Autophagy-related proteins Beclin-1 and LC3 predict cetuximab efficacy in advanced colorectal cancer

Table 1 Comparison of baseline clinicopathological characteristics between cetuximab-containing chemotherapy group and non-cetuximab-containing group n (%)

Clinical factors	Total	Cetuximab chemotherapy	Non-cetuximab chemotherapy	P value
Gender				0.85
Male	54 (63.5)	29 (64.4)	25 (62.5)
Female	31 (36.5)	16 (35.6)	15 (37.5)
Age (yr), median (range)	50 (12-79)			0.56
Risk group (40-60)	46 (54.1)	23 (51.1)	23 (57.5)
Non-riskgroup (< 40)	39 (45.9)	22 (48.9)	17 (42.5)
Family history of tumor				0.63
Yes	12 (14.1)	9 (20.0)	3 (15.0)
No	73 (85.9)	36 (80.0)	17 (85.0)
Tumor site				0.89
Rectum	24 (28.2)	13 (28.9)	11 (27.5)
Colon	61 (71.8)	32 (71.1)	29 (72.5)
Primary clinical stage				0.86
II	12 (14.1)	5 (11.1)	7 (17.5)
III	25 (29.4)	15 (33.3)	10 (25.0)
IV	48 (56.5)	25 (55.6)	23 (57.5)
Histological grade				0.93
Well differentiation	6 (7.1)	3 (6.7)	3 (7.5)
Moderate differentiation	57 (67.1)	30 (66.6)	26 (65.0)
Poor differentiation	22 (25.9)	12 (26.7)	11 (27.5)

Table 2 Expression of Beclin-1 and LC3 in colorectal cancer and colorectal normal tissues n (%)

Hscores	Beclin-1 expression		LC3 expression
	CRCtissues	Colorectal normal tissues	CRCtissues	Colorectal normal tissues
0	5 (5.9)	2 (7.1)	4 (4.7)	2 (7.1)
1	2 (2.4)	0 (0.0)	4 (4.7)	1 (3.6)
2	8 (9.4)	3 (10.7)	9 (10.6)	8 (28.6)
3	18 (21.2)	7 (25.0)	14 (16.5)	5 (17.9)
4	4 (4.7)	1 (3.6)	5 (5.9)	3 (10.7)
6	28 (32.9)	13 (46.4)	28 (32.9)	8 (28.6)
9	20 (23.5)	2 (7.1)	21 (24.7)	1 (3.6)
Z /P (K-M test)	-0.94/0.35		-2.63/0.00

K-M test was used to compare the expression of Beclin-1 or LC3 between CRC tissues and colorectal normal tissues. P value ≤ 0.05 was considered statistically significant. CRC: Colorectal cancer.

Table 3 Correlation between Beclin-1 and LC3 expression with objective response rate and disease control rate in cetuximab-containing chemotherapy group and non-cetuximab-containing group in patients with advanced colorectal cancer n (%)

	Beclin-1 expression		LC3 expression
	Low	High	Low	High
Cetuximab-containing chemotherapy
CR	0 (0)	0 (0)	0	0
PR	4 (26.7)	10 (33.3)	9 (52.9)	5 (17.9)
SD	8 (53.3)	7 (23.3)	4 (23.5)	11 (39.3)
PD	3 (20.0)	13 (43.3)	4 (23.5)	12 (42.8)
Non-cetuximab-containing chemotherapy
CR	0 (0)	0 (0)	0 (0)	0 (0)
PR	9 (42.9)	7 (36.8)	7 (43.7)	9 (37.5)
SD	9 (42.9)	9 (47.4)	6 (37.5)	12 (50.0)
PD	3 (14.2)	3 (15.8)	3 (18.8)	3 (12.5)

CR: Complete response; PR: Partial response; SD: Stable disease; PD: Progression disease.

Table 4 Objective response rate and disease control rate of patients with wild type KRAS and KRAS mutation in cetuximab-containing chemotherapy group n (%)

Effect	Wild type KRAS	Mutant type KRAS	Total
CR	0 (0)	0 (0)	0
PR	11 (42.3)	1 (9.1)	12 (32.4)
SD	8 (30.8)	3 (27.3)	11 (29.7)
PD	7 (26.9)	7 (63.6)	14 (37.8)
Total	26 (70.3)	11 (29.7)	37 (100)

CR: Complete response; PR: Partial response; SD: Stable disease; PD: Progression disease.

Table 5 Survival analysis of 45 patients with advanced colorectal cancer treated by cetuximab-containing chemotherapy

Clinical factors	n (%)	MOS (mo)	P value
Gender			0.93
Male	29 (64.4)	52.5
Female	16 (35.6)	33
Age (yr), median (range)
Risk group (40-60)	23 (51.1)	40	0.38
Non-riskgroup ( ≤ 40 or > 60)	22 (48.9)	35
Family history of tumor			0.23
No	36 (80.0)	40
Yes	9 (20.0)	42
Tumor site			0.88
Colon	32 (71.1)	42
Rectum	13 (28.9)	42
Primary clinical stage			< 0.01
II	5 (11.1)	137
III	15 (33.3)	43
IV	25 (55.6)	22
Histological grade			0.049
Well and moderate diff	34 (75.6)	43
Poor diff	11 (24.4)	23
Beclin-1 expression			0.75
Low	15 (33.3)	42.5
High	30 (66.7)	35
LC3 expression			0.27
Low	17 (37.8)	42.5
High	28 (62.2)	33
KRAS status			0.73
Wild type	28 (71.8)	43
Mutation	11 (28.2)	22

MOS: Median overall survival; Diff: Differentiation.

Table 6 Multivariate analysis of 37 patients with advanced colorectal cancer treated by cetuximab-containing chemotherapy

	B	SE	Wald	P value	OR	95.0% CI for OR
						Lower	Upper
Primary clinical stage	1.52	0.43	12.63	0.00	4.55	1.97	10.51
Histological grade	-0.06	0.54	0.01	0.92	0.95	0.33	2.72
Beclin-1 expression	-0.09	0.08	1.14	0.29	0.92	0.78	1.08
LC3 expression	0.01	0.10	0.01	0.92	1.01	0.83	1.22
KRAS status	0.52	0.46	1.27	0.26	1.68	0.68	4.15

Thirty-seven of 45 cases were included in COX regression model because the KRAS status of 8 patients was not available. B: Regression coefficient; SE: Standard Error; OR: Odds ratio; CI: Confidence Interval.