We appreciate the comments from Fitzgibbons et al and agree that additional information has emerged since our study was conducted.1, 2 Their comments, however, reinforce both the aims of our study and the importance of our findings. Our central objective was to characterize the current state of knowledge of utilization and cost-effectiveness of HER-2 testing in clinical practice in the United States. As Fitzgibbons et al correctly note, we found few recent relevant studies in the peer-reviewed literature and thus cited unpublished literature. We agree that a study of testing practices in 1999-2000 is not representative of the current state of practice, but more recent estimates have been limited. This is precisely why we concluded that there are major gaps in the evidence base regarding HER-2 testing and trastuzumab treatment. The paper noted by 1 of the authors on laboratory compliance with American Society of Clinical Oncology/College of American Pathologists guidelines will contribute important information to this evidence base, but is not yet publicly available. We have also been conducting additional research on these topics, which we expect to be publicly available in the near future.3

The success of a targeted cancer therapy such as trastuzumab depends on the use and accuracy of testing for the treatment target. Once therapeutic and diagnostic technologies are available to providers and patients, monitoring utilization patterns can help us understand whether they are being used appropriately. Our review of the literature suggests that there are important knowledge gaps regarding the real world use of HER-2 testing and trastuzumab. Filling these gaps may help optimize limited healthcare resources and improve care for women with breast cancer.


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  • 1
    Phillips KA, Marshall DA, Haas JS, et al. Clinical practice patterns and cost effectiveness of human epidermal growth receptor 2 testing strategies in breast cancer patients. Cancer. 2009; 115: 5166-5174.
  • 2
    Barron JJ, Cziraky MJ, Weisman T, Hicks DG. HER2 testing and subsequent trastuzumab treatment for breast cancer in a managed care environment. Oncologist. 2009; 14: 760-768.
  • 3
    Haas J, Phillips KA, Hassett MJ, et al. Breast cancer testing strategies and the utilization of targeted therapies: data from the real world [abstract]. J Clin Oncol. 2009; 27( suppl). Abstract e17518.