When given in combination with dose-dense chemotherapy for women with human epidermal growth factor receptor 2 (HER2)-positive breast cancer, adjuvant trastuzumab should be administered for 12 months rather than 6 months, a new study published in the journal Annals of Oncology has shown.
For the study, researchers sought to compare 12 versus 6 months of adjuvant trastuzumab in women with HER2-positive early breast cancer.
Researchers enrolled 481 patients with axillary node-positive or high-risk node-negative, HER2-positive early breast cancer and randomly assigned them to receive 12 or 6 months of adjuvant trastuzumab concurrently with dose-dense, G-CSF-supported docetaxel. All patients also received upfront dose-dense, G-CSF-supported FEC.
Results showed that the 3-year disease-free survival was 95.7% in the 12-month treatment group compared with 93.3% in the 6-month treatment group (HR = 1.57; 95% CI: 0.86-2.10; P = 0.137).
Researchers observed no difference in overall survival. The study showed that after 47 and 51 months of median follow-up, 7.1% and 11.7% of patients in the experienced disease relapses in the 12- and 6-month groups, respectively (P = 0.08).
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In regard to safety, there was no difference in cardiotoxicity between the two groups.
Because the study failed to show non-inferiority for the 6-month administration of adjuvant trastuzumab, the authors conclude that the current standard of care that is adjuvant trastuzumab for 12 months should be continued.
- Mavroudis D, Saloustros E, Malamos N, et al. Six versus twelve months of adjuvant trastuzumab in combination with dose-dense chemotherapy for women with HER2-positive breast cancer: a multicenter randomized study by the Hellenic Oncology Research Group (HORG). 2015. [Epub ahead of print]. doi: 10.1093/annonc/mdv213.