Do all lung cancer patients need genetic testing?

With the enhancement of people's health awareness and the widespread use of chest CT examinations, the detection rate of early lung cancer is getting higher and higher. At the same time, the progress and development of science and technology have also made genetic testing of tumor patients possible. So, do all lung cancer patients need to undergo genetic testing?

The relationship between genes and lung cancer

The secret of life lies in the weaving of genes. Scientific research has found that from the time we are born to the time we die, the cells in our bodies are constantly changing. Infection, eating habits, environmental factors and even natural aging can all be causes of DNA damage, causing mutations. When mutations accumulate to a certain extent, especially when genes related to lung cancer mutate, lung or bronchial epithelial cells may embark on the path of mutation and deteriorate into tumor cells. Therefore, the root cause of lung cancer is the accumulation of gene mutations.

Driver genes: the driving force behind lung cancer

The occurrence of lung cancer is closely related to "driver genes". The concept of driver genes was first proposed by Weinstein in 2002. He pointed out that the generation of tumor cells and the maintenance of their malignant biological phenotypes depend on one or some activated oncogenes, also known as oncogene dependence.

The significance of gene testing for lung cancer

Scientific research has found that lung cancer driver genes play a leading role in the occurrence and development of tumors. The stronger the leading role of driver genes, the better the effect of targeted therapy. After understanding lung cancer from a genetic level, the treatment model of lung cancer has undergone a revolutionary change, and individualized precision treatment has gradually become the mainstream. Simply put, genetic testing provides a scientific basis for patients' molecular targeted therapy and immunotherapy. The emergence of new therapies such as targeted therapy and immunotherapy has also greatly improved the quality of life of patients and increased the survival time of lung cancer patients. The clinical application of these therapies requires the formulation of accurate targeted treatment plans through genetic testing. Although targeted drugs have significant efficacy, it is difficult to completely avoid the emergence of drug resistance. When the disease progresses, genetic testing can be performed again to determine the resistance mechanism, find new treatment targets, and guide the treatment plan after drug resistance. Therefore, for lung cancer patients, genetic testing is not only a necessary preparation before treatment, but also an important auxiliary means throughout the entire treatment process.

Which patients need genetic testing?

In fact, not all lung cancer patients need genetic testing. Lung cancer is divided into small cell lung cancer and non-small cell lung cancer, the latter of which is further divided into adenocarcinoma, squamous cell lung carcinoma, adenosquamous carcinoma and large cell carcinoma, of which adenocarcinoma accounts for the majority, followed by squamous cell carcinoma, and small cell lung cancer accounts for less than 15%. For small cell lung cancer, there are currently no targeted drugs that require genetic testing to guide their use. Among non-small cell lung cancer, the type of lung cancer that most needs genetic testing is lung adenocarcinoma. Most lung adenocarcinoma patients can be matched with corresponding targeted drugs through genetic testing; patients with squamous cell lung carcinoma have a lower probability of gene mutation, but there is still a chance to match targeted drugs through genetic testing; patients who do not smoke and are diagnosed with squamous cell carcinoma or mixed adenocarcinoma components through small specimen biopsy are also recommended to undergo genetic testing, but drug resistance is difficult to avoid during targeted treatment. For these patients, genetic testing should be performed again after the targeted drug treatment progresses to understand whether there are drug-resistant mutations in the gene after treatment to guide subsequent treatment.

How to determine whether lung cancer is in the early or late stages?

A comprehensive staging examination is required to determine the early and late stages of lung cancer. This includes a comprehensive evaluation and examination based on the patient's condition after the pathological diagnosis of lung cancer. The most basic examinations include chest and abdominal CT, cervical lymph node ultrasound, head MRI, and even full-body bone scans. In addition, there are more advanced and high-end full-body PET-CT imaging examinations. Through these examination results, the staging of lung cancer can be clarified, which is generally divided into stages I, II, III, and IV. Among them, stage I belongs to the early stage, stage II and III can be regarded as mid-stage, and stage IV is late-stage lung cancer. There is still a chance of surgery for non-small cell lung cancer stages I to III. Advanced lung cancer, especially those patients who can no longer undergo surgery, mainly use radiotherapy and chemotherapy as the main treatment methods.