The study is the lead article in the May issue of the journal Preventive Medicine. The full text is available at http://www.ucdmc.ucdavis.edu/news/2004/Lung_cancer.pdf.
"African-American men have had the highest cancer burden of any group in this country for decades," said study author Bruce Leistikow, associate professor of epidemiology and preventive medicine at UC Davis School of Medicine and Medical Center. "This study demonstrates, for the first time, that this excess cancer burden can be clearly linked to smoking. Smoke exposure appears responsible for African-American males' high overall cancer mortality rates, not just their lung cancers."
Increasingly, research has linked smoking to deadly cancers other than lung cancer, including cancers of the colon, pancreas and prostate. In his new study, Leistikow found compelling data suggesting that tobacco smoke exposure is responsible for more than half the non-lung cancer death rate in African-American males and up to two thirds of their overall cancer death rate.
"This means that if black male smoking exposures fall dramatically, that alone is likely to erase the great majority of their cancer burden," said Leistikow, a physician epidemiologist who has conducted numerous other studies of smoking and health. "Going back to the low black male cancer burdens seen before the cigarette epidemic appears possible. Indeed, New York and, less so, California appear to be well on their way there."
Leistikow used lung cancer death rates as a measure of smoke exposure. He then analyzed the correlation between annual smoke exposure and non-lung cancer death rates for black males in the United States for the years 1969 through 2000. Throughout this 31-year period, he found that the non-lung cancer death rate closely shadowed the smoke exposure rate. Non-lung cancer mortality rose about 34 percent among black males during the first two decades of the study period, paralleling a steep rise in smoke exposure. During the final decade of the study, from 1990 through 2000, the mortality rate dropped 11 percent, as smoking declined.
"During two decades of a steep rise, and a subsequent decade of steep fall, U.S. black male smoke exposures and non-lung cancer death rates have moved in near-perfect lockstep up and down. The associations are very strong and have been consistent year-by-year for over 30 years," Leistikow said.
African-American male cancer burdens first surpassed white levels in the 1950s. Their cancer mortality rate excess peaked in 1995, at 44 percent above the rate for white males.
According to the latest figures from the U.S. Centers for Disease Control and Prevention, the overall age-adjusted cancer death rate for African-American men is 330.9 deaths per 100,000 individuals, compared to 239.2 for white men. In New York, the overall cancer death rate for black males is 256.7. In California, it's 309.3.
In 1950, before the onset of what Leistikow terms their "cigarette epidemic," the overall cancer mortality rate was 178.9 for black males versus 210 for white males. For the next smoking cessation class at UC Davis Medical Center, please call (916) 734-8493.
Smoking cessation help is also available from the California smokers' helpline at (800) NO BUTTS. Helpline numbers in other states are available at http://dccps.nci.nih.gov/TCRB/quitlines.html. Other sources of help include the American Cancer Society at (800) 227-2345, the American Lung Association at (800) 586-4872 and the National Cancer Institute at (800) 422-6237.
UC Davis Cancer Center is the only National Cancer Institute-designated cancer center between San Francisco and Portland, Ore., and is ranked by U.S. News & World Report as one of the nation's top 50 cancer treatment centers.
Copies of all news releases from UC Davis Health System are available on the Web at http://www.ucdmc.ucdavis.edu/news/.