Good News. New research suggests that cancer incidence and mortality rates are on the decline. Elizabeth Farnsworth speaks with a medical expert to find out more.
ELIZABETH FARNSWORTH: There was good news from the cancer front today. A new report shows that after almost 20 years of rising cancer incidence and death rates, both declined between 1990 and 1995. The incidence rate decreased an average 0.7 of a percent a year in those years, after having increased 1.2 percent per year in 1973 to 1990.
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And the cancer death rate decreased an average of 0.5 of a percent a year during 1990 to 1995, after increasing 0.4 of a percent per year during 1973 to 1990. And here to tell us more is Dr. Richard Klausner, director of the National Cancer Institute, one of the organizations which contributed to the new report.
Dr. Klausner, thanks for being with us.
DR. RICHARD KLAUSNER, Director, National Cancer Institute: Thank you, Elizabeth.
ELIZABETH FARNSWORTH: On the incidence figures, how many fewer cases a year does this translate into?
DR. RICHARD KLAUSNER: Well, as you said, incidence rates have been rising for decades, and then they began falling over the last three to five years. For the latest year that we have numbers--1995, which we reported, because of these changes, there's about seventy to a hundred thousand fewer cases of cancer than would have existed if the historical trends continued. Likewise, for mortality, it translates to about twenty-five to thirty thousand fewer deaths in 1995 than we would have expected.
ELIZABETH FARNSWORTH: Could it be a temporary fluke?
DR. RICHARD KLAUSNER: Well, we hope not. All of the signs that we have about the causes of this suggest that is a trend that will continue. And, indeed, we've taken a preliminary look at the following year's numbers and they show continuing encouraging results.
ELIZABETH FARNSWORTH: Speaking generally still, why do you think this is happening? We just heard the discussion about the new tobacco legislation. What does this have to do with decreasing smoking rates, if anything?
Decreasing smoking and cancer rates. A connection?
DR. RICHARD KLAUSNER: Well, decreasing smoking rates, among adults, smoking rates have decreased almost 50 percent over the last 20 to 30 years, since the first surgeon general's report, and that accounts for about 30 percent of the drop. Cancer rates and cancer trends are very complex. They represent the interaction of multiple factors, changing diet, changing medical care, changing early detection. All of these contribute to the changes that we reported today.
ELIZABETH FARNSWORTH: Okay. Now looking at some specific kind of cancer, beginning with lung cancer, talk to us--tell us about those figures. The lung cancer rate is down.
DR. RICHARD KLAUSNER: Lung cancer is an epidemic, has been an epidemic that exactly tracks with tobacco use. And its rise and then fall recently in men is due to the results of men stop--decreasing their tobacco use. Women have--took up tobacco later and stopped using it later, and so their cancer mortality rates are falling less rapidly.
ELIZABETH FARNSWORTH: What other sorts of cancer show a decrease--a decline in incidence?
DR. RICHARD KLAUSNER: Well, breast cancer incidence rates have been rising again for several decades. Now they're flat. Colorectal cancer, which is the second most common cause of cancer death, is falling a significant rate, and prostate cancer rates are falling.
Good news that has economic and ethnic qualifications.
ELIZABETH FARNSWORTH: Speaking of breast cancer, is it--I think I read in your report that the breast cancer for African-American women is 30 to 60 percent higher than it is for other women, is that right?
DR. RICHARD KLAUSNER: That's right. The mortality rate from breast cancer, not the incidence rate--
ELIZABETH FARNSWORTH: We'll get into mortality in a minute.
DR. RICHARD KLAUSNER: Incidence rates for breast cancer among African-American women are actually lower than for white women. But their mortality rates are higher. And this is something we're very concerned about. For black American women mortality rates are not dropping for breast cancer, where they are dropping quite significantly for white American women.
ELIZABETH FARNSWORTH: And let's stay on the subject of minority cancer rates. As you know, there's been some criticism of this study already from people who say that your figures are not representative of minority groups or of the rural poor. Is that true? Are you missing large groups of people here in this study?
DR. RICHARD KLAUSNER: These numbers are based upon a system that the National Cancer Institute runs that samples about 10 percent of the population. It samples about 10 percent of the white population, about 10 percent of the black population, about 50 percent of the Asian-American population, and about 30 percent of the Hispanic-American population. So, in fact, several of the minorities are what we call over-sampled to make sure that our numbers are reliable for minorities. We think these numbers are reliable.
ELIZABETH FARNSWORTH: Still on the incidence, which cancers are really going up in incidence?
Melanoma, non-Hodgkin's Lymphoma, and brain cancer still on the rise.
DR. RICHARD KLAUSNER: Cancers that are going up include melanoma, non-Hodgkin's Lymphoma, and brain cancer. Most other cancers are either flat or beginning to go down.
ELIZABETH FARNSWORTH: Do you know why those are going up?
DR. RICHARD KLAUSNER: No, we do not know why they are going up. And we are studying that, but that's part of the mystery behind these numbers.
ELIZABETH FARNSWORTH: Now, on the mortality rate, in general, you have reported a couple of years ago--and we talked to you about it--that the mortality rates were down. What's the most important finding on mortality this year?
DR. RICHARD KLAUSNER: That the mortality rates--the most important finding is that mortality rates continue to go down, and for some groups, especially younger Americans, that is, Americans below the age of 65, it's really quite significant. And so we're seeing mortality rate drops for lung cancer, for colorectal cancer, for prostate cancer, and for breast cancer, as well as bladder cancer, and several other important cancer sites.
ELIZABETH FARNSWORTH: And why is that? Why are the mortality rates staying down?
DR. RICHARD KLAUSNER: Well, cancer is many different diseases, and so there's no one answer. Some of it is due to decreased incidence, say for lung cancer, but for some it's due to improved therapy, we believe, such as for breast cancer, for colorectal cancer. For some, it's due to a combination of improved therapy and earlier detection when our current therapies are more effective. There is no one answer. This is not one disease. And it reflects the fact that it's important that we pay attention to both prevention, to early detection, to better diagnose, and to better treatment and to making sure that what we know is applied and applied to all Americans.
ELIZABETH FARNSWORTH: What about environmental factors, do they come into play here?
DR. RICHARD KLAUSNER: Environmental factors, of course, are complex. Tobacco is an environmental factor--alcohol use--diet--obesity--exercise. There are many factors. We're not--we don't know of any particular environmental factors in terms of environmental chemicals, per se, that we can attach these numbers to.
ELIZABETH FARNSWORTH: Dr. Klausner, about 1/2 million people still die of cancer every year. What do you say to people that are listening right now who--I suppose everybody has a family member or a friend who has cancer or who has had cancer--what do you say to them? What should they take from this report?
DR. RICHARD KLAUSNER: I think what they should take is a sense of hope. It means that the investment this country has made in understanding cancer and trying to reduce the burden is beginning to pay off. We expect these numbers will continue to go down. In order to continue to go down, we need to make sure we apply what we know, as I said, and we need to continue to do research. We have a long way to go, as you say. But for the first time in history cancer rates are beginning to move in the direction we'd like to see them go.
ELIZABETH FARNSWORTH: And what do you say to an individual about what they should do in their own lives to prevent cancer?
Prevention still important.
DR. RICHARD KLAUSNER: Well, of course, there's many things. The most important is not to start smoking, if you're not smoking, and to attempt to quit smoking if you are smoking. That's the most important thing. It's important to pay attention to diet, to decrease the amount of meats that you eat and increase the amount of fruits and vegetables. It's very important to pay attention to guidelines for early screening to make sure that people have access to regular medical care and pay attention to any potential signs or symptoms of cancer.
ELIZABETH FARNSWORTH: And finally, Dr. Klausner, are you really excited about these new results? It looks like, looking at the figures, that one could say that the cancer rate, the incidence peaked in the early--very early 1990's, and that it's on its way down. Do you think that graph just may continue going down?
DR. RICHARD KLAUSNER: We certainly hope so. And, as I said, all of our information about improved treatment and improved outcomes and even detection, we actually expect that the major effects of those changes are actually going to kick in over the next several years. So we're actually very excited and optimistic that these rates will--these trends will continue. But we're very concerned about disparities among older Americans and especially among African-Americans.
ELIZABETH FARNSWORTH: Okay. Thank you very much.