For T-CEA, the low and high expression scores were defined as < 6 and �� 6, respectively (Fig. 1) [9]. Figure 1 High expression of CEA in colorectal cancer (�� 75%). Statistical analysis All statistical calculations were performed using spss version 10.0 (SPSS Inc., Chicago, Illinois, USA). The differences in the clinico-pathological characteristics Tipifarnib leukemia between low and high S-CEA or T-CEA expression were performed by Pearson chi-square. The relationship between S-CEA and T-CEA was also calculated by Pearson chi-square. Disease-free survival time (in months) was measured from the date of surgery to the time of event (recurrence or metastasis) or to the last census prior to closure of the study (1 August 2003). Kaplan�CMeier survival analysis with the Log Rank test was used to evaluate the prognosis of serum and tissue CEA in CRC.

Multivariate analysis was performed with Cox��s proportional hazard regression model to assess the effects of different variables on patients�� survival. Differences were taken as significant when P (two-tailed) was < 0.05. Results In this study, there were 173 patients with CRC including 86 male subjects and 87 female subjects. The median age of all patients was 59 years (range 27�C85 years). 37.0% (64/173) patients had a high level of S-CEA including 29 male subjects and 35 female subjects, while 63.0% (109/173) patients were in the low S-CEA group. 39.3% (68/173) patients were in the high T-CEA group (38 male subjects and 30 female subjects).

Comparison of clinico-pathological features between high and low S-CEA or T-CEA There were no significant differences in gender, age, tumour size, tumour gross type, mucin production, differentiation grade, venous invasion, stage distribution, T and N classification between the low and high S-CEA or T-CEA groups (Table 1). Table 1 Clinico-pathological characteristics in S-CEA and T-CEA group n (%). The relationship between S-CEA and T-CEA groups There was no significant relationship between groups of S-CEA and T-CEA (P=0.215) (Table 2). Table 2 The relationship between S-CEA and T-CEA groups. Relationship of S-CEA to disease-free survival by univariate analyses The mean disease-free survival time after operation in the low S-CEA group was longer than patients of high level of S-CEA (68.4 vs 51.3 months, 95% CI), but there was no significant difference between them (P=0.3709) (Fig.

2). Figure 2 Kaplan�CMeier survival analysis for the difference of disease free survival time between low and high S-CEA. Relationship of T-CEA with disease-free survival by univariate analyses Kaplan�CMeier survival analysis with the Log Rank test showed that the mean disease-free survival time after operation in the low T-CEA Batimastat group was significantly longer than in the high T-CEA group (72.0 vs 55.8 months, P=0.028) (Fig. 3).