Immunotherapy is a therapeutic strategy developed in recent years in oncology for the treatment of different types of tumors. For us oncologists, this type of treatment has meant a spectacular development in terms of the different lines and therapies that have recently appeared. In fact, it is not only applied to patients with metastatic tumors, but is even used in patients who have undergone surgery and who require prevention of disease relapse.
In recent years, this therapy has initially appeared as an effective treatment in trials of advanced melanoma, a disease in which chemotherapy was previously the only weapon, with poor results and short survival rates, as well as response rates generally below 20%.
Immunotherapy has made it possible to change, for example, in the case of melanoma, the natural history of this disease in advanced stages. Currently, studies combining different immunotherapy drugs in patients with metastatic melanoma have managed to demonstrate a significant benefit in overall survival, which represents a significant success compared to previous results with chemotherapy, which were quite poor.
How does immunotherapy treatment work?
Immunotherapy is a different way of treating the patient with respect to classic therapies, such as chemotherapy, which directly attacks the different tumor cells and in general is usually highly toxic.
In the case of immunotherapy, we are talking about stimulating the activity of the immune system. The patient’s own immune system will be in charge of locating and destroying the tumor cells in a much more precise way.
Currently, immunotherapy can act at different levels, one of them at the level of CTLA-4, favoring the immune system to increase its capacity to fight cancer. On the other hand, when the lymphocyte locates the tumor cell, this tumor cell tries to evade the immune system so that it does not act on it. Anti PD1 drugs will help the tumor cell not to escape and thus the tumor is attacked by the immune system.
These would be, by way of summary, two ways that we currently use to attack different tumors through immunotherapy, which is based on the patient’s own immune system attacking the tumor, thus being a much more specific and effective treatment than other treatments, as has been demonstrated in clinical studies for certain tumors in comparison with chemotherapy.
When and what is immunotherapy used for?
The indication for immunotherapy depends on the type of tumor.
Currently it can be used in patients with different tumors where its efficacy has been demonstrated in clinical trials in advanced stages and also in patients who have already undergone surgery as a preventive measure to reduce the probability of relapse and increase survival.
Is immunotherapy effective?
Immunotherapy is, in my opinion, an effective treatment that has changed the natural history of some tumors in metastatic patients, for example in cases of melanoma or lung cancer. The efficacy is such that, in patients who previously had very short survival times, thanks to the use of combined immunotherapy, there are studies that confirm its effectiveness, such as in advanced melanoma, with improved 5-year survival.
Immunotherapy has changed the natural history of many oncological diseases, and in the future we hope that strategies with even better results will continue to be developed.
What are the differences between immunotherapy and chemotherapy?
The main difference is the mechanism of action. In the case of chemotherapy, it is the drug that will act directly on the tumor cell, whereas with immunotherapy it is the immune system itself that is responsible for locating and attacking the tumor cell.
On the other hand, the side effects are different, and the toxicity profile is generally worse with chemotherapy. Immunotherapy allows a higher quality of life and fewer side effects for the patient.
What are the side effects of immunotherapy?
Severe side effects are generally rare. One of the most important would be intestinal toxicity in the form of diarrhea. Among other side effects we can also observe alterations at the endocrine level, such as thyroid; alterations at the hepatic level, such as elevation of transaminases; skin toxicity in the form of rashes; renal toxicity and in some cases the involvement of the central nervous system.
However, these are side effects that in most cases are usually controlled with the use of systemic corticosteroids.
For more information on immunotherapy, please consult a specialist in Medical Oncology.