[The clinical value of multi-target stool fecal immunochemical test-DNA in early screening and diagnosis for colorectal cancer].

ABSTRACT

Objective: To investigate the clinical diagnostic value of multi-target stool fecal immunochemical test-DNA (FIT-DNA) test in colorectal cancer (CRC) and advanced adenoma (AA). Methods: A total of 235 patients who were undergoing colonoscopy or colorectal cancer surgery in the Cancer Hospital, Chinese Academy of Medical Sciences from April 2021 to January 2022 were prospectively enrolled. There were 141 males and 94 females, with an average age of (55±13) years (22-86). The patients were divided into two groups, including 215 patients who were first diagnosed but not treated (86 cases of CRC, 12 cases of AA, 25 cases of non-advanced adenoma, 8 cases of hyperplastic or other polyps and 84 apparently healthy cases) and 20 patients in the intervention group (2 cases with a history of CRC surgery, 6 cases with a history of endoscopic surgery, 4 non-CRC patients with special diseases and 8 cases with a history of neoadjuvant chemoradiotherapy). Fresh stool samples were collected before intestinal preparation or surgery for FIT-DNA test using the matching kit for sample processing and nucleic acid purification. KRAS mutation and methylation of BMP3 and NDRG4 genes were detected by fluorescence probe method, and FIT method was employed to detect fecal occult blood. Colonoscopy or pathological biopsy results were used as the gold standard. And the screening and diagnostic efficacy of FIT-DNA test for colorectal cancer and advanced adenoma were evaluated by receiver operating curve (ROC). Results: The sensitivity of FIT-DNA test for early colorectal cancer and advanced adenoma was 7/7 and 8/12, respectively. And the negative predictive value was 98.1% (104/106) and 93.7% (104/111), respectively. The overall screening sensitivity for both early colorectal cancer and advanced adenoma was 15/19, and the negative predictive value was 96.3% (104/108). Besides, the area under the curves (AUCs) were 0.982 (95%CI 0.960-1.000, P<0.05), 0.758 (95%CI 0.592-0.924, P<0.05) and 0.841 (95%CI 0.724-0.957, P<0.05), respectively. Moreover, the diagnostic sensitivity of FIT-DNA test was 98.8% (85/86) for colorectal cancer, 8/12 for advanced adenoma, and 94.9% (93/98) for both colorectal cancer and advanced adenoma, with a specificity of 88.9% (104/117). The AUCs were 0.968 (95%CI 0.937-0.997, P<0.05), 0.758 (95%CI 0.592-0.924, P<0.05) and 0.942 (95%CI 0.905-0.979, P<0.05), respectively. After the inclusion of intervention group, the overall diagnostic sensitivity and specificity of FIT-DNA test was 91.6% (98/107) and 89.1% (114/128), respectively. Conclusion: FIT-DNA test has a high early screening and diagnostic efficacy for colorectal cancer.