TABLE 1.
Patient characteristics
| Total number of patients | 568 |
| Main factor leading to detection | |
| Before/after treatment of esophageal cancer | 366 (64.4%) |
| Before/after treatment of head and neck cancer | 83 (14.6%) |
| Medical checkups | 55 (9.7%) |
| Pharyngolaryngeal paresthesia | 49 (8.6%) |
| Before/after treatment of gastric cancer | 15 (2.6%) |
| Age, median (range) | 66 (33–89) |
| Sex (male) | 534 (94.0%) |
| Performance status (0/1/2/3/4) |
539 (94.9%) / 22 (3.9%) / 6 (1.1%) / 1 (0.2%) / 0 (0.0%) |
| History of head and neck cancer | |
| Total number of previous head and neck cancers a | 141 |
| Hypopharynx | 43 (30.5%) |
| Oral cavity | 38 (27.0%) |
| Larynx | 31 (22.0%) |
| Oropharynx | 25 (17.7%) |
| Primary unknown | 2 (1.4%) |
| Maxilla | 2 (1.4%) |
| History of cancer in other organ | |
| Total number of previous cancers a | 531 |
| Esophageal cancer | 416 (78.3%) |
| Gastric cancer | 74 (13.9%) |
| Colorectal cancer | 12 (2.3%) |
| Prostate cancer | 9 (1.7%) |
| Lung cancer | 5 (0.9%) |
| Liver cancer | 3 (0.6%) |
| Breast cancer | 2 (0.4%) |
| Skin cancer | 2 (0.4%) |
| Bladder cancer | 2 (0.4%) |
| Malignant lymphoma | 2 (0.4%) |
| Bile‐duct cancer | 1 (0.2%) |
| Thyroid cancer | 1 (0.2%) |
| Duodenal cancer | 1 (0.2%) |
| Anal canal cancer | 1 (0.2%) |
a
Including overlapping patients.