Shore R E, Hildreth N, Dvoretsky P, Pasternack B, Andresen E
Department of Environmental Medicine, New York University Medical Center, New York 10010-2598.
Radiat Res. 1993 May;134(2):217-23.
Thyroid adenoma incidence in a cohort of 2657 infants given X-ray treatment for a supposedly enlarged thymus gland, along with 4833 unirradiated siblings, has been ascertained for an average of 37 years since irradiation. Estimated thyroid doses ranged from 0.03 to > 8 Gy, with 62% receiving < 0.5 Gy. After excluding 4 adenoma cases with concurrent or previous thyroid cancer, there were 86 cases with pathologically diagnosed thyroid adenomas in the irradiated group and 11 in the sibling controls. The estimated excess relative risk (ERR) was 6.3 per gray (90% CI = 3.7, 11.2). Once the dose group with > or = 6 Gy, which was producing downward curvature in the dose-response function, was removed, the curve was compatible with linearity and the ERR was 7.8 per gray. Thyroid adenoma rates were elevated even at low doses: the lowest dose group (< 0.25 Gy) showed a significant elevation in risk. The relative risk appeared to be constant over time and was comparable for both sexes. Excess adenoma risk was observed in the irradiated group to the maximum follow-up interval of about 50 years. A number of potential risk factors for thyroid adenoma were examined both as risk factors in their own right and as modifiers of the radiogenic risk. Parity and use of hormones in relation to menopause were significantly associated with thyroid adenoma risk in women, while education, Jewish origin, history of hyperthyroidism or hypothyroidism, and family history of cancer were also adenoma risk factors in both sexes. An examination of interactions between possible risk factors and radiation suggested that women with a history of oral contraceptive use or hysterectomy and persons with a family history of cancer may have greater risk (per unit dose) of radiogenic thyroid adenomas than their counterparts.
在一个队列中，2657名因胸腺腺疑似肿大而接受X射线治疗的婴儿，以及4833名未接受照射的同胞兄弟姐妹，自照射后平均37年的甲状腺腺瘤发病率已被确定。估计的甲状腺剂量范围为0.03至>8 Gy，62%的人接受的剂量<0.5 Gy。在排除4例并发或既往患有甲状腺癌的腺瘤病例后，照射组有86例经病理诊断为甲状腺腺瘤，同胞对照组有11例。估计的超额相对危险度（ERR）为每格雷6.3（90%可信区间=3.7，11.2）。一旦去除剂量≥6 Gy的剂量组（该剂量组使剂量反应函数呈向下弯曲），曲线符合线性，ERR为每格雷7.8。即使在低剂量时甲状腺腺瘤发病率也升高：最低剂量组（<0.25 Gy）显示风险显著升高。相对危险度似乎随时间保持恒定，且男女相当。在照射组中观察到腺瘤超额风险直至约50年的最长随访间隔。研究了一些甲状腺腺瘤的潜在危险因素，既作为其自身的危险因素，也作为辐射致癌风险的调节因素。生育状况和绝经相关激素的使用与女性甲状腺腺瘤风险显著相关，而教育程度、犹太血统、甲亢或甲减病史以及癌症家族史在男女中也都是腺瘤危险因素。对可能的危险因素与辐射之间相互作用的研究表明，有口服避孕药使用史或子宫切除术史的女性以及有癌症家族史的人可能比其他人有更高的（每单位剂量）辐射性甲状腺腺瘤风险。
