LeClair Karissa, Bell Katy J L, Furuya-Kanamori Luis, Doi Suhail A, Francis David O, Davies Louise
Geisel School of Medicine at Dartmouth, Hanover, New Hampshire.
Faculty of Medicine and Health, Sydney School of Public Health, The University of Sydney, New South Wales, Australia.
JAMA Intern Med. 2021 Oct 1;181(10):1351-1358. doi: 10.1001/jamainternmed.2021.4804.
Thyroid cancer is more common in women than in men, but the associated causes of these differences are not fully understood.
To compare sex-specific thyroid cancer rates in the US to the prevalence of subclinical thyroid cancer at autopsy.
Data on thyroid cancer incidence and mortality by sex among US adults (≥18 years) were extracted from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program (SEER) data for 1975 to 2017. Embase, PubMed, and Web of Science databases were searched for studies on the prevalence of subclinical thyroid cancer at autopsy of men and women, from inception to May 31, 2021.
The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was used to perform a systematic search for articles reporting the prevalence of subclinical thyroid cancer in autopsy results of both women and men. Of 101 studies identified, 8 studies containing 12 data sets met inclusion criteria; ie, they examined the whole thyroid gland, stated the number of thyroids examined, and reported results by sex. Excluded studies reported thyroid cancer in Japan after the atomic bombs or Chernobyl after the nuclear disaster; did not examine the whole thyroid gland or had incomplete information on thyroid examination methods; or did not report rates by sex.
Thyroid cancer incidence and mortality data by sex, histologic type, and tumor size were extracted from SEER. The inverse variance heterogeneity model was used to meta-analyze the prevalence and the odds ratio of subclinical thyroid cancer by sex from 8 studies (12 data sets) on thyroid cancer prevalence in autopsy results.
Incidence and mortality of thyroid cancer, by histologic type and tumor size; prevalence of thyroid cancer in autopsy results.
In 2017, 90% of thyroid cancers diagnosed were papillary thyroid cancer (PTC) and in 2013 to 2017, the women to men incidence ratio for small (≤2 cm) PTC was 4.39:1. The incidence ratio approached 1:1 as cancer type lethality increased. The ratio of thyroid cancer mortality by gender was 1.02:1 and remained stable from 1992 to 2017. Results of the meta-analysis showed that the pooled autopsy prevalence of subclinical PTC was 14% in women (95% CI, 8%-20%) and 11% in men (95% CI, 5%-18%). The pooled odds ratio of subclinical PTC in women compared with men was 1.07 (95% CI, 0.80-1.42).
This cohort study and meta-analysis found that the belief that women get thyroid cancer more often than men is an oversimplification. The gender disparity is mostly confined to the detection of small subclinical PTCs, which are equally common in both sexes at autopsy but identified during life much more often in women than men. As the lethality of the cancer type increases, the ratio of detection by gender approaches 1:1. This phenomenon may be associated with gender differences in health care utilization and patterns of clinical thinking and can harm both women, who are subject to overdetection, and men, who may be at risk of underdetection.
甲状腺癌在女性中比在男性中更为常见，但这些差异的相关原因尚未完全了解。
比较美国不同性别的甲状腺癌发病率与尸检时亚临床甲状腺癌的患病率。
从美国国家癌症研究所的监测、流行病学和最终结果计划（SEER）1975年至2017年的数据中提取美国成年人（≥18岁）按性别划分的甲状腺癌发病率和死亡率数据。检索了Embase、PubMed和Web of Science数据库，以查找从数据库建立至2021年5月31日关于男性和女性尸检中亚临床甲状腺癌患病率的研究。
采用系统评价和Meta分析的首选报告项目（PRISMA）报告指南对报告了男性和女性尸检结果中亚临床甲状腺癌患病率的文章进行系统检索。在检索到的101项研究中，8项研究包含12个数据集符合纳入标准；即，这些研究检查了整个甲状腺，说明了检查的甲状腺数量，并按性别报告了结果。排除的研究报告的是原子弹爆炸后的日本或核灾难后的切尔诺贝利的甲状腺癌；未检查整个甲状腺或甲状腺检查方法信息不完整；或未按性别报告发病率。
从SEER中提取按性别、组织学类型和肿瘤大小划分的甲状腺癌发病率和死亡率数据。采用逆方差异质性模型对8项关于尸检结果中甲状腺癌患病率的研究（12个数据集）按性别进行亚临床甲状腺癌患病率和比值比的Meta分析。
按组织学类型和肿瘤大小划分的甲状腺癌发病率和死亡率；尸检结果中甲状腺癌的患病率。
2017年，90%被诊断出的甲状腺癌为乳头状甲状腺癌（PTC），在2013年至2017年期间，小型（≤2 cm）PTC的女性与男性发病率之比为4.39:1。随着癌症类型致死率的增加，发病率之比接近1:1。按性别划分的甲状腺癌死亡率之比为1.02:1，在1992年至2017年期间保持稳定。Meta分析结果显示，亚临床PTC的汇总尸检患病率在女性中为14%（95%CI，8%-20%），在男性中为11%（95%CI，5%-18%）。女性与男性亚临床PTC的汇总比值比为1.07（95%CI，0.80-1.42）。
这项队列研究和Meta分析发现，认为女性比男性更容易患甲状腺癌的观点过于简单化。性别差异主要局限于小型亚临床PTC的检出，这些在尸检中两性同样常见，但在生前女性比男性更常被发现。随着癌症类型致死率的增加，按性别划分的检出率之比接近1:1。这种现象可能与医疗保健利用以及临床思维模式的性别差异有关，可能对受到过度检测的女性和可能存在检测不足风险的男性都造成伤害。
