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Study ties rise in some cancers to obesity, inactivity

Cancer deaths in the United States continue to fall, thanks to better screening, treatment advances and efforts to prevent some cancers by reducing smoking and other unhealthy behaviors. but a major, new government report highlights a worrisome rise in cases linked to obesity and inactivity.

Overall cancer death rates decreased an average of 1.6 percent a year between 2004 and 2008, the most recent years for which data is available.

Still, the report confirms research showing excess weight and a sedentary lifestyle are risk factors for one-quarter to one-third of common cancers. About one-third of adults — nearly 78 million — are obese, roughly 30 or more pounds over a healthy weight.

“Americans don’t understand the association between cancer and obesity,” says Dr. Marcus Plescia, director of the division of cancer prevention for the federal Centers for Disease Control and Prevention. “They know about the links [from obesity] to diabetes, heart disease and arthritis, but many don’t know about this.”

The report, published in the journal Cancer, is co-authored by researchers from the CDC, the North American Association of Central Cancer Registries, the National Cancer Institute and the American Cancer Society.

Maintaining a healthy weight and getting sufficient exercise could be among the most important ways to prevent cancer, the authors write. The risk factors are second only to tobacco as preventable causes of disease and death nationwide.

Obesity also diminishes quality of life for cancer survivors and may worsen the prognosis for several cancers, the authors write.

The American Cancer Society estimates that a third of the more than 572,000 cancer deaths in the United States each year can be attributed to diet and physical activity habits, including being overweight, while another third are caused by exposure to tobacco products.

The biggest increase in new cases was seen in kidney cancer: 2.9 percent a year among men from 1999 to 2008, 3.3 percent among women.

Also increasing: pancreatic cancer, adenocarcinoma of the esophagus and uterine cancer.

Obesity and inactivity can lead to cancer by altering hormone and insulin levels, causing chronic hypertension and contributing to damaging inflammatory agents.

“If we want to see continued decrease in the mortality rates for cancer, we have to promote behaviors such as losing weight, being active and giving up smoking,” says report co-author Ahmedin Jamal, vice president of surveillance research for the American Cancer Society.

Source: Gannett News Service