In his overview of recent adjuvant trastuzumab trials, Dr. Baselga discussed such trials as HERceptin Adjuvant trial, National Surgical Adjuvant Breast and Bowel Project trial B31, North Central Cancer Treatment Group trial N9831, Breast Cancer International Research Group trial 006, and the Finnish Herceptin FinHer trial.

Dr. Baselga initially described the general patient characteristics across these trials: HER2-positive, resected invasive breast cancer, node-positive or high-risk node-negative nodal status, no locally advanced or distant disease, and no previous or current cardiac disease.

He also stressed that there would always be problems in any cross-trial comparisons due to the different patient populations, in terms of node-negative inclusion/exclusion, HER2 testing methods and age distribution, and due to the timing of the randomisation, the median follow-up times, and the level of published information.

Despite these problems, and although assessed at different median follow-up periods, all of these recent trials have reported benefits from trastuzumab for disease-free survival (DFS) of women with early breast cancer, along with indications of beneficial trends for overall survival. Across these trials, reported hazard ratios were 0.48, 0.49, 0.61, 0.54, and 0.42 for DFS; 0.47, 0.51, and 0.43 for distant DFS; and 0.67, 0.76, and 0.41 for overall survival. Similarly, all subgroup analyses of DFS reported beneficial effects of trastuzumab.

There have been similar difficulties in determining cross-trial cardiac safety for trastuzumab in early breast cancer. However, the trend across these trials was for small increases in congestive heart failure (CHF) associated with trastuzumab, although these have generally remained below a cumulative CHF of 4%. At the same time, there has been no indication of an increase in cardiac deaths related to trastuzumab use.

On the basis of the risk-benefit ratios that arise from these combined trials, Dr. Baselga indicated that adjuvant trastuzumab should be considered for patients with early breast cancer, along with the use of prior or concurrent radiotherapy. However, there is also the proviso that monitoring of cardiac function should be obligatory.

Although it still remains to be determined whether sequential or anthracycline-free regimens will present a lower risk for cardiac events, the provision of prescriptions for trastuzumab treatment started soon after the May 2005 American Society of Clinical Oncology annual meeting. Trastuzumab has now received approval in Slovenia, Canada, France, Ireland, Italy, and The Netherlands.

Dr. Baselga stressed that this is a new era of trastuzumab use. However, he also noted that despite these supportive data and approval of trastuzumab use, there remain a number of important questions relating to its future use; namely, what is the optimum duration of trastuzumab use, can treatments be individualised further, and will it confer benefits, either alone or in combination with endocrine agents, for patients who cannot receive chemotherapy?


[Presentation title: Adjuvant Herceptin: From Clinical Trials to Clinical Practice.]

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