Multivariate analysis of prognostic determinants for colorectal cancer patients with high preoperative serum CEA levels: prognostic value of postoperative serum CEA levels.

High preoperative serum carcinoembryonic antigen (CEA) levels have been well investigated and found to be associated with poor prognosis in patients with colorectal cancer (CRC). However, it has been observed that the outcome varies after curative resection, along with postoperative serum CEA levels; some patients continue to have high postoperative serum CEA levels while postoperative CEA levels return to normal in others. The purpose of this study was to determine the prognostic significance of postoperative serum CEA levels in CRC patients with high preoperative serum CEA levels. Between January 2002 and December 2004, 423 CRC patients underwent operation in our hospital; 181 (42.8%) had high preoperative serum CEA levels and were enrolled in this study. Among the 181 patients, 165 patients had curative resection; the remaining 16 had stage IV disease, so they underwent palliative surgery and were subsequently excluded from analysis. Pre- and postoperative serum CEA levels were measured and analyzed. All patients had curative resection and were divided into two groups according to postoperative serum CEA levels: one group comprised patients with postoperative serum CEA > or = 5 ng/mL (n = 80) and the other group comprised patients with postoperative serum CEA levels < 5 ng/mL (n = 85). Postoperative serum CEA levels were significantly related to location of primary tumors (p = 0.042), lymph node metastases (p = 0.009), TNM stage (p = 0.001), and postoperative relapse (p = 0.004). The results of multivariate analysis showed that both lymph node metastases and high postoperative serum CEA levels (> or = 5 ng/mL) were independent prognostic factors for CRC patients after curative resection. Postoperative serum CEA levels can be a single independent prognostic determinant in CRC patients with high preoperative serum CEA levels. Intensive follow-up and adjuvant therapy may be necessary in CRC patients who continue to have high postoperative serum CEA levels even after curative resection.