Our study demonstrates the upregulation of HER-2/neu during ovarian ablation. These results are consistent with data showing that the percentage of HER-2/neu positive tumors, evaluated by standardized immunohistochemistry on the primary tumor, is significantly increased during the follicular phase of the menstrual cycle (Balsari et al., Am J Pathol 155: 1543-1547, 1999). Regulatory processes at the HER-2/neu gene should be considered when prescribing specific therapy for breast cancer.

The concordance between conventional IHC and computerized analysis was very good. The number of patients with stage IV breast cancer with an elevated sHER-2/neu level was much higher than HER-2/neu positivity in tissue. This discrepancy is only partially explained by the influence of tumor load. Patients with an elevated sHER-2/neu level and no tissue overexpression should be considered for retesting of tissue or a new biopsy.

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