Abstract
The efficiency of composite tests (liver scintigraphy, serum alkaline phosphatase, and serum carcinoembryonic antigen) in finding or excluding liver metastases pre-operatively was evaluated in 185 surgical patients with high probability for gastrointestinal cancer–142 with colorectal and 43 with gastric disorders. A pathoanatomic verification procedure showed liver metastases in 21 and 7 patients, respectively. For each test two cut-off levels were defined in accordance with the operational purpose of the test: either to diagnose metastases (no false-positive test results) or to exclude metastases (no false-negative test results). Generally, composite tests increased overall efficiency; in the colorectal group 39% of the patients were correctly classified by the combined, triple test; in the gastric group 94% were correctly classified. In conclusion, we think composite tests are useful, and the operational approach described may be helpful in decision-making and test evaluation.