Cancer and Radiation Group, Center for Research in Epidemiology and Population Health, INSERM U1018, Paris Sud-Paris Saclay University, Gustave Roussy, Villejuif, France.
Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
Endocr Relat Cancer. 2020 Apr;27(4):245-259. doi: 10.1530/ERC-19-0417.
In this study, we aimed to evaluate site-specific cancer risks associated with hyperthyroidism or hypothyroidism. We performed a systematic review of observational studies reporting associations between hyperthyroidism or hypothyroidism and subsequent site-specific cancer incidence, in MEDLINE and the COCHRANE library (inception-28/01/2019) (PROSPERO: CRD42019125094). We excluded studies with thyroid dysfunction evaluated as a cancer biomarker or after prior cancer diagnosis and those considering transient thyroid dysfunction during pregnancy or severe illnesses. Risk of bias was assessed using a modified Newcastle-Ottawa scale. Risk estimates were pooled using random-effects models when ≥5 studies reported data for a specific cancer site. Twenty studies were included, of which 15 contributed to the meta-analysis. Compared to euthyroidism, hyperthyroidism was associated with higher risks of thyroid (pooled risk ratio: 4.49, 95%CI: 2.84-7.12), breast (pooled risk ratio: 1.20, 95%CI: 1.04-1.38), and prostate (pooled risk ratio: 1.35, 95%CI: 1.05-1.74), but not respiratory tract (pooled risk ratio: 1.06, 95%CI: 0.80-1.42) cancers. Hypothyroidism was associated with a higher risk of thyroid cancer within the first 10 years of follow-up only (pooled risk ratio: 3.31, 95%CI: 1.20-9.13). There was no or limited evidence of thyroid dysfunction-related risks of other cancer sites. In conclusion, thyroid dysfunction was associated with increased risks of thyroid, breast, and prostate cancers. However, it remains unclear whether these findings represent causal relationships because information on treatments and potential confounders was frequently lacking.
在这项研究中，我们旨在评估与甲状腺功能亢进或甲状腺功能减退相关的特定部位癌症风险。我们对报告甲状腺功能亢进或甲状腺功能减退与随后特定部位癌症发病率之间关联的观察性研究进行了系统评价，检索了 MEDLINE 和 COCHRANE 图书馆（成立日期-2019 年 1 月 28 日）（PROSPERO：CRD42019125094）。我们排除了将甲状腺功能障碍评估为癌症生物标志物或在癌症诊断后以及考虑怀孕期间或严重疾病期间短暂性甲状腺功能障碍的研究。使用改良的纽卡斯尔-渥太华量表评估偏倚风险。当≥5 项研究报告了特定癌症部位的数据时，使用随机效应模型汇总风险估计值。共有 20 项研究纳入，其中 15 项研究纳入荟萃分析。与甲状腺功能正常相比，甲状腺功能亢进与甲状腺癌（汇总风险比：4.49，95%CI：2.84-7.12）、乳腺癌（汇总风险比：1.20，95%CI：1.04-1.38）和前列腺癌（汇总风险比：1.35，95%CI：1.05-1.74）的风险增加相关，但与呼吸道癌症（汇总风险比：1.06，95%CI：0.80-1.42）无关。只有在前 10 年的随访中，甲状腺功能减退与甲状腺癌风险增加相关（汇总风险比：3.31，95%CI：1.20-9.13）。没有或有限的证据表明甲状腺功能障碍与其他癌症部位的风险相关。总之，甲状腺功能障碍与甲状腺癌、乳腺癌和前列腺癌的风险增加相关。然而，由于治疗和潜在混杂因素的信息经常缺乏，因此这些发现是否代表因果关系仍不清楚。
