Table 1.
Median (interquartile range), characteristics of participants and adjusted RRs (95% CIs) for thyroid cancer according to maximum absorbed doses in thyroid glands, as estimated by UNSCEAR
| Lowest quartile | Low middle | High middle | Highest quartile | Total | |
|---|---|---|---|---|---|
| Age 6–14 years | |||||
| Absorbed dose (mGy), range | 14.00–18.81 | 18.82–22.82 | 23.96–28.73 | 31.16–58.0 | |
| No. at risk | 35 175 | 44 555 | 33 387 | 32 390 | 145 507 |
| Sex (female), % | 49.2 | 49.5 | 49.1 | 49.7 | 49.4 |
| Age at NPP accident (years), median (25–75%) | 10 (8–12) | 10 (8–12) | 10 (8–12) | 10 (8–12) | 10 (8–12) |
| Age at baseline thyroid examination (years), median (25–75%) | 14 (12–16) | 14 (12–16) | 13 (11–16) | 14 (12–16) | 14 (12–16) |
| Participants needing confirmatory testing, n (%) | 341 (0.97) | 448 (1.01) | 328 (0.98) | 320 (0.99) | 1437 (0.99) |
| Participants completing confirmatory testing, n (%) | 271 (0.77) | 357 (0.80) | 273 (0.82) | 269 (0.83) | 1170 (0.80) |
| Participants getting FNAC, n (%)a | 20 (7.4) | 45 (12.6) | 44 (16.1) | 31 (11.5) | 140 (12.0) |
| Examination year | |||||
| 2014 (%) | 7645 (21.7) | 38 370 (86.1) | 33 366 (99.9) | 8083 (25.0) | 87 464 (60.1) |
| 2015–17 (%) | 27 530 (78.3) | 6185 (13.9) | 21 (0.1) | 24 307 (75.0) | 58 043 (39.9) |
| Interval from baseline to follow-up examination (years), median (25–75%) | 2.0 (1.9–2.1) | 2.1 (2.0–2.2) | 2.1 (2.1–2.2) | 2.3 (2.1–2.6) | 2.1 (2.0–2.3) |
| No. of cases | 7 | 18 | 9 | 11 | 45 |
| Detection rate per 100 000 person-years | 10.1 | 19.2 | 12.5 | 14.7 | 14.5 |
| Age- and sex-adjusted RR (95% CI) | Ref. | 2.00 (0.84–4.80) | 1.34 (0.50–3.59) | 1.42 (0.55–3.67) | (Trend P = 0.76) |
| Age-, sex- and examination year-adjusted RR (95% CI) | Ref. | 1.42 (0.52–3.86) | 0.90 (0.29–2.77) | 1.41 (0.55–3.64) | (Trend P = 0.89) |
| Age ≥15 years | |||||
| Absorbed dose (mGy), range | 7.88–11.45 | 12.48–15.00 | 15.42–16.30 | 17.35–35.00 | |
| No. at risk | 4599 | 4827 | 4430 | 4936 | 18 792 |
| Sex (female), % | 57.9 | 55.5 | 56.7 | 56.2 | 56.6 |
| Age at NPP accident (years), median (25–75%) | 16 (15–17) | 16 (15–17) | 16 (15–17) | 16 (15–17) | 16 (15–17) |
| Age at baseline thyroid examination (years), median (25–75%) | 21 (20–22) | 20 (19–21) | 20 (19–21) | 21 (20–22) | 20 (19–21) |
| Participants needing confirmatory testing, n (%) | 125 (2.72) | 134 (2.78) | 109 (2.46) | 146 (2.96) | 514 (2.74) |
| Participants completing confirmatory testing, n (%) | 105 (2.28) | 113 (2.34) | 88 (1.99) | 114 (2.31) | 420 (2.23) |
| Participants getting FNAC, n (%)a | 7 (6.7) | 18 (15.9) | 14 (15.9) | 7 (6.1) | 46 (11.0) |
| Examination year | |||||
| 2014 (%) | 1778 (38.7) | 4825 (99.96) | 4426 (99.9) | 1349 (27.3) | 12 378 (65.9) |
| 2015–17 (%) | 2821 (61.3) | 2 (0.04) | 4 (0.1) | 3587 (72.7) | 6414 (34.1) |
| Interval from baseline to follow-up examination (years), median (25–75%) | 2.1 (2.0–2.3) | 2.1 (2.0–2.6) | 2.1 (2.0–2.2) | 2.2 (2.0–2.6) | 2.1 (2.0–2.5) |
| No. of cases | 5 | 12 | 3 | 3 | 23 |
| Detection rate per 100 000 person-years | 51.0 | 108.2 | 30.9 | 26.6 | 54.9 |
| Age- and sex-adjusted RR (95% CI) | Ref. | 1.99 (0.70–5.70) | 0.54 (0.13–2.31) | 0.51 (0.12–2.15) | (Trend P = 0.10) |
| Age-, sex- and examination year-adjusted RR (95% CI) | Ref. | 1.37 (0.43–4.34) | 0.38 (0.08–1.72) | 0.55 (0.13–2.33) | (Trend P = 0.08) |
aParticipants who underwent FNAC/participants who completed confirmatory testing.