Increased serum CEA levels have been detected in persons with primary colorectal cancer and in patients with other malignancies involving the gastrointestinal tract, breast, lung, ovarian, prostatic, liver and pancreatic cancers. Elevated serum CEA levels have also been detected in patients with nonmalignant disease, especially patients who are older or who are smokers. CEA levels are not useful in screening the general population for undetected cancers. However, CEA levels provide important information about patient prognosis, recurrence of tumors after surgical removal, and effectiveness of therapy.
The fecal occult blood test is an immunochromatographic fecal occult blood test that qualitatively detects human hemoglobin from blood in fecal samples. This is a useful screening aid for detecting primarily lower gastrointestinal (G.I.) disorders that may be related to iron deficiency anemia, diverticulitis, ulcerative colitis, polyps, adenomas, colorectal cancers or other G.I. lesions that can bleed. It is recommended for use by health professionals as part of routine physical examinations and in screening for colorectal cancer or other sources of lower G.I. bleeding.