1.What is targeted therapy? What is the difference compared with chemotherapy?
In fact, chemotherapy and targeted therapy are both drug therapies. Chemotherapy acts on various sites in the cell, such as the different timing of mitosis in each cell. However, the original cytotoxic drugs have reached a bottleneck in the road of chemotherapy, and it is very difficult to go up to many new drugs. In fact, tumor growth not only has intracellular mitotic processes but also other processes, such as pericellular angiogenesis and pericellular environmental changes on the tumor. Malignant tumors need to start and signal transduction to cause infinite proliferation process, if this signal transduction is blocked, cell proliferation can be stopped, and the drugs developed for these targets are the hot targeted drugs now.
2.What is the status of targeted therapy in lung cancer treatment so far?
At present, the three most familiar drugs for targeted lung cancer therapy are ERSA, Troche and Kemena. These three drugs actually have similar mechanisms of action, but the basic mechanism is the same, and they have made a huge difference in the survival of patients with EGFR (epidermal growth factor) mutations (patients with this target). They have improved their median survival from about one year to two and a half to three years. The prolongation of survival for patients with such genetic mutations by these drugs is very obvious and revolutionary.
3.Can targeted therapy significantly improve the survival rate of patients? Can it improve the survival rate of all lung cancer patients?
For some lung cancer patients, such as EGFR mutation-positive lung adenocarcinoma patients who are sensitive to drugs such as ERSA, Troche, and Kemena collectively known as TKI, the improvement in survival is relatively obvious, which can basically double to triple the survival time of patients at once. However, for patients without mutations who are mutation-negative, we have made limited progress in treatment up to today, but progress is being made, and the survival of such patients is relatively limited, ranging from one to one and a half years.
4. Is genetic testing recommended for all lung cancer patients and what kind of genes should be tested first?
If conditions allow, we recommend all patients to be tested. The probability of having a positive mutation in EGFR gene can reach more than 30% among non-small cell lung cancer patients in China, which is equal to 1/3 of patients who are suitable to take TKI drugs in the first line. Patients may have to wait longer for genetic testing (two weeks), but the wait is worth it (for deciding on a treatment plan). There is another type of EML4-ALK fusion gene testing, if this cell occurs fusion gene expression positive, another targeted drug therapy, the efficacy is similar to the current treatment of EGFR mutation positive patients with ERSA, Troche, Kemena, but the incidence in China combined is only 10%, we give priority to EGFR gene testing, and then EML4-ALK testing.
5.Which groups are more prone to mutation and is there any relationship with gender, age and race?
The overall chance of EGFR mutation in Caucasian population is less than 10%, while we have more than 30% of non-small cell lung cancer and 50% of lung adenocarcinoma in Chinese population. Although ERSA and Tricare are drugs invented by western companies, they actually bring far more benefits to us Chinese than to westerners, and some people call them God’s gift to the Chinese. In terms of population, generally speaking, the mutation rate of female, non-smoking, adenocarcinoma patients can be as high as 60% to 70%, which is a high mutation rate, in addition to some older people may have a higher mutation rate than some younger people, and the mutation rate of those over 70 years old is higher than that of those under 50 years old.
6.What are the drugs commonly used in targeted lung cancer treatment so far?
There are several types of targeted drugs for lung cancer, one of which is TKI drugs. The most typical of them are EGFR mutation drugs, including Erysal, Troche and the domestic Kemena. There is also a class of monoclonal antibodies that are ignored, which act outside the cell membrane and block this pathway. There are also anti-angiogenic drugs, such as Avastin. But all these drugs need to be combined with chemotherapy and should be strictly limited. Any drug has to be under the guidance of a medical professional and has its associated toxicity and side effects. Doctors will definitely tell you the benefits and side effects and risks associated with them, and only after weighing them, and only after monitoring, do you go for treatment, not simply use the drugs.
7.How is the course of targeted therapy for lung cancer determined?
Targeted therapy is traditionally represented by one tablet of ERSA and Tricare a day, and its process is to take one month to see the efficacy and whether the tumor grows or not, if the tumor grows in one month, we think the drug is ineffective. When the chemotherapy has reached a certain cycle and is no longer used, and there are no unbearable side effects, it can be used once a month until the disease progresses, which is called maintenance therapy.
8.Can targeted therapy for lung cancer be administered simultaneously with radiotherapy?
It is up to the doctor and patient to decide whether chemotherapy or targeted drug therapy should be used first, but at present, it is not recommended to use them simultaneously, mainly because it does not increase the efficacy. In addition, it has not been found that taking chemotherapy first and then taking TKI drugs after it is ineffective will reduce the efficacy of TKI drugs, and the same goes for radiotherapy. Anti-angiogenic drugs and monoclonal antibodies must be combined with chemotherapy to be effective in order to have a significant effect. As for radiotherapy, some drugs are OK, and no serious adverse effects have been observed. There is no clear increase in the data so far, but after all, the current data and related information are not particularly abundant, but in some specific patients, I think it is fine to do so when the doctor feels the need.
9. When radiotherapy is just finished, some patients have a tendency of tumor shrinkage, and some doctors suggest taking targeted drugs for such patients.
This is a very debatable issue, and there are also debates among doctors. In principle, if there is more tumor load, we consider adding TKI drugs in advance, and if the efficacy is very good or the patient is poorly tolerated or various other conditions, we can take a break and wait for the disease to progress before taking TKI drugs. There are also different stages, for example, patients with radiotherapy and chemotherapy in stage IIIA and IIIB, where the lesions are confined within the radiation field, and TKI drugs are not recommended for this group of patients after radiotherapy. There are some stage IV patients in some cases to change the drug maintenance, that is the need for doctors according to the specific circumstances of the patient to specific is not used, can not be generalized is or is not, but also need professional doctors to do analysis.
10.What are the common side effects of targeted therapy?
The main side effects are rash, diarrhea, itchy skin and other problems. But there is no special treatment for these minor problems. You can consult the dermatology department to use some ointment with hormone antibiotics. If it is really hard to tolerate and need to stop the drug, we first change one tablet a day to one tablet every other day before stopping the drug. In fact, we do not advocate this and are not willing to let patients stop the medication, after all, lung cancer is a life-threatening disease and we are willing to give the full amount and the full course of medication. In fact, the number of patients who stop taking the drug because they cannot tolerate the side effects is very small, probably around 3%-5%.
11.After taking targeted therapy drugs for several months, the efficacy decreases, does it prove that the drugs are resistant and should be changed?
This is also a very controversial issue, what is the decline in efficacy? Some lesions may have increased in size, some lesions may have remained unchanged, and some lesions may have shrunk. For example, if a patient takes a TKI drug and the tumor changes from 5cm to 3cm to 2cm to 2cm, it is considered effective for the patient and we keep on taking it. But when the tumor grows from 2cm to 3cm in one go, we think the tumor has progressed. However, there is still a debate on whether the drug should be stopped or changed immediately.