Table 4.
Associations between cell phone use and risk of well-differentiated thyroid cancer by tumor size
| Tumor size ≤ 10 mm |
Tumor size > 10mm |
|||||
|---|---|---|---|---|---|---|
| Cell phone user | Case | OR (95% CI)a | P for trend | Case | OR (95% CI)a | P for trend |
| No | 46 | 1.00 | 48 | 1.00 | ||
| Yes | 166 | 1.06 (0.68, 1.65) | 179 | 0.98 (0.63, 1.52) | ||
| Hands-free device | ||||||
| Yes | 5 | 1.52 (0.47, 0.95) | 3 | 0.68 (0.16, 2.82) | ||
| No | 161 | 1.05 (0.68, 1.64) | 176 | 0.99 (0.63, 1.54) | ||
| Daily use hour | 0.116 | 0.485 | ||||
| ≤1 hours/day | 59 | 1.07 (0.63, 1.81) | 60 | 1.05 (0.61, 1.79) | ||
| 1–2 hours/day | 25 | 1.51 (0.78, 2.95) | 31 | 1.26 (0.66, 2.41) | ||
| >2 hours/day | 28 | 1.55 (0.80, 3.03) | 30 | 1.19 (0.62, 2.25) | ||
| Daily phone call | 0.257 | 0.802 | ||||
| ≤3 calls/day | 56 | 0.92 (0.55, 1.54) | 61 | 0.97 (0.58, 1.61) | ||
| 3–6 calls/day | 45 | 1.06 (0.61, 1.83) | 52 | 0.83 (0.50, 1.40) | ||
| >6 calls/day | 51 | 1.32 (0.76, 2.31) | 56 | 1.18 (0.63, 2.21) | ||
| Phone use year | 0.259 | 0.951 | ||||
| ≤12 years | 53 | 0.90 (0.53, 1.51) | 71 | 1.03 (0.62, 1.71) | ||
| 12–15 years | 64 | 1.04 (0.62, 1.73) | 62 | 0.85 (0.50, 1.42) | ||
| >15 years | 46 | 1.33 (0.76, 2.32) | 45 | 1.12 (0.64, 1.95) | ||
| Age at first use | 0.503 | 0.685 | ||||
| ≤20 years old | 19 | 0.63 (0.25, 1.56) | 27 | 1.22 (0.51, 2.91) | ||
| 21–50 years old | 117 | 0.96 (0.60, 1.56) | 133 | 1.11 (0.68, 1.79) | ||
| >50 years old | 30 | 1.35 (0.71, 2.56) | 19 | 0.72 (0.36, 1.42) | ||
| Cumulative use hour | 0.062 | 0.518 | ||||
| ≤4,380 hours | 36 | 0.97 (0.54, 1.75) | 46 | 1.14 (0.64, 2.03) | ||
| 4,380–13140 hours | 35 | 1.19 (0.65, 2.17) | 33 | 0.97 (0.53, 1.79) | ||
| >13,140 hours | 40 | 1.75 (0.95, 3.23) | 42 | 1.30 (0.72, 2.34) | ||
| Cumulative phone call | 0.308 | 0.514 | ||||
| ≤10,220 calls | 56 | 1.00 (0.60, 1.68) | 59 | 1.03 (0.61, 1.72) | ||
| 10,220–41,975 calls | 38 | 0.80 (0.45, 1.41) | 58 | 0.93 (0.54, 1.60) | ||
| >41,975 calls | 56 | 1.42 (0.82, 2.46) | 51 | 0.86 (0.49, 1.49) | ||
CI, confidence interval; OR, odds ratio
a
Adjusted for age (continuous), sex (male, female), education (<college, college, >college), family history of thyroid cancer (yes, no), alcohol consumption (yes, no), BMI (<25, 25–29.9, ≥30 kg/m2), previous benign thyroid disease (yes, no), occupational radiation exposure (yes, no), and radiation treatment (yes, no).