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Cancer does not stand a chance – the promise of Immunotherapy
The substances can e.g. be applied
by infusion;© NCI Visuals Online
However, since cancer cells are cells that are naturally produced in the body and normally don’t initiate an inflammation process, the immune system is not able to recognize them. This is precisely what immunotherapy is meant to change.
Generally speaking, immunotherapies are supposed to activate the body’s defense mechanism. This can be omnidirectional – e.g. by stimulating the entire immune system (for instance by administering Interferon) – or more targeted on a cellular level.
There are several possibilities and techniques for this, some where processes are already being applied, while others are still being tested in clinical studies, i.e. new alternatives are being researched. There is a distinction between passive and active immunotherapies, where the versions of different processes could fill entire libraries.
The first trials to stop cancer cells by activating the immune system were attempted during the early years of the last century. An example is a bone marrow transplant for leukemia patients. Since donor cells essentially never match 100 percent with the recipient cells, the newly created immune system after the transfer is sometimes able to recognize and fight the leukemia cells.
Chances increase especially if donor- and recipient cells are very different. This procedure does not account for the specific characteristics of the tumor though. For this, it is necessary to create a more target-oriented therapy.
Tracking Dogs on a cellular level
So-called monoclonal antibodies are man-made tracking dogs, that attach themselves to a specific section of the antigen of the cancer cell (= everything that can be specifically attached to an antibody). In the best case scenario, they trigger cell dissolution or at least stop its growth. In therapy they are already used. Dr. Clemens Unger, Professor of the Clinic for Tumor Biology in Freiburg, Germany: “Monoclonal antibodies are often applied and are a real improvement in the area of oncological therapy. They can be applied for breast cancer, colorectal cancer and lung cancer, just to name the most important ones“.
Unfortunately their effect on lager tumors is currently not sufficient – more research needs to be done here. On the other hand, these types of antibodies have a well documented use for diagnostics, since they can be used to confirm cancer cells in the body.
To do this, they are “charged” with radioactive or fluorescent agents, whereby they can be detected in the body. If they attach themselves to the cancer cells, even smaller tumor sources (e.g. in the case of breast cancer) can be detected, but only if the tumor tissue differs enough from healthy tissue.
Monoclonal antibodies currently are only approved for certain tumors and can only be applied to selected patients. An example would be breast cancer patients, who alongside with monoclonal antibodies during their cancer therapy, can be treated to stop tumor growth. Unfortunately, the therapy is not effective with everybody.
Every patient's dream: an anti-cancer
Injections instead of suffering from cancer
Of course the wish of many physicians and patients would be a prophylactic vaccination, which could generally prohibit cancer development.
Dr. Djorde Atanackovic from the University Clinic Hamburg-Eppendorf is researching in this specific area. “Larger studies are currently testing several immunization therapies against cancer. I think it is entirely possible that this will be successful in several areas“.
These studies however only factor in apparent, i.e already clinically noticeable diseases. The buzz phrase “Vaccinate against Cancer“ has been in the media for several years. Well-known since 2006 in particular is the much advertised vaccine against cervical cancer at the gynecologist for girls between the ages of 12 and 17. However, the vaccine is administered to combat a virus, more specifically to fight several strands of the human papilloma virus, which are suspected to trigger cervical cancer – and is not a vaccine against the cancer as such.
Currently the biggest hope however lies in vaccines, which are tumor specific. This means, if possible they react to characteristics of individual tumor cells. If a specific type of cancer should appear, the harmful cells would be broken down or rendered harmless through the injection, i.e. by the substances it contains. Yet even in this case, the cancer needs to appear first so it can be treated – which is why even this vaccination is not a true prophylaxis!
Indeed, much laboratory work is currently still in the experimental stages. Thus far there are also only a few studies that actually work with cancer patients in this area. This is due to the fact that many patients or rather their type of cancer are not suitable for this kind of vaccination. Their cancer cells simply do not show the necessary characteristics that identify them as tumor cells. What’s more is that the different types of cancers differ drastically from each other, which makes a universal therapy very unlikely.
Even Dr. Unger points out that there will probably never be an injection against cancer: “There are over 200 different types of cancer and they require different types of therapies“. Nevertheless, there are always current reports that new vaccines, affected by different approaches, have been successfully tested at the laboratory.
(Translated by Elena O'Meara)