Current state and future direction of screening tool for colorectal cancer

Table 3 Characteristics of colorectal cancer screening of bio fluidic sample types (blood, urine, stool)

Sample types	Evidence of efficacy	Advantage	Disadvantage
Blood-based biomarkers (serum, plasma, and dried blood spot)	A combination of 8 metabolites (99.3% sensitivity, 93.8% specificity, and AUC 0.996)[94] Gastrointestinal tract acid 446 (83.3% sensitivity, 84.8% specificity, 85.7%, and 52.1% , respectively)[96,97] Decanoic acid (87.87% sensitivity, 80.0% specificity, 71.0%, and 75.0%, respectively)[98,99]	Easily accessible Less affected by diet than urine Less diurnal variation and Less inter- and intra-subject variability than urine Stable over a 4-mo period frozen at -80 °C except at room temperature	Affected by smoking status More invasive than urine and stool Analysis can be more complex than urine
Urine	Cross-validated panel of seven metabolites (97.5% sensitivity, 100% specificity, and AUC 0.998)[104] 10 different metabolites (100% sensitivity, 80% specificity but small sample size)[103] N1, N12-Diacetylspermine[105,106]	Easily accessible Less invasive than blood	More affected by diet than serum samples More diurnal variation and More inter- and intra-subject variability than serum A full day storing at room temperature or on cool packs altered metabolite concentration More than 2 freeze and thaw cycles affected the metabolic profile significantly
Stool	A three metabolite panel (AUC 1.0 but very small sample size)[107] A metabolomics panel (AUC 0.94)[108]	Easily accessible Less invasive than blood	Inconvenient to collect of stool samples Low compliance