Smoking, Obesity Trends Affect Cancer Rates

From the WebMD Archives

April 28, 2004 -- Americans smoke less but weigh much more than they did just a few years ago, and both trends will dramatically affect future cancer rates, according to a report from the American Cancer Society (ACS).

The society's annual report on cancer prevention trends also shows that screening rates have improved overall but still remain well below targeted levels for many malignancies, most notably colorectal cancer.

ACS officials estimate that the death rate from cancer could be cut in half if the prevention strategies now known to be effective were followed. More than 180,000 cancer deaths each year can be linked to tobacco use, and the report suggests that a third of all cancers are related to poor nutrition, physical inactivity, being overweight, or other lifestyle factors.

Among the report's highlights:

  • Smoking rates among high school students have dropped to the lowest levels in almost a decade but remain high at roughly 29%.
  • Among adults, roughly one in four men and one in five women still smoke, but smoking rates across all education levels continue to decline.
  • Almost 74% of women with health insurance aged 40 and over reported having had a mammogram within the past two years, but only 40% of women without health insurance and 41% of recent immigrants reported being screened.
  • Colorectal cancer screening rates are rising but remain low. Although early detection can boost survival from the cancer to more than 90%, fewer than half of adults aged 50 and older are screened.

Spotlight on Obesity

While smoking and screening have long been on the ACS radar screen, the focus on body weight and exercise in the 2004 report is somewhat new.

"We have known for a long time that obesity is strongly linked to diabetes and heart disease, but it is really only recently that we began to understand the important link between being overweight and cancer risk," ACS director of surveillance research Elizabeth Ward, PhD, tells WebMD.

Obesity has been linked to an increased risk of death from 11 different cancers in men and 12 in women. Almost 69% of the adults in the U.S. are overweight, with 21% considered obese. Obesity rates among adults increased by 75% between 1991 and 2001, with similar increases seen among children and teens.


Being morbidly obese -- having a body mass index (BMI) of 40 or more or being 100 pounds or more overweight -- has been shown to double a woman's risk of dying from breast cancer. It is associated with an even greater increase in death risk from less common cancers like those of the cervix, kidney, and uterus. The BMI measurement is one of the most accurate ways to determine whether an adult is overweight.

Among both sexes, obesity is linked to an increase in deaths due to colorectal cancer. And studies suggest that a man's risk of dying from liver cancer is more than quadrupled if he is obese.

Lost Opportunities

The decline in smoking among teens over just the last few years is one of the most promising trends outlined in the report. Smoking rates among white females, for example, dropped to 31% in 2001 from 39% just three years earlier. Similar declines were seen for males and across all racial groups.

The decline coincided with a ban on cigarette promotions targeting young people, which was part of the landmark 1998 tobacco settlement. The banishment of Joe Camel and the Marlboro Man from rock concerts and other teen-populated venues is considered a major success in terms of impact on smoking. But the promise of the $206 billion, 25-year settlement has yet to be fulfilled in other ways, ACS officials say.

The windfall was originally intended to go toward health care and tobacco control efforts. But only about half of the money paid out in 2001 went to health care and just 6% was spent on programs to prevent smoking and help people quit.

"To say this is disappointing is a huge understatement," says ACS director of cancer science and trends Thomas Glynn, MD. "This is a once-in-a-lifetime opportunity that was handed to the states and the American people on a silver platter. Instead of reducing the burden of tobacco use for generations to come, much of this money is being squandered."

The report calls on lawmakers to raise taxes on tobacco and increase funds for advertising aimed at reducing teen smoking and cessation programs targeting adults.


Ward tells WebMD that spending more on these programs is an investment in the future.

"Funding tobacco control programs will result in returns that are as good as or better than any stock investment," he says. "We can guarantee that states will spend less on health care 10 or 15 years down the line if they invest now. No stock can promise that."

WebMD Health News Reviewed by Charlotte E. Grayson Mathis, MD on April 28, 2004


SOURCES: American Cancer Society Cancer Prevention and Early Detection Facts and Figures 2004. Elizabeth Ward, PhD, director of surveillance research, department of epidemiology and surveillance research, American Cancer Society. Thomas Glynn, MD, ACS director of cancer science and trends.

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