Until recently, the three fundamental pillars of cancer treatment were: surgery, radiotherapy and chemotherapy. Recently, a fourth pillar was added: cancer immunotherapy.
Immunotherapy is based on the use of the body’s natural defenses, the immune system, to fight diseases. Oncological immunotherapy is the application of immunotherapy in the fight against cancer. But how? By stimulating our immune system to react and fight cancer cells. The discovery that the mechanisms of our immune system were “held back” by cancer and the elimination of this “brake”, led two researchers to the Nobel Prize in 2018.
Their studies laid the foundation for the development of drugs, based on immunotherapy. Such drugs are almost completely free of side-effects and can counteract the development of tumors that had been previously very difficult to treat.
Alongside the development of knowledge on immunotherapy (based on the elimination of the immune system’s brakes), another strategy called CAR-T (Chimeric Antigen Receptor T cell therapies) has recently been introduced. This therapy is based on the genetic engineering of T lymphocytes (our immune system’s cells), in order to strengthen them in their fight against tumors.
The T cells, in order to be genetically modified, are taken from the patient’s blood, engineered so that they can express on their surface the CAR receptor capable of increasing the immune response, and then they’re reinfused in the patient. We can therefore speak of “personalized medicine” in the context of the treatment of tumors.
The limitations of CAR-T immunotherapy
In this article, we’d like to point out two limitations in particular. Firstly, the difficulty in CAR-T cells actually reaching cancer cells. In fact, the therapeutic protocol provides for the intravenous reinfusion of cells. This means that T cells don’t reach a sufficient number of tumors, such as brain tumors. Researchers are working to find a solution for the local administration of CAR-T. The first studies are being conducted on intrapleural space administration for the treatment of lung cancer.
Secondly, the selection of the appropriate antigenic target. CAR-T cells should be selected, in order to detect and fight only cancer cells — and not healthy cells. To improve the selection of antigenic targets, researchers are using cells called spheroids in laboratories. These are still experimental studies and therefore not conducted on humans, and for this reason, it’s necessary to use cells produced in the lab; but they must be as similar as possible to solid tumor cells. Spheroid cells display these same characteristics and are called spheroids because of their shape.
Soon, clinicians will have this fourth pillar of cancer treatment at their disposal, in order to cure tumors that are difficult (or even impossible) to treat today.
This post is also available in: Italiano