Pre-operative serum levels of CA 242 and CEA predict outcome in colorectal cancer.

The prognostic value of the preoperative serum levels of CA 242 and CEA in patients with colorectal cancer was investigated. The serum concentrations of CA 242 and CEA were determined from preoperative serum samples of 259 patients with colorectal cancer (39 Dukes' A, 100 Dukes' B, 59 Dukes' C and 61 Dukes' D). Survival data of these patients were obtained to the end of 1993. There was a significantly longer survival in patients with a CA 242 level below 20 U/ml compared with patients with an elevated serum level. A difference was seen in overall survival (P < 0.0001), and in Dukes' B (P = 0.016) and Dukes' D (P = 0.009) stages. In Dukes' A and C colorectal cancer, the difference was not significant (P = 0.67 and P = 0.07, respectively). When 5 ng/ml was used as cut-off value for CEA, there was a significant difference in overall survival (P < 0.0001), but not within the different Dukes' stages. The prognosis was considerably worse in patients with concomitant elevation of CA 242 and CEA, compared with the prognosis of patients with normal levels or only one marker elevated (P < 0.0001). When analysing according to stage, a significant difference was seen in Dukes' B (P = 0.0004) and Dukes' C (P = 0.0007) stages. In a multivariate analysis, CA 242 was an independent prognostic factor (P < 0.0001). CEA was also an independent prognostic factor (P = 0.03), but only after exclusion of CA 242. Concomitant rise of CA 242 and CEA was found to be a strong independent prognostic factor (P < 0.0001). This study shows that the pre-operative serum CA 242 level is an independent prognostic factor in patients with colorectal cancer and that the prognosis of patients having a concomitant pre-operative elevation of CA 242 and CEA is poor.