It has to be said that in recent years, the number of lung cancer patients has been increasing day by day, and lung cancer has truly become the “cancer boss”. Lung adenocarcinoma has become the most common pathological type of lung cancer, accounting for half of the total incidence of lung cancer, and squamous cell carcinoma of the lung ranks second, accounting for about 30% of the incidence. Based on my country’s huge population base, the overall incidence of lung squamous cell carcinoma Also quite a lot.
Causes of squamous cell carcinoma of the lung
All causes of cancer can be summed up as a combination of genetic and environmental factors. However, compared with lung adenocarcinoma, lung squamous cell carcinoma has a very different etiology.
1.Smoking
The incidence of squamous cell carcinoma of the lung is directly related to smoking. The greater the amount of smoking, the higher the probability of squamous cell carcinoma of the lung. We usually use the smoking index to express it. Smoking index of more than 400 belongs to the high-risk group of lung cancer. Not only active smoking, but passive smoking also increases the risk of lung cancer. Lung adenocarcinoma and smoking are relatively less closely related.
2.Genetics
Individuals with a family history of lung cancer and previous history of malignancy and a first-degree relative diagnosed with squamous cell carcinoma of the lung are at significantly higher risk of developing squamous cell carcinoma of the lung.
3.Chronic underlying lung disease
Especially in patients with chronic obstructive pulmonary disease, tuberculosis, interstitial pneumonia, pneumoconiosis, etc., the incidence of lung squamous cell carcinoma is much higher than that of healthy people.
4.Environmental factors and occupational exposure
Environmental factors need not be mentioned. Whether it is outdoor natural environment PM2.5 pollution or indoor pollution, it will increase the risk of lung cancer. People who have long-term exposure to dust, radioactive substances and high carcinogens such as asbestos, arsenic, radon and their compounds are more susceptible to lung cancer.
Squamous cell carcinoma of the lung has three characteristics:
1. Lung squamous cell carcinoma is mostly central type, mostly growing in the hilar large airways and around the large blood vessels. In the early stage, it can be manifested as cough, expectoration, fever and other symptoms similar to respiratory tract infections. It is easy to be ignored. Once symptoms such as chest pain and hemoptysis occur, the disease is already late.
2. Lung squamous cell carcinoma is mainly manifested as slow-growing tumor lesions. In layman’s terms, lung squamous cell carcinoma does not like to “run around” relatively, and mostly involves local invasion, or is accompanied by regional lymph nodes swollen. Hematogenous metastasis occurs late, and the malignancy is lower than that of small cell lung cancer and adenocarcinoma, and some advanced stages can also metastasize to brain, bone, liver and other parts.
3. From the age of onset, due to the greater relationship between lung squamous cell carcinoma and smoking, lung squamous cell carcinoma mostly occurs in elderly men, less common under the age of 45, and less common in young women. .
Lung squamous cell carcinoma treatment
1. For all non-small cell lung cancers, the principles of early treatment are the same. For those who can undergo radical surgery, surgery is the first choice. For patients who are late in the mid-stage stage and cannot determine whether complete resection can be performed, neoadjuvant therapy can be considered. Except for stage IA, conventional adjuvant chemotherapy after surgery is recommended for other stages.
2. Due to the central type of lung squamous cell carcinoma, although some patients have small lesions, they are still inoperable because they are close to the great blood vessels and main bronchus. This is a locally advanced lung cancer. The preferred treatment method is: Concurrent chemoradiotherapy, immunotherapy drugs (current guidelines recommend durvalumab) can be considered for 1 year after chemoradiotherapy.
3. Due to the older age of lung squamous cell carcinoma patients, many of them have chronic underlying lung diseases, especially chronic obstructive pulmonary disease, and poor lung function. Such patients cannot be operated even in the early stage. At this time, it can be considered Stereotactic radiotherapy, those who are unwilling to radiotherapy, and lesions within 3 cm, can also consider radiofrequency ablation.
4. Compared with lung adenocarcinoma, lung squamous cell carcinoma patients rarely have sensitive gene mutations, so targeted drugs for EGFR, ALK and other genes cannot be used. However, lung squamous cell carcinoma usually has a large tumor mutation load and the effect of immunotherapy is better, so immunotherapy has long been recommended by guidelines as the first-line treatment for advanced lung squamous cell carcinoma. Patients with high PD-L1 expression can be treated with immune monotherapy, and patients with low or no PD-L1 expression can consider chemotherapy combined with immunotherapy.
5. In addition to advanced lung squamous cell carcinoma, PD1/PD-L1 immune checkpoint inhibitors are gradually expanding their indications in other lung squamous cell carcinoma patients. Preoperative neoadjuvant immunotherapy and postoperative Adjuvant immunotherapy will soon be included in the recommended use of guidelines.