Risk Assessment of Liver Metastasis in Pancreatic Cancer Patients Using Multiple Models Based on Machine Learning: A Large Population-Based Study
Table 1
Demographic and tumor characteristics of pancreatic cancer patients.
Characteristic
All patients
Training set
Test set
None ()
Liver metastasis ()
None ()
Liver metastasis ()
None ()
Liver metastasis ()
Age at PC diagnosis, no. (%) (years)
20-49
2175 (6.8)
1143 (7.2)
1701 (6.7)
945 (7.4)
474 (7.3)
198 (6.4)
50-69
15,834 (49.5)
8721 (54.8)
12,606 (49.4)
7064 (55.1)
3228 (49.8)
1657 (53.5)
≥70
14,001 (43.7)
6045 (38.0)
11,218 (43.9)
4802 (37.5)
2783 (42.9)
1243 (40.1)
Gender, no. (%)
Female
15,996 (49.9)
7128 (44.8)
12,734 (49.9)
5728 (44.7)
3262 (50.3)
1400 (45.2)
Male
16,014 (50.1)
8781 (55.2)
12,791 (50.1)
7083 (55.3)
3223 (49.7)
1698 (54.8)
Year of PC diagnosis, no. (%)
2010-2013
12,797 (40.0)
6086 (38.3)
10,207 (40.0)
4912 (38.3)
2590 (39.9)
1174 (37.9)
2014-2018
19,213 (60.0)
9823 (61.7)
15,318 (60.0)
7899 (61.7)
3895 (60.1)
1924 (62.1)
Race, no. (%)
White
25,194 (78.7)
12,460 (78.3)
20,079 (78.7)
10,052 (78.5)
5115 (78.9)
2408 (77.7)
Black
3823 (11.9)
2204 (13.9)
3063 (12.0)
1765 (13.8)
760 (11.7)
439 (14.2)
Other
2993 (9.4)
1245 (7.8)
2383 (9.3)
994 (7.8)
610 (9.4)
251 (8.1)
Primary tumor site, no. (%)
Head of the pancreas
20,040 (62.6)
6205 (39.0)
15,925 (62.4)
4951 (38.6)
4115 (63.5)
1254 (40.5)
Body of the pancreas
4177 (13.0)
2859 (18.0)
3399 (13.3)
2341 (18.3)
778 (12.0)
518 (16.7)
Tail of the pancreas
3546 (11.1)
3834 (24.1)
2805 (11.0)
3115 (24.3)
741 (11.4)
719 (23.2)
Overlapping lesion of the pancreas, no. (%)
4247 (13.3)
3011 (18.9)
3396 (13.3)
2404 (18.8)
851 (13.1)
607 (19.6)
AJCC T stage
T1/T2
10,010 (31.3)
7507 (45.3)
8001 (31.3)
5771 (45.0)
2009 (31.0)
1436 (46.4)
T3/T4
22,000 (68.7)
8702 (54.7)
17,524 (68.7)
7040 (55.0)
4476 (69.0)
1662 (53.6)
AJCC N stage, no. (%)
N0
18,803 (58.7)
9803 (61.6)
15,010 (58.8)
7901 (61.7)
3793 (58.5)
1902 (61.4)
N1/N2
13,207 (41.3)
6106 (38.4)
10,515 (41.2)
4910 (38.3)
2692 (41.5)
1196 (38.6)
Tumor histology, no. (%)
Adenocarcinomas
22,944 (71.7)
13,542 (85.1)
18,342 (71.9)
10,874 (84.9)
4602 (71.0)
2668 (86.1)
Other
9066 (28.3)
2367 (14.9)
7183 (28.1)
1937 (15.1)
1883 (29.0)
430 (13.9)
Tumor size, no. (%) (cm)
0-2
3956 (12.4)
839 (5.3)
3177 (12.4)
665 (5.2)
779 (12.0)
174 (5.6)
2-5
17,325 (54.1)
6789 (42.7)
13,779 (54.0)
5475 (42.7)
3546 (54.7)
1314 (42.4)
>5
10,729 (33.5)
8281 (52.1)
8569 (33.6)
6671 (52.1)
2160 (33.3)
1610 (52.0)
Number of nodes examined, no. (%)
None
17,918 (56.0)
14,865 (93.4)
14,332 (56.1)
11,945 (93.2)
3586 (55.3)
2920 (94.3)
One or more
14,092 (44.0)
1044 (6.6)
11,193 (43.9)
866 (6.8)
2899 (44.7)
178 (5.7)
Surgery, no. (%)
No
18,580 (58.0)
15,339 (96.4)
14,821 (58.1)
12,336 (96.3)
3759 (58.0)
3002 (96.9)
Yes
13,430 (42.0)
571 (3.6)
10,704 (41.9)
475 (3.7)
2726 (42.0)
96 (3.1)
Chemotherapy, no. (%)
No
12,164 (38.0)
6576 (41.3)
9744 (38.2)
5272 (41.2)
2420 (37.3)
1302 (42.1)
Yes
19,846 (62.0)
9333 (58.7)
15,781 (61.8)
7539 (58.8)
4065 (62.7)
1794 (57.9)
Radiation, no. (%)
No
24,096 (75.3)
15,174 (95.4)
19,233 (75.3)
12,201 (95.2)
4863 (75.0)
2973 (96.0)
Yes
7914 (24.7)
735 (4.6)
6292 (24.7)
610 (4.8)
1622 (25.0)
125 (4.0)
Note: all of the patients included in this study were randomly divided into independent training and independent testing sets in a ratio of 8 : 2. Abbreviations: AJCC: American Joint Committee on Cancer; PC: pancreatic cancer.
