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Why Belgium still needs animal testing in the fight against cancer

In a piece first published in the Belgian news magazine Knack (in Dutch), Prof. Damya Laoui, from the Flemish Institute for Biotechnology (VIB, an EARA member), in Belgium, together with Dr. Liesbeth Aerts and Dr. Jeroen Aerts from Infopunt Proefdieronderzoek (IPPO, also an EARA member), explain that researchers don’t take the use of animals in biomedical research lightly. 


Many people are critical of animal testing, and from an emotional point of view this is very understandable. Animals are living beings. They have basic emotions and they also experience physical pain. As researchers, we are not blind or insensitive to animal suffering, but neither can we ignore the pain of almost 10 million people who die of cancer worldwide every year.


In 2018, some 70,000 Belgians received a new cancer diagnosis. Fortunately, their prognosis is in many cases a lot better than for people who received the same diagnosis 10 or 20 years ago. Thanks to advances in biomedical research – including through animal testing – the treatment options for cancer are rapidly expanding. Nevertheless, the number of cancer cases continues to increase as well, and the disease continues to take many lives.

To the people who claim that we can face this challenge without animal research, we would say: please walk the talk. From our hands-on experience as biomedical researchers, we would like to argue for greater nuance in the debate against animal testing. Let’s bust some often heard myths:


Myth One: Animal testing is no longer necessary because we can get the same results through computer simulations


Unfortunately, we cannot simulate what we do not understand; that’s kind of the definition of a simulation. Despite our increasing knowledge, there are still a lot of body processes that we do not understand well enough to be able to fully predict them. If we could, we would already have a solution to all diseases.


Just like animal experiments, computer simulations are one type of tool in our experimental toolbox and they can certainly help us in the search for answers. For example, computer simulations are useful to screen different versions of a candidate drug molecule, or to predict possible negative effects of a drug on a cell. Depending on the substance and the application, additional (animal) tests will nevertheless be required.


Myth Two: Researchers use laboratory animals because it is easier and cheaper


Researchers who work with laboratory animals don’t do this for fun. The breeding and housing of experimental animals is – depending on the species – time-consuming and very expensive. There are strict rules and conditions (and rightly so!) which mean that for each test an ethical file has to be drawn up and submitted to an ethical committee.

If an experiment can be done in a cell culture dish, then the animal experiment simply cannot take place. Can human samples be used instead? Also then, animal tests are prohibited.


Myth Three: Animal experiments are useless, because mice are not the same as humans


Mice are indeed not people, but they do show a lot of similarities. The functioning of many organs is similar and by changing certain genes in mice, we are able to answer very fundamental questions, for example about the interaction between the immune system and cancer cells in a complex organism. That’s exactly why mice are used to study new immunotherapies.


Exactly because there are also important differences in mice and humans, researchers sometimes need to use other animal species such as dogs or monkeys. As these are more evolved animal species, they are only used in very exceptional situations.


We have achieved many medical breakthroughs thanks to animal experiments; think of organ transplants, blood transfusions, treatments for diabetes and AIDS, or the development of vaccines against polio, hepatitis and, most recently, the Ebola virus. More than 80% of the Nobel Prizes in Medicine also went to breakthroughs that were based on animal research.

VIDEO: In a lecture for the University of Flanders, Prof. dr. Damya Laoui, of VIB, in Belgium, underscores the need for animal research for her pioneering work into immunotherapy for metastatic breast cancer.


Animal experiments are not a perfect fix; of course they also have limitations. They shouldn’t be the default option, rather, it’s about using the right model for the right questions. Just as for other non-animal research methods, such as computer simulations or experiments in cell lines, there are advantages and disadvantages that have to be weighted.


The legislation on animal testing is therefore built around the principle of the 3Rs: Reduce, Refine, Replace.


Reduction means that only the absolutely required number of animals is used for each experiment. It is up to the researchers to make a statistically solid estimate for each experiment, and up to the ethics committee to finally decide.Refinement means that an animal test must be done under the best possible conditions, e.g. with painkillers if necessary, and that animal welfare should be considered at all times. This includes legally specified conditions relating to the number of animals per cage, the control of temperature and humidity in the room, and the provision of toys.Replacement emphasises the legal need to replace animal testing where alternatives exist.


As researchers, we also apply the fourth ‘R’ of responsibility. It goes without saying that there should be zero tolerance policy of researchers who would flout these rules.

Scientists would love to have the tools available to map the complex mechanisms of cancer metastases, for example, or to explore new avenues for immunotherapy, without animal testing. For the time being, however, we don’t. That does not stop us from trying to do better every day. We keep pushing, not only for new treatments for patients, but also for better, more refined research methods.


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