Figure 7.

Treatment progress. Transition and progression of tumor marker levels. February 12, 2010: Initiation of trastuzumab administration. The HER2 serum concentration immediately declined to below the reference value following initiation of therapy. December 2010: A patch of eczema appeared in the area between the upper left breast and axilla, which was identified as skin metastases; the HER2 serum concentration was normal when this occurred. February 19, 2011: Initiated lapatinib administration. Skin metastases disappeared two months after switching to lapatinib; however, the HER2 serum concentration was 18.8 ng/ml, which exceeded the reference value (15.2 ng/ml). Thereafter, no evident new lesions were observed, and the HER2 serum concentration was maintained between 18.1 and 22.9 ng/ml, marginally greater than the reference value. CA15-3, cancer antigen 15-3; HER2, human epidermal growth factor receptor 2, CEA, carcinoembryonic antigen.