Usefulness of Serum Tumor Markers CEA, CA 19-9 and CA 72-4 in Patients with Colorectal Cancer and Benign Colorectal Diseases. A Retrospective Multicentric Study

Background: Carcinoembryonic antigen (CEA), CA 19-9, and CA 72-4 are the most frequently used serum markers in patients with colorectal cancer. The aim of this study was to evaluate their usefulness in differentiating between benign and malignant colorectal diseases. Methods: A series of 195 consecutive patients (121 men, 74 women; median age 67 years, range 38-79 years) who underwent curative surgery for colorectal cancer (cases), and a group of 195 sex- and age-matched patients suffering from benign colorectal diseases (controls) were reviewed. Patients with history of previous cancer were excluded from the study, as well as those who have undergone preoperative adjuvant chemotherapy. Cases were classified according to Dukes staging a follows: A=31 (16%), B=66 (34%), C=52 (27%), D=46 (24%). CEA was measured with a time-resolved immunofluorimetric assay with a cutoff of 5 lg/L, while CA 19-9 and CA 72-4 were measured with immunoenzymometric assays and cutoff values of 35 and 6 kU/L, respectively. Ethical permission and written informed patient consent were obtained. Results: The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 44.1%, 93.8%, 87.7, 62.7%, and 69.0% (OR=12.03, 95% CI 6.28-23- 0, p<0.001) for CEA; 20.0%, 95,9%, 83.0%, 54.5%, and 57.9% (OR=5.84, 95% CI 2.65- 12.87, p<0.001) for CA 19-9; and 26.7%, 93.8%, 81.2%, 56.1%, and 60.0% (OR=5.54, 95% CI 2.85-10.70, p<0.001) for CA 72-4, respectively. The sensitivity of CEA (25.5- 33.3% vs. 48.1-67.4%), CA 19-9 (9.7-12.1% vs. 26.1-30.8%), and CA 72-4 (6.4-18.2% vs. 24.5-54-3%) was higher (p<0.01) in Duke-C and D patients with respect to Duke- A and B ones. A weak correlation (R=0.31, p=0.044) between CEA and CA 72-4 was found, while there was no correlation (p=NS) between CEA and CA 19-9, and between CA 19-9 and CA 72-4. The combination of CEA and CA 72-4 had a higher (p<0.01) sensitivity, reaching 70.8%. Conclusions: In patients with colorectal cancer, both CEA and CA 72-4 may be safely used in preoperative screening of patients with colorectal lesions, with a specificity ranging from 93.8% to 95.9%, and their sensitivity significantly increases when CEA and CA 72-4 are used in combination.