Clinicopathological characteristics of non-pathological complete response patients
| Characteristic | Training cohort (n=5466) | Validation cohort (n=352) | ||
| Patients’ distribution* | Median OS (months) | Patients’ distribution* | Median OS (months) | |
| Age at diagnosis | ||||
| <60 | 2034 (37%) | 32.9 | 116 (33%) | 54.0 |
| ≥60 | 3432 (63%) | 29.3 | 236 (67%) | 48.0 |
| Sex | ||||
| Female | 793 (15%) | 37.1 | 50 (14%) | NR† |
| Male | 4673 (85%) | 29.8 | 302 (86%) | 48.0 |
| Year of diagnosis | 2011 (2009, 2013) | NA‡ | 2018 (2017, 2019) | NA‡ |
| Race | ||||
| White | 5207 (95%) | 30.9 | 0 (0%) | / |
| Asian | 69 (1.3%) | 28.9 | 352 (100%) | 51.0 |
| Black | 151 (2.8%) | 25.9 | 0 (0%) | / |
| Other | 39 (0.7%) | 27.4 | 0 (0%) | / |
| Comorbidity score§ | ||||
| 0 | 3987 (73%) | 31.8 | 303 (86%) | 54.0 |
| ≥1 | 1479 (27%) | 27.2 | 49 (14%) | 43.2 |
| Cancer sequence¶ | ||||
| Only malignancy | 4510 (83%) | 30.4 | 344 (98%) | 51.0 |
| First malignancy | 281 (5.1%) | 39.2 | 0 (0%) | / |
| Second or further malignancy | 675 (12%) | 28.8 | 8 (2.3%) | NR† |
| Tumour location | ||||
| Lower third | 4418 (81%) | 31.1 | 107 (30%) | 55.0 |
| Middle third | 402 (7.4%) | 31.6 | 198 (56%) | 48.0 |
| Upper third | 59 (1.1%) | 20.5 | 34 (9.7%) | 50.3 |
| Other | 587 (11%) | 27.6 | 13 (3.7%) | 33.0 |
| Histology | ||||
| AC | 4157 (76%) | 31.2 | 18 (5.1%) | 33.0 |
| SCC | 730 (13%) | 31.7 | 330 (94%) | 51.0 |
| Other | 579 (11%) | 25.7 | 4 (1.1%) | 34.0 |
| Differentiation grade | ||||
| Well differentiated (G1) | 219 (4.0%) | 51.1 | 22 (6.2%) | NR† |
| Moderately differentiated (G2) | 1989 (36%) | 34.9 | 98 (28%) | 47.1 |
| Poorly differentiated (G3) | 2556 (47%) | 26.1 | 116 (33%) | 48.0 |
| Undifferentiated (G4) | 98 (1.8%) | 27.7 | 1 (0.3%) | NR† |
| Unknown (Gx) | 604 (11%) | 34.4 | 115 (33%) | 54.0 |
| Neoadjuvant therapy | ||||
| CRT | 4106 (75%) | 30.6 | 170 (48%) | 48.0 |
| CT | 954 (17%) | 31.1 | 142 (40%) | 50.3 |
| RT | 138 (2.5%) | 30.3 | 5 (1.4%) | 13.0 |
| IO±other | 25 (0.5%) | 37.1 | 35 (9.9%) | NR† |
| Other | 243 (4.4%) | 31.3 | 0 (0%) | / |
| Total radiation dose | ||||
| 0 Gy | 1083 (20%) | 31.2 | 134 (38%) | 50.3 |
| 0–40 Gy | 426 (7.8%) | 25.5 | 2 (0.6%) | NR† |
| ≥40 Gy | 3957 (72%) | 31.4 | 216 (61%) | 51.0 |
| Pretreatment cT stage | ||||
| cT0-1 | 331 (6.1%) | 31.5 | 0 (0%) | / |
| cT2 | 1060 (19%) | 37.1 | 18 (5.1%) | 34.0 |
| cT3 | 3913 (72%) | 29.3 | 263 (75%) | 55.0 |
| cT4 | 162 (3.0%) | 20.6 | 71 (20%) | 43.2 |
| Pretreatment cN stage | ||||
| cN0 | 1931 (35%) | 36.5 | 61 (17%) | 47.1 |
| cN1 | 2960 (54%) | 27.7 | 195 (55%) | 39.0 |
| cN2 | 498 (9.1%) | 31.7 | 85 (24%) | 26.0 |
| cN3 | 77 (1.4%) | 18.4 | 11 (3.1%) | NR† |
| Pretreatment cM stage | ||||
| cM0 | 5272 (96%) | 31.2 | 350 (99%) | 51.0 |
| cM1 | 194 (3.5%) | 20.6 | 2 (0.6%) | 12.5 |
*Categorical variables were presented as frequency (percentage). Continuous variables were presented as median (IQR) due to non-normal distribution.
†Median OS was not reached (NR) in certain groups due to limited number of events (death).
‡Median OS was not available (NA) for continuous variable.
§Calculated by Charlson-Deyo Comorbidity Score but ignoring cancer condition.
¶Indicates the sequence of oesophageal cancer among the malignancies over the lifetime of the patient.
AC, adenocarcinoma; CRT, chemoradiotherapy; CT, chemotherapy; IO, immuno-oncology therapy; LOS, length of stay; NA, not available; NR, not reached; OS, overall survival; RT, radiotherapy; SCC, squamous cell carcinoma.