“…While the specificity of the original CEA radioimmunoassay has been questioned, its use as a prognostic tool following surgery, chemotherapy, and/or radiotherapy in patients with cancer of the gut is widely accepted. Rising levels of circulating CEA are associated with primary or disseminating malignancy of poor prognosis (Reynoso et al, 1972;Zamcheck, Moore, Dhar, and Kupchik, 1972;Moore, Kantrowitz, and Zamcheck, 1972;Dhar, Moore, Zamcheck, and Kupchik, 1972).…”