pubmed-article:21528673 | pubmed:abstractText | Elevated beta-HCG serum levels are usually an indication of pregnancy or pregnancy-related disorders, but beta-HCG can also be elevated in testis and germ cell tumors. HCG expression by osteosarcoma is a rare phenomenon, with a few documented cases. CA-125 is commonly used to monitor disease progression and treatment response in ovarian cancer. CA-125 expression in patients with osteosarcoma has not previously been documented. | lld:pubmed |