Table 2.
CTCs as predictive factors for cancer therapy efficacy in gastric and colorectal cancer.
| Cancer types | Cut-off value | Technique | Patients (n) | Treatment | Conclusions | References |
|---|---|---|---|---|---|---|
| Gastric cancer | ≥1 CTC | 3D-IF-FISH method | Unresectable metastatic or recurrent GC (15) | 1st-line CT + trastuzumab | ORR was 53.3% in CTCs-HER2 positive patients at first response evaluation (6 weeks) vs. 7.7% in CTCs-HER2 negative patients (p = 0.016) | (98) |
| ≥3 CTCs | CellSearch® | Advanced GC (106) | 1st-line CT | ORR was 30.0% in CTCs-negative patients at first response evaluation | (61) | |
| ≥5 CTCs | CellSearch® | Metastatic GC (100) | ≥1st-line CT | Chemotherapy response (CR or PR or SD) was 76.6% in CTCs-negative patients vs. 40.0% in CTCs-positive patients (p = 0.004) | (60) | |
| ≥1 of the marker genes positive | EpCAM + RT-PCR | Advanced GC (61) | 1st or 2nd-line CT | 100% of progressive patients were CTCs-positive at baseline vs. 73.5% of non-progressive patients (p = 0.003) | (96) | |
| Colorectal cancer | 2 + PCR results | RT-PCR | LARC (79) | CRT + surgery | After CRT, CTCs were detected in 54.4% of the non-responders vs. 27.2% of the responders (p = 0.030) | (95) |
| ≥1 CTC | CellSearch® | LARC (85) | CRT + surgery | pCR/downstaging/downsizing rate was 80% in baseline CTCs-negative patients vs. 40% in CTCs-positive patients (p = 0.02) | (97) | |
| ≥1 out of 3 CTCs markers | AdnaTest® | Metastatic RAS-BRAF wt CRC (38) | ≥1st-line CT | ORR in unfavorable and favorable CTCs-changes profiles were respectively 0% and 59% (p <0.0001) | (83) | |
| ≥3 CTCs | CellSearch® | Metastatic KRAS wt CRC (61) | 3rd-line CT | ORR was not different between the high and the low CTCs groups (27.7 vs. 18.36%, p = 0.498) | (85) | |
| ≥3 CTCs | CellSearch® | mCRC (180) | 1st-line CT | CTCs negativity after 3 cycles of CT was associated with higher ORR (OR, 3.22; 95% CI 1.25–9.43) | (87) | |
| ≥3 CTCs | CellSearch® | mCRC (60) | 1st or 2nd-line CT | CTCs positivity at 8–12 weeks was 2% in non-PD patients vs. 43% in PD patients (p = 0.004) | (88) | |
| ≥3 CTCs | CellSearch® | mCRC (307) | 1st-line CT | ORR was 40% in patients with low CTCs count at 1–2 weeks vs. 11% in patients with high CTCs count (p = 0.022) | (90) | |
| ≥3 CTCs | CellSearch® | mCRC (430) | 1st, 2nd, or 3rd CT | CTCs positivity at 3–5 weeks was 7% in non-PD patients vs. 27% in PD patients | (91) |
CTCs, circulating tumor cells; GC, gastric cancer; CRC, colorectal cancer; mCRC, metastatic CRC; LARC, localize advanced rectum cancer; IF, immunofluorescence; FISH, fluorescent in situ hybridization; EpCAM, epithelial marker epithelial cell adhesion molecule; HER2, human epidermal growth factor receptor 2; RT-PCR, real-time polymerase chain reaction; CT, chemotherapy; CRT, chemoradiotherapy; CR, complete response; PR, part response; SD, stable disease; ORR, overall response rate = complete response + partial response; OR, odds ratio.