Good Can Come From Bad: Genetic Testing For The BRCA Breast Cancer Genes
Our ability to test for the presence of genetic mutations has become extremely cost-efficient and private companies, such as 23andMe now offer genetic testing for consumers who want to find out about their predisposition for genetic diseases. The results of such tests are sent directly to the consumers, without the involvement of genetic counselors or other healthcare providers. This has lead to a growing concern about how people will respond to finding out that they are carriers of mutations that predispose them to certain life-threatening diseases. Will the individuals be burdened by excessive anxiety? Will they tell their relatives and their healthcare providers that they carry mutations?
A study published in the new open access journal PeerJ addressed these questions by contacting male and female individuals who has received genetic testing by 23andMe for mutations in the BRCA genes which are strongly associated with breast cancer. The study "Dealing with the unexpected: consumer responses to direct-access BRCA mutation testing" by Uta Francke and colleagues (who are all employees of 23andMe) surveyed 16 women and 16 men who had received the news that they were carriers of BRCA1 or BRCA2 mutations, as well as control subjects who received the fortunate news that they did not carry any of the common BRCA mutations. Among the 16 women who tested positive (i.e. found out that they had a significant likelihood of developing breast cancer), none were extremely upset and six were either mildly or moderately upset. Surprisingly, nine mutation-positive women reported that they felt "neutral".
The majority of the mutation-positive participants shared the test results with their spouses / partners or their blood relatives. Importantly, 13 of the 16 mutation-positive women contacted their primary care physician, gynecologist or oncologist for medical advice. There were 11 mutation-positive women who received this information through 23andMe for the first time (the others had already been diagnosed with breast cancer or had previously undergone testing), and these women indicated that they were planning to either undergo surgeries or have further breast cancer work-up and regular exams. The majority of mutation-positive men, on the other hand, did not consult their physicians, but did indicate that they would participate in future cancer screening.
Nearly all the participants said that they would undergo the testing again and felt good about knowing the results, independent of whether they positive or negative for the BRCA mutations. Only one of the participants (a mutation positive man with a family history of breast cancer) said that he would have preferred not to know, because of the "emotional cost". A significant proportion of the participants who tested positive also had their relatives tested. This lead to the identification of 13 additional carriers, many of whom received medical counseling and were planning to take risk-reducing measures.
These findings suggest that the identification of mutations that indicate a high risk for developing breast cancer did not lead to severe anxiety or panic, but actually resulted in pro-active steps and medical care to help reduce their risk of developing breast cancer. One has to bear in mind that the sample size is small and that the study and the salaries of the authors were all funded by 23andMe, a genetic testing company that would financially benefit from widespread genetic testing. Nevertheless, the presented data seem solid and the responses of the participants do suggest that such testing was on the whole very beneficial for the participants. Hopefully, we will see more data emerge in the future regarding the psychological impact of genetic testing and whether the findings of this small study hold up in larger cohorts and when it comes to other genetic diseases.
On a side note, there is a very intriguing aspect to this paper that will be of benefit to many readers. The PeerJ journal gives the authors of a manuscript the option of disclosing the peer review process to the public. The authors of this paper took advantage of this option and we can all have a close look at the peer reviewer comments as well as the rebuttal of the authors. For anyone who is not used to reviewing scientific manuscripts, this is an excellent opportunity to learn about the inner workings of the peer review process.
Image Credit: Cartoon representation of the molecular structure of BRCA1 by Jawahar Swaminathan and MSD staff at the European Bioinformatics Institute, via Wikimedia Commons
Francke, U., Dijamco, C., Kiefer, A., Eriksson, N., Moiseff, B., Tung, J., & Mountain, J. (2013). Dealing with the unexpected: consumer responses to direct-access BRCA mutation testing PeerJ, 1 DOI: 10.7717/peerj.8