DNA Finding May Aid Breast Cancer Fight

Breast cancer runs in families, but finding the genes responsible has proven difficult. Now scientists have found five more regions of DNA that may be tied to an increased risk of breast cancer.

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DEBBIE ELLIOTT, host:

Several promising new studies on the genetics of breast cancer are out today and they could provide a new direction for researchers. In recent weeks, there's been an explosion of new information about the genetics of common diseases. Scientists have found potential genetic culprits for obesity, diabetes, heart disease and bipolar disease, to name a few, as well as breast cancer.

Here to talk about the reasons behind this recent flood of genetic news and explained what it means for medicine is NPR science correspondent Joe Palca. Hello, Joe.

JOE PALCA: Hey, Debbie.

ELLIOTT: What are the latest findings on breast cancer?

PALCA: Well, Debbie, there are a couple of papers - actually I should say there's a group in England, there's a group in the U.S., there's a group even in Iceland, and what they've found is specific areas in the human genome -that's all the DNA that we have in all our cells, these are specific areas in this giant three billion letters of DNA that seemed to be related to breast cancer.

Now, what are we talking about when we say seemed to be related? What does this mean? Well, in the past, when scientists were looking for genes related for diseases, they kind of went house to house, you can think of - if you think of the genomes, three billion letters, a bunch of neighborhoods - this going to house to house and saying, you're involved, and you're involved, and you're involved. This new approach says, I don't know which house is involved, I have no idea. So I'm going to stand back, sort of like if you're in a satellite taking a picture of Earth from orbit.

So now, they're standing back and they're looking at the entire genome, all the DNA, and they're saying, which areas are involved? Which area is light up, let's say? And they compare women who have breast cancer and women who don't, and they try to find areas that are only lighting up in the breast cancer women and not lighting up in the other women. So it's these regions that they're identifying using this new techniques that's called Genome-Wide Association Studies. They know what the areas do yet, but they're pretty sure that they're involved in breast cancer.

ELLIOTT: Well, how many women have this region that lights up?

PALCA: Well, in the current case, it's quite common. And so you go, oh, well, that's bad news, everybody - but it's really not because these are common diseases, right? And they're many genetic causes. And so, this little regions that there's finding now are important in the fact that they really do seem to be associated with breast cancer, but they're not big risk factors. They don't mean you will get breast cancer. They mean you have slightly elevated risk. And if you don't have this particular area lighting up, it doesn't mean, you know, forget about breast cancer. Unfortunately, there are lots of others that could be important, but it just means that this particular spot has some elevated risk.

ELLIOTT: Why is this significant? Why is it making news?

PALCA: Well, scientists are looking for new understanding of diseases - breast cancer, especially. You know the treatments for cancer are not that great. And so, basically, they're trying to find something new and what this says is we had no idea that this little region in the breast - just to maintain our little analogy - that we've no idea that this is involved. Gee, I wondered what's going on there. Maybe it's really important in some basic way and we can tinker with just that little place and change the whole course of the disease.

ELLIOTT: But it sounds like it's too soon to say that everybody should go get tested to see whether they have this genetic region that lights up.

PALCA: Oh, absolutely. I mean, that's part of the reason that these findings now are both exciting, that it's very important to keep them in context. There is this temptation to say, ooh, do I have, I mean - any kind of risk, I want to know everything I can. The balance is it does not clear yet how important these are going to be, and it would be goofy to try to demand to have this information. A, because there's much you can do with it. I mean - so you're at an increased risk, it's not clear how you're going to change your life because of that; but B, because it hasn't been validated. But it's scientifically very exciting.

ELLIOTT: NPR's Joe Palca. Thank you.

PALCA: You're welcome.

(Soundbite of music)

ELLIOTT:

Coming up, getting back to business on the Mississippi Gulf Coast. We'll tour a small town still without a grocery store nearly two years after Hurricane Katrina.

You're listening to ALL THINGS CONSIDERED from NPR News. Stay with us.

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