Our research institute, the Netherlands Cancer Institute, is among the world leaders in research to better understand and treat cancer. For this we use many different research methods. Our researchers also use mice, and sometimes rats, to study cancer and develop new treatments. We find it important to be open about this. This is why we co-drafted and signed the Dutch 'Transparency Agreement on Animal Testing' in 2021. This agreement aims at creating a more transparent climate around animal testing, a subject that usually leads to fierce discussions in society, the media and politics.
Research with laboratory animals has led to major breakthroughs in cancer treatment, and is currently still indispensable to better understand and treat cancer. One example is cancer immunotherapy, which does not attack the cancer cells themselves, but helps the immune system to fight cancer. Without animal research, there would have been no immunotherapy. Similarly, for research into new cancer combination therapies developed in the lab, research on mice provides the knowledge that is indispensable for starting clinical trials in patients.
The main reason that animal experiments are necessary to increasingly understand and treat cancer is that cancer is a very complex disease, affecting the entire body. Big questions in cancer research, for example how cancer spreads to other organs, or how our immune system fights cancer, we can never study alone in cells or with pieces of tissue, or in clinical trials with humans. To better understand these complicated but important questions of cancer, we use laboratory animals.
Animal testing is only permitted in Europe when there are no other possibilities to answer a research question. In addition, for each animal test, careful consideration is given to whether the necessity of the test outweighs the use of animals and the discomfort, or even pain, that the animals may experience as a result. Our veterinarians ensure that the work is done professionally and carefully during the animal experiment and that the animals are not subjected to any unnecessary discomfort or pain.
The bodies of mice and rats are as complicated as our own. What's more, the way cancer forms and develops in mice and rats is very similar to how it happens in humans. The same is true for the treatment of cancer. Therefore, mice and rats could very well be used to solve important questions about the origin and treatment of cancer in humans.
In 2014, our new laboratory animal building opened. This contains the Mouse Cancer Clinic. Here we develop and test new treatments that we hope to give to people in our hospital. Mice can be treated here in the same way as humans, with chemotherapy, radiation, surgery or immunotherapy, or a combination of treatments. Using the same methods as in humans, we are looking at the effects of the treatment, for example by using MRI and CT scans.
If possible, of course, we do not use laboratory animals. We are also investigating other methods to solve the important questions about cancer that do not require the use of laboratory animals, or use fewer of them. For example, we use pieces of healthy tissue and cancer tissue from patients to test drugs on.
Our animals are housed and cared for according to the latest animal welfare insights and in compliance with current laws and regulations. Our animal care takers pay close attention to the animals and warn if the animals suddenly become ill or experience pain or distress in any other way. We employ three veterinarians, they are present in the laboratory animal house and take care of checking the experiments and the welfare of the animals. When it comes to the welfare of the animals, our veterinarians always have the final word.
We do everything we can to only carry out well thought out and necessary animal experiments, to keep the suffering and discomfort for the animals to a minimum and, if possible, to use other methods that require fewer animals or even no animals at all. In doing so, the so-called "three Rs" are leading: Replacement, Reduction and Refinement. The three Rs have been enshrined in law since the 1970s. Dutch legislation is also more stringent than that of most European countries.
- Replacement: for every research question, we first look for other methods to investigate the problem.
- Refinement: We make every effort to minimize distress to the experimental animals, using the latest research on housing, nutrition, and pain management; for example, mice are put in a cage alone as little as possible and have materials to hide in and play with.
- Reduction: we use as few animals as possible. For example, by reusing data from previous studies, or through technological innovations. For example, we can now use vital imaging microscopy to follow the development of a tumor at the cellular level in the same test animal.
The Dutch legislation on laboratory animals is very strict (even stricter than the European directive) and control is also strict. Each animal must be accounted for to the government's Central Committee on Animal Experiments (CCE), which issues the permits for animal experiments. The Dutch Food and Consumer Product Safety Authority (NVWA) then strictly supervises use and living conditions and makes the Netherlands' laboratory animal data public every year.
In addition, we have our own Institute for Animal Welfare that monitors the welfare of laboratory animals and the quality of animal testing. Our veterinarians have the duty of ensuring that we do is legally compliant, check that everyone is competent and skilled to carry out animal research and keep a close eye on the animals.
The NKI is a member of EARA, the European Animal Research Association