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Researchers Aim For Wider Genetic Screening For Breast Cancer


There is a big new debate over breast cancer. The scientist who first identified a breast cancer gene now says all women over 30 should be tested for mutations that could lead to the disease. This a very controversial recommendation, and we brought in NPR's Rob Stein to help us understand it. Rob, good morning.

ROB STEIN, BYLINE: Good morning, David.

GREENE: So, Rob, there are breast cancer genes, and if there are mutations in these genes, it makes you more likely to get breast cancer. Just remind us of the science here.

STEIN: Right, David. There are two genes we're talking about. One is called BRCA1. The other one is called BRCA2. Some people call them BRCA1, BRCA2. And women who have certain mutations in these genes are much, much more likely to get either breast cancer and sometimes ovarian cancer and these mutations tend to run in families which is why women whose mothers or sisters or other relatives had breast cancer tend to be a much higher risk for those diseases.

GREENE: OK. So what exactly were the recommendations up until this point about who should get screened?

STEIN: Yeah. At the moment, doctors only recommend that women get tested if they have a family history of one of these diseases or maybe if they are Ashkenazi Jewish heritage since mutations in these genes tend to be much more common in those women as well.

GREENE: And we have new recommendations out today from a prominent scientist. What exactly is she saying, and who is she?

STEIN: That's right. Mary-Claire King is a geneticist at the University of Washington who discovered BRCA1, the first breast cancer gene, and she says it's time to start screening not just women who have a family history of these diseases, and that would be a huge change. It would mean many, many, many more women getting screened.

GREENE: And why does she think it's time for that change?

STEIN: Well, until now, there's been a big question about these genes which is no one knew how much it increased the risk for the average women. And she did a study to try to answer that key question. She just published the results of that study, and she says that it showed that the mutations in these genes increased the risk for ovarian and breast cancer the same for women, no matter whether or not they have a family history or not. So based on that she thinks it's time to expand screening significantly.

GREENE: Brand-new study - have other scientists had a chance to react to this yet?

STEIN: You know, it's all brand-new and really just come out, but I've spent some time over the last few days talking to advocates and other scientists to see what they think about this. Some other scientists agree with her. They say, yeah, this is really convincing evidence, and it's time that women could really use this information to take steps to protect themselves. They could undergo regular MRIs or mammography to try to detect cancer early. They could do things like make sure that they eat well, don't smoke to reduce the risk for breast cancer.

Now, others are saying wait a minute, this could be the case, but it's way too early for any of that. First of all, we have to validate what Dr. King has found and we also - there's a big debate already about mammography and the value of mammography, and there's big concerns about what would happen if we started screening so many women.

GREENE: You mention the debate over mammography. There has been a long-standing conversation about how much testing to do and whether there can be over-testing. Why are some scientists concerned about over-testing?

STEIN: You know, well, testing has implications, and women tend to do things based on the results. And their fear with mammography is that women end up getting treated for things that never would have been life-threatening. They end up getting surgery, radiation, chemotherapy when they didn't need to be treated in the first place, and there are similar concerns in this situation. Their worry is that, what are women going to do if they test positive?

A lot of people might have heard about Angelina Jolie. She had a double mastectomy after testing positive, and a lot of women might consider getting double mastectomies; they get their ovaries removed to protect themselves from ovarian cancer. And these are major surgeries, and so the people who are worried about this are saying, we got to be absolutely sure that we know what these results mean and what to tell women if they test positive.

GREENE: That was NPR's Rob Stein. We were speaking to him about a controversial new recommendation that all women over 30 be tested for gene mutations linked to a higher risk of breast cancer. Transcript provided by NPR, Copyright NPR.

Rob Stein is a correspondent and senior editor on NPR's science desk.