Is Thyroid Cancer Common? What Is Its Incidence Rate?

Here's the translation:

Hey, that's a really great question. With health check-ups becoming more common these days, a lot of people are concerned about this. I also have friends who've been diagnosed with thyroid nodules, so I've made a point to learn about it. I'll try to explain my understanding in plain language.

Summary Up Front: Common, But Don't Panic

Simply put, the incidence rate of thyroid cancer is indeed skyrocketing, especially among women, where it's now among the top cancers diagnosed. Statistically speaking, it absolutely qualifies as a "common cancer."

However! There are two sides to this coin. While the incidence is high, its mortality rate is very low. So, you might often hear about someone having thyroid cancer, but it's rare to hear about serious consequences from it.

Let me break it down for you below.

Why Does It Feel Like More People Around Us Are Getting Thyroid Cancer?

This is mainly due to two reasons:

1. Health checks are too good, especially the widespread use of high-resolution ultrasound.

   • Think of it like this: Before, we might have looked for things with the naked eye. Now, we all have a high-powered magnifying glass (that's the high-definition color ultrasound). Many very tiny "thyroid lumps" (medically called nodules) that might never cause problems in a lifetime are being detected by this "magnifying glass."
   • Among these detected nodules, a small portion are cancerous. So, it's not that the number of people getting sick has suddenly exploded; it's that our ability to detect it has greatly improved. Many of the cancers found are "microcarcinomas," possibly less than 1 cm in diameter.

2. There are indeed some underlying risk factors.

   • While "increased detection" is the main reason, some aspects of modern life, like ionizing radiation (e.g., receiving radiation therapy to the head/neck as a child), unhealthy routines, high stress, etc., might also contribute somewhat to the incidence rate. However, this is far less significant than the first reason.

Is Thyroid Cancer a "Lazy Cancer" or "Happy Cancer"? Is This Accurate?

This idea is widespread and has some truth, but you shouldn't think of it entirely that way.

• Why is it called "Lazy Cancer"? Because the vast majority (over 90%) of thyroid cancers are differentiated thyroid cancers (like papillary carcinoma). These cancer cells grow extremely slowly, like a lazy bug, not keen on "invasion and expansion," nor fond of "traveling" around (metastasizing). Therefore, if caught early and treated properly (usually surgery), the prognosis is excellent, with a 10-year survival rate over 95%. Many people live and work normally after surgery.

• Why shouldn't you be complacent?

  1. "Lazy" doesn't mean "inactive": It's still cancer. If left untreated, it will slowly grow, potentially invading surrounding tissues or spreading to lymph nodes.
  2. There's a small group of "bad actors": A very small number of thyroid cancer types (like anaplastic carcinoma) are extremely aggressive and progress rapidly. So, once a nodule is found, it's crucial to have a professional doctor determine if it's "friendly" or a "bad actor." You can't just assume it's a "lazy cancer" and ignore it.

So What Should We Ordinary People Do?

1. Take check-up results calmly: Finding a thyroid nodule during a check-up is super common! Most nodules are benign. Don't scare yourself. Your first thought should be, "Go see a reliable doctor."
2. Listen to the professionals: The doctor will give you a professional assessment (like the TI-RADS classification) based on the nodule's size, shape, borders, presence of calcification, etc., from the ultrasound report. Most nodules only require regular monitoring (e.g., an ultrasound check once a year). Only if malignancy is highly suspected will the doctor recommend a fine-needle aspiration biopsy for a definitive diagnosis.
3. Maintain a healthy lifestyle: While there's no specific "anti-cancer diet," a balanced diet, regular exercise, managing stress, and avoiding unnecessary radiation exposure are beneficial for overall health, including the thyroid.
4. Don't over-test: For ordinary people without any symptoms or family history, there's no need for constant anxiety or frequent thyroid ultrasounds. Following your doctor's advice or the routine check-up schedule is sufficient.

Hope this information helps. In short: Don't fear it strategically (don't panic), but handle it properly tactically (follow standard procedures).