Cancer incidences, deaths decline

Reports of cancer and deaths attributed to cancer are on the decline in the United States for the first time in nearly 20 years, according to the latest report from the American Cancer Society, the National Cancer Institute and Centers for Disease Control and Prevention.

In the report, "Cancer Incidence and Mortality, 1973-1995: A Report Card for the United States," which appeared in the March 15, 1998 issue of Cancer, researchers stated that incidences and death rates for most of the top 10 cancers dropped between 1990 and 1995.

Explanations for the decline are debatable, the researchers said, and deserve further examination. For example, more aggressive screening programs for breast cancer, colon cancer and prostate cancer may be reasons for declines in those cancer sites.

New adjuvant therapies and surgical treatments may also contribute to the trend. But national trends in cigarette smoking may deserve the most attention.

"[One of] the three important messages in the report has to do with lung cancer and smoking," said key researcher Phyllis Wingo, Ph.D., epidemiologist.

Smoking habits in the United States, particularly among white males, changed significantly over the past 30 years. Fewer than 25% of adults smoked as of 1995 compared with 42% of adults in 1965, according to the report.

Smoking habits changed the most among white males. Not coincidentally, this population group also showed the greatest decline in lung cancer incidences.

"While that sounds very good, we need to be vigilant about cigarette use in high schools, where smoking among teens is on the rise" Wingo said. "We need to stay focused on smoking cessation programs. Ninety percent of adult smokers started smoking when they were teenagers," she added.

According to the report, the incidence rates for all cancers fell a combined average of 0.7% per year during that time period. The biggest drop occurred after 1992, when incidence rates for all cancers began decreasing by an average of 2.7% per year. From 1973 to 1990, rates had increased an average 1.2% per year.

Differences among age groups, the sexes and most racial and ethnic groups were minimal, the report showed.

There were two exceptions, however: black men, whose incidence rate increased due to a 3.9% annual increase in prostate cancer reports, and Asian and Pacific Islander women, who showed no change in rate.

Cancer deaths, meanwhile, declined by approximately 0.5% per year from 1990 to 1995. From 1973 to 1990, cancer death rates had risen 0.4% per year.

Men and people between ages 35 and 44 or older than 75 have reason to be optimistic, as they accounted for the greatest decreases in the death rate. The rate for men, for example, fell 0.9% while the rate for women fell 0.1%.

The report's findings were based on incidence data from the National Cancer Institute's Surveillance, Epidemiology and End Results Program, which represents about 9.5% of the U.S. population, and on mortality data from the Centers for Disease Control and Prevention's National Center for Health Statistics, which includes 100% of the population's death certificates. PR