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 seru m CA 242 as a marker in colorectal cancer patients. Patients and methods: S erum samples from 1,013 subjects (440 healthy volunteers, 384 patients with primary or recurrent colorectal carcinoma and 189 with benign colorectal d iseases) were; evaluated. Results: The measurement of serum CA 242 levels i n 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 5 8.8% of Stage C and D patients, respectively, indicating a correlation with the stage of disease. A comparison between preoperative and immediate post operative CA 242 levels showed a consistent relationship between the effica cy of surgery and the reduction in serum CA 242 levels; further; elevated C A 242 levels were present in the immediate post surgical follow-up of patie nts undergoing palliative surgery. A longitudinal evaluation of serum CA 24 2 levels demonstrated that this marker was indicative : of the status of di sease. Conclusions: The results obtained suggest the possible utility of CA 242 in monitoring the disease status, providing a rationale for future stu dies focusing on the longitudinal monitoring of colorectal cancer patients.