Table 3. Recurrence-free survival analysis by clinicopathological variables and postoperative ctDNA status.
VariableUnivariate analysisMultivariate analysis
HR95% CIPHR95% CIP
Patients not treated with chemotherapy (n = 178)
Age, <70 versus ≥700.920.43–2.00.8
Sex, male versus female1.30.62–2.80.5
Tumor site, right versus left1.50.69–3.30.3
Tumor differentiation, well/moderate versus poor0.390.09–1.70.2
T stage, T3 versus T44.01.7–9.50.0028.13.1–21<0.001
Lymph node yield, ≥12 versus <123.11.3–7.40.009
Lymphovascular invasion, no versus yes2.41.1–5.40.03
MMR status, deficient versus proficient3.60.86–150.08
Clinicopathologic risk group, low versus high3.21.5–6.90.002
Postoperative CEA, normal versus elevated1.60.37–6.80.5
Postoperative ctDNA status, negative versus positive187.9–40<0.0012811–68<0.001
All patients (n = 230)
Age, <70 versus ≥701.00.50–2.01.0
Sex, male versus female1.10.57–2.20.7
Tumor site, right versus left1.10.55–2.10.8
Tumor differentiation, well/moderate versus poor0.320.08–1.30.1
T stage, T3 versus T42.41.2–5.10.022.61.2–5.50.01
Lymph node yield, ≥12 versus <122.20.97–4.80.06
Lymphovascular invasion, no versus yes1.90.92–4.10.08
MMR status, deficient versus proficient3.50.83–14.50.09
Clinicopathologic risk group, low versus high2.11.06–4.20.03
Adjuvant chemotherapy, no versus yes0.790.34–1.80.6
Postoperative CEA, normal versus elevated2.80.98–7.90.06
Postoperative ctDNA status, negative versus positive136.6–27<0.001146.8–28<0.001