Evaluation of the CA 242 tumor antigen as a potential serum marker for colorectal cancer

Objective: The present study was designed to define the performance of serum CA 242 as a marker in colorectal cancer patients. Patients and methods: Serum samples from 1,013 subjects (440 healthy volunteers, 384 patients with primary or recurrent colorectal carcinoma and 189 with benign colorectal diseases) were; evaluated. Results: The measurement of serum CA 242 levels in the population of healthy subjects demonstrated the presence of positive levels in approximately 5% of the cases. Interestingly, similar results (5.8%) were obtained in patients with benign colorectal disease, demonstrating the high specificity of CA 242. When serum samples from colorectal cancer patients were analyzed a sensitivity of 34.9% was observed. Moreover, 18.6% Stage A and B patients had positive CA 242 levels, compared to 33.3% and 58.8% of Stage C and D patients, respectively, indicating a correlation with the stage of disease. A comparison between preoperative and immediate postoperative CA 242 levels showed a consistent relationship between the efficacy of surgery and the reduction in serum CA 242 levels; further; elevated CA 242 levels were present in the immediate post surgical follow-up of patients undergoing palliative surgery. A longitudinal evaluation of serum CA 242 levels demonstrated that this marker was indicative : of the status of disease. Conclusions: The results obtained suggest the possible utility of CA 242 in monitoring the disease status, providing a rationale for future studies focusing on the longitudinal monitoring of colorectal cancer patients.