Breast Cancer Research Without Using Animals

Breast cancer is the most common cancer in women all around the world, and it can be a devastating illness for those experiencing it, as well as their family and friends. While breast cancer in its early stages can be treated in most patients, there is a high rate of recurrence and it is considered incurable with currently available treatment if the cancer spreads to distant organs in the body. This is why more — and better — treatments for the disease are needed.

Scientists rely heavily on using animals to find out if new drugs, procedures, or treatments are likely to be helpful in dealing with cancer, but this comes with significant costs. For one, animal testing is expensive and takes a long time. As well, the reliability of results are affected by the fact that conditions are not the same across research laboratories and because animals are physically very different to humans. Not least of all, the cost to the animals themselves cannot be ignored. Animals used in medical research experience the distress of captivity and the effects of being forced to undergo a treatment where the physical consequences are not known. 

With this in mind, researchers at The Joint Research Centre’s (JRC) European Union Reference Laboratory for Alternatives to Animal Testing explored the trends of non-animal methods in breast cancer research. To do this, they examined 935 scientific peer-reviewed articles that didn’t use animals in their studies of breast cancer. All of the articles were published between January 2014 and March 2019. The non-animal methods that the researchers looked at were in vitro, which means that the process is performed outside of a human — for example, taking cells from a tumour and growing them in a culture to perform the experimental treatment on — and in silico, which means the treatment is performed on a computer or through computer simulation.

Five percent of the articles represented studies that used in silico approaches, mainly computational models and algorithms, and another four percent used both in silico and in vitro.  While the use of in silico models alone decreased by half from 2017 to 2018, studies combining both in vitro and in silico increased. The researchers felt that, although the number of publications using both approaches was small, combining in vitro and in silico models in breast cancer research has a lot of potential.

Results also showed that the use of non-animal methods in breast cancer research are widespread, with the vast majority (91%) of reviewed articles using in vitro models. Human ex vivo models, in which living tissue is taken from someone, made up 12% of the in vitro studies examined by the researchers. Mostly though, the in vitro studies in the articles used cell-based models. The researchers found that use of in vitro models was increasing over time.

Human-based models were mostly used to look at the cause and progression of breast cancer, as well as to test treatments. Two-thirds of the reviewed studies used a non-animal method to study disease features of interest, particularly breast cancer initiation and development at cellular levels. During the five-year period analysed by the researchers, the interest in using non-animal models for drug development in breast cancer grew, with the number of publications in this area almost doubling. The results of this study show new approaches to breast cancer research, and are heartening for those of us seeking an end to the use of animals in medical research more broadly.