Long-term follow-up of HER2 overexpression in patients with rectal cancer after preoperative radiotherapy: A prospective cohort study

Table 1 Clinicopathological characteristics of the enrolled cohort (n = 151)

Characteristic	Result
Age diagnosis (yr)	55.85 ± 13.26
Gender (%)
Male	93 (61.6)
Female	58 (38.4)
Distance to anal verge (cm) (%)	4.91 ± 2.04
> 6	45 (29.8)
≤ 6	106 (70.2)
Pre-CEA (%)
Normal range	98 (64.9)
Elevated	53 (35.1)
Pre-T (%)
T1	2 (1.3)
T2	10 (6.6)
T3	133 (88.1)
T4	6 (4.0)
Pre-N (%)
N0	38 (25.2)
N+	113 (74.8)
Post-T (%)
pT0	7 (4.6)
pT1	6 (4.0)
pT2	48 (31.8)
pT3	84 (55.6)
pT4	4 (4.0)
Post-N (%)
pN0	89 (58.9)
pN+	62 (41.1)
Tumor regression grade (%)
Grade 0	9 (6.3)
Grade 1	34 (23.9)
Grade 2	42 (29.6)
Grade 3	57 (40.1)
HER2 (%)
-	124 (82.1)
+	27 (17.9)
LVI (%)
+	20 (13.2)
-	131 (86.8)
Median follow-up period	134
Distant metastasis, number (%)
Yes	60 (39.7)
No	91 (60.3)
Local recurrence, number (%)
Yes	24 (15.9)
No	127 (84.1)

Pre-CEA: Preoperative CEA; LVI: Lympho-vascular invasion.

Table 2 Correlations among HER2 expression and the clinicopathological parameters

Variable	HER2- (%)	HER2+ (%)	χ2	P value
Age (yr)			0.558	0.455
< 60	74 (59.7)	14 (51.9)
≥ 60	50 (40.3)	13 (48.1)
Sex			2.166	0.141
Male	73 (58.9)	20 (74.1)
Female	51 (41.1)	7 (25.9)
Pre-CEA			0.045	0.832
Normal range	80 (64.5)	18 (66.7)
Elevated	44 (35.5)	9 (33.3)
Distance to anal verge (cm)			0.236	0.627
> 6	38 (30.6)	7 (25.9)
≤ 6	86 (69.4)	20 (74.1)
Pre-T				0.6941
T1-2	11	1
T3-4	113	26
Pre-N			4.235	0.040
N0	27 (21.8)	11 (40.7)
N+	97 (78.2)	16 (59.3)
Post-T			1.583	0.208
T1-2	53	8
T3-4	71	19
Post-N			1.582	0.208
N0	76 (61.3)	13 (48.1)
N+	48 (38.7)	14 (51.9)
LVI
+	17 (13.7)	3 (11.1)	0.002	0.9622
-	107 (86.3)	24 (88.9)
Distant metastasis			9.959	0.002
+	42 (33.9)	18 (66.7)
-	82 (66.1)	9 (33.3)
Local recurrence			1.083	0.2982
+	22 (17.7)	2 (7.4)
-	102 (82.3)	25 (92.6)

¹Fisher’s exact test.

²Logistic regression model.

LVI: Lympho-vascular invasion.

Table 3 Correlations among distant metastasis and the clinicopathological parameters

Variable	Distant metastasis		χ2	P value
	- (%)	+ (%)
Age (yr)			0.121	0.728
< 60	52 (59.1)	36 (40.9)
≥ 60	39 (61.9)	24 (38.1)
Sex			0.446	0.504
Male	58 (62.4)	35 (37.6)
Female	33 (56.9)	25 (43.1)
Pre-CEA			9.704	0.002
Normal range	68 (69.4)	30 (30.6)
Elevated	23 (43.4)	30 (56.6)
Distance to anal verge (cm)			0.103	0.749
> 6	28 (62.2)	17 (37.8)
≤ 6	63 (59.4)	43 (40.6)
Pre-T				0.2211
T1-2	5	7
T3-4	86	53
Pre-N			0.001	1.000
N0	23 (60.5)	15 (39.5)
N+	68 (60.2)	45 (39.8)
Post-T			3.782	0.052
T1-2	43	18
T3-4	48	42
Post-N			7.995	0.005
N0	62 (69.7)	27 (30.3)
N+	29 (46.8)	33 (53.2)
LVI			1.014	0.314
+	10 (50.0)	10 (50.0)
-	81 (61.8)	50 (38.2)
HER2, number			9.959	0.002
-	82 (66.1)	42 (33.9)
+	9 (33.3)	18 (66.7)

¹Fisher’s exact test.

Table 4 Multivariate logistic regression analysis results

Variable	Odds ratio	97.5%CI	P value
CEA level before radiotherapy
Normal range	1
Elevated	3.277	1.543-7.163	0.002
Post-treatment N
N0	1
N+	2.437	1.143-5.308	0.022
HER2
-	1
+	4.222	1.667-11.409	0.003

CI: Confidence interval.