Sensitivity, specificity, and predictive value of laparoscopy for the staging of gastric cancer and for the detection of liver metastases

Abstract

Three hundred and sixty patients with gastric carcinoma were evaluated by laparoscopy. The following tumor attributes were used in the staging workup: serosal infiltration, tumor fixation, metastasis to lymph nodes, peritoneal dissemination, and liver metastasis. For the detection of liver metastases, subgroups of these patients were also tested by liver scintigraphy, ultrasonography, and serum alkaline phosphatase determination. Use of diagnostic indexes with their confidence intervals provided an objective means of assessing performance for the various combinations of tests and attributes. The attributes which were most accurately detected by laparoscopy were peritoneal dissemination and liver metastases with 89.4% and 96.5% efficiency, respectively. Laparoscopy was a superior diagnostic method when compared to the other tests for detection of liver involvement. Scintigraphy and ultrasonography presented comparable sensitivities, 78.7% and 78.6%, respectively (as opposed to 87.2% of laparoscopy), but the former yielded a high rate of false-positive results, 62.6%. Detection of liver metastases by assaying alkaline phosphatase levels was the least sensitive diagnostic alternative examined.