1.
Patients’ baseline characteristics (N=28)
| Characteristics | n (%) |
| PD-1, programmed cell death 1; CR, complete response; PR, partial response; SD, stable disease; PD, progressive disease; CNS, central nervous system; VEGFR, vascular endothelial growth factor receptor; TKI, tyrosine kinase inhibitor; *, at salvage chemotherapy after PD-1 blockade. | |
| Age* [median (range)] (year) | 62 (38−69) |
| Gender | |
| Male | 27 (96.4) |
| Female | 1 (3.6) |
| Histologic grade at the time of diagnosis | |
| G1 | 3 (10.7) |
| G2 | 12 (42.9) |
| G3 | 9 (32.1) |
| GX | 4 (14.3) |
| Esophagectomy before systemic therapy | |
| Yes | 12 (42.9) |
| No | 16 (57.1) |
| Radiotherapy before PD-1 blockade | |
| Yes | 19 (67.9) |
| No | 9 (32.1) |
| Number of previous lines of systemic therapy before PD-1 blockade | |
| 1 | 20 (71.4) |
| 2 | 6 (21.4) |
| >2 | 2 (7.1) |
| Best response of PD-1 blockade | |
| CR | 1 (3.6) |
| PR | 7 (25.0) |
| SD | 8 (28.6) |
| PD | 12 (42.9) |
| Irinotecan-based chemotherapy before PD-1 blockade | |
| Yes | 4 (14.3) |
| No | 24 (85.7) |
| Staging at initiation of salvage chemotherapy | |
| III | 1 (3.6) |
| IV | 27 (96.4) |
| Site of metastasis at initiation of salvage chemotherapy | |
| Distant lymph node | 21 (75.0) |
| Liver | 4 (14.3) |
| Lung | 10 (35.7) |
| Bone | 4 (14.3) |
| Adrenal gland | 2 (7.1) |
| Pleura | 2 (7.1) |
| CNS | 2 (7.1) |
| Regimen of salvage chemotherapy | |
| Single agent irinotecan | 3 (10.7) |
| FOLFIRI, or irinotecan with S-1 or capecitabine | 19 (67.9) |
| Irinotecan with raltitrexed | 2 (7.1) |
| Irinotecan with a VEGFR2 TKI | 3 (10.7) |
| Irinotecan with S-1 and a VEGFR2 TKI | 1 (3.6) |