Clinical significance of carcinoembryonic antigen in peritoneal lavage from patients with gastric cancer.

BACKGROUND: Peritoneal carcinomatosis is the most common pattern of recurrence of gastric cancer, and it is important to identify patients at high risk for recurrence. Although the carcinoembryonic antigen level in peritoneal lavage (pCEA) was reported to be a useful biomarker to predict peritoneal recurrence in a small series, its clinical significance has not been fully validated. We evaluated the clinical significance of pCEA in a large cohort of patients with gastric cancer.
METHODS: We prospectively analyzed the pCEA level in 597 patients with histologically proven gastric cancer who underwent laparotomy.
RESULTS: A significant relationship was demonstrated between the value of pCEA and clinicopathologic features, such as the peritoneal lavage cytology, peritoneal metastasis, the depth of tumor invasion, and the lymph node metastasis. The cutoff value was set at 100 ng/g of protein, and 134 of the 462 patients who underwent curative surgery had positive pCEA findings. The overall and the intraperitoneal-recurrence-related survival of patients positive for pCEA were significantly poorer than those of pCEA-negative patients. When we analyzed the patients with pathologic stage I through III gastric cancers separately, the pCEA-positive patients had poorer prognoses than the pCEA-negative patients who had stage III gastric cancer. In a univariate analysis, the tumor size, depth of tumor invasion, lymph node metastasis, histologic type, serum CEA (sCEA), and pCEA were found to affect the patients' outcomes, although a multivariate analysis found only the extent of lymph node metastasis to be an independent prognostic factor.
CONCLUSION: The pCEA level is a useful biomarker to predict gastric cancer-related death. Moreover, the pCEA level may be useful to identify a cohort of patients with gastric cancer who need more intensive adjuvant chemotherapy to improve their prognoses.