Smoking may cause most premature cancer deaths in U.S. black men, says a new study.

The study estimates that smoking may have been involved in 63 percent of black men's cancer deaths in 2001. The figures, published in Preventive Medicine, come from Bruce Leistikow, MD, MS, and Alexander Tsodikov, PhD, of the University of California, Davis.

To put that in perspective, consider statistics from the American Cancer Society (ACS). Blacks' cancer death rates have been dropping but remain higher than for other ethnic groups, says the ACS. The cancer death rate for black men is 40 percent higher than for white men, says the ACS, which does not lay the blame on any one cause.

"There is a lot of confusion about what causes the worst cancers — those that destroy families by ending lives prematurely," says Leistikow in a news release. "This study clarifies that the best explanation for most premature cancer deaths for African-American males is tobacco smoke exposure, whether from secondhand or active smoking."

Read WebMD's "Quit Smoking: Your Guide to Kicking the Habit"

Regional Results

The South had the worst numbers for smoking-related cancer death rates in 2001, followed by the Midwest. Still, the lowest rate — seen in the Northeast — showed that more than four out of 10 cancer deaths in black men could have been related to smoking.

Here are the study's regional estimates for black men's 2001 cancer deaths:

— U.S.: 63 percent

— Northeast: 43 percent

— Midwest: 63 percent

— South: 67 percent

— West: 60 percent

The South "by far" had the steepest smoking-cancer death figures from 1969-2001, says the study.

Leistikow says states in the North and West have some of the country's strongest tobacco-control programs, while those in the South and Midwest have been slower to adopt policies like higher cigarette taxes, smoke-free spaces, antismoking education programs, and penalties for selling tobacco to minors.

The findings only cover black men and should not be applied to black women or people in other ethnic groups, says the report.

Estimates are based on cancer and smoking statistics from sources including the CDC, National Cancer Institute, and other studies. Previously, Leistikow reported that smoking might have caused 38 percent to 72 percent of black men's cancer deaths in 2000. The new study tried to narrow down that range.

Medical screening and a healthy lifestyle may help manage cancer risk in people of any race.

The researchers say that more research is needed to better assess the relevance of the study's findings to women and other ethnic groups, time periods, and diseases.

Read WebMD's "Why 7 Deadly Diseases Strike Blacks Most"

By Miranda Hitti, reviewed by Brunilda Nazario, MD

SOURCES: Leistikow, B. Preventive Medicine, August 2005; vol 41: pp 380-385. American Cancer Society: "Closing the Black-White Cancer Gap." News release, University of California, Davis.