CORRELATION BETWEEN CIRCULATING FREE DNA LEVELS AND PREOPERATIVE SERUM CARCINOEMBRYONIC ANTIGEN LEVELS IN PATIENTS WITH COLORECTAL CANCER

Introduction Colorectal cancer is the third most common malignancy and the second leading cause of cancer-related deaths worldwide, accounting for over 930,000 deaths annually. Given the significance of this public health issue, early detection and effective monitoring are crucial for improving clinical outcomes. New potential tumor markers are being widely studied for this purpose. CEA is a marker traditionally used in clinical practice, despite its limitations, such as low specificity. cfDNA, on the other hand, is an emerging approach that promises greater precision in detecting recurrences and monitoring treatment responses.

Objective To investigate the correlation between preoperative serum CEA levels and cfDNA levels in patients with colorectal cancer, while evaluating their relationship and the influence of comorbidities and clinical characteristics.

Methods This prospective study included 22 patients with colorectal adenocarcinoma. Preoperative cfDNA was collected through liquid biopsy immediately before surgery. CEA was collected immediately after diagnosis. Clinical and epidemiological variables were extracted from medical records. Variables collected included age, gender, diabetes mellitus, alcoholism, smoking, number of medications used, hypertension, and body mass index (BMI). Nine patients were male, and 13 were female, with a mean age of 51 years. Thirteen patients had hypertension (59%). Continuous variables with normal distribution were presented as mean ± standard deviation, while non-parametric continuous variables were presented as median and interquartile range. The direct correlation between cfDNA and CEA was analyzed using Pearson, Spearman, and Kendall tests.

Results 47% of patients presented CEA levels higher than 5, while cfDNA levels ranged from 0.52 to 58.2. The direct correlation between cfDNA and CEA, according to the tests, was positive but weak. Hypertension emerged as a significant variable with a negative effect on the likelihood of positive CEA levels. Other clinical characteristics did not show significant importance.

Conclusion Considering the limitations of the study, particularly the small sample size, and based on the results obtained, it is reasonable to conclude that preoperative circulating cfDNA serum levels do not correlate with CEA levels.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
25 April 2025