107 Lung nodules found in human body examinations have attracted attention. Is it related to decoration? Will it turn into lung cancer?

Real points:

There is a certain correlation between decoration pollution and lung nodules, but there is no direct causal relationship between the two. Lung nodules can be benign or malignant, and only a small number of lung nodules may turn into lung cancer.

Verifier: Jiao Peng | Deputy Chief Physician of Thoracic Surgery, Beijing Hospital

Recently, the news that more than 100 people in Changshu Rural Commercial Bank were diagnosed with lung nodules has attracted attention. According to the latest news reported by the media: Among the 356 people who completed the physical examination, the Rural Commercial Bank has collected 107 physical examination reports of lung nodules, including 2 people with carcinoma in situ. Is it normal for so many people to be diagnosed with lung nodules? What is the relationship between lung nodules and lung cancer? Do they need emergency treatment? Jiuzhen invited a thoracic surgeon to popularize relevant knowledge.

1. Why are more and more people being diagnosed with lung nodules?

In recent years, with the popularization of health examinations and the development of medical imaging technology, especially the development of large equipment such as CT, the clinical detection rate of small lung nodules has been greatly improved. So what is a lung nodule? Clinically, we are accustomed to calling the round or irregular space-occupying lesions in the lungs with a diameter greater than 5mm and less than or equal to 3cm lung nodules, and those with a diameter less than 5mm micronodules (some radiologists also call lung nodules less than 7mm micronodules). Whether it is a lung nodule or a micronodule, it is a general term for doctors who have not taken measures to further clarify the specific nature of the lesion. In other words, lung nodules may be of any nature, either benign or malignant.

How high is the detection rate of lung nodules? The clinical practice guidelines of the American College of Chest Physicians summarize eight large studies. Due to different definitions of nodule conditions (such as the minimum diameter), the detection rate of lung nodules in the study population was found to be about 8% to 51%, and the proportion of lung cancer in these patients with nodules was 1.1% to 12%. Among the 53,202 physical examination populations in my country, the detection rate of lung nodules was 67.31%, and the incidence of lung cancer was 0.22%. The nodule detection rate in the group aged over 55 was as high as 81.23%, and the incidence of lung cancer was as high as 0.33%.

The different detection rates of the above nodules are mainly due to the different definitions of nodules by researchers or radiologists. For example, some doctors may not make specific reports or records for micronodules with very small diameters, while some doctors may describe and report all micronodules one by one. Especially now that medical imaging reports are included in artificial intelligence reports, the detection rate may be greatly increased. Therefore, when normal people undergo chest CT scans, the detection rate of lung nodules is very high. If diagnosed by different radiologists in different hospitals, the detection rate will also be different. It is debatable whether to call it "mass lung nodules" because of the high detection rate. It is necessary to comprehensively evaluate the number of people participating in the examination, the detection rate, and re-examinations by other medical institutions.

2. What causes lung nodules?

The incidence of lung nodules or lung micronodules is very high, but it is not entirely clear what factors may cause lung nodules. Currently, a relatively clear cause is smoking, because smoking is a clear pathogenic factor of lung cancer, and the early imaging manifestation of lung cancer is lung nodules, so smoking is a relatively clear cause of lung nodules. Other factors such as radiation (long-term, large-scale exposure), chronic lung infections, genetics, industrial waste gas, arsenic, asbestos, chromium compounds, etc. are considered to be possible pathogenic factors of lung cancer, so they are also possible pathogenic factors of lung nodules.

As for the question of whether indoor decoration can cause lung nodules, it is known that the six pollutants detected by the "new national standard", namely radon, benzene, ammonia, TVOC, toluene, and xylene, are likely to increase the risk of malignant tumors and have a certain correlation with the occurrence of lung nodules, but whether it constitutes a direct causal relationship, there is no clear clinical research or relevant data to support it. The news mentioned that two employees of the bank were diagnosed with lung cancer during physical examinations, and from the current information, it is difficult to directly link it with the office environment. However, it is still recommended that everyone try to avoid long-term work and life in an environment with obvious decoration pollution.

3. Will lung nodules turn into lung cancer?

Lung nodules can be benign or malignant. The so-called malignant nodules are generally what we usually call lung cancer. Usually, lung nodules can be divided into solid nodules, partially solid nodules, and ground glass nodules. Among them, partially solid nodules have the highest probability of malignancy, followed by ground glass density nodules and solid nodules.

It can also be seen from the above classification that a small number of lung nodules may turn into lung cancer, because some lung nodules are actually precancerous lesions. Lung cancer comes from normal alveolar epithelium or bronchial epithelium. First of all, these epithelia have atypical hyperplasia due to various reasons, ranging from mild atypical hyperplasia to moderate and severe atypical hyperplasia. Severe atypical hyperplasia is actually a precancerous lesion. If it gets worse, it will become carcinoma in situ. If carcinoma in situ continues to develop, it will begin to grow invasively, from the initial microinvasive carcinoma to invasive lung cancer. This whole process usually takes from two to three years to more than ten or even twenty years.

4. What should I do if lung nodules are detected during a physical examination?

Generally speaking, if it is a micronodule, no treatment is needed for the time being. Based on all current guidelines and expert consensus, micronodules do not require any treatment or prevention, only regular check-ups are needed, and the specific check-up time is also determined according to the patient's specific situation.

If it is a pure ground glass nodule, there is no need to worry too much. Even if this lesion is lung cancer, it grows very slowly and may not change much for several years. Moreover, it is early stage lung cancer. This type of lung cancer can be completely cured through minimally invasive thoracoscopic surgery by thoracic surgeons. No treatment is required after surgery and there is basically no recurrence or metastasis.

If it is a partially solid nodule, more aggressive surgery is required, because this type of lesion is most likely to be malignant and has begun to show solid components. In terms of the staging of lung cancer, partially solid nodules are later than pure ground glass nodules. Of course, most of these lesions are early, and the chance of recurrence or metastasis after the above surgery is also extremely low, almost negligible, so there is no need to worry too much, and it will basically not affect the patient's natural life span. Surgery should be performed as soon as possible while lung cancer is in the early stages.

If it is a solid nodule, the chance of malignant lesions is usually lower than the above two nodules, but if it is lung cancer, its stage is later than the above two nodules. Therefore, thoracoscopic minimally invasive surgery should be performed as early as possible. Because the nodules are all smaller than 3 cm, even if the stage of this type of solid nodule lung cancer is later than the previous two nodules, most of them are early lung cancer, and the prognosis is mostly good through minimally invasive surgical resection. Only a very small number of patients may have nearby lymph node metastasis, pleural metastasis, or even distant metastasis before surgery. The latter two have lost the opportunity for radical surgery and have a very poor prognosis.

In short, if you find lung nodules during physical examination, you don't need to be too nervous. You must go to a regular hospital's thoracic surgery department to distinguish whether it is lung cancer, and then further diagnose and treat according to the doctor's advice, and have regular checkups. If the thoracic surgeon recommends surgery, don't worry too much. Most lung nodules can be cured through minimally invasive thoracoscopic surgery. Don't delay treatment because of fear of surgery.

Editor of this article: yhxi