pooled relative risk of 1.49 (95% confidence interval, 1.36-1.64; P < 0.00001; test for heterogeneity = 0.08) was estimated. A second meta-analysis limited to tumors that were either estrogen receptor positive, estrogen receptor unknown, or estrogen receptor negative/progesterone receptor positive yielded comparable results.

CONCLUSIONS

HER-2-positive metastatic breast cancer is less responsive to any type of endocrine treatment. This effect holds in the subgroup of patients with positive or unknown steroid receptors.

Urokinase-type plasminogen activator system in breast cancer: association with tamoxifen therapy in recurrent disease

The prognostic value of components of the urokinase-type plasminogen activator (uPA) system, its receptor uPAR (CD87), and plasminogen activator inhibitors PAI-1 and PAI-2 is well established. We studied the predictive value of these proteolytic factors by evaluating the association of their tumor expression level and the efficacy of tamoxifen therapy in patients with recurrent breast cancer. The antigen levels of the four factors were determined by ELISA in cytosols prepared from estrogen receptor-positive primary breast tumors of 691 hormone-naive breast cancer patients with recurrent disease and treated with tamoxifen as first-line systemic therapy. High tumor levels of uPA (P < 0.001), uPAR (P < 0.01), and PAI-1 (P = 0.01) were associated with a lower efficacy of tamoxifen therapy. In the multivariable analysis, uPA (P < 0.001) provided additional information independent of the traditional predictive factors to predict benefit from tamoxifen therapy. High levels of uPA, uPAR, and PAI-1 predicted a shorter progression-free survival (PFS) on tamoxifen in an analysis of the first 9 months of therapy. However in the analysis during the total follow-up period, high PAI-2 levels (P = 0.01) showed a longer response to tamoxifen. In conclusion, uPA, uPAR, and PAI-1, components of the urokinase system, are predictive for the efficacy of tamoxifen therapy in patients treated for recurrent breast cancer. Knowledge of their tumor expression levels might be helpful for future individualized therapy protocols, including possible new-targeted therapies based on the interference in the urokinase system.

Initially metastatic breast carcinoma has a distinct disease pattern but an equivalent outcome compared with recurrent metastatic breast carcinoma

BACKGROUND

To date, the clinical features and outcomes of patients with initially metastatic breast carcinoma (IMBC) have not been compared with the corresponding characteristics in patients with recurrent metastatic breast carcinoma (RBC). This issue may be particularly relevant to clinical research, as it may shed light on a potential bias with respect to the selection of patients for clinical trials.

METHODS

A retrospective analysis of the medical records of 1350 patients with breast carcinoma was performed. Outcome variables included overall survival, response rate, and progression-free survival.

RESULTS

One hundred nineteen of 370 patients with metastatic breast carcinoma had IMBC, whereas the remaining 251 had RBC. The median follow-up duration was 39.4 months, and the median overall survival duration was 24 months. With regard to clinical characteristics, patients with IMBC were older than patients with RBC (61.7 years vs. 58.1 years; P < 0.001) and had a higher incidence of lobular carcinoma (15.9% vs. 7.7%; P = 0.018), a greater proportion of T3-4 tumors (58.8% vs. 27.9%; P < 0.001), a higher incidence of bone as the dominant metastatic site (41.2% vs. 21.5%; P < 0.001), a lower incidence of soft tissue as the dominant metastatic site (10.1% vs. 26.7%; P < 0.001), and a similar incidence of the viscera as the dominant metastatic site (48.7% vs. 51.8%; P = 0.78). Median overall survival duration was similar for patients with IMBC (25.1 months) and patients with RBC (23.3 months; P = 0.81). Statistical analyses also revealed nonsignificant differences between patients with IMBC and patients with RBC in terms of response rate (40.7% vs. 35.2%, respectively; P = 0.35) and median progression-free survival duration (10.2 months vs. 9.0 months, respectively; P = 0.58).

CONCLUSIONS

Although patients with IMBC and patients with RBC exhibit distinct histologic and clinical characteristics, similar treatment efficacy results and survival outcomes are observed in these two groups.

Clinical and endocrine data for goserelin plus anastrozole as second-line endocrine therapy for premenopausal advanced breast cancer

A total of 16 premenopausal women with metastatic breast cancer (N=13) or locally advanced primary breast cancer (N=3) were treated with a combination of a gonadotropin-releasing hormone agonist goserelin, and a selective aromatase inhibitor anastrozole. All had previously been treated with goserelin and tamoxifen. In all, 12 patients (75%) achieved objective response or durable stable disease at 6 months, with a median duration of remission of 17+ months (range 6–47 months). Four patients still have clinical benefit. Introduction of goserelin and tamoxifen resulted in an 89% reduction in mean oestradiol levels (pretreatment vs 6 months=224 vs 24 pmol l⁻¹) (P<0.0001). Substitution of tamoxifen by anastrozole on progression resulted in a further 76% fall (to 6 pmol l⁻¹ at 3 months) (P<0.0001). Treatment with goserelin and tamoxifen led to a 90% fall in the mean follicle-stimulating hormone (P<0.001). This was reversed once therapy was changed to goserelin and anastrozole. A similar initial reduction was seen in the mean luteinising hormone levels, but substitution of tamoxifen by anastrozole on progression resulted in no significant change. Goserelin and tamoxifen did not lead to any significant change in testosterone and androstenedione levels. The combined use of goserelin and anastrozole as second-line endocrine therapy produces a significant clinical response of worthwhile duration, with demonstrable endocrine changes, in premenopausal women with advanced breast cancer, and offers them another therapeutic option. Further studies involving more patients and longer follow-up are indicated.

Letrozole versus tamoxifen in the treatment of advanced breast cancer and as neoadjuvant therapy

Letrozole, a third generation aromatase inhibitor, has been compared with tamoxifen in the treatment of advanced breast cancer and as neoadjuvant therapy. In a first-line trial in advanced disease, 939 post menopausal women were randomised double blind to receive treatment with letrozole 2.5 mg daily or tamoxifen 20 mg daily. Letrozole was significantly superior in terms of median time to progression (9.4 months versus 6.1 months, P=0.0001), objective response (30% versus 20%, P=0.0006), and clinical benefit (49% versus 38%, P=0.0001). Superiority of letrozole was independent of disease site, receptor status, or prior adjuvant anti-oestrogen therapy. In an extended phase of this trial, 200 patients were crossed over to tamoxifen after letrozole, compared with 197 crossed over to letrozole after tamoxifen. Median overall survival was 34 months for letrozole versus 30 months for tamoxifen (not significant). In a similar randomised double-blind neoadjuvant trial, 337 post menopausal patients with large ER/or PgR positive T2-T4 cancers, either requiring mastectomy or locally advanced, were randomised to preoperative letrozole or tamoxifen for 4 months prior to surgery. Overall response was 55% for letrozole versus 36% for tamoxifen (P<0.001). Conservative surgery was possible in 45% of patients treated with letrozole versus 35% with tamoxifen (P=0.022). In both trials, both treatments were well tolerated with no significant differences in side effects. These results indicate that letrozole is more active than tamoxifen both as neoadjuvant therapy and as first-line treatment in advanced disease. They support the importance of current adjuvant trials comparing the two treatments.

Anastrozole versus tamoxifen as first-line therapy in postmenopausal patients with hormone-dependent advanced breast cancer: a prospective, randomized, phase III study

A prospective phase III trial comparing anastrozole with tamoxifen as first-line therapy in postmenopausal, hormone-dependent, advanced breast cancer (ABC). Patients were randomized to anastrozole 1 mg daily (n = 121) or tamoxifen 40 mg daily (n = 117). Efficacy and tolerability were evaluated after 3 months' therapy, and survival was evaluated at median time of follow-up. At a median follow-up of 13.3 months, clinical benefit (CB) was achieved in 83% and 56% of anastrozole and tamoxifen patients, respectively (p < 0.001); median time to disease progression (TTP) in patients achieving CB was 18.0 months and 7.0 months, respectively, (hazard ratio [HR] = 0.13, 95% CI = 0.08-0.20, p < 0.01). At data cutoff, 89% of tamoxifen patients had died, compared with 60% of anastrozole patients; median time to death was 17.4 months and 16.0 months, respectively (HR = 0.64, 95% CI = 0.47-0.86, p = 0.003). Therapy was well tolerated in both groups. Anastrozole showed significant advantages over tamoxifen for CB, median TTP in patients gaining CB, and survival. These data further support routine use of anastrozole as first-line treatment for postmenopausal hormone-dependent ABC.

Primary endocrine therapy of locally advanced breast cancer patients

Primary endocrine therapy has been traditionally reserved for elderly and unfit locally advanced breast cancer patients (LABC patients). In this group, the primary endocrine therapy could not be adequately compared to primary chemotherapy. Rare studies of primary endocrine therapy, and careful subgroup analyses of their results, showed that primary endocrine therapy could achieve at least the similar magnitude of response rate, compared to primary chemotherapy, in selected patients' population. Thus, the primary treatment with tamoxifen in steroid receptor (SR)-positive LABC patients became the standard arm in current studies of primary endocrine therapy. Several questions, concerning the use of endocrine primary treatment in routine clinical practice, should be answered, including the definition of optimum endocrine agents, biomarkers for prediction of response, and patients' selection criteria.

Fulvestrant

Fulvestrant, a novel oestrogen receptor (ER) downregulator, is a pure anti-oestrogen which completely blocks the trophic actions of oestrogens without exerting any partial agonist effects. It reduces expression of oestrogen receptor, progesterone receptor and proliferative and cell turnover indices. The drug is well-tolerated with minimal systemic side effects. Large randomised trials have demonstrated similar efficacy to anastrozole in the treatment of postmenopausal advanced breast cancer. While results of a Phase III trial comparing fulvestrant with tamoxifen as first-line endocrine therapy for postmenopausal advanced breast cancer are awaited, future studies on its role in adjuvant and neoadjuvant settings, as well as in premenopausal women are required. With the role of tamoxifen as the gold standard of first-line therapy being challenged by the third generation aromatase inhibitors, direct comparison of the latter with fulvestrant in the first-line setting may also be worthwhile.

Formestane, a steroidal aromatase inhibitor after failure of non-steroidal aromatase inhibitors (anastrozole and letrozole): is a clinical benefit still achievable?

BACKGROUND

There are few clinical data on the sequential use of aromatase inhibitors (AI). This paper focuses on the relevance of clinical benefit CB (CR + PR + SD > or = 6 months) in postmenopausal metastatic breast cancer (MBC) patients treated with the steroidal aromatase inhibitor (SAI) formestane (FOR). who had already received non-steroidal aromatase inhibitor (nSAI): letrozole (LTZ) or anastrozole (ANZ).

PATIENTS AND METHODS

Twenty postmenopausal women with MBC were analysed in this retrospective two-centre study with the sequence nSAI-FOR. When receiving ANZ, 1 of 11 achieved a complete response and 9 of 11 a stable disease > or = 6 months, and receiving LTZ 1 of 9 achieved a partial response and 4 of 9 a stable disease > or = 6 months. The analysis of the entire population treated with FOR showed an overall CB of 55% (11 of 20) with a median duration of 15 months and median time to progression (TTP) of 6 months.

CONCLUSIONS

Formestane 250 mg once bi-weekly seems to be an attractive alternative third-line hormonal therapy for the treatment of patients with MBC, previously treated with nSAI.

Anastrozole is superior to tamoxifen as first-line therapy in hormone receptor positive advanced breast carcinoma

BACKGROUND

Two randomized, double-blind trials have compared tamoxifen 20 mg daily and the selective, nonsteroidal aromatase inhibitor anastrozole 1 mg daily as first-line therapy for advanced breast carcinoma (ABC) in postmenopausal women. The trials were prospectively designed to allow for combined data analyses.

METHODS

The combined study population included 1021 postmenopausal women (median age, 67 years [range, 30-92]) with ABC whose tumors were either estrogen and/or progesterone receptor positive or of unknown receptor status. Primary endpoints were time to progression (TTP), objective response, and tolerability.

RESULTS

At a median duration of follow-up of 18.2 months, anastrozole was at least equivalent to tamoxifen in terms of median TTP (8.5 and 7.0 months, respectively; estimated hazard ratio [tamoxifen relative to anastrozole], 1.13 [lower 95% confidence level, 1.00]). In a retrospective subgroup analysis, anastrozole was superior to tamoxifen with respect to TTP (median values of 10.7 and 6.4 months for anastrozole and tamoxifen, respectively, two-sided P = 0.022) in patients with estrogen and/or progesterone receptor positive tumors (60% of combined trial population). In terms of objective response, 29.0% of anastrozole and 27.1% of tamoxifen patients achieved either a complete response (CR) or a partial response (PR). Clinical benefit (CR + PR + stabilization of > or = 24 weeks) rates were 57.1% and 52.0% for anastrozole and tamoxifen, respectively. Both anastrozole and tamoxifen were well tolerated. Anastrozole led to significantly fewer venous thromboembolic (P = 0.043; not adjusted for multiple comparisons) events, and vaginal bleeding was reported in fewer patients treated with anastrozole than with tamoxifen.

CONCLUSIONS

In postmenopausal women with hormonally sensitive ABC, anastrozole should be considered as the new standard first-line treatment.

The use of blood tumour markers in the monitoring of metastatic breast cancer unassessable for response to systemic therapy

The role of blood tumour markers is established in the monitoring of response to systemic therapy for patients with metastatic breast cancer assessable by UICC criteria. This paper examines the use of marker measurements (in the form of a previously devised biochemical index score comprising CA15.3, CEA and ESR) in patients with metastatic lesions unassessable for response by UICC criteria. Of 218 patients with metastatic breast cancer treated over a 2-year period in the Nottingham Breast Unit, 43 patients (20%) had unassessable disease and 36 of them with blood marker results available were studied. Eighty-six per cent of patients were biochemically assessable. All patients who achieved biochemical response remained unassessable by UICC criteria. Twenty-two patients progressed initially or subsequently (after an initial biochemical response), either biochemically or by UICC criteria. Biochemical assessment completely paralleled UICC assessment in all eight patients who progressed by both assessments. Biochemical progression occurred ahead of UICC assessment in four of them with a median lead-time of 4.5 months. Biochemical assessment by blood tumour markers is useful in patients with metastatic breast cancer unassessable for response to systemic therapy. These findings need to be confirmed in a larger patient series.

Metabolic flare: indicator of hormone responsiveness in advanced breast cancer

PURPOSE

The purpose of this study was to investigate whether positron emission tomography (PET) with the glucose analog [(18)F]fluorodeoxyglucose (FDG) and the estrogen analog 16 alpha-[(18)F]fluoroestradiol-17 beta (FES), performed before and after treatment with tamoxifen, could be used to detect hormone-induced changes in tumor metabolism (metabolic flare) and changes in available levels of estrogen receptor (ER). In addition, we investigated whether these PET findings would predict hormonally responsive breast cancer.

PATIENTS AND METHODS

Forty women with biopsy-proved advanced ER-positive (ER(+)) breast cancer underwent PET with FDG and FES before and 7 to 10 days after initiation of tamoxifen therapy; 70 lesions were evaluated. Tumor FDG and FES uptake were assessed semiquantitatively by the standardized uptake value (SUV) method. The PET results were correlated with response to hormonal therapy.

RESULTS

In the responders, the tumor FDG uptake increased after tamoxifen by 28.4% +/- 23.3% (mean +/- SD); only five of these patients had evidence of a clinical flare reaction. In nonresponders, there was no significant change in tumor FDG uptake from baseline (mean change, 10.1% +/- 16.2%; P =.0002 v responders). Lesions of responders had higher baseline FES uptake (SUV, 4.3 +/- 2.4) than those of nonresponders (SUV, 1.8 +/- 1.3; P =.0007). All patients had evidence of blockade of the tumor ERs 7 to 10 days after initiation of tamoxifen therapy; however, the degree of ER blockade was greater in the responders (mean percentage decrease, 54.8% +/- 14.2%) than in the nonresponders (mean percentage decrease, 19.4% +/- 17.3%; P =.0003).

CONCLUSION

The functional status of tumor ERs can be characterized in vivo by PET with FDG and FES. The results of PET are predictive of responsiveness to tamoxifen therapy in patients with advanced ER(+) breast cancer.

Selection of primary breast cancer patients for adjuvant endocrine therapy--is oestrogen receptor alone adequate?

Among 834 patients who had primary breast cancer treated by surgery without adjuvant systemic therapy, 363 had relapse treated by endocrine therapy alone. Patients with oestrogen receptor positive tumours (median: 70 vs. 45 months, p < 0.0001) or with non-progression at 6 months of therapy (median: 111 vs. 37 months, p < 0.0001) survived longer than those with oestrogen receptor negative tumours or with disease progression respectively, presumably due to the effect of therapy. On the other hand, the median disease-free interval, uninfluenced by therapy, showed a similar difference: oestrogen receptor positive versus negative = 29 versus 21 months, p < 0.005; non-progression versus progression = 40 versus 19 months, p < 0.0001. Patients with oestrogen receptor-positive tumours and non-progression at 6 months had the longest disease-free interval. The present study has established that there are factors, other than the oestrogen receptor, inherent in the primary tumour as reflected by the disease-free interval, which affect hormone sensitivity. Selection of adjuvant endocrine therapy based on the oestrogen receptor alone would deem inadequate. Further studies to elucidate other possible factors are warranted to refine the use of endocrine therapy, especially in the adjuvant setting when no indication of response is available.

Anastrozole is superior to tamoxifen as first-line therapy for advanced breast cancer in postmenopausal women: results of a North American multicenter randomized trial. Arimidex Study Group

PURPOSE

The efficacy and tolerability of anastrozole (Arimidex; AstraZeneca, Wilmington, DE, and Macclesfield, United Kingdom) and tamoxifen were compared as first-line therapy for advanced breast cancer in 353 postmenopausal women.

PATIENTS AND METHODS

The randomized, double-blind, multicenter study was designed to evaluate anastrozole 1 mg once daily relative to tamoxifen 20 mg once daily in patients with hormone receptor-positive tumors or tumors of unknown receptor status who were eligible for endocrine therapy. Primary end points were objective response (OR), defined as complete (CR) or partial (PR) response, time to progression (TTP), and tolerability.

RESULTS

Anastrozole was as effective as tamoxifen in terms of OR (21% v 17% of patients, respectively), with clinical benefit (CR + PR + stabilization > or = 24 weeks) observed in 59% of patients on anastrozole and 46% on tamoxifen (two-sided P =.0098, retrospective analysis). Anastrozole had a significant advantage over tamoxifen in terms of TTP (median TTP of 11.1 and 5.6 months for anastrozole and tamoxifen, respectively; two-sided P =.005). The tamoxifen:anastrozole hazards ratio was 1.44 (lower one-sided 95% confidence limit, 1.16). Both treatments were well tolerated. However, thromboembolic events and vaginal bleeding were reported in fewer patients who received anastrozole compared with those who received tamoxifen (4.1% v 8.2% [thromboembolic events] and 1.2% v 3.8% [vaginal bleeding], respectively).

CONCLUSION

Anastrozole satisfied the predefined criteria for equivalence to tamoxifen. Furthermore, we observed both a significant increase in TTP and a lower incidence of thromboembolic events and vaginal bleeding with anastrozole. These findings indicate that anastrozole should be considered as first-line therapy for postmenopausal women with advanced breast cancer.

Anastrozole versus tamoxifen as first-line therapy for advanced breast cancer in 668 postmenopausal women: results of the Tamoxifen or Arimidex Randomized Group Efficacy and Tolerability study

PURPOSE

To compare the efficacy and tolerability of anastrozole (Arimidex; AstraZeneca, Wilmington, DE, and Macclesfield, United Kingdom) with that of tamoxifen as first-line therapy for advanced breast cancer (ABC) in postmenopausal women.

PATIENTS AND METHODS

This randomized, double-blind, multicenter study evaluated the efficacy of anastrozole 1 mg once daily relative to tamoxifen 20 mg once daily in patients with tumors that were hormone receptor-positive or of unknown receptor status who were eligible for endocrine therapy. The primary end points were time to progression (TTP), objective response (OR), and tolerability.

RESULTS

A total of 668 patients (340 in the anastrozole arm and 328 in the tamoxifen arm) were randomized to treatment and followed-up for a median of 19 months. Median TTP was similar for both treatments (8.2 months in patients who received anastrozole and 8.3 months in patients who received tamoxifen). The tamoxifen:anastrozole hazards ratio was 0.99 (lower one-sided 95% confidence limit, 0.86), demonstrating that anastrozole was at least equivalent to tamoxifen. Anastrozole was also as effective as tamoxifen in terms of OR (32.9% of anastrozole and 32.6% of tamoxifen patients achieved a complete response [CR] or partial response [PR]). Clinical benefit (CR + PR + stabilization of > or = 24 weeks) rates were 56.2% and 55.5% for patients receiving anastrozole and tamoxifen, respectively. Both treatments were well tolerated. However, incidences of thromboembolic events and vaginal bleeding were reported in fewer patients treated with anastrozole than with tamoxifen (4.8% v 7.3% [thromboembolic events] and 1.2% v 2.4% [vaginal bleeding], respectively).

CONCLUSION

Anastrozole satisfied the predefined criteria for equivalence to tamoxifen. Together with the lower observed incidence of thromboembolic events and vaginal bleeding, these findings indicate that anastrozole should be considered as first-line therapy for postmenopausal women with ABC.

New calmodulin antagonists inhibit in vitro growth of human breast cancer cell lines independent of their estrogen receptor status

Calmodulin plays a key role in the regulation of cell proliferation and calmodulin antagonists may offer a new therapeutic approach in the treatment of breast cancer. Three new specific calmodulin antagonists with improved potency were synthesized and screened on human breast cancer cell lines known to be estrogen receptor (ER)-positive or -negative. These calmodulin antagonists significantly inhibited cell growth as measured by the MTT proliferation assay (p<0.001). Their IC50 values were in the low micromolar range against both ER-positive and -negative variants of the MCF-7 cell line. Two other breast cancer cell lines (ER-positive T-47D and ER-negative MDA-MB-231) were also inhibited by these calmodulin antagonists with IC50 values in a similar range. The level of inhibition was independent of any stimulation of cell growth by estradiol. Calmodulin antagonists effectively reduced cell growth of both ER-positive and -negative human breast cancer cell lines in vitro. Calmodulin antagonists represent a novel therapeutic approach requiring further investigation.

Bcar1/p130Cas protein and primary breast cancer: prognosis and response to tamoxifen treatment

BACKGROUND

The product of the Bcar1/p130Cas (breast cancer resistance/p130Crk-associated substrate) gene causes resistance to antiestrogen drugs in human breast cancer cells in vitro. To investigate its role in clinical breast cancer, we determined the levels of Bcar1/p130Cas protein in a large series of primary breast carcinomas.

METHODS

We measured Bcar1/p130Cas protein in cytosol extracts from 937 primary breast carcinomas by western blot analysis. The levels of Bcar1/p130Cas protein were tested for associations and trends against clinicopathologic and patient characteristics, the lengths of relapse-free survival and overall survival (n = 775), and the efficacy of first-line treatment with tamoxifen for recurrent or metastatic disease (n = 268).

RESULTS

Bcar1/p130Cas levels in primary tumors were associated with age/menopausal status and the levels of estrogen receptor and progesterone receptor. In univariate survival analysis, higher Bcar1/p130Cas levels were associated with poor relapse-free survival and overall survival (both two-sided P =.04; log-rank test for trend). In multivariate analysis, a high level of Bcar1/p130Cas was independently associated with poor relapse-free survival and overall survival. The response to tamoxifen therapy in patients with recurrent disease was reduced in patients with primary tumors that expressed high levels of Bcar1/p130Cas. In multivariate analysis for response, Bcar1/p130Cas was independent of classical predictive factors, such as estrogen receptor status, age/menopausal status, disease-free interval, and dominant site of relapse.

CONCLUSION

Patients with primary breast tumors expressing a high level of Bcar1/p130Cas protein appear to experience more rapid disease recurrence and have a greater risk of (intrinsic) resistance to tamoxifen therapy. Thus, measurement of Bcar1/p130Cas may provide useful prognostic information for patients with primary or metastatic breast cancer.

Static disease on anastrozole provides similar benefit as objective response in patients with advanced breast cancer

BACKGROUND

This paper reports on the clinical relevance of durable static disease (SD) (> or = 24 weeks) in breast cancer patients treated with the aromatase inhibitor anastrozole.

PATIENTS AND METHODS

All patients were part of two prospective, randomised, multicentre studies in postmenopausal women with advanced disease in which megestrol acetate was compared with anastrozole 1 mg. Survival from initiation of treatment was analysed by the response type, i.e., complete response (CR)/partial response (PR), static disease (SD) (> or = 24 weeks), or progressive disease (PD), achieved on therapy.

RESULTS

Median survival with anastrozole 1 mg was similar between patients who obtained CR/PR and SD (> or = 24 weeks). Similarly, no difference in survival was observed in patients treated with megestrol acetate who achieved CR/PR and SD. With both treatments patients with CR/PR and SD had improved survival over those patients with PD within 24 weeks. There was no difference between treatment arms for patients showing PD within 24 weeks.

CONCLUSIONS

These data confirm that durable SD (> or = 24 weeks) is a clinically useful remission criterion in postmenopausal women with advanced breast cancer with predictive value for overall survival. It also confirms the value of this endpoint with anastrozole, a new generation aromatase inhibitor.

Quality of life in postmenopausal patients with breast cancer after failure of tamoxifen: formestane versus megestrol acetate as second-line hormonal treatment. Swiss Group for Clinical Cancer Research (SAKK)

The Swiss Group for Clinical Cancer Research (SAKK) compared efficacy and toxicity of formestane (250 mg intramuscularly (i.m.) every 2 weeks) versus megestrol acetate (MGA; 160 mg orally daily) as second-line treatment in postmenopausal patients with advanced breast cancer and disease progression while on tamoxifen treatment in a randomised trial (Thürlimann B, Castiglione M, Hsu Schmitz SF, et al. Eur J Cancer 1997, 33, 1017-1024). Quality of life (QL) was evaluated as a secondary endpoint (n = 177). Overall, 83% (669/805) of expected QL forms were received, 88% (155/177) at baseline, 88% (402/457) on study treatment, and 65% (112/171) at treatment failure. Patients with no impairment in performance status reported better physical well-being (P = 0.0001), mood (P = 0.0007) and coping (P = 0.03), and less tiredness (P = 0.0001) and appetite/sense of taste disturbance (P = 0.0001) at baseline. After adjustment for baseline, there was no statistically significant difference in QL by treatment. Baseline QL was strongly predictive for QL under treatment but not for time to treatment failure. In conclusion, the question of whether oestrogen deprivation (e.g. formestane) or addition of progesterone (MGA) has a more beneficial impact on QL needs further investigation. The subjective experience of second-line endocrine treatment varies considerably as a consequence of the large variation in the individual course of the disease and has to be judged on an individual basis.

Measurement of urinary collagen cross-links indicate response to therapy in patients with breast cancer and bone metastases

Objective assessment of response in bone metastases from breast cancer using radiological techniques takes up to 6 months of treatment to be certain of a response, and sclerotic metastases are not evaluable. Standard serum and urinary tumour markers may not always be utilized to predict response, as they may not be elevated, and therefore may not change on treatment. The development of the urinary pyridinoline cross-link assays which measure mature bone breakdown products have been shown to be highly sensitive and specific as a measure of bone change in osteoporosis. We have measured pyridinoline (Pyr) and deoxypyridinoline (Dpyr) cross-links sequentially in 36 breast cancer patients with bone metastases, to determine if the measurement of these analytes predicts response at an earlier stage than radiological assessment. Response was assessed by UICC criteria. Seventeen women responded to hormonal therapy, whilst 19 developed progressive disease. Both Pyr and Dpyr increased sequentially in women with progressive disease with changes becoming apparent by 8 weeks (P<0.03). In responding women, cross-link levels did not change significantly. Pyr and Dpyr were more sensitive and specific than the standard serum tumour marker CA 15-3. Urinary cross-link measurements provide a novel objective method of assessing response to treatment in women with bone metastases. Initial elevated urinary cross-link markers identify patients who tend not to respond to changes in hormonal therapy.

Defining clinical benefit in postmenopausal patients with breast cancer under second-line endocrine treatment: does quality of life matter?

PURPOSE

In endocrine therapy trials in advanced breast cancer, patients with response (complete response/partial response [CR/PR]) and patients with stable disease for at least 6 months (SD(6m)) have shown similar survival and therefore are often defined as a population with clinical benefit (patients with CR/PR or SD(6m)). We evaluated the impact of response and/or clinical benefit on quality of life (QL) in postmenopausal patients under second-line endocrine treatment after failure of tamoxifen.

PATIENTS AND METHODS

One hundred twenty-eight of 177 eligible patients of a randomized trial (Swiss Group for Clinical Cancer Research 20/90) receiving either formestane (250 mg intramuscularly biweekly) or megestrol acetate (160 mg orally daily) were analyzed. The baseline characteristics (with the exception of site of metastases) were balanced among patients with CR/PR, SD(6m), and progressive disease (PD). Patients completed QL indicators at baseline and at 1, 3, 5, 7, 9, and 11 months. Responders were separately compared with nonresponders (patients with SD(6m) or PD) and with patients with SD(6m), and patients with clinical benefit were compared with patients with PD by analysis of covariance with adjustment for baseline scores.

RESULTS

Overall, 88% (557 of 634) of expected QL forms were received. In the comparison of responders versus patients with both SD(6m) and PD, responders indicated better physical well-being (P =. 004) and mood (P =.02) at month 3. Compared only with patients with SD(6m), responders showed no significant difference in baseline QL and time to treatment failure (328.5 v 340 days). While under treatment, responders reported significantly better physical well-being (months 3 to 11), mood (months 5 to 11), coping (months 5 to 9), and appetite (months 7 to 11) and less dizziness (month 9) than patients with SD(6m). The changes between baseline and months 5 and 7, respectively, indicated improvement in responders but heterogeneous patterns in patients with SD(6m).

CONCLUSION

Although the CR/PR and SD(6m) groups had similar times to treatment failure, patients with CR/PR reported better QL, suggesting more beneficial response to second-line endocrine treatment. Patients' subjective perspective should be taken into account in this mainly palliative setting. Future trials should be designed so that the CR/PR and SD(6m) groups are investigated separately.

Onapristone, a progesterone receptor antagonist, as first-line therapy in primary breast cancer

The progesterone receptor antagonist, Onapristone, is an effective endocrine agent in experimental breast cancer models. This study aimed to investigate this agent as first-line endocrine therapy in patients with breast cancer. However, owing to the recognition in this and other clinical studies that some patients on Onapristone developed liver function test abnormalities, the development of this drug and recruitment to the study stopped in 1995. 19 patients either with locally advanced breast cancer (n = 12) or who were elderly, unfit patients with primary breast cancer (n = 7) received Onapristone 100 mg/day. Seventeen of the 19 tumours expressed oestrogen receptors (ER) whilst 12 of the 18 tumours tested expressed progesterone receptors (PgR). Tumour remission was categorised by International Union Against Cancer criteria. One patient was withdrawn after 4.5 months while her disease was static. Of the remaining 18 patients, 10 (56%) showed a partial response and 2 (11%) durable static disease (> or = 6 months), giving an overall tumour remission rate of 67%. The median duration of remission was 70 weeks. Transient liver function test abnormalities developed in a number of patients, mainly during the first 6 weeks of treatment. In conclusion Onapristone can induce tumour responses in human breast cancer.

The objective measurement of remission and progression in metastatic breast cancer by use of serum tumour markers. European Group for Serum Tumour Markers in Breast Cancer

An established biochemical index for monitoring therapy in patients with metastatic breast cancer was tested prospectively in a multicentre study. The index uses two serum tumour markers--carcinoembryonic antigen (CEA) and carbohydrate antigen 15-3 (CA15-3) along with erythrocyte sedimentation rate (ESR). 67 patients treated by either endocrine or chemotherapy had CA15-3, CEA and ESR measured at diagnosis of metastases and sequentially during therapy. Two markers, CA15-3 and CEA, were measured on a further 16 patients giving a total of 83 patients who were assessable for CA15-3 and CEA. Of the patients with CA15-3, CEA and ESR measured at diagnosis of metastases 84% (56/67) had elevation of 1 or more markers. During therapy the number with elevated marker(s) rose to 96% (64/67). Changes in the markers were in line with and often pre-dated therapeutic outcome as assessed by the International Union Against Cancer (UICC) criteria both for remission and progression. Patients without elevation of markers on diagnosis subsequently showed a rise in the marker(s) at or before documented disease progression by UICC. The 3 women in whom markers were at no time significantly elevated remain in remission. The results using CA15-3 and CEA were similar but 12% less patients were assessable. CA15-3 and CEA (with and without ESR) provide an objective method to guide therapy in patients with metastatic breast cancer.