Carcinoembryonic antigen in osteosarcoma.

Plasma carcinoembryonic antigen (CEA) assay was done in 30 patients with osteosarcoma. CEA was found positive (greater 2.5 ng/ml) in 17 of 21 patients who had active evidence of disease and negative (less than 2.5 ng/ml) in all 9 patients who were in complete remission resulting from previous amputation of chemotherapy. Serial CEA determinations demonstrated a fall to normal in 7 of 9 patients following successful surgery of chemotherapy and a ruse and fall (fluctuation) of levels in 8 patients who had tumor progression while on chemotherapy. Clinical recurrence of disease in two instances preceded or coincied with CEA elevation. The CEA assay in osteosarcoma although non-specific could be used as an inportant adjunct to experienced clinical judgment, periodic x-ray examination, and laboratory study to prognosticate the course of osteosarcoma during therapy. The interpretation of a rising or falling CEA titer alone, however, must be made with caution.