Postoperative circulating tumor DNA detection predicts recurrence and guides adjuvant chemotherapy duration in high-risk stage III colorectal cancer

Table 1 Relationship between postoperative circulating tumor DNA status and clinicopathological features of high-risk stage III colorectal cancer

Clinicopathological features	n	Postoperative ctDNA		χ2	P value
		Negative (n = 29)	Positive (n = 21)
Age
< 60 years	20	9	11	2.313	0.128
≥ 60 years	30	20	10
Sex
Male	27	15	12	0.144	0.704
Female	23	14	9
Tumor location
Rectum	16	11	5	1.116	0.291
Colon	34	18	16
Tumor differentiation
Moderate/well-differentiated	30	17	13	0.055	0.815
Poorly differentiated/mucinous carcinoma	20	12	8
Tumor stage
IIIb	29	20	9	3.408	0.065
IIIc	21	9	12
T stage
T3	26	17	9	1.213	0.271
T4	24	12	12
N stage
N1	17	11	6	0.475	0.490
N2	33	18	15
Perineural invasion
Yes	31	19	12	0.363	0.547
No	19	10	9
Vascular invasion
Yes	25	12	13	2.053	0.152
No	25	17	8
CEA (ng/mL)
< 5	23	12	11	0.539	0.441
≥ 5	27	17	10
Recurrence
Yes	15	5	10	5.352	0.021
No	35	24	11

ctDNA: Circulating tumor DNA; CEA: Carcinoembryonic antigen.