Table 2.
Association of cHER2 status with PFS and effect of anti-HER2 targeted therapy stratified by cHER2 status
| Variables | N | Univariate analysis | Multivariate analysis* | ||
|---|---|---|---|---|---|
| HR (95% CI) | P | HR (95% CI) | p | ||
| cHER2 status | |||||
| Low-risk | 90 | 1.00 | 1.00 | ||
| High-risk | 15 | 2.16 (1.20–3.88) | 0.010 | 1.93 (1.03–3.61) | 0.041 |
| Anti-HER2 targeted therapy according to cHER2 status | |||||
| High-risk cHER2 without anti-HER2 targeted therapy | 9 | 1.00 | 1.00 | ||
| High-risk cHER2 with anti-HER2 targeted therapy | 6 | 0.30 (0.10–0.92) | 0.035 | 0.30 (0.10–0.93) | 0.037 |
| Low-risk cHER2 without anti-HER2 targeted therapy | 75 | 1.00 | 1.00 | ||
| Low-risk cHER2 with anti-HER2 targeted therapy | 15 | 0.70 (0.36–1.38) | 0.306 | 0.72 (0.35–1.48) | 0.368 |
Abbreviations: CI, confidence interval; cHER2, human epidermal growth factor receptor 2 phenotype on circulating tumor cell; HR, hazard ratio; PFS, progression-free survival.
*
Adjusted for significant variables in univariate analysis, including tumor stage, numbers of previous chemotherapy, hormonal therapy and chemotherapy after baseline blood draw, and CTC enumeration.