Table 1.
Demographic and clinical characteristics of cases and controls
| Characteristic | DTC cases (%) | PTC cases (%) | Controls (%) |
|---|---|---|---|
| n=288 | n=263 | n=591 | |
| Sex | |||
| Male | 95 (33.0) | 83 (31.6)* | 228 (38.6) |
| Female | 193 (67.0) | 180 (68.4) | 363 (61.4) |
| Age, years | |||
| <45 | 155 (53.8)* | 147 (55.9)* | 148 (25.0) |
| ≥45 | 133 (46.2) | 116 (44.1) | 443 (75.0) |
| Ethnicity | |||
| Non-Hispanic Whites | 198 (68.7)* | 181 (68.8)* | 449 (76.0) |
| Other | 90 (31.3) | 82 (31.2) | 142 (24.0) |
| Residence | |||
| Texas | 229 (79.5) | 207 (78.7) | 488 (82.6) |
| Others | 59 (20.5) | 56 (21.3) | 103 (17.4) |
| Educational level | |||
| High school graduate or less | 68 (23.7) | 61 (23.3) | 178 (30.1) |
| Some college | 89 (31.0) | 83 (31.7) | 178 (30.1) |
| College graduate or advanced | 130 (45.3) | 118 (45.0) | 235 (39.8) |
| Family income ($/year) | |||
| Under 35,000 | 64 (23.3)* | 54 (21.3)* | 122 (21.7) |
| 35,000–75,000 | 74 (26.9) | 73 (28.9) | 214 (38.0) |
| Over 75,000 | 137 (49.8) | 126 (49.8) | 227 (40.3) |
| Smoking status | |||
| Never | 193 (67.0) * | 176 (66.9) * | 334 (56.5) |
| Former | 58 (20.1) | 51 (19.4) | 163 (27.6) |
| Current | 37 (12.9) | 36 (13.7) | 94 (15.9) |
| Alcohol drinking status | |||
| Never | 165 (57.3) | 149 (56.6) | 330 (55.9) |
| Former | 25 (8.7) | 21 (8.0) | 80 (13.5) |
| Current | 98 (34.0) | 93 (35.4)* | 181 (30.6) |
| Radiotherapy history | |||
| Yes | 4 (1.4) | 4 (1.5) | 8 (1.4) |
| No | 284 (98.6) | 259 (98.5) | 583 (98.6) |
| Histological type | |||
| Papillary | 263 (91.0) | ||
| Classic PTC | 188 (72.9) | ||
| Follicular variant PTC | 60 (23.2) | ||
| Others | 10 (3.9) | ||
| Follicular/Hurthle cell | 26 (9.0) | ||
| Multifocal primary | |||
| Yes | 100 (35.3) | 97 (37.6) | |
| No | 183 (64.7) | 161 (62.4) | |
| Thyroiditis | |||
| Yes | 63 (22.3) | 57 (22.1) | |
| No | 220 (77.7) | 201 (77.9) | |
*
Chi-square test, P < 0.05 using controls as reference group.