Endocrine therapy plus zoledronic acid in premenopausal breast cancer.

BACKGROUND: Ovarian suppression plus tamoxifen is a standard adjuvant treatment in premenopausal women with endocrine-responsive breast cancer. Aromatase inhibitors are superior to tamoxifen in postmenopausal patients, and preclinical data suggest that zoledronic acid has antitumor properties. METHODS: We examined the effect of adding zoledronic acid to a combination of either goserelin and tamoxifen or goserelin and anastrozole in premenopausal women with endocrine-responsive early breast cancer. We randomly assigned 1803 patients to receive goserelin (3.6 mg given subcutaneously every 28 days) plus tamoxifen (20 mg per day given orally) or anastrozole (1 mg per day given orally) with or without zoledronic acid (4 mg given intravenously every 6 months) for 3 years. The primary end point was disease-free survival; recurrence-free survival and overall survival were secondary end points. RESULTS: After a median follow-up of 47.8 months, 137 events had occurred, with disease-free survival rates of 92.8% in the tamoxifen group, 92.0% in the anastrozole group, 90.8% in the group that received endocrine therapy alone, and 94.0% in the group that received endocrine therapy with zoledronic acid. There was no significant difference in disease-free survival between the anastrozole and tamoxifen groups (hazard ratio for disease progression in the anastrozole group, 1.10; 95% confidence interval [CI], 0.78 to 1.53; P=0.59). The addition of zoledronic acid to endocrine therapy, as compared with endocrine therapy without zoledronic acid, resulted in an absolute reduction of 3.2 percentage points and a relative reduction of 36% in the risk of disease progression (hazard ratio, 0.64; 95% CI, 0.46 to 0.91; P=0.01); the addition of zoledronic acid did not significantly reduce the risk of death (hazard ratio, 0.60; 95% CI, 0.32 to 1.11; P=0.11). Adverse events were consistent with known drug-safety profiles. CONCLUSIONS: The addition of zoledronic acid to adjuvant endocrine therapy improves disease-free survival in premenopausal patients with estrogen-responsive early breast cancer. (ClinicalTrials.gov number, NCT00295646.)

Adjuvant endocrine therapy plus zoledronic acid in premenopausal women with early-stage breast cancer: 62-month follow-up from the ABCSG-12 randomised trial.

BACKGROUND: Analysis of the Austrian Breast and Colorectal Cancer Study Group trial-12 (ABCSG-12) at 48 months' follow-up showed that addition of zoledronic acid to adjuvant endocrine therapy significantly improved disease-free survival. We have now assessed long-term clinical efficacy including disease-free survival and disease outcomes in patients receiving anastrozole or tamoxifen with or without zoledronic acid. METHODS: ABSCG-12 is a randomised, controlled, open-label, two-by-two factorial, multicentre trial in 1803 premenopausal women with endocrine-receptor-positive early-stage (stage I-II) breast cancer receiving goserelin (3.6 mg every 28 days), comparing the efficacy and safety of anastrozole (1 mg per day) or tamoxifen (20 mg per day) with or without zoledronic acid (4 mg every 6 months) for 3 years. Randomisation (1:1:1:1 ratio) was computerised and based on the Pocock and Simon minimisation method to balance the four treatment arms across eight prognostic variables (age, neoadjuvant chemotherapy, pathological tumour stage; lymph-node involvement, type of surgery or locoregional therapy, complete axillary dissection, intraoperative radiation therapy, and geographical region). Treatment allocation was not masked. The primary endpoint was disease-free survival (defined as disease recurrence or death) and analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00295646; follow-up is ongoing. FINDINGS: At a median follow-up of 62 months (range 0-114.4 months), more than 2 years after treatment completion, 186 disease-free survival events had been reported (53 events in 450 patients on tamoxifen alone, 57 in 453 patients on anastrozole alone, 36 in 450 patients on tamoxifen plus zoledronic acid, and 40 in 450 patients on anastrozole plus zoledronic acid). Zoledronic acid reduced risk of disease-free survival events overall (HR 0.68, 95% CI 0.51-0.91; p=0.009), although the difference was not significant in the tamoxifen (HR 0.67, 95% CI 0.44-1.03; p=0.067) and anastrozole arms (HR 0.68, 95% CI 0.45-1.02; p=0.061) assessed separately. Zoledronic acid did not significantly affect risk of death (30 deaths with zoledronic acid vs 43 deaths without; HR 0.67, 95% CI 0.41-1.07; p=0.09). There was no difference in disease-free survival between patients on tamoxifen alone versus anastrozole alone (HR 1.08, 95% CI 0.81-1.44; p=0.591), but overall survival was worse with anastrozole than with tamoxifen (46 vs 27 deaths; HR 1.75, 95% CI 1.08-2.83; p=0.02). Treatments were generally well tolerated, with no reports of renal failure or osteonecrosis of the jaw. Bone pain was reported in 601 patients (33%; 349 patients on zoledronic acid vs 252 not on the drug), fatigue in 361 (20%; 192 vs 169), headache in 280 (16%; 147 vs 133), and arthralgia in 266 (15%; 145 vs 121). INTERPRETATION: Addition of zoledronic acid improved disease-free survival in the patients taking anastrozole or tamoxifen. There was no difference in disease-free survival between patients receiving anastrozole and tamoxifen overall, but those on anastrozole alone had inferior overall survival. These data show persistent benefits with zoledronic acid and support its addition to adjuvant endocrine therapy in premenopausal patients with early-stage breast cancer. FUNDING: AstraZeneca; Novartis.

Adjuvant endocrine therapy plus zoledronic acid in premenopausal women with early-stage breast cancer: 5-year follow-up of the ABCSG-12 bone-mineral density substudy.

BACKGROUND: The Austrian Breast and Colorectal Cancer Study Group trial-12 (ABCSG-12) bone substudy assesses zoledronic acid for preventing bone loss associated with adjuvant endocrine therapy and reports on long-term findings of bone-mineral density (BMD) during 3 years of treatment and 2 years after completing adjuvant treatment with or without zoledronic acid. The aim of this substudy is to gain insight into bone health in this setting. METHODS: ABCSG-12 is a randomised, open-label, phase III, 4-arm trial comparing tamoxifen (20 mg/day orally) and goserelin (3.6 mg subcutaneously every 28 days) versus anastrozole (1 mg/day orally) and goserelin (3.6 mg subcutaneously every 28 days), both with or without zoledronic acid (4 mg intravenously every 6 months) for 3 years in premenopausal women with endocrine-responsive breast cancer. This prospective bone subprotocol measured BMD at 0, 6, 12, 36, and 60 months. The primary endpoint of the bone substudy (secondary endpoint in the main trial) was change in BMD at 12 months, assessed by dual-energy X-ray absorptiometry in assessable patients. Analyses were intention to treat. Statistical significance was assessed by t tests. The ABCSG-12 trial is registered on the ClinicalTrials.gov website, number NCT00295646. FINDINGS: 404 patients were prospectively included in the bone substudy and randomly assigned to endocrine therapy alone (goserelin and anastrozole or goserelin and tamoxifen; n=199) or endocrine therapy concurrent with zoledronic acid (goserelin, anastrozole, and zoledronic acid or goserelin, tamoxifen, and zoledronic acid; n=205). After 3 years of treatment, endocrine therapy alone caused significant loss of BMD at the lumbar spine (-11.3%, mean difference -0.119 g/cm(2) [95% CI -0.146 to -0.091], p<0.0001) and trochanter (-7.3%, mean difference -0.053 g/cm(2) [-0.076 to -0.030], p<0.0001). In patients who did not receive zoledronic acid, anastrozole caused greater BMD loss than tamoxifen at 36 months at the lumbar spine (-13.6%, mean difference -0.141 g/cm(2) [-0.179 to -0.102] vs -9.0%, mean difference -0.095 g/cm(2) [-0.134 to -0.057], p<0.0001 for both). 2 years after the completion of treatment (median follow-up 60 months [range 15.5-96.6]), patients not receiving zoledronic acid still had decreased BMD at both sites compared with baseline (lumbar spine -6.3%, mean difference -0.067 g/cm(2) [-0.106 to -0.027], p=0.001; trochanter -4.1%, mean difference -0.03 g/cm(2) [-0.062 to 0.001], p=0.058). Patients who received zoledronic acid had stable BMD at 36 months (lumbar spine +0.4%, mean difference 0.004 g/cm(2) [-0.024 to 0.032]; trochanter +0.8%, mean difference 0.006 g/cm(2) [-0.018 to 0.028]) and increased BMD at 60 months at both sites (lumbar spine +4.0%, mean difference 0.039 g/cm(2) [0.005-0.075], p=0.02; trochanter +3.9%, mean difference 0.028 g/cm(2) [0.003-0.058], p=0.07) compared with baseline. INTERPRETATION: Goserelin plus tamoxifen or anastrozole for 3 years without concomitant zoledronic acid caused significant bone loss. Although there was partial recovery 2 years after completing treatment, patients receiving endocrine therapy alone did not recover their baseline BMD levels. Concomitant zoledronic acid prevented bone loss during therapy and improved BMD at 5 years.

Lumpectomy plus tamoxifen or anastrozole with or without whole breast irradiation in women with favorable early breast cancer.

PURPOSE: In women with favorable early breast cancer treated by lumpectomy plus tamoxifen or anastrazole, it remains unclear whether whole breast radiotherapy is beneficial. METHODS AND MATERIAL: Between January 1996 and June 2004, the Austrian Breast and Colorectal Cancer Study Group (ABCSG) randomly assigned 869 women to receive breast radiotherapy +/- boost (n = 414) or not (n = 417) after breast-conserving surgery (ABCSG Study 8A). Favorable early breast cancer was specified as tumor size <3 cm, Grading 1 or 2, negative lymph nodes, positive estrogen and/or progesterone receptor status, and manageable by breast-conserving surgery. Breast radiotherapy was performed after lumpectomy with 2 tangential opposed breast fields with mean 50 Gy, plus boost in 71% of patients with mean 10 Gy, in a median of 6 weeks. The primary endpoint was local relapse-free survival; further endpoints were contralateral breast cancer, distant metastases, and disease-free and overall survival. The median follow-up was 53.8 months. RESULTS: The mean age was 66 years. Overall, there were 21 local relapses, with 2 relapses in the radiotherapy group (5-y rate 0.4%) vs. 19 in the no-radiotherapy group (5.1%), respectively (p = 0.0001, hazard ratio 10.2). Overall relapses occurred in 30 patients, with 7 events in the radiotherapy group (5-y rate 2.1%) vs. 23 events in the no-radiotherapy group (6.1%) (p = 0.002, hazard ratio 3.5). No significant differences were found for distant metastases and overall survival. CONCLUSION: Breast radiotherapy +/- boost in women with favorable early breast cancer after lumpectomy combined with tamoxifen/anastrazole leads to a significant reduction in local and overall relapse.

Multi-institutional comparison of non-sentinel lymph node predictive tools in breast cancer patients with high predicted risk of further axillary metastasis.

Although axillary lymph node dissection (ALND) has been the standard intervention in breast cancer patients with sentinel lymph node (SLN) metastasis, only a small proportion of patients benefit from this operation, because most do not harbor additional metastases in the axilla. Several predictive tools have been constructed to identify patients with low risk of non-SLN metastasis who could be candidates for the omission of ALND. In the present work, predictive nomograms were used to predict a high (>50 %) risk of non-SLN metastasis in order to identify patients who would most probably benefit from further axillary treatment. Data of 1000 breast cancer patients with SLN metastasis and completion ALND from 5 institutions were tested in 4 nomograms. A subset of 313 patients with micrometastatic SLNs were also tested in 3 different nomograms devised for the micrometastatic population (the high risk cut-off being 20 %). Patients with a high predicted risk of non-SLN metastasis had higher rates of metastasis in the non-SLNs than patients with low predicted risk. The positive predictive values of the nomograms ranged from 44 % to 64 % with relevant inter-institutional variability. The nomograms for micrometastatic SLNs performed much better in identifying patients with low risk of non-SLN involvement than in high-risk-patients; for the latter, the positive predictive values ranged from 13 % to 20 %. The nomograms show inter-institutional differences in their predictive values and behave differently in different settings. They are worse in identifying high risk patients than low-risk ones, creating a need for new predictive models to identify high-risk patients.

Tamoxifen and anastrozole as a sequencing strategy: a randomized controlled trial in postmenopausal patients with endocrine-responsive early breast cancer from the Austrian Breast and Colorectal Cancer Study Group.

PURPOSE: Anastrozole (ANA) alone delivers significant disease-free survival benefits over tamoxifen (TAM) monotherapy in postmenopausal women with early estrogen receptor-positive breast cancer. The ABCSG-8 (Austrian Breast and Colorectal Cancer Study Group 8) study is a large phase III clinical trial addressing the sequence strategy containing ANA in comparison with 5 years of TAM in a low- to intermediate-risk group of postmenopausal patients. PATIENTS AND METHODS: Endocrine receptor-positive patients with G1 or G2 tumors were eligible. After surgery, patients were randomly assigned to 5 years of TAM or 2 years of TAM followed by 3 years of ANA. Adjuvant chemotherapy and G3 and T4 tumors were exclusion criteria. Intention-to-treat and censored analyses of on-treatment recurrence-free survival (RFS) were performed, and exploratory survival end points and toxicity were investigated. RESULTS: Information from 3,714 patients, including 17,563 woman-years, with a median of 60 months of follow-up was available for this analysis. Median age was 63.8 years, 75% were node negative, and 75% had T1 tumors. Sequencing of ANA after identical 2-year treatment with TAM in both arms did not result in a statistically significant improvement of RFS (hazard ratio [HR], 0.80; 95% CI, 0.63 to 1.01; P = .06). Exploratory analyses of distant relapse-free survival indicated a 22% improvement (HR, 0.78; 95% CI, 0.60 to 1.00). On-treatment adverse events and serious adverse events were consistent with known toxicity profiles of ANA and TAM treatment. CONCLUSION: Despite a low overall rate of recurrence in a population with breast cancer at limited risk of relapse, the a priori sequence strategy of 2 years of TAM followed by 3 years of ANA led to small outcome and toxicity benefits.

International multicenter tool to predict the risk of nonsentinel node metastases in breast cancer.

BACKGROUND: Axillary treatment of breast cancer patients is undergoing a paradigm shift, as completion axillary lymph node dissections (ALNDs) are being questioned in the treatment of patients with tumor-positive sentinel nodes. This study aims to develop a novel multi-institutional predictive tool to calculate patient-specific risk of residual axillary disease after tumor-positive sentinel node biopsy. METHODS: Breast cancer patients with a tumor-positive sentinel node and a completion ALND from five European centers formed the original patient series (N = 1000). Statistically significant variables predicting nonsentinel node involvement were identified in logistic regression analysis. A multivariable predictive model was developed and validated by area under the receiver operating characteristics curve (AUC), first internally in 500 additional patients and then externally in 1068 patients from other centers. All statistical tests were two-sided. RESULTS: Nine tumor- and sentinel node-specific variables were identified as statistically significant factors predicting nonsentinel node involvement in logistic regression analysis. A resulting predictive model applied to the internal validation series resulted in an AUC of 0.714 (95% confidence interval [CI] = 0.665 to 0.763). For the external validation series, the AUC was 0.719 (95% CI = 0.689 to 0.750). The model was well calibrated in the external validation series. CONCLUSIONS: We present a novel, international, multicenter, predictive tool to assess the risk of additional axillary metastases after tumor-positive sentinel node biopsy in breast cancer. The predictive model performed well in internal and external validation but needs to be further studied in each center before application to clinical use.

Exemestane as primary systemic treatment for hormone receptor positive post-menopausal breast cancer patients: a phase II trial of the Austrian Breast and Colorectal Cancer Study Group (ABCSG-17).

BACKGROUND: A multicenter phase II study was conducted to analyze the clinical activity of the steroidal aromatase inhibitor exemestane in the neoadjuvant treatment of post-menopausal women with strongly ER- and/or PgR- positive operable breast cancer. PATIENTS AND METHODS: From September 2000 to December 2003, 80 women were recruited for treatment with exemestane 25 mg once daily for 4 months. The primary end-point was the clinical response rate according the WHO criteria; the secondary end-points included toxicity and the number of patients who qualified for breast conserving surgery at the end of treatment, comparability of evaluation methods for response, potential alterations of hormone receptor and Her2/neu status during treatment. RESULTS: On an intention to evaluate analysis, according to the prespecified criteria the overall clinical objective response rate was 34%, the pCR rate was 3% and the rate of breast conserving surgery was 76%. When sonographic and mammographic longitudinal measurements were included in patients with missing palpation data, response rates were 38% and 41%, respectively. The tumor response was independent of the Her2/neu status which remained unchanged during treatment. In contrast, while the ER expression remained unaltered, downregulation of the PgR was observed. The treatment was well tolerated with no grade 3 and 4 toxicities except gastrointestinal (one grade 3 case) and hot flushes (two grade 3 cases). CONCLUSION: This study shows that exemestane is effective and safe as a preoperative therapy in post-menopausal patients with strongly hormone receptor-positive breast cancer.

Zoledronic acid prevents cancer treatment-induced bone loss in premenopausal women receiving adjuvant endocrine therapy for hormone-responsive breast cancer: a report from the Austrian Breast and Colorectal Cancer Study Group.

PURPOSE: Adjuvant therapy for breast cancer can be associated with decreased bone mineral density (BMD) that may lead to skeletal morbidity. This study examined whether zoledronic acid can prevent bone loss associated with adjuvant endocrine therapy in premenopausal patients. PATIENTS AND METHODS: This study is a randomized, open-label, phase III, four-arm trial comparing tamoxifen (20 mg/d orally) and goserelin (3.6 mg every 28 days subcutaneously) +/- zoledronic acid (4 mg intravenously every 6 months) versus anastrozole (1 mg/d orally) and goserelin +/- zoledronic acid for 3 years in premenopausal women with hormone-responsive breast cancer. In a BMD subprotocol at three trial centers, patients underwent serial BMD measurements at 0, 6, 12, 24, and 36 months. RESULTS: Four hundred one patients were included in the BMD subprotocol. Endocrine treatment without zoledronic acid led to significant (P < .001) overall bone loss after 3 years of treatment (BMD, -14.4% after 36 months; mean T score reduction, -1.4). Overall bone loss was significantly more severe in patients receiving anastrozole/goserelin (BMD, -17.3%; mean T score reduction, -2.6) compared with patients receiving tamoxifen/goserelin (BMD, -11.6%; mean T score reduction, -1.1). In contrast, BMD remained stable in zoledronic acid-treated patients (P < .0001 compared with endocrine therapy alone). No interactions with age or other risk factors were noted. CONCLUSION: Endocrine therapy caused significant bone loss that increased with treatment duration in premenopausal women with breast cancer. Zoledronic acid 4 mg every 6 months effectively inhibited bone loss. Regular BMD measurements and initiation of concomitant bisphosphonate therapy on evidence of bone loss should be considered for patients undergoing endocrine therapy.

Pathologic complete response with six compared with three cycles of neoadjuvant epirubicin plus docetaxel and granulocyte colony-stimulating factor in operable breast cancer: results of ABCSG-14.

PURPOSE: Preoperative (neoadjuvant) chemotherapy for operable breast cancer downstages tumors initially not suitable for breast-conserving surgery. A pathologic complete response (pCR) to neoadjuvant chemotherapy may be a surrogate for longer overall survival, but this beneficial effect remains to be established. This phase III trial evaluated whether doubling the number of cycles of neoadjuvant treatment increased the pCR rate. PATIENTS AND METHODS: Patients with biopsy-proven breast cancer (T1-4a-c, N+/-, M0; stage I to III) were eligible and randomly assigned to either three or six cycles of epirubicin 75 mg/m2 and docetaxel 75 mg/m2 on day 1 and granulocyte colony-stimulating factor on days 3 through 10 (ED+G), every 21 days. The primary end point was the pCR rate of the breast tumor. Secondary end points were pathologic nodal status after surgery and the rate of breast-conserving surgery. RESULTS: A total of 292 patients were accrued, and 288 patients were assessable for efficacy and safety. Groups were well balanced for known prognostic factors. Six cycles of ED+G, compared with three cycles, resulted in a significantly higher pCR rate (18.6% v 7.7%, respectively; P = .0045), a higher percentage of patients with negative axillary status (56.6% v 42.8%, respectively; P = .02), and a trend towards more breast-conserving surgery (75.9% v 66.9%, respectively; P = .10). Rates of adverse events were similar, and no patients died on treatment. CONCLUSION: Doubling the number of neoadjuvant ED+G cycles from three to six results in higher rates of pCR and negative axillary nodal status with no excess of adverse effects. Thus, six cycles of ED+G should be the standard neoadjuvant treatment for operable breast cancer if this combination is chosen.

Microsatellite analysis of breast carcinoma and corresponding local recurrences.

Local recurrence is a serious complication of breast carcinoma that reduces quality of life and influences prognosis. The aim of this study was to determine whether local recurrences of breast carcinoma are genetically related to the primary tumours. Forty cases of locally recurrent breast carcinomas (median onset: 3.6 years after primary surgery) were analysed: 22 patients had undergone breast-conserving therapy and 18 mastectomy. Eighteen microsatellites on chromosomes 2p, 3p, 5q, 10q, 11p, 11q, 13q, 17q, 17p, 18p were amplified by PCR using fluorescent-labelled primers, automatically detected after polyacrylamide gel electrophoresis and analysed for loss of heterozygosity (LOH) or microsatellite instability (MSI). Follow-up data were available for 39 cases with a median value of 89 months. All LOH and MSI found in the primary tumours were also present in the corresponding recurrences, indicating that they are genetically related to the primary tumours and not secondary malignancies in the same breast. MSI was found in three cases, of which one harboured MSI at more than two loci. The median value of LOH per case was significantly higher in the recurrent (four per case) compared to the primary tumours (two per case; p < 0.001, Mann-Whitney test), reflecting the genotype of tumour progression. Early local recurrence was associated with specific LOH for TP53.15 (p = 0.018, log-rank test) in the primary tumours. LOH on D13S1699 or D17S855 was associated with lymph node metastases (p = 0.024 and p = 0.019, respectively; chi-square test). In addition, tumour grade, lack of oestrogen or progesterone receptor expression, young patient age and early appearance of local recurrence significantly correlated with poor survival. The development of local recurrence despite clear resection margins may result from residual DCIS distant from the invasive carcinoma, homing of circulating tumour cells, or genetically altered, histologically normal breast tissue not immediately adjacent to the invasive carcinoma.