Fioretti F, Tavani A, Gallus S, Franceschi S, Negri E, La Vecchia C
Istituto di Ricerche Farmacologiche Mario Negri, Milan, Italy.
Int J Epidemiol. 1999 Aug;28(4):626-30. doi: 10.1093/ije/28.4.626.
The percentage of thyroid cancer cases attributable to specific risk factors can be calculated to focus preventive strategies. The per cent population attributable risks (PAR) for thyroid cancer were estimated in relation to history of benign thyroid diseases, history of radiotherapy, residence in endemic goitre areas and selected indicators of a poor diet, using data from a case-control study conducted between 1986 and 1992 in Northern Italy.
Cases were 399 histologically confirmed incident thyroid cancers and controls were 617 patients, admitted to hospital for a wide range of acute, non-neoplastic, non-hormone-related diseases. The PAR were computed on the basis of multivariate odds ratios (OR) and on the distribution of risk exposure among cases, assuming they are representative of the general population of cases.
A history of benign thyroid disease accounted for 18.9% of cases, radiotherapy for 1.2%, residence for > or =20 years in endemic goitre areas for 2.4% of cases, and their combination for 21.7% of thyroid cancer cases; selected indicators of a poor diet accounted for 40.9% of thyroid cancer cases in this population. The combination of all factors considered explained over 57% of thyroid cancer cases in both sexes. The estimates for thyroid-related conditions were higher in women than men, whereas the opposite was true for dietary indicators. The overall PAR were somewhat higher in people aged > or =45 years (63.8%) than in younger subjects, and for follicular (69.1%) rather than papillary (53.7%) cancers.
Exposure to a few simply identified and potentially modifiable risk factors or indicators (benign thyroid disease, residence in endemic goitre area and a poor diet) explained about 60% of thyroid cancer cases in this Italian population, indicating the theoretical scope for prevention.
可计算出归因于特定风险因素的甲状腺癌病例百分比，以聚焦预防策略。利用1986年至1992年在意大利北部进行的一项病例对照研究的数据，估算了与良性甲状腺疾病史、放疗史、居住在地方性甲状腺肿流行区以及不良饮食的选定指标相关的甲状腺癌人群归因风险百分比（PAR）。
病例为399例经组织学确诊的新发甲状腺癌患者，对照为617例因各种急性、非肿瘤性、非激素相关疾病入院的患者。PAR根据多变量优势比（OR）以及病例中风险暴露的分布情况进行计算，假设病例代表了病例的总体人群。
良性甲状腺疾病史占病例的18.9%，放疗史占1.2%，在地方性甲状腺肿流行区居住≥20年占病例的2.4%，它们共同作用占甲状腺癌病例的21.7%；不良饮食的选定指标占该人群甲状腺癌病例的40.9%。所有考虑因素的组合解释了男女甲状腺癌病例的57%以上。与甲状腺相关疾病的估计值女性高于男性，而饮食指标则相反。总体PAR在年龄≥45岁的人群中（63.8%）略高于年轻受试者，在滤泡状癌（69.1%）中高于乳头状癌（53.7%）。
暴露于一些易于识别且可能可改变的风险因素或指标（良性甲状腺疾病、居住在地方性甲状腺肿流行区和不良饮食）解释了该意大利人群中约60%的甲状腺癌病例，表明了预防的理论空间。
