Table 3.
Multivariate cox regression analysis for overall survival, adjusted for prognostic factors at baseline, after one cycle of chemotherapy and after surgery, respectively, with p values < 0.05 in the univariate regression analysis (clinical nodal stage, ctDNA status, pathological tumor stage, and pathological nodal stage)
| Variable | OS, baseline, n = 79 | OS, after one cycle of chemotherapy, n = 73 | OS, after surgery, n = 53 | |||
|---|---|---|---|---|---|---|
| HR (95% CI) | p value | HR (95% CI) | p value | HR (95% CI) | p value | |
| ctDNA status | ||||||
| Not detected (negative) | Reference | Reference | Reference | |||
| Detected (positive) | 1.02 (0.45–1.97) | 0.90 | 2.40 (1.09–5.26) | 0.03 | 7.33 (2.39–22.47) | < 0.001 |
| Clinical nodal stage | ||||||
| cN0 | Reference | Reference | – | |||
| cN + | 2.18 (1.05–4.55) | 0.04 | 1.70 (0.77–3.72) | 0.18 | – | – |
| Pathological tumor stage | ||||||
| ypT1/T2 | – | – | Reference | |||
| ypT3/T4 | – | – | – | – | 12.63 (1.63–98.93) | 0.02 |
| Pathological nodal stage | ||||||
| ypN0 | – | Reference | ||||
| ypN + | – | – | – | – | 1.51 (0.51–4.50) | 0.45 |
p values in bold indicate statistical significance (p ≤ 0.05)
OS overall survival; HR hazard ratio; ctDNA circulating tumor DNA