What you think about breast cancer and genetic testing

The Progress Educational Trust (PET)'s project 'Breast Cancer: Chances, Choices and Genetics', supported by the Wellcome Trust, sought to clarify breast cancer and risk for the benefit of current and prospective patients, professionals and the general public. The project was inspired by the discussion surrounding the double mastectomy undergone by actress Angelina Jolie, who carries a genetic mutation that predisposes her to breast cancer. A recent study credits the 'Angelina Jolie Effect' with doubling the number of UK women referred to breast cancer clinics (reported in BioNews 772).

At four public events organised by PET in 2014, audiences were asked to submit questions about breast cancer they wanted to see put to the wider public, in order that the issues raised by the 'Chances, Choices and Genetics' project could be further explored. Questions were then selected from these audience suggestions, and were incorporated into a poll that was conducted on the BioNews website between July and November.

The poll elicited responses from 878 people, representing a range of perspectives on breast cancer and genetic testing. 84 percent of poll respondents were women, and 16 percent were men. Men as well as women were invited to respond, because although breast cancer is a rare form of cancer in men (whereas it is a common form of cancer in women), men may nonetheless carry mutations in breast cancer risk genes that may then be inherited by their daughters (or their sons).

The majority of respondents (72 percent) resided in the UK. 13 percent were from the USA, 4 percent were from Australia, 2 percent were from Canada and 2 percent were from New Zealand, with the remaining 7 percent distributed across the globe.

The first poll question was 'If you had a strong family history of breast cancer, would you want to be tested for possible genetic mutations associated with breast cancer?'. Of the women who responded to this question, an overwhelming majority (91 percent) said they would want to be tested, while 3 percent said they would not want to be tested, and 6 percent were unsure. Of the men who responded to this question, a slightly smaller majority (85 percent) said they would want to be tested, while 5 percent said they would not want to be tested, and 10 percent were unsure.

The next poll question was 'Would concerns about the cost or availability of insurance discourage you from being tested for genetic mutations associated with breast cancer?'. A moratorium on the use of genetic information means that the result of predictive genetic tests cannot affect directly one's insurance premiums within the UK, but this fact is not universally known or understood, and in any case may not assuage all concerns.

Of the women who responded to this question, 37 percent said they would be discouraged from undergoing a genetic test by concerns about insurance, while a greater number (44 percent) said they would not be discouraged, and 18 percent were unsure. Of the men who responded to this question, 44 percent said they would be discouraged from undergoing a genetic test by concerns about insurance, while a slightly greater number (47 percent) said they would not be discouraged, and 9 percent were unsure.

Like the UK, the USA has a prohibition on the use of predictive genetic tests by the insurance industry (part of the Genetic Information Nondiscrimination Act), but health insurance is a more politically charged subject in the USA (where private insurers cover the majority of healthcare costs). We therefore thought it would be instructive to isolate US responses to the poll question concerning insurance, and we found that insurance was indeed of greater concern to US respondents. Of those living in the USA who responded to the question, 62 percent said they would be discouraged from undergoing a genetic test by concerns about insurance, 32 percent said they would not be discouraged, and 6 percent were unsure.

We thought it would interesting to look at whether people's response to the insurance question was connected to their response to the earlier question about willingness to undergo a genetic test. Of those who would not be discouraged from undergoing a genetic test by concerns about insurance, an overwhelming majority - 93 percent - said they would want a genetic test if they had a strong family history of breast cancer. This is perhaps unsurprising.

More surprising is the fact that of those would be discouraged from undergoing a genetic test by concerns about insurance, an almost equally large majority - 89 percent - said they would want a genetic test if they had a strong family history of breast cancer. While insurance is undoubtedly a subject of concern, people do not seem to think that this concern would dissuade them from undergoing a genetic test for breast cancer mutations, if they had a strong family history of the disease.

Having asked about people's willingness to undergo a test themselves, we then asked 'If you had a strong family history of breast cancer, would you want to have your child tested for possible genetic mutations at a young age?'.

Genetic tests for children are a notoriously contentious area of medical ethics, due to children lacking the capacity to consent. Tests for genetic mutations associated with hereditary breast cancer, which is an adult onset disease, are not currently available for children in the UK. Of those who responded to the question, there was an almost equal split between those who would want their child tested (42 percent), and those who would not want their child tested (39 percent). 19 percent of respondents said they were unsure.

Next, we asked 'If it were possible, would you like to know your lifetime risk of getting breast cancer?'. Lifetime risk is the probability that an individual will be diagnosed with breast cancer at some point during their entire lifetime (which is not the same thing as the probability that they will be diagnosed during a specified time period, such as the next year or the next five years).

Of those who responded to this question, 79 percent said they would like to know their lifetime risk of getting breast cancer, while 17 percent said they would not like to know their lifetime risk of getting breast cancer. Respondents also had the option of answering 'I'm not sure what this question means', but only 4 percent did so. This suggests that even though it can be difficult to disentangle different ways of understanding risk, lifetime risk is a measure that people feel they understand.

The final questions in the poll concerned the sources of information that people used to find out about breast cancer. Responses to these questions will be discussed in BioNews next week.

PET would like to thank everyone who took the time to respond to the poll, and would also like to thank those who attended its 'Relative Risk', 'Risk Assessment', 'Risk Management' and 'Breast Cancer Risk' events and suggested poll question. Podcasts of interviews with the experts who spoke at these events can be listened to here.