Human chorionic gonadotropin in gastric carcinoma. A useful marker for bone metastasis.

Twenty patients with bone metastases from gastric carcinoma resected during the 13 years from 1974 through 1987 were investigated in relation to the serum and tissue carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG). The incidence of bone metastases was 2.1% (20/933). The serum AFP, CEA and hCG positive rates were found to be 14.3, 42.9 and 69.2% for patients with bone metastases and 18.3, 19.4 and 14.1% for those without bone metastases, respectively. In addition, the tissue AFP, CEA and hCG positive rates were 11.1, 100 and 77.8% for such patients with bone metastases, and 8.0, 80.8 and 21.1% for those without bone metastases. Only the serum and tissue hCG positive rate was significantly higher for the patients with bone metastases than those without bone metastases. The bone metastatic lesions were investigated for tissue hCG in four cases, and found to be positive in all the four bone lesions. In four of the patients with metachronous bone metastases, serum hCG levels were elevated before or at the time when bone metastases were diagnosed. Furthermore, serum hCG levels fell in response to chemotherapy or tumor resection. On the contrary, the serum AFP or CEA levels did not correlate with the clinical course in patients with bone metastases. These results indicate that the measurement of the tissue and serum hCG in patients with gastric carcinomas could be of extreme value in the search for bone metastases and the serum hCG level could be a useful marker for the prediction of bone metastases in gastric carcinoma.