Personalized Decision Making in Early Stage Breast Cancer: Applying Clinical Prediction Models for Anthracycline Cardiotoxicity and Breast Cancer Mortality Demonstrates Substantial Heterogeneity of Benefit-Harm Trade-off.

BACKGROUND: Anthracycline agents can cause cardiotoxicity. We used multivariable risk prediction models to identify a subset of patients with breast cancer at high risk of cardiotoxicity, for whom the harms of anthracycline chemotherapy may balance or exceed the benefits. PATIENTS AND METHODS: A clinical prediction model for anthracycline cardiotoxicity was created in 967 patients with human epidermal growth factor receptor-negative breast cancer treated with doxorubicin in the ECOG-ACRIN study E5103. Cardiotoxicity was defined as left ventricular ejection fraction (LVEF) decline of ≥ 10% to < 50% and/or a centrally adjudicated clinical heart failure diagnosis. Patient-specific incremental absolute benefit of anthracyclines (compared with non-anthracycline taxane chemotherapy) was estimated using the PREDICT model to assess breast cancer mortality risk. RESULTS: Of the 967 women who initiated therapy, 51 (5.3%) developed cardiotoxicity (12 with clinical heart failure). In a multivariate model, increasing age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.01-1.08), higher body mass index (OR, 1.06; 95% CI, 1.02-1.10), and lower baseline LVEF (OR, 0.93; 95% CI, 0.89-0.98) at baseline were significantly associated with cardiotoxicity. The concordance statistic of the risk model was 0.70 (95% CI, 0.63-0.77). In patients with low anticipated treatment benefit (n = 176) from the addition of anthracycline (< 2% absolute risk difference of breast cancer mortality at 10 years), 16 (9%) of 176 had a > 10% risk of cardiotoxicity and 61 (35%) of 176 had a 5% to 10% risk of cardiotoxicity at 1 year. CONCLUSION: Older age, higher body mass index, and lower baseline LVEF were associated with increased risk of cardiotoxicity. We identified a subgroup with low predicted absolute benefit of anthracyclines but with high predicted risk of cardiotoxicity. Additional studies are needed incorporating long-term cardiac outcomes and cardiotoxicity model external validation prior to implementation in routine clinical practice.

Chemoendocrine therapy for premenopausal women with axillary lymph node-positive, steroid hormone receptor-positive breast cancer: results from INT 0101 (E5188).

PURPOSE: Chemotherapy, tamoxifen, and ovarian ablation/suppression (OA/OS) are effective adjuvant approaches for premenopausal, steroid hormone receptor-positive breast cancer. The value of combined therapy has not been clearly established. PATIENTS AND METHODS: Premenopausal women with axillary lymph node-positive, steroid hormone receptor-positive breast cancer (1,503 eligible patients) were randomly assigned to six cycles of cyclophosphamide, doxorubicin, and fluorouracil (CAF), CAF followed by 5 years of monthly goserelin (CAF-Z), or CAF followed by 5 years of monthly goserelin and daily tamoxifen (CAF-ZT). The primary end points were time to recurrence (TTR), disease-free survival (DFS), and overall survival (OS) for CAF-Z versus CAF, and CAF-ZT versus CAF-Z. RESULTS: With a median follow-up of 9.6 years, the addition of tamoxifen to CAF-Z improved TTR and DFS but not OS. There was no overall advantage for addition of goserelin to CAF. CONCLUSION: Addition of tamoxifen to CAF-Z improves outcome for premenopausal node-positive, receptor-positive breast cancer. The role of OA/OS alone or with other endocrine agents should be studied more intensely.

A pilot phase II trial of valspodar modulation of multidrug resistance to paclitaxel in the treatment of metastatic carcinoma of the breast (E1195): a trial of the Eastern Cooperative Oncology Group.

BACKGROUND: To assess the activity and toxicity of valspodar (PSC-833) in combination with paclitaxel in women with anthracycline refractory, metastatic breast cancer. PATIENTS AND METHODS: Limited, multi-institutional, Phase II trial of valspodar at 5 mg/kg/dose orally every 6 hours for 12 doses in combination with paclitaxel 70 mg/m2 administered intravenously as a 3-hour infusion beginning 4 hours after the fifth dose of valspodar, every 3 weeks. Eligible patients had bi-dimensionally measurable metastatic carcinoma of the breast, prior anthracycline therapy or a medical contraindication to anthracycline therapy, no more than one prior chemotherapy for recurrent or metastatic breast cancer, and adequate organ function. Treatment was continued until disease progression or unacceptable toxicity. RESULTS: Thirty-four patients are evaluable for response and 37 for toxicity. Two (6 percent) patients achieved a complete response and 5 (15 percent) a partial response for an objective response rate of 21 percent (95 percent confidence interval of 9 to 38 percent). Median duration of response was 9.7 months (95 percent confidence interval 8.0-17.2 months), median time to progression was 3.3 months (95 percent confidence interval 2.0-4.2 months), and median survival was 12 months (95 percent confidence interval 8.1-17.3 months). The toxicity experienced was acceptable. CONCLUSIONS: Combination valspodar plus paclitaxel is an active regimen and has acceptable toxicity. The combination is not clearly more active than single agent paclitaxel.