Table 1.
Summary of studies that have tested DNA integrity and genetic alteration markers in blood samples in colorectal cancer
| Study | Biomarker(s) | Methods | Case analyzed | Main results | |
| Flamini et al[17], 2006 | Serum cfDNACEAcfDNA and CEA | qRT PCR | CRC: 75HD: 75 | Sensitivity | Specificity |
| 81% | 73% | ||||
| 39% | 97% | ||||
| 88% | 71% | ||||
| Frattini et al[51], 2006 | Plasma cfDNA | DNA Dipstick Kit | CRC: 70HD: 20 | CRC (T0) mean value DNA: 495.7 ng/mL | |
| CRC (FU at 4 mo) mean value DNA: 170.6 ng/mL | |||||
| CRC (FU at 10 mo) mean value DNA: 240.9 ng/mL | |||||
| CRC (FU at 10 mo)(DFP) mean value DNA: 136.2 ng/mL | |||||
| CRC (FU at 10 mo)(RP) mean value DNA: 694.4 ng/mL | |||||
| HD: mean value DNA 10.3 ng/mL | |||||
| Altered in only 37% of CRC patients | |||||
| Umetani et al[61], 2006 | Plasma cfDNASerum cfDNA | ALU qRT PCR | Breast, Colorectal, Thyroid Cancer: 22Thyroid A: 2 | Mean ± SD value plasma cfDNA: 180 ± 150 pg/μL | |
| Mean ± SD value serum cfDNA: 970 ± 730 pg/μL | |||||
| Umetani et al[64], 2006 | Absolute serum DNAIntegrity serum DNA Alu repeats (2 sites) | ALU qRT PCR | CRC: 32HD: 51 | CRC (I-II) mean absolute value DNA: 1.63 ng/μL | |
| CRC (I-II) mean integrity DNA: 0.22 ng/μL | |||||
| CRC (III-IV) mean absolute DNA: 1.73 ng/μL | |||||
| CRC (III-IV) mean integrity DNA: 0.22 ng/μL | |||||
| Boni et al[52], 2007 | Plasma cfDNACEA | qRT PCR | CRC: 67HD: 67 | CRC: Mean value DNA 57.93 ng/mL | |
| HD: Mean value DNA 0.85 ng/mL | |||||
| Evaluated in only 47% of patients | |||||
| Danese et al[65], 2010 | Serum cfDNACEA | RT-PCR | CRC: 118P: 49HD: 26 | Sensitivity | Specificity |
| 83% | 92% | ||||
| 36% | 100% | ||||
| Mead et al[31], 2011 | Plasma cfDNA (4 DNA markers) CEA | PCRELISA | CRC: 24P: 26HD: 35 | AUC: cfDNA: 0.81 | |
| AUC (CEA and cfDNA): 0.855 | |||||
| P: Sensitivity: 83%; Specificity 72% | |||||
| Czeiger et al[66], 2011 | Serum cfDNA | Fluorometric Assay | CRC: 38HD: 34 | Sensitivity | Specificity |
| 42% | 94% | ||||
| da Silva Filho et al[67], 2013 | Serum cfDNAAlu repeats (2 sites) | qPCR | CRC not operated on: 27CRC operated on: 33HD: 30 | CRC not operated on: 0.08-62.10 pg/μL | |
| CRC operated on: 0.01-186.7 pg/μL | |||||
| HD: 0.01-26.11 pg/μL | |||||
| Mean value range (according to different Alu analysis) | |||||
cfDNA: Cell-free circulating DNA; HD: Healthy donors; A: Adenomas; P: Polyps; T0: Time 0; FU: Follow up; DFP: Disease free patients; RP: Recurrence patients; AUC: Area under the receiver-operating characteristic (ROC) curve; qRT PCR: Quantitative real time polymerase chain reaction; ELISA: Enzyme-linked immunosorbent assay.