. 2018 May 16;10:63. doi: 10.1186/s13148-018-0500-5

Table 1.

Plasma BCAT1, IKZK1 and overall ctDNA positivity for different clinicopathological findings of patients with invasive colorectal cancer (n = 187)

Factor	Category	N	Methylated BCAT1 DNA			Methylated IKZF1 DNA			ctDNA positivity (combined BCAT1/IKZF1)
			No. positive	% positive (95% CI¹)	P ²	No. positive	% positive (95% CI¹)	P ²	No. positive	% positive (95% CI¹)	P ²
Age	< 65 years	67	29	43.3 (31.2–56.0)	0.154	28	41.8 (29.8–54.5)	0.332	39	58.2 (45.5–70.2)	0.421
Age	≥ 65 years	120	65	54.2 (44.8–63.3)		59	49.2 (39.9–58.4)		77	64.2 (54.9–72.7)
Gender	Female	75	34	45.3 (33.8–57.3)	0.270	31	41.3 (30.1–53.3)	0.244	42	56.0 (44.1–67.5)	0.164
Gender	Male	112	60	53.6 (43.9–63.0)		56	50.0 (40.4–59.6)		74	66.1 (56.5–74.7)
Stage	I	40	4	10.0 (2.8–23.7)	< 0.001	2	5.0 (0.6–16.9)	< 0.001	6	15.0 (5.7–29.8)	< 0.001
	II	54	29	53.7 (39.6–67.4)		25	46.3 (32.6–60.4)		35	64.8 (50.6–77.3)
	III	63	37	58.7 (45.6–71.0)		36	57.1 (44.0–69.5)		47	74.6 (62.1–84.7)
	IV	30	24	80.0 (61.4–92.3)		24	80.0 (61.4–92.3)		28	93.3 (77.9–99.2)
T stage	T1	26	2	7.7 (0.9–22.1)	< 0.001	1	3.8 (0.1–19.6)	< 0.001	2	7.7 (0.9–25.1)	< 0.001
	T2	23	6	26.1 (10.2–48.4)		3	13.0 (2.8–33.6)		8	34.8 (16.4–57.3)
	T3	96	55	57.3 (46.8–67.3)		56	58.3 (47.8–68.3)		69	71.9 (61.8–80.6)
	T4	34	24	70.6 (52.5–84.9)		21	61.8 (43.6–77.8)		29	85.3 (68.9–95.0)
	Unknown	8	7	87.5 (47.3–99.7)		6	75.0 (34.9–96.8)		8	100.0 (63.1–100.0)
N stage	N0	100	41	41.0 (31.3–51.3)	0.024	36	36.0 (26.6–46.2)	0.007	50	50.0 (39.8–60.2)	0.001
	N1/N2	73	44	60.3 (48.1–71.5)		44	60.3 (48.1–71.5)		56	76.7 (65.4–85.8)
	Unknown	14	9	64.3 (35.1–87.2)		7	50.0 (23.0–77.0)		10	71.4 (41.9–91.6)
M stage	M0	147	66	44.9 (36.7–53.3)	0.002	58	39.5 (31.5–47.8)	< 0.001	82	55.8 (47.4–64.0)	0.001
	M1	30	24	80.0 (61.4–92.3)		24	80.0 (61.4–92.3)		28	93.3 (77.9–99.2)
	Unknown	10	4	40.0 (12.2–73.8)		5	50.0 (18.7–81.3)		6	60.0 (26.2–87.8)
Size (mm)	< 20 mm	14	2	14.3 (1.8–42.8)	< 0.001	2	14.3 (1.8–42.8)	< 0.001	3	21.4 (4.7–50.8)	< 0.001
	20–50 mm	100	44	44.0 (34.1–54.3)		37	37.0 (27.6–47.2)		56	56.0 (45.7–65.9)
	> 50 mm	65	44	67.7 (54.9–78.8)		45	69.2 (56.6–80.1)		52	80.0 (68.2–88.9)
	Unknown	8	4	50.0 (15.7–84.3)		3	37.5 (8.5–75.5)		5	62.5 (24.5–91.5)
Location	Proximal	75	28	37.3 (26.4–49.3)	0.011	31	41.3 (30.1–53.3)	0.306	37	49.3 (37.6–61.1)	0.011
	Distal	111	65	58.6 (48.8–67.8)		56	50.5 (40.8–60.1)		78	70.3 (60.9–78.6)
	Unknown	1	1	100.0 (2.5–100.0)		0	0.0 (0.0–97.5)		1
Lymphatic invasion	Yes	38	24	63.2 (46.0–78.2)	0.014	25	65.8 (48.6–80.4)	0.001	30	78.9 (62.7–90.4)	0.002
Lymphatic invasion	No	121	49	40.5 (31.7–49.8)		44	36.4 (27.8–45.6)		61	50.4 (41.2–59.6)
Perinueural invasion	Yes	20	9	45.0 (23.1–68.5)	0.860	10	50.0 (27.2–72.8)	0.541	15	75.0 (50.9–91.3)	0.104
Perinueural invasion	No	138	65	47.1 (38.6–55.8)		59	42.8 (34.4–51.4)		77	55.8 (47.1–64.2)
Extramural vascular invasion	Yes	9	6	66.7 (29.9–92.5)	0.313	7	77.8 (40.0–97.2)	0.054	8	88.9 (51.8–99.7)	0.089
Extramural vascular invasion	No	178	88	49.4 (41.9–57.0)		80	44.9 (37.5–52.6)		108	60.7 (53.1–67.9)
Intramural vascular invasion	Yes	3	2	66.7 (9.4–99.2)	0.567	2	66.7 (9.4–99.2)	0.481	2	66.7 (9.4–99.2)	0.868
Intramural vascular invasion	No	184	92	50.0 (42.6–57.4)		85	46.2 (38.8–53.7)		114	62.0 (54.5–69.0)
Differentiation	Poor	34	21	61.8 (43.6–77.8)	0.241	20	58.8 (40.7–75.4)	0.124	25	73.5 (55.6–87.1)	0.160
	Moderate	118	54	45.8 (36.6–55.2)		48	40.7 (31.7–50.1)		67	56.8 (47.3–65.9)
	Well	14	6	42.9 (17.7–71.1)		6	42.9 (17.7–71.1)		7	50.0 (23.0–77.0)
	Unknown	21	13	61.9 (38.4–81.9)		13	61.9 (38.4–81.9)		17	81.0 (58.1–94.6)

¹Confidence interval

²P value, Pearson’s chi-square test