a. Advanced patients with EGFR mutation should be treated with targeted therapy as early as possible In advanced non-small cell lung cancer, some patients have a specific gene mutation, which causes cancer cells to proliferate indefinitely and easily invade outward to destroy the function of normal cells. This specific gene mutation is like a target, and targeted therapy is to attack this target. In advanced non-small cell lung cancer, there are more gene mutations as targets, the most common one is EGFR gene mutation, and the drug to attack this mutation is called EGFR-TKI (epidermal growth factor receptor tyrosine kinase inhibitor). The current Chinese version of lung cancer guidelines approves that patients with advanced non-small cell lung cancer with EGFR gene mutations need to be treated with EGFR-TKI as early as possible. Studies have shown that patients have a median progression-free survival of up to 13 months after EGFR-TKi treatment. In other words, when the time from the start of treatment to the appearance of tumor expansion and metastasis (i.e., progression-free survival) was counted for each patient, the cumulative time corresponding to 50% of patients was 13 months, meaning that 50% of patients could have their tumors not progress within 13 months. In addition, the median overall survival of patients was 27 months. B. adenocarcinoma is an advantageous population for using targeted therapy Theoretically, genetic screening is used to detect the presence of specific genetic mutations in patients in order to decide whether to proceed with targeted therapy. However, the survey found that only 20% of non-small cell lung cancer patients in China had EGFR gene mutation testing in 2012 due to perception, cost, and difficulty in obtaining materials, and 40% of doctors surveyed said their hospitals were unable to perform EGFR testing. So, how to treat without knowing whether there is a gene mutation or not? In fact, non-small cell lung cancer includes squamous carcinoma, adenocarcinoma, and large cell carcinoma. In China, the EGFR mutation rate of lung adenocarcinoma patients is about 50.2%, which means that 1 out of 2 lung adenocarcinoma patients has EGFR mutation. The mutation rate among non-smokers with lung adenocarcinoma is even higher, about 60.7%. Therefore, Asian, female, non-smoking lung adenocarcinoma patients are also considered to be an advantageous population for targeted therapy, and this group has a longer time to have their disease controlled and tumors not progressing after treatment with erlotinib. C. Patients with advanced non-small cell lung cancer who neither have mutations nor are in the advantaged population also have the opportunity to use targeted therapy If patients with advanced non-small cell lung cancer neither have EGFR mutations nor are in the advantaged population for targeted therapy, does it mean that targeted therapy cannot be used? The study found that when patients with advanced lung cancer who failed chemotherapy were treated with placebo, the median overall survival was 4.7 months, meaning that one and only 50% of patients would live beyond 4.7 months, while with erlotinib, the figure was 6.7 months. This means that the risk of death can be reduced by 30% when patients undergo targeted therapy after chemotherapy failure. Therefore, patients with advanced non-small cell lung cancer should be given a chance for targeted therapy throughout their treatment even if they are not mutated patients or in the dominant population. D. Targeted therapy can be tried even if you don’t want chemotherapy or don’t tolerate chemotherapy Some patients with advanced lung cancer are facing the situation of “no drug available” for chemotherapy regimen because they can’t tolerate the toxic side effects of chemotherapy. For these patients who cannot or do not want to receive chemotherapy, such as those of advanced age and severe disease, they can also consider using targeted therapy directly. Because targeted therapy is less harmful to normal cells and has mild side effects, patients can tolerate it better than chemotherapy, and it is suitable for patients with poor health condition.