Common tumor markers predict extent of disease and success of cytoreductive surgery in patients with appendiceal malignancies

Abstract

15527 Background: There are few reliable criteria for selecting patients with peritoneal carcinomatosis of appendiceal origin for cytoreductive surgery (CS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Tumor markers are known to correlate with prognosis in patients with resectable liver metastases. The hypothesis was that elevated tumor markers are associated with extensive disease and inability to perform complete cytoreduction. Methods: Fifty-four patients underwent CS and HIPEC by a single surgeon for appendiceal malignancies between 1999 and 2007. Tumor markers (CEA, CA 19–9, and CA 125) were measured preoperatively. Preoperative Peritoneal Cancer Index (PCI) score and completeness of cytoreduction (CC) score were recorded. Robust regression analysis assessed the relationship of tumor markers to PCI and CC scores. Overall survival analyses were performed using Kaplan-Meier method. Cox proportional hazard regression models were computed to estimate the hazard ratios (HR) and 95% confidence intervals (CI) for disease related mortality and CC score. Results: CEA was elevated in 50.0% of patients, CA 125 in 46.0%, and CA 19–9 in 40.8%. Elevated levels of CEA (>5 ng/mL), CA 125 (>35 U/mL), or CA 19–9 (>37 U/mL) were associated with higher PCI scores (Odds Ratio (OR), 95% CI, p-value: 11.46, 5.90 to 17.01, p<0.0001; 14.92, 9.20 to 20.43, p<0.0001; 10.83, 4.11 to 17.55, p=0.002, respectively). High CC scores (2–3) were associated with elevated CEA and CA 125 (OR, 95%CI, p-value: 6.82, 1.46 to 31.92, p=0.015; 9.89, 1.84 to 53.10, p=0.008 respectively). The overall median survival was 41 months for all patients, 53 months for low CC (0–1) and 30.3 months for high CC (p=0.01). Hazard ratio of disease related death was 7.0 (95% CI, 1.55 to 31.61) among patients with high CC score as compared to those with low CC scores. Conclusions: Elevated tumor markers were associated with high tumor burden and incomplete cytoreduction in patients with peritoneal carcinomatosis of appendiceal origin. Patients with low CC score survived longer. Thus, CEA, CA 125 and CA 19–9 may be useful in selecting patients for CS and HIPEC. No significant financial relationships to disclose.