What Is the Main Idea?
Some people have mutations (changes) in their genes that increase their risk of developing particular types of cancer. In the open-access research article “Evaluating the Effectiveness of a Telehealth Cancer Genetics Program: A BRCA Pilot Study”, published in the journal Public Health Genomics, the authors describe the use of a telehealth platform for BRCA education and testing in people of Ashkenazi Jewish descent (PAJD) in the USA.
What Else Can You Learn?
In this blog post, tumor suppressor genes and their roles in the body are discussed, along with how telehealth can be used to aid genetic testing and education, and the role of genetic counseling.
What Is BRCA?
BRCA (pronounced “bra-ka”) is an abbreviation of BReast CAncer gene (genes are short sections of DNA that carry the genetic information for the growth, development, and function of your body, often in the form of instructions to make proteins). Everyone has two copies of two types of BRCA gene, called BRCA1 and BRCA2. They are both tumor suppressor genes.
What Are Tumor Suppressor Genes?
Tumor suppressor genes code for a type of protein, called tumor suppressor proteins, that help to control cell growth. They tend to play one of three roles: stopping cells from dividing and producing new cells, repairing damaged DNA, or causing damaged cells to be broken down through a process called apoptosis (this is also known as programmed cell death and is a normal part of development and aging; it removes cells that have become damaged or that are no longer needed). If a tumor suppressor gene gains a mutation (a change in the DNA code), the protein that it codes for may no longer be produced or may not work properly. As a result, the cell may start to grow and divide uncontrollably, which can eventually lead to the development of cancer.
How Are BRCA1 and BRCA2 Linked to Cancer?
Both BRCA1 and BRCA2 code for proteins that help repair damaged DNA. Everyone gets one copy of each gene from their mother and another from their father. If someone has a mutation in one of the BRCA genes that stops it from working properly, they will have a higher risk of developing cancer over their lifetime than someone that does not have a mutated BRCA gene. In particular, BRCA mutations are linked to breast and ovarian cancer. Although most cases of breast and ovarian cancer are thought to be sporadic (i.e., they develop in people who do not have a family history of that cancer or a DNA mutation that is known to increase their risk of developing it), 5–10% of cases are inherited. Of these cases of inherited breast and ovarian cancer, around 60% are caused by mutations in BRCA1 and BRCA2. All people with a BRCA mutation are at increased risk of developing breast and pancreatic cancer, and melanoma. Women and men are also at increased risk of developing ovarian and prostate cancer, respectively.
Are Harmful BRCA Mutations More Common in Some Populations than Others?
Individuals in some populations are more likely to have harmful BRCA mutations than others, and different racial/ethnic populations also tend to have different types of mutations. Although the exact prevalence of BRCA1 and BRCA2 mutations that can lead to cancer in the general population is not known, it’s estimated to be around 1 in 400 (0.2–0.3%). Norwegian, Dutch, and Icelandic peoples are known to have common mutations, as are PAJD. The prevalence of BRCA mutations in PAJD is around 1 in 40 (around 2.5%, which is 10 times greater than that of the general population), and in the USA, the mutations tend to be 1 of 3 types: two in BRCA1 and 1 in BRCA2. These are described as “founder mutations”: mutations that occur at high frequency in a group that is, or was, geographically or culturally isolated.
What Did the Research Article Investigate?
Although BRCA mutations are known to be more common in PAJD than the general population, it is not known whether rates of BRCA mutations are similar between those with or without a family or personal history of cancer. For many years, US national BRCA testing guidelines were defined by personal or significant family histories of cancer and/or the presence of mutations that were frequently found in families. These guidelines are often used by health insurance companies to set rules regarding what is covered. However, the national testing criteria have now expanded and the US Preventative Services Task Force has specified that being a PAJD is a risk factor. Despite this, in the USA, PAJD who do not have a family or personal history of cancer are not eligible for BRCA testing under their health insurance. Some have suggested that all PAJD should be offered BRCA testing, partly because it would reduce the number of cases of breast and ovarian cancer, which would save money and lives. All individuals with a BRCA mutation have a 50% chance of passing it on to future children, whether or not they have a family or personal history of cancer.
The authors of the above-mentioned article used a telehealth-based platform for BRCA education and testing with the goal of creating an effective model for BRCA testing in low-risk PAJD who do not meet US national testing criteria. They also sought to determine the rate of BRCA mutation in this group, to see if it is the same as in those with a family or personal history of cancer. The participants (501 people) received pre-test education in the form of a video and written summary, followed by complimentary BRCA1/2 testing (to determine whether there were any mutations), and post-test genetic counseling.
What Is Telehealth?
Telehealth, sometimes called telemedicine, describes the distribution of health-related services and information through the use of digital information and communication technologies. The advantages include increased access to healthcare of people in rural areas or who have difficulties with obtaining transport or mobility, and cost reduction. However, there are also disadvantages, including potential technical issues, the need for stable internet access, and (particularly in the USA) issues around billing and licensure between states. Examples of telehealth include apps on smartphones, test results being sent to a specialist, home monitoring through patients continuously sending health data, robotic surgery controlled by a surgeon at a different location, and health consultations such as genetic counseling using video conferencing rather than an in-person visit.
What Is Genetic Counseling?
Genetic counseling gives people information about how genetic conditions or specific gene mutations might affect them and/or their families. In relation to cancer, a genetic counselor can evaluate a person’s risk of getting certain types of cancer based on their family history. They can also help them decide whether or not to have genetic tests, explain the different types of test available, help work out whether some of the costs of testing are covered by the person’s medical insurance, and make suggestions for additional testing based on the results.
What Did the Study Find?
The study identified the rate of BRCA founder mutations in the low-risk PAJD participants to be around 0.6%, significantly lower than the generally reported rate of 2.5% for PAJD. However, one participant was found to have a non-founder mutation and the authors noted that, had only founder mutations been screened for, the participant’s BRCA mutation would not have been identified. There is a risk that carriers of BRCA mutations can be missed if only the presence of founder mutations is tested, with one potential reason being that many individuals that identify as Ashkenazi Jewish are actually of mixed Jewish ancestry.
The study also identified that most of the individuals that registered for the study but who did not participate because they did not meet eligibility criteria (because of their family histories) did not follow up with genetic counseling and testing, despite being sent information about its importance. Many of these individuals noted that this was, at least in part, because they had concerns about the ease of accessing genetic counseling. Telehealth has the potential to make this less of a problem. Of the PAJD that did take part in the study, feedback was very positive, with 97.9% stating that they were satisfied with the pre- and post-test education provided, and 99.5% stating that their post-test genetic counseling session was valuable.
What’s the Take-Home Message?
Individuals in populations with known founder mutations may benefit from considering genetic testing and counseling, whether or not they have a family or personal history of cancer. Genetic testing and counseling through telehealth is a good model for those that do not wish to, or cannot, access traditional in-person genetic counseling.