SCIENTIFIC ADVANCES

Disease-Free Breast Cancer Survival Improves When Trastuzumab is Used With Chemotherapy

Results from a large, randomized clinical trial (N9831) clarify the importance of administering trastuzumab (Herceptin) along with chemotherapy in an adjuvant setting. Information from this study presented at the 2009 San Antonio Breast Cancer Symposium found a 25 percent reduction in the risk of breast cancer recurrence when trastuzumab was administered concurrently with taxane compared to sequentially administering trastuzumab following completion of taxane chemotherapy.

This study is the only phase 3 randomized clinical trial to assess chemotherapy alone (Arm A) versus either sequential (Arm B) or concurrent (Arm C) incorporation of trastuzumab in patients with invasive HER2+ breast cancer. Chemotherapy used in the study was doxorubicin and cyclophosphamide then paclitaxel, and was administered for approximately six months. Trastuzumab was given for 52 weeks. The results of the comparison in the trial of the outcomes between Arms A and C (chemotherapy alone vs concurrent incorporation of trastuzumab with chemotherapy) have been presented previously as part of a joint analysis with the National Surgical Adjuvant Breast and Bowel Project (NSABP) trial B-31. And now the updated information from the N9831 provides additional information on the timing of trastuzumab therapy. The first comparison of outcomes in 1,087 women in Arm A (chemotherapy alone) compared to 1,097 women in Arm B (sequential trastuzumab) found that five-year disease-free survival was increased from 72 percent (Arm A) to 80 percent (Arm B). The comparison of 954 women enrolled in Arm B with 949 women enrolled in Arm C found that the patients in Arm C (concurrent trastuzumab) fared the best overall, with a 5-year disease-free-survival of 84 percent compared to 80 percent for patients in Arm B (sequential trastuzumab).

This study was conducted as a collaborative effort, with researchers participating via the NCI-sponsored cooperative group clinical trials program, led by the North Central Cancer Treatment Group (NCCTG) in collaboration with the Eastern Cooperative Oncology Group (ECOG), the Cancer and Leukemia Group B group (CALGB), and the Southwest Oncology Group (SWOG).

Recent follow-up findings from this study can be found in the Journal of Clinical Oncology.

Perez EA, Suman VJ, Davidson NE, et al. Sequential versus concurrent trastuzumab in adjuvant chemotherapy for breast cancer. J Clin Oncol 2011:29;4491-7. http://www.ncbi.nlm.nih.gov/pubmed/22042958