Fig. 1A representative case of microsatellite instability-high colorectal carcinoma demonstrating complete loss of EPCAM expression and MSH2 deficiency. Note the complete loss of EPCAM expression (A), loss of MSH2 expression (B), loss of MSH6 expression (C), and retained MLH1 expression (D).
Fig. 2A representative case of microsatellite instability-high colorectal carcinoma demonstrating focal loss of EPCAM expression and MLH1 promoter methylation. Note the focal loss of EPCAM expression (A), loss of MLH1 expression (B), loss of PMS2 expression (C), and retained MSH2 expression (D).
Table 1.Clinicopathological characteristics of MSI-H CRCs according to EPCAM expression status
Variable |
|
No. of cases |
Complete loss of EPCAM expression |
Focal loss of EPCAM expression |
Retained EPCAM expression |
p-value |
Age (yr) |
< 59 |
85 |
2 (100) |
11 (50) |
72 (50) |
.372 |
≥ 59 |
83 |
0 |
11 (50) |
72 (50) |
|
Gender |
Male |
89 |
1 (50) |
9 (41) |
79 (55) |
.473 |
Female |
79 |
1 (50) |
13 (59) |
65 (45) |
|
Tumor location |
Proximal |
113 |
2 (100) |
16 (73) |
95 (66) |
.501 |
Distal |
55 |
0 |
6 (27) |
49 (34) |
|
Gross tumor type |
Polypoid |
25 |
1 (50) |
1 (4) |
23 (16) |
.14 |
Ulcerative |
143 |
1 (50) |
21 (96) |
121 (84) |
|
Tumor multiplicity |
Solitary |
147 |
2 (100) |
19 (86) |
126 (87) |
.856 |
Multiple |
21 |
0 |
3 (14) |
18 (13) |
|
TNM stage |
Stage I/II |
108 |
1 (50) |
9 (41) |
98 (68) |
.043 |
Stage III/IV |
60 |
1 (50) |
13 (59) |
46 (32) |
|
Depth of tumor invasion (pT category) |
pT1/pT2 |
22 |
1 (50) |
2 (9) |
19 (13) |
.259 |
pT3/pT4 |
146 |
1 (50) |
20 (91) |
125 (87) |
|
Lymph node metastasis (pN category) |
pN0 |
112 |
1 (50) |
10 (45) |
101 (70) |
.064 |
pN1/pN2 |
56 |
1 (50) |
12 (55) |
43 (30) |
|
Distant metastasis (M category) |
M0 |
154 |
2 (100) |
16 (73) |
136 (94) |
.003 |
M1 |
14 |
0 |
6 (27) |
8 (6) |
|
Lymphovascular invasion |
Absent |
124 |
2 (100) |
13 (59) |
109 (76) |
.179 |
Present |
44 |
0 |
9 (41) |
35 (24) |
|
Perineural invasion |
Absent |
157 |
2 (100) |
19 (86) |
136 (94) |
.336 |
Present |
11 |
0 |
3 (14) |
8 (6) |
|
Tumor grade |
WD/MD |
128 |
2 (100) |
10 (45) |
116 (81) |
.001 |
PD |
40 |
0 |
12 (55) |
28 (19) |
|
Mucinous component |
Absent |
74 |
1 (50) |
8 (36) |
65 (45) |
.731 |
Present |
94 |
1 (50) |
14 (64) |
79 (55) |
|
Signet ring cell component |
Absent |
157 |
2 (100) |
17 (77) |
138 (96) |
.004 |
Present |
11 |
0 |
5 (23) |
6 (4) |
|
Medullary component |
Absent |
162 |
2 (100) |
21 (95) |
139 (97) |
.933 |
Present |
6 |
0 |
1 (5) |
5 (3) |
|
Table 2.Molecular characteristics of MSI-H CRCs according to EPCAM expression status
Variable |
|
No. of cases |
Complete loss of EPCAM expression |
Focal loss of EPCAM expression |
Retained EPCAM expression |
p-value |
MLH1 expression |
Negative |
105 |
0 |
13 (59) |
92 (64) |
.169 |
Positive |
63 |
2 (100) |
9 (41) |
52 (36) |
|
MSH2 expression |
Negative |
55 |
2 (100) |
9 (41) |
44 (31) |
.079 |
Positive |
113 |
0 |
13 (59) |
100 (69) |
|
PMS2 expression |
Negative |
111 |
0 |
14 (64) |
97 (67) |
.131 |
Positive |
57 |
2 (100) |
8 (36) |
47 (33) |
|
MSH6 expression |
Negative |
59 |
2 (100) |
9 (41) |
48 (33) |
.121 |
Positive |
109 |
0 |
13 (59) |
96 (67) |
|
MLH1 promoter methylation |
Methylated |
51 |
0 |
9 (41) |
42 (29) |
.345 |
Unmethylated |
117 |
2 (100) |
13 (59) |
102 (71) |
|