ERBB2 and neoplasm: The ECOG performance status, the presence of BM or subcutaneous metastases, the number of previous metastatic CT lines, the tumor biological subtype, and high serum CA 15-3, S100ß (cut-off at 0.12 μg/L) and HER2 ECD (cut-off at 30 ng/mL) levels were independently associated with poor prognosis (Table 3).