Re-Challenging Taxanes in Recurrent Breast Cancer in Patients Treated with (Neo-)Adjuvant Taxane-Based Therapy.

SUMMARY: Background: Docetaxel and paclitaxel are among the most active substances for the treatment of breast cancer. As both drugs are used today in adjuvant regimens, efficacy data from pivotal trials in the metastatic setting in taxane-naive populations cannot reliably be used as references. Patients and Methods: The Taxane Re-Challenge Cohort Study identified participants from 6 prospective (neo-)adjuvant taxane-based studies with recurrent disease and collected data on their subsequent treatment. Out of 381 recurrent patients, 106 (27.8%) were re-challenged with a taxane-based treatment as first- or later-line therapy for recurrent disease. Results: Taxanes were used as first-line therapy in 74 patients and showed a response rate of 48.6% (including complete responses in 27.0%). The response rate was dependent on the disease-free interval (<1 year: 34.8%; 1-2 years: 42.9%; >2 years: 63.3%; p = 0.04) and visceral metastasis (present: 62.5%; not present 32.4%; p = 0.01). Patients without visceral metastasis and with a disease-free interval of >2 years achieved the longest overall survival. Hormone and HER2 receptor status were not predictive; however, triple-negative tumors responded in 50.0%. The overall response rate of later-line taxane-based treatment was 28.2%. Conclusion: Re-challenging taxanes appears to be effective and therefore represents a reasonable option in this population.