甲状腺功能亢进症的治疗会增加癌症死亡风险 Treatment of hyperthyroidism raises cancer death risk

评论：这是一项很好的研究，可以帮助消费者了解辐射风险。 医疗辐射和现在的手机辐射可以导致癌症并增加癌症死亡的风险。 医疗辐射的风险是众所周知的。 继续使用这种有害辐射的原因是医学界声称它的好处超过了它的风险。 但患者需要学会聪明。 手机或其他无线设备/设备的辐射风险对很多人来说都是新的。

美国国立卫生研究院的研究发现甲状腺功能亢进常见治疗后癌症死亡的风险会增加

接受放射性碘（RAI）治疗甲状腺功能亢进症患者的研究结果表明，治疗剂量与包括乳腺癌在内的实体癌症的长期死亡风险之间存在关联。该研究由国家癌症研究所（NCI）的研究人员领导，该研究是美国国立卫生研究院的一部分，于2019年7月1日在JAMA Internal Medicine上发表。

“我们发现这种广泛使用的治疗方法与包括乳腺癌在内的实体癌死亡的长期死亡风险之间存在明显的剂量 – 反应关系，这是迄今为止治疗甲亢患者的最大队列研究，”Cari Kitahara博士说。该研究的主要作者，NCI的癌症流行病学和遗传学部门。 “我们估计，目前使用标准剂量范围治疗的每1000名患者中，由于辐射照射，将会发生约20至30次额外的实体癌症死亡。”

RAI自20世纪40年代以来在美国被广泛用于治疗甲状腺功能亢进症，是甲状腺功能亢进的三种常用治疗方法之一。另外两种是抗甲状腺药物，它们越来越受欢迎，手术治疗也是最少使用的。

这项新发现来自于一项针对甲状腺功能亢进症患者（主要是格雷夫斯病）的长期随访研究，他们在1946年至1964年期间接受了放射治疗，即合作性甲状腺毒症治疗随访研究。在新的分析中 – 研究人员使用了一种新颖，全面的方法来估计每个器官或组织的辐射剂量，其中包括来自原始队列的近19,000人，他们都曾接受过RAI，并且没有人患有癌症。大部分辐射被甲状腺吸收，但其他器官如乳房和胃也在治疗期间暴露。

研究人员观察到器官吸收的剂量与该部位癌症死亡率之间存在正相关的剂量 – 反应关系。这种关系对于女性乳腺癌具有统计学意义，其中每100毫克（mGy）的剂量导致乳腺癌死亡率的相对风险增加12％，并且对于所有其他一起考虑的实体肿瘤，其相对死亡风险增加每100 mGy减少5％。

根据这些研究结果，研究人员估计，每1000名患有甲状腺功能亢进症的40名患者接受目前治疗典型的放射剂量治疗，预计终生超过19至32名可归因于固体癌的死亡患者。

据研究人员称，在美国，大约1.2％的人口患有甲状腺功能亢进症，女性患病的可能性要大于男性。 Kitahara博士说，因此，乳腺癌死亡率的发现与大量接受甲状腺功能亢进症治疗的女性特别相关。

她说：“我们发现整体实体癌和乳腺癌死亡的风险增加更为明显，但RAI仍然是治疗甲状腺功能亢进的广泛药物。” “对于患者及其医生来说，讨论每种可用治疗方案的风险和益处非常重要。我们的研究结果可能有助于这些讨论。“

研究人员写道，需要进一步的研究来更全面地评估辐射的风险 – 效益比与甲状腺功能亢进的其他可用治疗方案。此外，由于原始队列中给予患者的抗甲状腺药物类型与最近开出的药物不同，研究人员写道，需要更多的研究来评估目前抗甲状腺药物的长期健康影响，包括对比到RAI治疗。

Comment: This is a good study that helps consumers understand the risk of radiation. Medical radiation and now the cell phone radiation can cause cancer and increase risk of cancer death. The risk of medical radiation is well known. The reason for continued use of this harmful radiation is that the medical circle claims that its benefits over-weigh its risks. But patients need to learn to be smart. The radiation risk of cell phone or other wireless devices/equipment is new to many people.

NIH study finds long-term increased risk of cancer death following common treatment for hyperthyroidism

Findings from a study of patients who received radioactive iodine (RAI) treatment for hyperthyroidism show an association between the dose of treatment and long-term risk of death from solid cancers, including breast cancer. The study, led by researchers at the National Cancer Institute (NCI), part of the National Institutes of Health, was published July 1, 2019 in JAMA Internal Medicine.

“We identified a clear dose–response relationship between this widely used treatment and long-term risk of death from solid cancer, including breast cancer, in the largest cohort study to date of patients treated for hyperthyroidism,” said Cari Kitahara, Ph.D., of NCI’s Division of Cancer Epidemiology and Genetics, lead author of the study . “We estimated that for every 1,000 patients treated currently using a standard range of doses, about 20 to 30 additional solid cancer deaths would occur as a result of the radiation exposure.”

RAI, which has been used widely in the United States for the treatment of hyperthyroidism since the 1940s, is one of three commonly used treatments for hyperthyroidism. The other two are anti-thyroid drugs, which have been rising in popularity, and surgical treatment, which is used least often.

The new findings are from a long-term follow-up study of a large cohort of people with hyperthyroidism (mainly Graves’ disease) who were treated with radiation between 1946 and 1964, the Cooperative Thyrotoxicosis Therapy Follow-up Study. In the new analysis — which included nearly 19,000 people from the original cohort, all of whom had received RAI and none of whom had had cancer at study entry — the researchers used a novel, comprehensive method of estimating radiation doses to each organ or tissue. Most of the radiation is absorbed by the thyroid gland, but other organs like the breast and stomach are also exposed during treatment.

The researchers observed positive dose–response relationships between the dose absorbed by an organ and mortality from cancer at that site. The relationship was statistically significant for female breast cancer, for which every 100 milligray (mGy) of dose led to a 12% increased relative risk of breast cancer mortality, and for all other solid tumors considered together, for which relative risk of mortality was increased by 5% per every 100 mGy.

Based on these findings, the researchers estimated that for every 1,000 patients aged 40 years with hyperthyroidism who were treated with the radiation doses typical of current treatment, a lifetime excess of 19 to 32 radiation-attributable solid cancer deaths would be expected.

According to the researchers, in the United States, about 1.2% of the population has hyperthyroidism, and women are much more likely to develop the condition than men. Therefore, the findings for breast cancer mortality are particularly relevant for the large population of women treated for hyperthyroidism, Dr. Kitahara said.

“We found the increased risks of death from solid cancer overall and from breast cancer more specifically to be modest, but RAI is still a widely used treatment for hyperthyroidism,” she said. “It’s important for patients and their physicians to discuss the risks and benefits of each available treatment option. The results of our study may contribute to these discussions.”

The researchers wrote that additional research is needed to more comprehensively assess the risk–benefit ratio of radiation versus other available treatment options for hyperthyroidism. Furthermore, because the types of anti-thyroid drugs administered to patients in the original cohort were different from those prescribed more recently, the researchers wrote that more studies are needed to evaluate long-term health effects of current anti-thyroid drugs, including in comparison to RAI treatment.

About the National Cancer Institute (NCI): NCI leads the National Cancer Program and NIH’s efforts to dramatically reduce the prevalence of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. For more information about cancer, please visit the NCI website at cancer.gov or call NCI’s contact center, the Cancer Information Service, at 1-800-4-CANCER (1-800-422-6237).

About the National Institutes of Health (NIH): NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.