Metastatic breast cancer with HER2/neu-positive cells tends to have a morbid prognosis

Background. Clinically, human epidermal growth factor receptor 2 (HER2) overexpression is associated with a faster rate of tumor growth and an increased rate of metastasis, and a patient who is HER2 strongly positive tends to have a poor prognosis and a decreased disease free survival and overall survival (OS) time. Methods. We analyzed data on 526 Japanese adult women with breast cancer with respect to the relationship between the status of HER2/neu receptor expression and the recurrent state and survival from detection of the first recurrence. All these women were treated from 1982 to 2000 in the Department of Surgery, National Beppu Hospital, Kyushu, Japan. In 95 patients with metastatic breast cancer after curative resection, the expression of HER2/neu status was examined by using immunohistochemical staining methods (Hercep Test). Scores of 0, 1+, 2+, and 3+ were given according to the HercepTest data. Only scores of 2+ and 3+ were assessed as an overexpression of HER-2/neu protein and HER2-positive patients. Between the HER2-positive and HER2-negative patients, the survival after surgical intervention, the disease-free survival time, and the survival time after the initial recurrence were compared. Results. An overexpression of HER2/neu receptor protein occurred at a rate of 23.7% (23/97) in the 97 women with metastatic breast cancer. There was no difference in age, tumor size, TN staging system, and the number of lymph node metastases between HER2-positive and HER2-negative patients. Almost all HER2-positive patients had a negative estrogen receptor status (14/15 [93.3%]). The initial sites of recurrence were classified as (1) soft tissue, bone, and viscera or (2) soft tissue, bone, lung-pleura, liver, and brain. For the HER2-positive patient, viscera, especially the liver and lung, were predominant initial sites of recurrence. Survival rates, OS, disease-free survival time, and time after first recurrence were all analyzed. Although there was no difference in disease-free survival time, there were significant differences between the HER2-positive and HER2-negative groups in OS and the time after initial recurrence. Conclusions. Metastatic breast cancer with overexpression of HER2/neu tends toward a poor prognosis, especially after the first recurrence. For such patients with metastatic breast cancer, a high-dose anthracycline-containing regimen might be needed.