For Sarah Theresa Gonzales of Bronx, N.Y., her cousin's death last year from lung cancer was a wake-up call.
"I was fearful that I was going to get cancer," Gonzales, 55, said. "I think it was this anxiety that got to me. I just grabbed my cigarettes, grabbed my lighter, grabbed everything and dumped it down the incinerator."
Gonzales had smoked for 31 years. She decided to quit June 15, after logging on to the "cold turkey" quitting-forum-cum-support-group WhyQuit.com. She has not taken a puff since.
In the past decade, the fear of cancer has driven Gonzales and millions of other Americans to kick the smoking habit -- a fact that some doctors say could be a major contributor to an overall down-tick in cancer incidence reported today in the Journal of the National Cancer Institute.
Looking at the 15 most common cancers found in men and women, researchers found that the overall cancer rate has dropped 0.8 percent per year from 1999 to 2005.
Never before in the history of the annual study -- a collaboration between the American Cancer Society, the Centers for Disease Control and Prevention, the National Cancer Institute and the North American Association of Central Cancer Registries -- has the number of cancer cases in the United States decreased.
Cancer experts agreed that the drop is good news. "The decline in both incidence and mortality together is exceptional, and has not been seen in the previous years that the report has been published," said Dr. Len Lichtenfeld, deputy chief medical officer for the national office of the American Cancer Society.
"For the most part, it is a good news story in that much of the decline can be attributed to things we have done, such as stopping smoking [for men] and getting screened for colorectal cancer."
But the study does not provide all the answers as to why the downturn may have occurred. And it remains uncertain whether the lower cancer incidence rate will be sustained in years to come.
The overall decline is mostly a function of drops in some of the most prevalent cancers. Among men, for example, lung, colorectal and prostate cancers all showed declines. Rates of breast and colorectal cancer in women also decreased.
But even among those cancers, the declines are likely less a function of one particular factor and are due more to a combination of changes in behavior and screening.
Still, noted ABC News medical editor Dr. Tim Johnson, smoking cessation likely played a yeoman's role in the downturn, particularly because it is implicated not only in lung cancer but in other cancers too.
"The most significant thing to talk about now is for people to stop smoking," he said. "There's nothing that comes close to it in terms of direct impact on cancer rates."
Dr. John Spangler, director of tobacco-intervention programs and a professor of family medicine at Wake Forest University School of Medicine in Winston-Salem, N.C., agreed. "Many of the cancers that reported declines are smoking-related, such as lung, breast and prostate cancers. So I think this is a remarkable statement on the progress of tobacco control we have made nationally."