Significance of CA 72.4 serum levels in gastrointestinal diseases

In order to evaluate the usefulness of Ca 72.4 tumor associated antigen assay in gastrointestinal diseases, we have studied 751 patients suffering from benign (376) and neoplastic (375) digestive diseases and 305 normal controls. The cut-off point was fixed at 6 U/ml. The Ca 72.4 assay, with the proposed method, provides additional information only in gastric cancers; the positivity of the marker in gastric neoplasms is 38.4% and the specificity vs gastric ulcers and atrophic gastritis is 99%. In six patients with gastric cancer, the Ca 72.4 is the only positive test. The most striking observation to be made from the current study is a no good sensitivity of the marker for gastrointestinal cancers (29.6% vs 35.7 and 37.6% for CEA and Ca 19-9 respectively), but rather the excellent specificity of the Ca 72.4 immunoassay with respect to being gastrointestinal diseases (98.7%), vs values of specificity for CEA and Ca 19-9 of 94 and 92%. In conclusion, the high specificity of this marker for gastrointestinal neoplasms may be very interesting in follow-up studies. In fact, an elevation of serum levels of Ca 72.4 should always be taken seriously.