Comparison of serum levels of CA 72-4 and CEA in patients with gastric and colorectal cancer

-39- SUMMARY COMPARISON OF SERUM LEVELS OF CA 72-4 AND CEA IN PATIENTS WITH GASTRIC AND COLORECTAL CANCER Serum levels of the new tumor- associated marker CA 72-4 and CEA were measured in patients with gastric cancer (n=35), colorectal cancer (n=48) and healthy controls (n=7). Raised serum CA 72-4 levels (>5 U/ml) were found 42.9% (n=15) and 18.75% (n=9) of the patients with gastric and colorectal cancer, respectively. High serum CEA levels were also detected 45.7% (n=16) and 54.2% (n=26) of the patients with gastric and colorectal cancer patients. In all controls, serum CA 72-4 values were found <3 U/ml. Serum CA 72-4 or CEA levels were raised 63% (n=22) and 58.3% of the patients with gastric and colorectal cancer, respectively. Only raised serum CA 72-4 values were determined in 17.1% (n=6) and 4% (n=2) of patients, only raised CEA levels were found in 20% (n=7) and 40% (n=19) of patients with gastric and colorectal cancer, respectively. Both CA 72-4 and CEA levels were found normal in 37% of patients with gastric cancer and 41.7% of patients with colorectal cancer. The correlation of between the serum CA 72-4 and CEA values was poor (r=0.69) in patients with gastric cancer, and no correlation was found between these two markers in patients with colorectal cancer. We concluded that the CA 72-4 and CEA assay could be used in parallel to detect a greater population of gastric cancer than either of these two assays alone. However, since CA 72-4 sensitivity is very low in colorectal cancer, use in parallel of these two markers could not be useful to diagnose the patients with colorectal cancer.