The aim of this study was to evaluate the role of serum CA125 levels and computerized tomography (CT) scans in predicting pathologic response of intraperitoneal chemotherapy in patients with ovarian cancer. We prospectively analyzed serum CA125 levels and abdominopelvic CT scans obtained after the completion of intraperitoneal chemotherapy in 52 patients with ovarian cancer and compared the results with subsequent laparotomic findings, which served as the gold standard for statistical analysis. Laparatomy revealed either microscopic or macroscopic residual disease in 20 patients, while 32 patients were completely tumor-free. CA125 levels correlated significantly with laparotomic findings (p=0.003, u=1405). Median CA125 values in patients with residual tumors and in tumor-free patients following intraperitoneal chemotherapy were 14.6 (1-775) and 7.2 (1-37) U/ml, respectively. Although CT-imaging and CA 125 levels had a high specificity (100% and 96.9%, respectively), they showed a low sensitivity rate (50% and 40%, respectively). Similarly, despite high positive predictive values (100% and 88.9%, respectively), the negative predictive values were 76.2% and 72.1%, respectively.
Conclusion: Although highly specific, CT scans and CA125 levels do not accurately indicate the presence of disease. Due to a high false-negative rate, a normal CT scan or a normal CA125 value is not sufficient to replace a laparotomy.