Clinical significance of circulating tumor cells testing in auxiliary diagnosis of gastrointestinal cancer

Routine diagnostic tools and serum biomarkers of gastrointestinal (GI) cancer have limitations in detecting early and micro-metastasis, and circulating tumor cells (CTCs) have emerged as a promising metrics to complement this gap. The present study is designed to explore technical feasibility of using CTCs as an auxiliary diagnostic tool in GI cancer. Over all, 70 inpatients with GI cancer and 30 healthy volunteers were recruited, and 10 mL of peripheral venous blood was collected from all subjects. CTCs were detected by microfluidic blood rare cell analysis technique, and the sensitivity and specificity of CTCs in GI cancer diagnosis were derived from comparison with the pathological diagnosis results and serum tumor marker results. Compared with the healthy volunteers, the CTCs levels of the patients in gastrointestinal cancer group were significantly increased. Advanced stage subjects demonstrated higher level of CTCs, yet without statistical significance. The sensitivity of CTCs to diagnose stage I to IV disease were 84.62, 94.12, 94.44, and 100.00%, respectively, yielding a comprehensive sensitivity of 92.56% and specificity to be 89.66%. Combined detection of CTCs and four tumor serum markers was helpful in detecting positivity rate, but without statistical signifiance compared with detecting CTCs alone. Our study demonstrates the value of CTCs as an auxiliary diagnostic method for gastrointestinal cancer, and could meet the deficiency of routine tissue biopsy, which can be used alone or in combination with conventional serum tumor markers and thereby facilitate the clinical diagnosis of gastrointestinal cancer.