Clinical significance of fecal Syndecan-2 gene methylation combined with blood tumor abnormal protein detection in the diagnosis of colorectal cancer and precancerous lesions.

Objective: To investigate the clinical significance of fecal Syndecan-2 (SDC2) gene methylation combined with blood tumor abnormal protein (TAP) detection for the diagnosis of colorectal cancer (CRC) and its precancerous lesions.

Methods: A retrospective study was conducted to collect patients diagnosed with CRC or colorectal adenoma (Ade) from March 2020 to March 2023, and healthy people (Nor) without any gastrointestinal diseases during the same period as the control group. All participants underwent the fecal SDC2 gene methylation test, blood TAP test and fecal occult blood test (FOBT). The differences in the positivity rates of each index were compared, receiver operator characteristic curves were plotted and the area under the curve (AUC) was calculated to evaluate the diagnostic effects of different testing methods on CRC and its precancerous lesions.

Results: A total of 146 individuals were included in the study, including 69 CRC patients, 47 patients with Ade and 30 healthy individuals. The results showed that, SDC2, TAP and the combined assay had high comprehensive diagnostic efficacy for the diagnosis of CRC, but there was no significant difference between the three methods in terms of AUC, sensitivity, and specificity. However, for Ade, the combined detection was statistically significant, with a high AUC (0.905), high sensitivity (95.7%), and high specificity (86.7%).

Conclusion: Fecal SDC2 gene methylation combined with blood TAP detection is an effective noninvasive screening and diagnostic method to enhance the early detection and treatment of CRC precancerous lesions, such as Ade, thereby reducing the incidence and mortality of CRC.