Clinicopathological characteristics of patients achieving pathological complete response status
| Characteristic | Training cohort (n=1051) | Validation cohort (n=92) | |
| Patients’ distribution* | Median OS (months) | Patients’ distribution* | |
| Age at diagnosis | |||
| <60 | 371 (35%) | 90.3 | 27 (29%) |
| ≥60 | 680 (65%) | 58.0 | 65 (71%) |
| Sex | |||
| Female | 207 (20%) | 73.9 | 15 (16%) |
| Male | 844 (80%) | 60.9 | 77 (84%) |
| Year of diagnosis | 2012 (2010, 2013) | NA† | 2018 (2017, 2019) |
| Race | |||
| White | 963 (92%) | 67.8 | 0 (0%) |
| Asian | 13 (1.2%) | NR‡ | 92 (100%) |
| Black | 67 (6.4%) | 44.7 | 0 (0%) |
| Other | 8 (0.8%) | NR‡ | 0 (0%) |
| Comorbidity score§ | |||
| 0 | 753 (72%) | 76.4 | 79 (86%) |
| ≥1 | 298 (28%) | 52.8 | 13 (14%) |
| Cancer sequence¶ | |||
| Only malignancy | 857 (82%) | 69.2 | 91 (99%) |
| First malignancy | 50 (4.8%) | 65.3 | 0 (0%) |
| Second or further malignancy | 144 (14%) | 59.4 | 1 (1.1%) |
| Tumour location | |||
| Lower third | 780 (74%) | 69.2 | 33 (36%) |
| Middle third | 143 (14%) | 60.2 | 48 (52%) |
| Upper third | 16 (1.5%) | NR‡ | 11 (12%) |
| Other | 112 (11%) | 53.8 | 0 (0%) |
| Histology | |||
| AC | 663 (63%) | 65.3 | 1 (1.1%) |
| SCC | 293 (28%) | 67.8 | 91 (99%) |
| Other | 95 (9.0%) | 84.3 | 0 (0%) |
| Differentiation grade | |||
| Well differentiated (G1) | 51 (4.9%) | 90.3 | 3 (3.3%) |
| Moderately differentiated (G2) | 371 (35%) | 68.6 | 10 (11%) |
| Poorly differentiated (G3) | 413 (39%) | 54.0 | 13 (14%) |
| Undifferentiated (G4) | 7 (0.7%) | NR‡ | 0 (0%) |
| Unknown (Gx) | 209 (20%) | 110.4 | 66 (72%) |
| Neoadjuvant therapy | |||
| CRT | 875 (83%) | 68.6 | 67 (73%) |
| CT | 110 (10%) | 52.5 | 4 (4.3%) |
| RT | 27 (2.6%) | 69.2 | 0 (0%) |
| IO±other | 9 (0.9%) | 33.2 | 21 (23%) |
| Other | 30 (2.9%) | 40.4 | 0 (0%) |
| Total radiation dose | |||
| 0 Gy | 128 (12%) | 49.6 | 4 (4.3%) |
| 0–40 Gy | 68 (6.5%) | 59.4 | 0 (0%) |
| ≥40 Gy | 855 (81%) | 68.6 | 88 (96%) |
| Pretreatment cT stage | |||
| cT0-1 | 62 (5.9%) | 61.7 | 0 (0%) |
| cT2 | 242 (23%) | 69.2 | 8 (8.7%) |
| cT3 | 706 (67%) | 68.6 | 71 (77%) |
| cT4 | 41 (3.9%) | 35.8 | 13 (14%) |
| Pretreatment cN stage | |||
| cN0 | 415 (39%) | 73.9 | 18 (20%) |
| cN1 | 519 (49%) | 61.7 | 49 (53%) |
| cN2 | 101 (9.6%) | 69.2 | 21 (23%) |
| cN3 | 16 (1.5%) | 26.3 | 4 (4.3%) |
| Pretreatment cM stage | |||
| cM0 | 1023 (97%) | 68.6 | 92 (100%) |
| cM1 | 28 (2.7%) | 35.8 | 0 (0%) |
*Categorical variables were presented as frequency (percentage). Continuous variables were presented as median (IQR) due to non-normal distribution.
†Median OS was not available (NA) for continuous variable.
‡Median OS was not reached (NR) in certain groups due to limited number of events (death).
§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, immune-oncology therapy; NA, not available; NR, not reached; OS, overall survival; RT, radiotherapy; SCC, squamous cell carcinoma.