ALEX CHADWICK, host:
From the studios of NPR West, this is DAY TO DAY. I'm Alex Chadwick.
MADELEINE BRAND, host:
And I'm Madeleine Brand. Coming up, Israel's top military official has resigned. What will that mean for Mideast politics?
CHADWICK: First, for once a lead that's good news: Cancer deaths are actually falling in this country. A report released today says the total number of cancer deaths in the U.S. declined for two consecutive years. The biggest decline was in deaths from colorectal cancer.
Researchers credit fewer people smoking, more people getting screening tests. NPR's science correspondent Jon Hamilton has been looking at the figures. Jon, welcome back. Tell us about the study.
JON HAMILTON: Well all right. This is a study that's done every year by the American Cancer Society. And it looks at death certificates. Death certificates include the cause of death, so you know how many people died of cancer.
And those statistics are a couple years old. But this year they were looking at changes in cancer deaths between 2003 and 2004. And what they found, was there was an overall decrease.
That was primarily because there were fewer deaths from the most common cancers like lung cancer, breast cancer, prostate cancer. The most dramatic decrease was actually in cancer of the colon and rectum.
CHADWICK: So the number was what - how big was this drop?
HAMILTON: Well, it was a small but significant drop. In 2003, there were about 557,000 cancer deaths in the U.S. In 2004, the second year they looked at, there were about 554,000. So that's a drop of 3,000 deaths.
Now, that's less than 1 percent. But the actual drop is larger because you have to remember that the U.S. population is growing. So what's happened is that the lung cancer - is that the cancer deaths are decreasing faster now than the population is increasing.
CHADWICK: So now we've noted that this is the second year in a row. The first year of this study they noted a very slight decline in deaths - what, a few hundred. So you didn't even know if that was just kind of a statistical aberration.
HAMILTON: That's exactly right. There was a lot of arguing about last year's number. It was a very small drop. And with such a small drop in such large numbers - you know, the well over a million Americans get cancer every year; more than a half a million die of it.
So when you're talking about a few hundred cases, that's not enough to really draw conclusions. This year was important because one, it showed the same trend, another decrease, and two, because it was a much larger decrease than last year.
So I think a lot of statisticians are going to be much happier about this year than last year, although there will be others who say we still need to go out several more years to be sure we know what's going on.
CHADWICK: And Jon, what about the biggest decline here: colon cancer?
HAMILTON: Well, colon cancer is an interesting case because it may give some indication of why these cancer deaths are declining.
Colon cancer is a cancer that you can actually stop before it starts. And that's unusual. Colon cancers start out as colon polyps, which are not cancerous. And if you do screening tests, you can find these polyps and you can actually remove them before they become cancers.
So if more people are having these screening procedures, like colonoscopy, then fewer people actually develop colon cancer and so fewer people will die of it.
CHADWICK: Are there better treatments for cancer that are a big part of this decline?
HAMILTON: There are better treatments for some cancers. But it's not at all clear that that's why this decline is going on. In fact, the evidence suggests that it's better detection and changes in lifestyle, things like not smoking, that are responsible for this decline, not huge improvements in cancer treatments.
The dramatic improvements in treatment have been with relatively rare cancers. But when you look at the major cancers - lung cancer and breast cancer and prostate cancer and colon cancer - the treatments are not hugely better than they used to be.
CHADWICK: So what is the Cancer Society hoping people get from this?
HAMILTON: Clearly what they're hoping is that people get that screening is the way to save lives. If you have colonoscopy, if you have these screening tests for breast and prostate and colon cancer, then you are much less likely to die.
CHADWICK: From the NPR science desk, Jon Hamilton, reporter. Thanks, Jon.
HAMILTON: You're welcome.
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