Table 1. Baseline demographics and clinical characteristics of patients.
| Characteristic | All patients | Training cohort | Validation cohort | |||
|---|---|---|---|---|---|---|
| n = 2752 | n = 2477 | n = 275 | ||||
| No. | % | No. | % | No. | % | |
| Categorical variables | ||||||
| Gender | ||||||
| Female | 569 | 20.7 | 503 | 20.3 | 66 | 24.0 |
| Male | 2183 | 79.3 | 1974 | 79.7 | 209 | 76.0 |
| Race | ||||||
| White | 2019 | 73.4 | 1820 | 73.5 | 199 | 72.4 |
| Black | 617 | 22.4 | 547 | 22.1 | 70 | 25.5 |
| Other1 | 116 | 4.2 | 110 | 4.4 | 6 | 2.2 |
| Marital status | ||||||
| Married | 1380 | 50.1 | 1254 | 50.6 | 126 | 45.8 |
| Unmarried2 | 1372 | 49.9 | 1223 | 49.4 | 149 | 54.2 |
| Grade | ||||||
| Well differentiated | 257 | 9.3 | 237 | 9.6 | 20 | 7.3 |
| Moderately differentiated | 1568 | 57.0 | 1426 | 57.6 | 142 | 51.6 |
| Poorly differentiated | 888 | 32.3 | 794 | 32.1 | 94 | 34.2 |
| Undifferentiated | 39 | 1.4 | 20 | 0.8 | 19 | 6.9 |
| Site | ||||||
| Glottis | 855 | 31.1 | 773 | 31.2 | 82 | 29.8 |
| Supraglottis | 1576 | 57.3 | 1418 | 57.2 | 158 | 57.5 |
| Subglottis | 93 | 3.4 | 84 | 3.4 | 9 | 3.3 |
| Overlapping lesion | 228 | 8.3 | 202 | 8.2 | 26 | 9.5 |
| Cancer-directed surgery | ||||||
| No cancer-directed surgery | 85 | 3.1 | 70 | 2.8 | 15 | 5.5 |
| Local excision/destruction3 | 459 | 16.7 | 403 | 16.3 | 56 | 20.4 |
| Total/Radical laryngectomy | 2208 | 80.2 | 2004 | 80.9 | 204 | 74.2 |
| Radiotherapy | ||||||
| No radiotherapy | 838 | 30.5 | 751 | 30.3 | 87 | 31.6 |
| Receive radiotherapy | 1914 | 69.5 | 1726 | 69.7 | 188 | 68.4 |
| AJCC T status | ||||||
| T1 | 322 | 11.7 | 288 | 11.6 | 34 | 12.4 |
| T2 | 755 | 27.4 | 700 | 28.3 | 55 | 20.0 |
| T3 | 404 | 14.7 | 346 | 14.0 | 58 | 21.1 |
| T4a | 1175 | 42.7 | 1049 | 42.3 | 126 | 45.8 |
| T4b | 98 | 3.6 | 94 | 3.8 | 4 | 1.5 |
| AJCC N status | ||||||
| N0 | 1300 | 47.2 | 1165 | 47.0 | 135 | 49.1 |
| N1 | 420 | 15.3 | 372 | 15.0 | 48 | 17.5 |
| N2a | 119 | 4.3 | 108 | 4.4 | 11 | 4.0 |
| N2b | 573 | 20.8 | 534 | 21.6 | 39 | 14.2 |
| N2c | 292 | 10.6 | 255 | 10.3 | 37 | 13.5 |
| N3 | 48 | 1.7 | 43 | 1.7 | 5 | 1.8 |
| AJCC M status | ||||||
| M0 | 2691 | 97.8 | 2424 | 97.9 | 267 | 97.1 |
| M1 | 61 | 2.2 | 53 | 2.1 | 8 | 2.9 |
| Continuous variables | ||||||
| Age at diagnosis | ||||||
| Median (Range) | 60 (24–96) | 60 (24–96) | 60 (25–85) | |||
| Tumor size (cm) | ||||||
| Median (Range) | 3.0 (0.1–23.0) | 3.0 (0.1–23.0) | 3.1 (0.2–10.0) | |||
| Number of LN examined | ||||||
| Median (Range) | 25 (1–89) | 25 (1–89) | 27 (1–89) | |||
| Number of positive LNs | ||||||
| Median (Range) | 1 (0–58) | 1 (0–58) | 1 (0–17) | |||
| Lymph node ratio | ||||||
| Median (Range) | 0.019 (0–1) | 0.019 (0–1) | 0.017 (0–1) | |||
1Including American Indian/Alaska Native, Asian/Pacific Islander.
2Including patients who are never married, divorced, separated or widowed.
3Local destruction includes photodynamic therapy, electrocautery, cryosurgery, laser ablation, etc.
SEER 1988–2008.