Tumor antigen TA-4: an aid in detecting post-operative recurrences of esophageal carcinoma.

Radioimmunoassay for serum TA-4 was performed in 35 patients with squamous cell carcinoma of the esophagus. The results were positive in 13 of 35 patients (37.1 per cent) in whom squamous cell carcinoma of the esophagus was present at the time of assay. Preoperatively, undetectable TA-4 levels in patients with esophageal carcinoma suggested localized tumor and a good prognosis, whereas, strongly positive TA-4 levels correlated with extensive tumors and a poor prognosis. Postoperatively, a positive result for TA-4 levels indicated the presence of a residual tumor. Negative TA-4 levels, however, did not exclude a residual tumor. Therefore, assessment of periodic TA-4 levels in patients who have undergone resection of esophageal carcinoma may lead to detection of a tumor recurrence.