In line with the results obtained with immunohistochemistry, patients who had HER2 amplification in the breast tumor had more often the first distant metastases detected in the lung as compared with women whose cancer was HER2-negative (20 (28.2%) of 71 vs. 20 (13.5%) of 148, P = 0.010), whereas HER2-amplified breast cancers seldom gave first rise to bone metastases compared with HER2-negative cancers (32 (45.1%) of 71 vs. 90 (60.8%) of 148, P = 0.028). This evidence concerns the gene ERBB2 and breast neoplasm.