CANCER DEATHS, CASES ON DECLINE; STUDY SHOWS TURNAROUND.

Byline: David R. Baker Daily News Staff Writer

In what researchers say could be a turning point in the fight against cancer, a national report released Thursday showed the first sustained drop in cancer rates in 20 years.

Driving much of the decrease was a decline in the number of lung cancer cases as more Americans swear off smoking. Although the study didn't include Los Angeles County, the American Cancer Society projects a slight decrease in new lung cancer cases here, from 4,345 last year to 4,300 this year.

After decades of rising cancer incidence and death rates, many doctors greeted the five-year study with cautious relief. Perhaps, they said, years of preaching the importance of cancer screening tests and healthy lifestyles was starting to pay off. Also new treatments are keeping alive patients who in an earlier time would have died, doctors said.

``There are many people who are survivors - people who are living with cancer,'' said co-author Harry M. Rosenberg, of the National Center for Health Statistics. ``This used to be a death sentence.''

By extending the trend, the number of people who die from cancer each year could be cut in half from where it stands now, at 500,000 nationwide, said Dr. Lowell Irwin, a professor at the University of Southern California and medical director of the Cancer Detection Center in Los Angeles.

``If we keep going, if we keep pounding the pavement, telling patients what they need to do, cajoling them and kicking them in the butt - we can save 250,000 lives,'' Irwin said.

California's concerted anti-smoking campaign is credited with pushing down the number of smokers to record lows.

The study - a collaboration among the American Cancer Society, the National Cancer Institute and the Centers for Disease Control and Prevention - looked at data collected between 1990 and 1995. It examined the incidence and deaths attributed to more than 20 types of cancer.

Researchers also studied how incidence and death rates differed between races and sexes.

Most of the results were encouraging.

After climbing 1.2 percent per year between 1973 and 1990, the rate of new cases for all cancers dropped an average of 0.7 percent per year. Cancer death rates fell by an average of 0.5 percent per year of the study.

Not everyone shared equally in the good news. The drop in mortality rates was greater among men than among women, a difference the study's authors attributed to the rising number of women who smoke. And cancer incidence rates actually rose among African-American men and stayed level for Asian-American and Pacific Island women.

``We realize that the declines in cancer incidence and deaths have not been seen for all Americans and that our collective efforts must be directed at reaching populations with a disproportionate cancer burden,'' said James S. Marks with the CDC.

Some doctors said Thursday that part of the apparent turnaround in cancer rates may be due to underreporting cancer among African-Americans, Latinos and other ethnic and racial groups.

Lovell A. Jones, a professor at the University of Texas and co-director of the Intercultural Cancer Council, noted that the study only looked at 9.5 percent of the United States population.

Researchers studied cancer information from five states - Connecticut, Hawaii, Iowa, New Mexico and Utah - as well as four metropolitan areas, including Atlanta, Detroit, San Francisco-Oakland and Seattle-Puget Sound.

``If you're talking about Hispanic Americans, you don't have Texas - if you're talking about African-Americans, you don't have Louisiana or Alabama,'' Jones said. ``You're eliminating a lot of the American population.''

Other doctors welcomed the apparent turnaround in cancer rates, even if they didn't know all of the forces behind the changes.

For example, the decline in mortality rates can be tied, in part, to more aggressive screening for different kinds of cancer. But the drop in new cases of cancers not related to smoking could be due to a number of things, like better eating habits or decreasing levels of carcinogens in the environment.

``The more you look, the more questions you find,'' said study co-author Brenda K. Edwards, with the National Cancer Institute.