Prognostic value of the glycoprotein TAG-72 in patients with gastric cancer.

The specificity of the tumor markers used to date in patients with gastric cancer has not been satisfactory. For this reason we decided to evaluate the utility of TAG-72 in this disease. Between 1993 and 1998 we determined the levels of TAG-72 in 638 subjects (148 healthy volunteers, 33 patients with chronic renal failure (CRF), 149 patients with benign diseases of the liver, 95 patients with benign gastrointestinal diseases and 213 patients with gastric cancer). TAG-72 was measured using an IRMA method. Statistical analysis of the data was performed with the BMDP package. We established a cutoff for TAG-72 of 3 U/mL, corresponding to the 92.6th percentile of the healthy controls. We observed that neither CRF nor benign liver diseases affected TAG-72 levels, while certain benign gastrointestinal diseases did cause alterations of the marker. Using Cox multivariate analysis we discovered that the preoperative TAG-72 level was an independent prognostic variable associated with both disease-free and overall survival. We conclude that, although TAG-72 is not useful for the diagnosis of gastric cancer, it is a suitable tool for disease monitoring and prognostic assessment.

Utility of tumor marker CA 72.4 in patients with chronic renal failure.

The tumor marker CA 72.4 is composed of two monoclonal antibodies, B 72.3 and cc49, which detect the glycoprotein TAG 72 present in tumor cells. The levels of CA 72.4 may be modified depending on the route of excretion of the antigen TAG 72. The objective of this study was to evaluate the behavior of CA 72.4 in healthy subjects and to assess the influence of chronic renal failure (CRF) on the levels of this tumor marker. Random serum samples were collected in 181 individuals (148 healthy volunteers and 33 patients with CRF) and 214 determinations of CA 72.4 were performed. We also performed 66 determinations of plasma creatinine. In healthy subjects the cutoff value of CA 72.4 was established at 3 U/mL, with a sensitivity of 53% and a specificity of 85.8%. In the CRF patients we found no statistically significant differences when we compared the values of CA 72.4 predialysis and postdialysis (p = 0.197). However, a statistically significant difference was found in the plasma creatinine levels (p < 0.001). Chronic renal failure does not affect the result of CA 72.4 determinations; this tumor marker may therefore be useful in the monitoring of patients with cancer, independent of their renal function.