Research Article

An External-Validated Prediction Model to Predict Lung Metastasis among Osteosarcoma: A Multicenter Analysis Based on Machine Learning

Table 2

Baseline data for patients presenting with and without lung metastases.

LevelOverall (N = 1201)No (N = 987)Yes (N = 214)

Race (%)Black163 (13.6)132 (13.4)31 (14.5)0.847
Other216 (18.0)176 (17.8)40 (18.7)
White822 (68.4)679 (68.8)143 (66.8)
Age (mean (SD))NA32.98 (24.08)32.83 (23.67)33.69 (25.93)0.637

Sex (%)Female549 (45.7)471 (47.7)78 (36.4)0.003
Male652 (54.3)516 (52.3)136 (63.6)

Primary site (%)Axis bone313 (26.1)263 (26.6)50 (23.4)0.468
Limb bone787 (65.5)639 (64.7)148 (69.2)
Other101 (8.4)85 (8.6)16 (7.5)

Grade (%)Moderately differentiated41 (3.4)36 (3.6)5 (2.3)0.206
Poorly differentiated294 (24.5)236 (23.9)58 (27.1)
Undifferentiated; anaplastic553 (46.0)450 (45.6)103 (48.1)
Unknown286 (23.8)239 (24.2)47 (22.0)
Well differentiated27 (2.2)26 (2.6)1 (0.5)

Laterality (%)Left514 (42.8)425 (43.1)89 (41.6)0.426
Not a paired site161 (13.4)137 (13.9)24 (11.2)
Right526 (43.8)425 (43.1)101 (47.2)

Stage group (%)I198 (16.5)194 (19.7)4 (1.9)<0.001
II562 (46.8)550 (55.7)12 (5.6)
III51 (4.2)50 (5.1)1 (0.5)
IV278 (23.1)83 (8.4)195 (91.1)
UNK stage112 (9.3)110 (11.1)2 (0.9)

T (%)T1420 (35.0)382 (38.7)38 (17.8)<0.001
T2562 (46.8)448 (45.4)114 (53.3)
T340 (3.3)25 (2.5)15 (7.0)
TX179 (14.9)132 (13.4)47 (22.0)

N (%)N01088 (90.6)913 (92.5)175 (81.8)<0.001
N136 (3.0)24 (2.4)12 (5.6)
NX77 (6.4)50 (5.1)27 (12.6)

M (%)M0931 (77.5)911 (92.3)20 (9.3)<0.001
M1270 (22.5)76 (7.7)194 (90.7)

Surgery (%)No225 (18.7)143 (14.5)82 (38.3)<0.001
Yes976 (81.3)844 (85.5)132 (61.7)

Radiation (%)No1054 (87.8)878 (89.0)176 (82.2)0.009
Yes147 (12.2)109 (11.0)38 (17.8)

Chemotherapy (%)No236 (19.7)204 (20.7)32 (15.0)0.07
Yes965 (80.3)783 (79.3)182 (85.0)

Bone metastases (%)No1144 (95.3)965 (97.8)179 (83.6)<0.001
Yes57 (4.7)22 (2.2)35 (16.4)

Category (%)Multicenter data (validation group)107 (8.9)87 (8.8)20 (9.3)0.908
SEER data (training group)1094 (91.1)900 (91.2)194 (90.7)
Times (mean (SD))NA30.32 (22.75)32.96 (22.96)18.13 (17.12)<0.001