News Summary

New research from the University of Minnesota School of Public Health and Masonic Cancer Center provides further evidence that maintaining normal body weight may reduce the risk of dying from colon cancer.

Quotes

“The exact mechanisms underlying the link between obesity and higher mortality of colon cancer patients are unknown,” said Anna Prizment, Ph.D., M.P.H., University of Minnesota School of Public Health and Masonic Cancer Center. “Obese people may be diagnosed at a later stage, receive different treatment, or have other health problems."

“Obese women, especially those with higher abdominal obesity, have higher hormone levels and may have a more aggressive cancer," Prizment said. "These types of women are already known to have a higher risk of developing colon cancer.”

“This may be especially beneficial for women diagnosed with colon cancer later in life,” she said. “It also looks like abdominal obesity may be an indicator of higher colon cancer mortality.”

Full Text

New research from the University of Minnesota School of Public Health and Masonic Cancer Center provides further evidence that maintaining normal body weight may reduce the risk of dying from colon cancer.

University researchers have found that postmenopausal women who carry an increased amount of weight around their abdomen, known as the apple-shaped body type, are more likely to die after being diagnosed with colon cancer. This is among the first research studies to examine the link between waist-to-hip and waist obesity and survival of cancer patients.

Anna Prizment, Ph.D., M.P.H., cancer researcher with the University of Minnesota School of Public Health and Masonic Cancer Center, is a lead author of the study recently published in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Prizment and her colleagues used data from 1,096 women enrolled in the Iowa Women’s Health Study who were diagnosed with colon cancer and followed during a 20-year period. During that time, 493 of the women died and 289 of them died specifically from colon cancer.

The researchers found:

• Obese women with a body mass index (BMI) of at least 30kg/m2 had a 45 percent increased overall mortality rate.
• Women classified as underweight, with a BMI less than 18.5 kg/m2, had an 89 percent increased mortality rate compared to women with normal BMI.
• Apple-shaped women with high waist-to-hip ratio had a 30 to 40 percent greater risk of death related to colon cancer.

“The exact mechanisms underlying the link between obesity and higher mortality of colon cancer patients are unknown,” Prizment said. “Obese people may be diagnosed at a later stage, receive different treatment, or have other health problems."

However, the facts that the increased abdominal obesity was associated with colon cancer death and those associations persisted after correcting for age, stage of cancer diagnosis, and other health problems, indicate that obesity may have a direct biological effect, she said.

“Obese women, especially those with higher abdominal obesity, have higher hormone levels and may have a more aggressive cancer," Prizment said. "These types of women are already known to have a higher risk of developing colon cancer.”

More research is needed to determine the effect of obesity, and particularly abdominal obesity, on the prognosis of older women diagnosed with colon cancer.

Meanwhile, Prizment encourages women to maintain a healthy body weight throughout their lives.

“This may be especially beneficial for women diagnosed with colon cancer later in life,” she said. “It also looks like abdominal obesity may be an indicator of higher colon cancer mortality.”

The study was funded by the National Cancer Institute.