Patient demographics and baseline characteristics
| Variable* | Patients with advanced OC, n=482 |
| Male | 422 (87.6) |
| Mean age at diagnosis, years (SD) | 63.3 (8.2) |
| ≤60 | 183 (38.0) |
| >60 | 299 (62.0) |
| Smoking status | |
| Current smoker | 120 (24.9) |
| Former smoker† | 127 (26.3) |
| Non-smoker | 185 (38.4) |
| Unknown | 50 (10.4) |
| Alcohol consumption | |
| Alcohol dependent‡ | 80 (16.6) |
| Heavy drinker§ | 44 (9.1) |
| Occasional drinker¶ | 75 (15.6) |
| Abstinent | 224 (46.5) |
| Unknown | 59 (12.2) |
| Family history of OC | |
| Yes | 64 (13.3) |
| No | 307 (63.7) |
| Unknown | 111 (23.0) |
| ECOG PS | |
| 0 | 27 (5.6) |
| 1 | 206 (42.7) |
| 2 | 1 (0.2) |
| 3 | 0 |
| 4 | 4 (0.8) |
| Unknown | 244 (50.6) |
| Clinical stage | |
| III | 226 (47.0) |
| IV | 140 (29.1) |
| Others** | 47 (9.8) |
| Missing†† | 1 (0.2) |
| Unknown§§ | 68 (14.1) |
| Histology | |
| OSCC | 478 (99.4) |
| Siewert type I adenocarcinoma of the OGJ | 1 (0.2) |
| Others¶¶ | 2 (0.4) |
| Missing†† | 1 (0.2) |
*Data are n (%) unless stated.
†‘Former smoker’ is defined as an adult who has smoked at least 100 cigarettes in his or her lifetime but who had quit smoking at the time of interview.54
‡‘Alcohol dependent’, sometimes known as ‘alcoholism’, is defined as the most serious form of drinking problem and describes a strong, often uncontrollable, desire to drink.54
§‘Heavy drinker’ is defined as a person who has frequent episodes of heavy drinking (>5 drinks at a time), which can be defined by sex and periodicity.54
¶‘Occasional drinker’ is defined as an individual who drinks <1 day per week (for instance, once or twice per month) and drinking a maximum of three drinks for men and two for women.54 Binge drinkers were incorporated into the heavy drinker category.
**Other patients with a recorded clinical stage.
††Information missing from the patient’s medical record.
§§Information unknown based on the patient’s medical record.
¶¶Other patients with recorded histology.
ECOG PS, Eastern Co-Operative Oncology Group Performance Score; OC, oesophageal cancer; OGJ, oesophagogastric junction; OSCC, oesophageal squamous cell carcinoma; SD, standard deviation.