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.