Thyroid cancer is besieging more and more young people

Recently, the topic #Why does thyroid cancer like to target young people? # has become a hot search, attracting widespread attention.

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Indeed, the incidence of thyroid cancer has been increasing year by year in recent years, and more and more young people are being diagnosed with thyroid cancer. Why is thyroid cancer increasing? Today, we invite an endocrine expert to talk about it in detail.

Thyroid cancer, why does it target young people?

A study published in The Lancet titled "Epidemiology of thyroid cancer worldwide: GLOBOCAN incidence and mortality estimates to 2020" pointed out that the incidence of thyroid cancer has increased in many countries and regions.

Another global review of thyroid cancer mortality and morbidity also shows that the incidence of thyroid cancer in men and women has shown a clear upward trend in most countries and regions in the world since 1960. If this growth trend continues, thyroid cancer is likely to become the fourth most common cancer in the United States by 2030.

From 1960 to 2007, the overall trend of male thyroid cancer incidence in different countries and regions showed a clear upward trend. Image source: Reference [4]

From 1960 to 2007, the overall trend of the incidence of thyroid cancer in women in different countries and regions showed a clear upward trend. Image source: Reference [4] At the same time, the incidence of thyroid cancer also showed two obvious characteristics:

The incidence rate in women is significantly higher than that in men. In 2020, there were 449,000 newly diagnosed cases of thyroid cancer in women and 137,000 in men. The age-standardized incidence rates for women and men in the global population were 10.1 cases per 100,000 people and 3.1 cases per 100,000 people, respectively.

The incidence of thyroid cancer is higher among young people, especially those aged 20 to 29.

Distribution of major cancer types among adolescents and young adults from 2012 to 2016 (%), Image source: Reference [5]

Why is thyroid cancer increasing, and targeting young people? This may be related to the widespread development of ultrasound and other imaging examinations and the increase in the frequency of examinations. Many studies believe that this increase is likely related to the improvement of disease diagnosis technology. After all, in the past, thyroid nodules could only be felt by hand, and the detection rate was only about 3% to 7%. Now the accuracy of B-ultrasound has been greatly improved, and even small nodules of two or three millimeters can be detected, with a detection rate of more than 70%.

On the other hand, as the economic level improves, most people, especially young people, pay more and more attention to their health, and thyroid ultrasound is often included in the company's or spontaneous physical examinations. The more people do the examination, the more thyroid cancer is detected.

Thyroid cancer mortality rates are steadily declining

Although the incidence of thyroid cancer is increasing year by year worldwide, fortunately, the mortality rate of thyroid cancer has been steadily declining. From this perspective, thyroid cancer can be said to be the "mildest cancer."

From 1970 to 2012, the mortality rate of male thyroid cancer has steadily decreased in different countries and regions. Image source: Reference [4]

From 1970 to 2012, the mortality rate of thyroid cancer in women has steadily decreased in different countries and regions. Image source: Reference [4]

Thyroid cancer is divided into papillary thyroid cancer, follicular thyroid cancer, oncocytic cancer, differentiated high-grade thyroid cancer, poorly differentiated thyroid cancer, anaplastic thyroid cancer and medullary thyroid cancer. They are all malignant tumors originating from thyroid follicular epithelial cells or parafollicular epithelial cells.

Don’t assume the mortality rate is high when you hear the word “malignant tumor”. Although these names all contain the word “cancer”, fortunately most of them are relatively mild and have a good prognosis.

Among thyroid cancers, papillary carcinoma is the most common, accounting for 85% to 90% of all thyroid cancers. It grows slowly, has a low degree of malignancy, and has a 5-year survival rate of up to 97%, so it is also nicknamed "lazy cancer" and "happy cancer." What you need to be careful about is anaplastic thyroid cancer, which is the most "evil" of the brothers.

How to prevent thyroid cancer?

If you want to prevent thyroid cancer, you must first understand the causative factors of thyroid cancer, which mainly include the following four aspects:

1. Ionizing radiation

Ionizing radiation is currently the most clear risk factor for thyroid cancer. The longer the radiation time and the younger the age, the higher the morbidity rate. A follow-up study of more than 100,000 survivors of the atomic bomb explosion found that nuclear radiation increased the risk of thyroid cancer by 1.28 times.

2. Iodine intake

There is currently a great deal of controversy regarding the relationship between iodine and thyroid cancer. Since some countries and regions implemented iodized salt policies, the incidence of thyroid tumors has increased significantly, but the overall incidence of thyroid tumors in my country has remained basically unchanged. Some studies also suggest that consuming more iodine-containing foods in moderation will not induce risk factors for thyroid cancer, and may even play a protective role.

3. History and family history of thyroid disease

If you have thyroid disease, you are more likely to get thyroid cancer later. Many people may have hyperthyroidism, autoimmune thyroiditis, etc. before they develop thyroid cancer. The latter means that if someone in your family has thyroid cancer, the probability of their offspring getting it is higher than others.

4. Psychological and social factors

If the first few points are not common to everyone, then this one is relevant to most of you. Studies have found that people who often feel stressed have a 2.127 times higher risk of thyroid cancer than those who feel less stressed; people who like to sulk have a 3.429 times higher risk of thyroid cancer than those who don’t sulk.

In other words, you must learn to relieve your stress and learn to let yourself go when life is not easy.

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In addition to avoiding the above pathogenic factors, everyone should also pay attention to reasonable exercise and healthy diet in daily life. This can not only relieve physical and mental fatigue, keep a happy mood, but also enhance immunity and stay away from various tumors and chronic diseases.

References

[1]Margherita Pizzato, et al. The epidemiological landscape of thyroid cancer worldwide: GLOBOCAN estimates for incidence and mortality rates in 2020. Lancet Diabetes Endocrinol. 2022 Apr;10(4):264-272.

[2] Hou Zhenjiang, Li Weidong. Pay attention to the risk factors of thyroid cancer, prevent and treat cancer, and improve the health level of the whole people. Medical Review 2020, Vol.26, No.23

[3] Guidelines for the diagnosis and treatment of thyroid nodules and differentiated thyroid cancer (Second Edition). Chinese Journal of Endocrinology and Metabolism. March. Vol. 39. No. 3

[4] La Vecchia C, Malvezzi M, Bosetti C, Garavello W, Bertuccio P, Levi F, Negri E. Thyroid cancer mortality and incidence: a global overview. Int J Cancer. 2015 May 1;136(9):2187-95.

[5]Miller KD, Fidler-Benaoudia M, Keegan TH, Hipp HS, Jemal A, Siegel RL. Cancer statistics for adolescents and young adults, 2020. CA Cancer J Clin. 2020 Nov;70(6):443-459.

Author: Xu Ke, Chief Endocrinologist, First Affiliated Hospital of Wenzhou Medical University

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Reviewer: Tang Qin, Director and Researcher of the Science Popularization Department of the Chinese Medical Association