1

Supplemental Data 1.

Table 1.Comparison of Demographic and Therapeutic Characteristics of IC and Non-IC Groups in High-risk Patients.

Characteristic / Total / Before matching / After propensity score matching
(n = 123), % / IC (n = 66) , % / Non-IC (n = 57), % / P / IC (n = 43) , % / Non-IC (n = 43), % / P
Age (years) / 0.893 / 1.000
< 60 / 51 (41.5) / 27 (40.9) / 24 (42.1) / 17 (39.5) / 17 (39.5)
≥ 60 / 72 (58.5) / 39 (59.1) / 33 (57.9) / 26 (60.5) / 26 (60.5)
Sex / 0.258 / 0.738
Male / 108 (87.8) / 60 (90.9) / 48 (84.2) / 39 (9.3) / 37 (86.0)
Female / 15 (12.2) / 6 (9.1) / 9 (15.8) / 4 (90.7) / 6 (14.0)
Race / 0.110 / 0.265
Caucasian / 112 (91.1) / 63 (95.5) / 49 (86.0) / 41 (95.3) / 37 (86.0)
Others / 11 (8.9) / 3 (4.5) / 8 (14.0) / 2 (4.7) / 6 (14.0)
Smoking history / 0.055 / 0.159
Yes / 88 (71.5) / 52 (78.8) / 36 (63.2) / 33 (76.7) / 27 (62.8)
No / 35 (28.5) / 14 (21.2) / 21 (36.8) / 10 (23.3) / 16 (37.2)
Alcohol history / 0.086 / 0.110
Yes / 85 (69.1) / 50 (75.8) / 35 (61.4) / 32 (74.4) / 25 (58.1)
No / 38 (30.9) / 16 (24.2) / 22 (38.6) / 11 (25.6) / 18 (41.9)
ECOG performance status / 0.549 / 0.825
0 / 51 (41.5) / 29 (43.9) / 22 (38.6) / 17 (39.5) / 16 (37.2)
1–2 / 72 (58.5) / 37 (56.1) / 35 (61.4) / 26 (60.5) / 27 (62.8)
Weight loss / 0.073 / 0.058
< 10% / 101 (82.1) / 58 (87.9) / 43 (75.4) / 38 (88.4) / 31 (72.1)
≥ 10% / 22 (17.9) / 8 (12.1) / 14 (24.6) / 5 (11.6) / 12 (27.9)
Histology / 0.036 / 0.202
Adenocarcinoma / 110 (89.4) / 63 (95.5) / 47 (82.5) / 42 (97.7) / 38 (88.4)
Squamous cell carcinoma / 13 (10.6) / 3 (4.5) / 10 (17.5) / 1 (2.3) / 5 (11.6)
Histologic subtype / 0.540 / 0.149
Signet ring cell / 29 (23.6) / 17 (25.8) / 12 (21.1) / 15 (34.9) / 9 (20.9)
None / 94 (76.4) / 49 (74.2) / 45 (78.9) / 28 (65.1) / 34 (79.1)
Histologic grade / 1.000 / 1.000
Gx/G1/G2 / 2 (1.6) / 1 (1.5) / 1 (1.8) / 1 (2.3) / 1 (2.3)
G3 / 121 (98.4) / 65 (98.5) / 56 (98.2) / 42 (97.7) / 42 (97.7)
Tumor location / 0.030 / 1.000
Upper/middle / 15 (12.2) / 4 (6.1) / 11 (19.3) / 2 (4.7) / 2 (4.7)
Distal/GEJ / 108 (87.8) / 62 (93.9) / 46 (80.7) / 41 (95.3) / 41 (95.3)
Primary tumor length / 0.529 / 0.816
≤ 5 cm / 46 (37.4) / 23 (34.8) / 23 (40.4) / 13 (30.2) / 14 (32.6)
> 5 cm / 77 (62.6) / 43 (65.2) / 34 (59.6) / 30 (69.8) / 29 (67.4)
Non-traversability by endoscopic ultrasound / 0.897 / 0.243
Yes / 21 (17.1) / 11 (16.7) / 10 (17.5) / 9 (20.9) / 5 (11.6)
No / 102 (82.9) / 55 (83.3) / 47 (82.5) / 34 (79.1) / 38 (88.4)
Clinical T stage (7th) / 1.000 / /
T1b-2 / 4 (3.3) / 2 (3.0) / 2 (3.5) / 0 (0.0 / 0 (0.0)
T3-4 / 119 (96.7) / 64 (97.0) / 55 (96.5) / 43 (100.0) / 43 (100.0)
Clinical N stage (7th) / 0.097 / /
N0 / 3 (2.4) / 0 (0.0) / 3 (5.3) / 0 (0.0) / 0 (0.0)
N1-3 / 120 (97.6) / 66 (100.0) / 54 (94.7) / 43 (100.0) / 43 (100.0)
Baseline PET SUVmax / 0.381 / 1.000
< 5.3 / 12 (9.8) / 5 (7.6) / 7 (12.3) / 2 (4.7) / 2 (4.7)
≥ 5.3 / 111 (90.2) / 61 (92.4) / 50 (87.7) / 41 (95.3) / 41 (95.3)
Maximum lymph node diameter (cm) / 0.048 / /
< 1.0 / 7 (5.7) / 1 (1.5) / 6 (10.5) / 0 (0.0) / 0 (0.0)
≥ 1.0 / 116 (94.3) / 65 (98.5) / 51 (89.5) / 43 (100.0) / 43 (100.0)
Celiac lymph node metastases / 0.258 / 0.049
Yes / 15 (12.2) / 6 (9.1) / 9 (15.8) / 2 (4.7) / 9 (20.9)
No / 108 (87.8) / 60 (90.9) / 48 (84.2) / 41 (95.3) / 34 (79.1)
Distant lymph node metastases* / 0.615 / 1.000
Yes / 34 (27.6) / 17 (25.8) / 17 (29.8) / 13 (30.2) / 13 (30.2)
No / 89 (72.4) / 49 (74.2) / 40 (70.2) / 30 (69.8) / 30 (69.8)
Radiotherapy modality / 0.986 / 0.507
3DCRT / 28 (22.8) / 15 (22.7) / 13 (22.8) / 14 (32.6) / 11 (25.6)
IMRT / 72 (58.5) / 39 (59.1) / 33 (57.9) / 26 (60.5) / 26 (60.5)
Proton therapy / 23 (18.7) / 12 (18.2) / 11 (19.3) / 3 (7.0) / 6 (14.0)

Abbreviations: IC, induction chemotherapy; ECOG, Eastern Cooperative Oncology Group; GEJ, gastroesophageal junction; PET, position emission tomography; SUV, standard uptake value; 3DCRT, three-dimensional conformal radiation therapy; IMRT, intensity-modulated radiation therapy.

*For distal esophageal cancer/GEJ: lymph node metastases in upper mediastinum (levels 1-6); Upper/middle esophageal cancer: lymph node metastases in abdomen (left gastric, perigastric, and celiac region).