A Grading System of Microvascular Invasion for Patients with Hepatocellular Carcinoma Undergoing Liver Resection with Curative Intent: A Multicenter Study

Figures & data

Figure 1 Diagnostic criteria of the MVI grading system. (A) M0; (B). M1; (C) M2a; (D). M2b; (E) Hep Par-1; (F). Arginase-1; (G) Glypican-3; (H) CD34; Arrow: MVI; Magnification of all images: 40×.

Table 1 Baseline Characteristics of All Patients

Characteristics	Crude Cohort (N=1546)	M0 (N=827)	M1+M2a+M2b (N=719)	P value	M1 (N=447)	M2a (N=242)	M2b (N=30)
Age, years	53.0 [46.0; 61.0]	55.0 [47.0; 62.0]	51.0 [45.0; 60.0]	<0.001	52.9 ± 10.7	50.4 ± 11.6	51.1 ± 11.3
Sex:				0.340
Female	226 (14.6%)	128 (15.5%)	98 (13.6%)		67 (15.0%)	27 (11.2%)	4 (13.3%)
Male	1320 (85.4%)	699 (84.5%)	621 (86.4%)		380 (85.0%)	215 (88.8%)	26 (86.7%)
TBIL, μmol/L	13.6 [10.6; 17.7]	13.6 [10.7; 17.6]	13.6 [10.6; 17.9]	0.722	13.7 [10.8; 17.6]	13.6 [10.6; 18.4]	12.2 [9.2; 17.7]
DBIL, μmol/L	5.1 [3.9; 6.7]	5.0 [3.8; 6.6]	5.2 [3.9; 6.9]	0.130	5.1 [3.9; 6.8]	5.3 [4.0; 7.0]	4.8 [3.4; 7.1]
IBIL, μmol/L	8.4 [6.6; 11.0]	8.6 [6.7; 11.0]	8.3 [6.6; 11.0]	0.435	8.4 [6.7; 10.9]	8.3 [6.6; 11.1]	7.1 [5.3; 11.1]
TBA, μmol/L	6.6 [3.8; 11.5]	6.7 [3.9; 11.7]	6.4 [3.7; 11.1]	0.161	6.4 [3.9; 11.2]	6.3 [3.5; 10.6]	8.6 [3.6; 20.3]
TP, g/L	68.5 [65.4; 72.2]	68.3 [65.3; 71.9]	68.8 [65.5; 72.5]	0.148	69.1 ± 5.1	68.8 ± 5.3	68.6 ± 5.3
ALB, g/L	41.6 [39.1; 43.8]	41.8 [39.3; 44.0]	41.5 [39.0; 43.8]	0.107	41.4 ± 3.6	41.3 ± 3.5	40.8 ± 3.1
GLB, g/L	27.0 [24.3; 29.9]	26.7 [24.1; 29.4]	27.5 [24.6; 30.5]	0.002	27.7 ± 4.2	27.2 [24.2; 30.4]	27.9 ± 4.2
PA, mg/L	236.0 [188.0; 284.0]	247.0 [194.0; 292.0]	228.0 [179.0; 272.0]	<0.001	224.0 [175.0; 273.0]	232.0 ± 67.0	205.0 ± 69.4
ALT, U/L	30.0 [21.0; 46.0]	29.0 [20.0; 44.0]	32.0 [22.0; 48.0]	0.001	31.0 [21.0; 48.0]	33.0 [24.0; 46.0]	40.5 [26.2; 50.5]
AST, U/L	29.0 [22.0; 42.0]	27.0 [21.0; 39.0]	32.0 [23.0; 46.5]	<0.001	30.0 [23.0; 45.0]	33.0 [25.0; 51.5]	40.0 [27.8; 53.2]
GGT, U/L	57.0 [33.0; 108.0]	49.0 [29.0; 93.0]	71.0 [37.2; 126.0]	<0.001	65.0 [36.0; 116.0]	81.0 [38.0; 155.0]	85.5 [47.5; 187.0]
ALP, U/L	79.0 [64.0; 100.0]	75.0 [62.0; 96.0]	83.5 [66.0; 104.0]	<0.001	82.0 [66.0; 100.0]	84.0 [65.0; 109.0]	98.0 [67.5; 134.0]
LDH, U/L	158.0 [139.0; 188.0]	153.0 [137.0; 180.0]	163.0 [141.0; 201.0]	<0.001	161.0 [140.0; 198.0]	170.0 [146.0; 208.0]	170.0 [150.0; 207.0]
BUN, mmol/L	5.2 [4.4; 6.2]	5.4 [4.5; 6.2]	5.1 [4.3; 6.1]	0.009	5.2 [4.4; 6.1]	5.0 [4.3; 6.1]	5.0 ± 1.5
SCR, μmol/L	72.0 [63.0; 80.0]	72.0 [63.0; 80.0]	71.0 [63.0; 79.0]	0.057	71.0 [63.0; 79.0]	72.0 [63.0; 79.0]	67.5 ± 15.2
PT, s	11.4 [10.9; 11.9]	11.3 [10.9; 11.9]	11.4 [10.9; 12.0]	0.022	11.4 [10.8; 12.0]	11.4 [11.1; 11.9]	11.5 ± 0.9
INR	1.0 [0.9; 1.0]	0.9 [0.9; 1.0]	1.0 [0.9; 1.0]	0.010	1.0 [0.9; 1.0]	1.0 [0.9; 1.0]	1.0 ± 0.1
TT, s	20.1 [19.1; 20.9]	20.1 [19.1; 20.9]	20.0 [19.0; 20.9]	0.293	20.0 [19.0; 21.0]	20.0 [19.0; 20.9]	20.0 ± 1.6
Fbg, g/L	2.3 [2.0; 2.9]	2.2 [1.9; 2.7]	2.4 [2.0; 3.0]	<0.001	2.4 [2.0; 3.0]	2.5 [2.1; 3.1]	2.4 [2.2; 2.8]
WBC, ×109/L	5.1 [4.1; 6.2]	5.1 [4.0; 6.2]	5.1 [4.2; 6.2]	0.296	5.1 [4.2; 6.2]	5.1 [4.4; 6.1]	5.3 ± 1.6
Lym, ×109/L	1.5 [1.2; 1.9]	1.6 [1.2; 2.0]	1.5 [1.1; 1.9]	0.008	1.5 [1.1; 1.9]	1.5 [1.1; 1.8]	1.5 ± 0.6
Mono, ×109/L	0.3 [0.3; 0.4]	0.3 [0.3; 0.4]	0.3 [0.3; 0.4]	0.498	0.3 [0.3; 0.4]	0.3 [0.3; 0.4]	0.3 [0.2; 0.4]
Neut, ×109/L	3.0 [2.3; 3.8]	2.9 [2.2; 3.7]	3.1 [2.4; 3.8]	0.003	3.0 [2.3; 3.8]	3.1 [2.6; 3.8]	3.4 ± 1.3
EOS, ×109/L	0.1 [0.1; 0.2]	0.1 [0.1; 0.2]	0.1 [0.1; 0.2]	0.794	0.1 [0.1; 0.2]	0.1 [0.1; 0.2]	0.1 [0.1; 0.2]
BASO, ×109/L	0.0 [0.0; 0.0]	0.0 [0.0; 0.0]	0.0 [0.0; 0.0]	0.131	0.0 [0.0; 0.0]	0.0 [0.0; 0.0]	0.0 [0.0; 0.0]
RBC, ×1012/L	4.5 [4.2; 4.9]	4.5 [4.2; 4.8]	4.6 [4.2; 4.9]	0.015	4.6 [4.2; 4.9]	4.6 [4.3; 4.9]	4.7 ± 0.5
PCV, %	41.3 [38.7; 44.0]	41.2 [38.6; 43.8]	41.5 [38.7; 44.2]	0.313	41.1 [38.5; 43.9]	41.9 [39.2; 44.7]	41.5 ± 3.4
MCV, fL	91.2 [88.4; 94.1]	91.4 [88.8; 94.3]	90.9 [88.0; 93.9]	0.016	90.9 [88.2; 93.7]	91.0 [87.7; 94.3]	89.4 ± 8.4
MCH, pg	31.6 [30.5; 32.7]	31.7 [30.6; 32.8]	31.5 [30.3; 32.5]	0.001	31.4 [30.3; 32.5]	31.6 [30.3; 32.5]	31.7 [29.7; 32.6]
MCHC, g/L	345.0 [338.0; 352.0]	346.0 [339.0; 353.0]	344.0 [338.0; 351.0]	0.004	344.0 [337.0; 351.0]	345.0 [339.0; 351.0]	343.0 [333.0; 349.0]
RDW, %	13.0 [12.5; 13.5]	13.0 [12.5; 13.5]	12.9 [12.5; 13.5]	0.299	12.9 [12.5; 13.5]	12.9 [12.6; 13.5]	13.0 [12.7; 13.8]
PLT, ×109/L	156.0 [115.0; 200.0]	150.0 [109.0; 193.0]	162.0 [123.0; 204.0]	<0.001	162.0 [124.0; 205.0]	162.0 [120.0; 200.0]	169.0 ± 82.9
MPV, fL	11.6 [10.9; 12.4]	11.6 [10.9; 12.4]	11.6 [10.8; 12.4]	0.609	11.6 ± 1.1	11.5 [11.0; 12.3]	11.6 [10.8; 12.1]
PCT, %	0.2 [0.1; 0.2]	0.2 [0.1; 0.2]	0.2 [0.2; 0.2]	0.002	0.2 [0.2; 0.2]	0.2 [0.1; 0.2]	0.2 [0.2; 0.3]
PDW, fL	14.2 [12.7; 16.1]	14.2 [12.7; 16.2]	14.2 [12.6; 16.0]	0.626	14.2 [12.6; 16.0]	14.2 [12.9; 16.1]	14.2 [12.8; 15.9]
AFP, μg/L	80.2 [5.8; 1070.0]	17.5 [4.0; 373.0]	322.0 [17.6; 1210.0]	<0.001	166.0 [9.5; 1210.0]	826.0 [61.5; 1210.0]	552.0 [67.8; 1210.0]
CEA, μg/L	2.1 [1.4; 3.2]	2.1 [1.4; 3.2]	2.1 [1.4; 3.1]	0.164	2.1 [1.4; 3.2]	2.0 [1.3; 2.9]	2.5 [1.8; 3.3]
CA199, U/mL	16.1 [9.0; 28.7]	15.4 [8.4; 27.1]	17.2 [9.7; 30.4]	0.020	16.6 [9.0; 29.6]	17.2 [10.4; 31.4]	23.3 [11.8; 54.3]
HBsAg:				0.375
Negative	225 (14.6%)	127 (15.4%)	98 (13.6%)		60 (13.4%)	32 (13.2%)	6 (20.0%)
Positive	1321 (85.4%)	700 (84.6%)	621 (86.4%)		387 (86.6%)	210 (86.8%)	24 (80.0%)
HBsAb:				0.343
Negative	1391 (90.0%)	738 (89.2%)	653 (90.8%)		409 (91.5%)	217 (89.7%)	27 (90.0%)
Positive	155 (10.0%)	89 (10.8%)	66 (9.2%)		38 (8.5%)	25 (10.3%)	3 (10.0%)
HBeAg:				0.001
Negative	1150 (74.4%)	643 (77.8%)	507 (70.5%)		317 (70.9%)	170 (70.2%)	20 (66.7%)
Positive	396 (25.6%)	184 (22.2%)	212 (29.5%)		130 (29.1%)	72 (29.8%)	10 (33.3%)
HBeAb:				0.128
Negative	536 (34.7%)	272 (32.9%)	264 (36.7%)		164 (36.7%)	88 (36.4%)	12 (40.0%)
Positive	1010 (65.3%)	555 (67.1%)	455 (63.3%)		283 (63.3%)	154 (63.6%)	18 (60.0%)
HBcAb:				0.262
Negative	31 (2.0%)	13 (1.6%)	18 (2.5%)		15 (3.4%)	3 (1.2%)	0 (0.0%)
Positive	1515 (98.0%)	814 (98.4%)	701 (97.5%)		432 (96.6%)	239 (98.8%)	30 (100.0%)
HBV DNA load:				0.006
<50 IU/mL	626 (40.5%)	362 (43.8%)	264 (36.7%)		174 (38.9%)	79 (32.6%)	11 (36.7%)
≥50 IU/mL	920 (59.5%)	465 (56.2%)	455 (63.3%)		273 (61.1%)	163 (67.4%)	19 (63.3%)
HCV:				0.304
Negative	1520 (98.3%)	810 (97.9%)	710 (98.7%)		444 (99.3%)	238 (98.3%)	28 (93.3%)
Positive	26 (1.7%)	17 (2.1%)	9 (1.3%)		3 (0.7%)	4 (1.7%)	2 (6.7%)
Ultrasonic tumor echo:				<0.001
Low	718 (46.4%)	431 (52.1%)	287 (39.9%)		185 (41.4%)	90 (37.2%)	12 (40.0%)
High	593 (38.4%)	293 (35.4%)	300 (41.7%)		185 (41.4%)	102 (42.1%)	13 (43.3%)
Uneven strength	160 (10.3%)	70 (8.5%)	90 (12.5%)		47 (10.5%)	39 (16.1%)	4 (13.3%)
NA	75 (4.9%)	33 (4.0%)	42 (5.8%)		30 (6.7%)	11 (4.6%)	1 (3.3%)
Ultrasonic tumor boundary:				<0.001
Clear	851 (55.0%)	514 (62.2%)	337 (46.9%)		228 (51.0%)	97 (40.1%)	12 (40.0%)
Unclear	617 (39.9%)	278 (33.6%)	339 (47.1%)		188 (42.1%)	134 (55.4%)	17 (56.7%)
NA	78 (5.1%)	35 (4.2%)	43 (6.0%)		31 (6.9%)	11 (4.6%)	1 (3.3%)
Ultrasonic intratumoral echo:				0.097
Evenness	162 (10.5%)	97 (11.7%)	65 (9.0%)		46 (10.3%)	16 (6.6%)	3 (10.0%)
Unevenness	1293 (83.6%)	688 (83.2%)	605 (84.1%)		366 (81.9%)	213 (88.0%)	26 (86.7%)
NA	91 (5.9%)	42 (5.1%)	49 (6.8%)		35 (7.8%)	13 (5.4%)	1 (3.3%)
Splenomegaly:				0.635
No	1312 (84.9%)	708 (85.6%)	604 (84.0%)		378 (84.6%)	207 (85.5%)	19 (63.3%)
Yes	189 (12.2%)	95 (11.5%)	94 (13.1%)		54 (12.1%)	30 (12.4%)	10 (33.3%)
NA	45 (2.9%)	24 (2.9%)	21 (2.9%)		15 (3.4%)	5 (2.1%)	1 (3.3%)
Surgery:				<0.001
Anatomic	281 (18.2%)	121 (14.6%)	160 (22.3%)		84 (18.8%)	63 (26.0%)	13 (43.3%)
Nonanatomic	1265 (81.8%)	706 (85.4%)	559 (77.7%)		363 (81.2%)	179 (74.0%)	17 (56.7%)
Surgical margin:				0.003
>0.1cm	577 (37.3%)	337 (40.7%)	240 (33.4%)		167 (37.4%)	67 (27.7%)	6 (20.0%)
≤0.1cm	969 (62.7%)	490 (59.3%)	479 (66.6%)		280 (62.6%)	175 (72.3%)	24 (80.0%)
Cholecystectomy:				0.004
No	878 (56.8%)	498 (60.2%)	380 (52.9%)		248 (55.5%)	118 (48.8%)	14 (46.7%)
Yes	668 (43.2%)	329 (39.8%)	339 (47.1%)		199 (44.5%)	124 (51.2%)	16 (53.3%)
Tumor size, cm	4.6 [3.0; 8.1]	4.0 [2.7; 6.3]	5.8 [3.3; 10.2]	<0.001	5.1 [3.1; 9.4]	6.8 [4.2; 11.0]	9.4 ± 4.6
Tumor number:				<0.001
Single	1235 (79.9%)	718 (86.8%)	517 (71.9%)		334 (74.7%)	164 (67.8%)	19 (63.3%)
Multiple	311 (20.1%)	109 (13.2%)	202 (28.1%)		113 (25.3%)	78 (32.2%)	11 (36.7%)
Portal invasion:				<0.001
No	1396 (90.3%)	819 (99.0%)	577 (80.3%)		403 (90.2%)	159 (65.7%)	15 (50.0%)
Yes	150 (9.7%)	8 (1.0%)	142 (19.7%)		44 (9.8%)	83 (34.3%)	15 (50.0%)
Extrahepatic metastasis:				<0.001
No	1508 (97.5%)	820 (99.2%)	688 (95.7%)		430 (96.2%)	234 (96.7%)	24 (80.0%)
Yes	38 (2.5%)	7 (0.8%)	31 (4.3%)		17 (3.8%)	8 (3.3%)	6 (20.0%)
Tumor grading:				<0.001
I–II	224 (14.5%)	191 (23.1%)	33 (4.6%)		28 (6.3%)	4 (1.7%)	1 (3.3%)
III–IV	1322 (85.5%)	636 (76.9%)	686 (95.4%)		419 (93.7%)	238 (98.3%)	29 (96.7%)
Tumor capsule:				<0.001
Intact	245 (15.8%)	211 (25.5%)	34 (4.6%)		28 (6.3%)	5 (2.1%)	1 (3.3%)
Incomplete	1301 (84.2%)	616 (74.5%)	685 (95.4%)		419 (93.7%)	237 (97.9%)	29 (96.7%)
Liver cirrhosis:				0.288
No	1196 (77.4%)	649 (78.5%)	547 (76.1%)		340 (76.1%)	184 (76.0%)	23 (76.7%)
yes	350 (22.6%)	178 (21.5%)	172 (23.9%)		107 (23.9%)	58 (24.0%)	7 (23.3%)
BCLC:				<0.001
0	137 (8.9%)	101 (12.2%)	36 (5.0%)		33 (7.4%)	3 (1.2%)	0 (0.0%)
A	1025 (66.3%)	625 (75.6%)	400 (55.6%)		284 (63.5%)	107 (44.2%)	9 (30.0%)
B	208 (13.5%)	87 (10.5%)	121 (16.8%)		73 (16.3%)	44 (18.2%)	4 (13.3%)
C	176 (11.4%)	14 (1.69%)	162 (22.5%)		57 (12.8%)	88 (36.4%)	17 (56.7%)
TNM:				<0.001
I	744 (48.1%)	708 (85.6%)	36 (5.0%)		33 (7.4%)	3 (1.2%)	0 (0.0%)
II	486 (31.4%)	48 (5.8%)	438 (60.9%)		311 (69.6%)	118 (48.8%)	9 (30.0%)
III	301 (19.5%)	68 (8.2%)	233 (32.4%)		95 (21.3%)	117 (48.3%)	21 (70.0%)
IV	15 (1.0%)	3 (0.4%)	12 (1.7%)		8 (1.8%)	4 (1.7%)	0 (0.0%)

Abbreviations: TBIL, total bilirubin; DBIL, direct bilirubin; IBIL, indirect bilirubin; TBA, total biliary acid; TP, total protein; ALB, albumin; GLB, globulin; PA, prealbumin; ALT, alanine amino transferase; AST, aspartate amino transferase; GGT, γ-glutamyl transpeptidase; ALP, alkaline phosphatase; LDH, lactate dehydrogenase; BUN, blood urea nitrogen; SCR, serum creatinine; PT, prothrombin time; INR, international normalized ratio; TT, thrombin time; Fbg, fibrinogen; WBC, white blood cell; Lym, lymphocyte; Mono, monocyte; Neut, neutrophil; EOS, eosinophil; BASO, basophil; RBC, red blood cell; PCV, packed cell volume; MCV, mean corpuscular volume; MCH, mean corpuscular hemoglobin; MCHC, mean corpuscular hemoglobin concentration; RDW, red blood cell volume distribution width; PLT, platelet; MPV, mean platelet volume; PCT, thrombocytocrit; PDW, platelet distribution width; AFP, alpha fetoprotein; CEA, carcinoembryonic antigen; CA199, carbohydrate antigen 199; HBsAg, hepatitis B surface antigen; HBsAb, hepatitis B surface antibody; HBeAg, hepatitis B e antigen; HBeAb, hepatitis B e antibody; HBcAb, hepatitis B core antibody; HBV DNA, hepatitis B virus deoxyribonucleic acid; HCV, hepatitis C virus; BCLC, Barcelona Clinic Liver Cancer; TNM, Tumor-Node-Metastasis.

Figure 2 Survival analysis of HCC patients based on the MVI grading system. (A) RFS; (B) OS; (C) Early RFS; (D) Late RFS.

Figure 3 Survival analysis of HCC patients with different amounts of proximal MVI in the M2b group. (A) RFS; (B). OS.

Figure 4 Multivariate Cox regression analysis of prognosis and forest plots. (A) RFS; (B); OS; (C) early RFS; (D) late RFS.

Abbreviations: HR, hazard ratio; CI, confidence interval; PA, prealbumin; LDH, lactate dehydrogenase; Lym, lymphocyte; HBsAg, hepatitis B surface antigen; MVI, microvascular invasion; GGT, γ-glutamyl transpeptidase; PT, prothrombin time; RBC, red blood cell; AFP, alpha fetoprotein; PCT, thrombocytocrit; HBV DNA, hepatitis B virus deoxyribonucleic acid.

Table 2 Multivariate Logistic Analysis for the Related Factors of MVI

Characteristics	B	SE	P value	OR	95% CI
PLT, ×10^9/L	0.002	0.001	0.031	1.002	1.000–1.004
AFP, μg/L	0.001	0.000	<0.001	1.001	1.000–1.001
HBeAg, yes	0.356	0.134	0.008	1.428	1.098–1.859
Ultrasonic tumor boundary, unclear	0.477	0.119	<0.001	1.611	1.274–2.035
Tumor size, cm	0.052	0.016	0.001	1.054	1.021–1.088
Tumor number, multiple	0.607	0.149	<0.001	1.836	1.370–2.459
Portal invasion, yes	2.732	0.377	<0.001	15.363	7.343–32.143

Abbreviations: MVI, microvascular invasion; PLT, platelet; AFP, alpha fetoprotein; HBeAg, hepatitis B e antigen.

Figure 5 Two kinds of occurrence patterns of distal MVI. (A) Pattern I: the push-out mode. An evolving tumor gradually invades into multifocal vascular wall and spreads from close to distant parts from the tumor boundary. (B) Pattern II: the rush-out mode. A cluster of highly metastatic tumor cells firstly break into a blood vessel within or near the tumor, thus directly causing a distal dissemination of MVI from a sporadic proximal MVI. Arrow: distal MVI; Dotted line: 1 cm from tumor boundary.