Most cancers less common, less deadly.

Cancer deaths in the United States declined steadily between 1990 and 1996, resulting in a total drop of about 4 percent, according to a new report. The number of new cancer cases diagnosed annually also dropped, by 0.9 percent each year.

Reductions in lung cancer helped drive the overall decrease in cancer rates, but this trend could change since more young people are smoking, warns Phyllis A. Wingo of the American Cancer Society in Atlanta. She and her colleagues from the National Cancer Institute (NCO in Bethesda, Md., and the Centers for Disease Control and Prevention in Atlanta present their results in the April 21 JOURNAL OF THE NATIONAL CANCER INSTITUTE.

The researchers analyzed cancer data from five states and six cities, representing 14 percent of the U.S. population. Many of the most common and most deadly cancer types declined during the 7-year period. Diagnoses of leukemia and colon, bladder, and oral cancer dropped, while the rates of breast- and uterine-cancer diagnoses in women remained steady. However, new melanoma and non-Hodgkin's lymphoma cases increased.

Death rates declined for cancers of the colon, pancreas, brain, prostate, and stomach, as well as for breast cancer in women. However, melanoma and non-Hodgkin's lymphoma fatalities, like diagnoses, rose.

No one knows why non-Hodgkin's lymphoma rates are increasing, says Brenda K. Edwards of NCI. It's a cancer of the immune system that could be triggered by chemicals or viruses, including HIV, she says.

The number of new lung-cancer cases and deaths from that disease are dropping in men, but the incidence and death rate continue to climb for women. The rate of new diagnoses was highest among blacks and lowest among Hispanics.

"Tobacco ... has condemned our nation to a grimy sea of preventable cancer," says Howard K. Koh of the Massachusetts Department of Public Health in Boston in an article accompanying the report. Lung cancer, once a medical rarity, now kills more people than any other type of cancer. "Future medical historians will undoubtedly recall the 1900s as the 'tobacco and cancer' century," he predicts.