Obesity a colon cancer risk for young women

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Obese young women have nearly double the risk of developing early onset colon cancer compared to those in the normal weight range, according to US research. The study looked at over 80,000 women aged 25 to 42, and found that overweight women had a 37 per cent increased risk of developing colon cancer by age 50 while for obese women the risk was 93 per cent higher, nearly double, although the total number of cases was still low. Women's current size, their size at 18 years of age, and weight gain since early adulthood were all linked to the colon cancer risk.

Journal/conference: JAMA Oncology

Organisation/s: Washington University School of Medicine, USA

Funder: This work was supported by grants UM1 CA176726 (Willett), R01 CA205406 (Ng), R35 CA197735 (Ogino), R01 CA137178 (Chan), K24 DK098311 (Chan), and K07 CA218377 (Cao) from the National Institutes of Health. Dr Chan is also supported by a Crohn’s and Colitis Foundation Senior Investigator Award and a Stuart and Suzanne Steele Massachusetts General Hospital Research Scholars Award. Dr Cao is supported by the Raymond P. Lavietes Foundation and a National Comprehensive Cancer Network Young Investigator Award

Media Release

From: JAMA

Obesity Associated With Higher Colorectal Cancer Risk Among Younger Women

Bottom Line: Obesity was associated with an increased risk of early onset colorectal cancer (CRC) among women younger than 50.

Why The Research Is Interesting: New cases of CRC and death are increasing among people younger than 50 and the reasons for this are largely unknown. This study used data from a large group of women in the Nurses’ Health Study II to examine the association of obesity with CRC diagnosed before age 50.

Who and When: 85,256 women ages 25 to 42 who were free of cancer and inflammatory bowel disease when they enrolled in the study and followed up from 1989 through 2011.

What (Study Measures and Outcomes): Current body mass index (BMI), BMI at age 18 and weight gain since age 18 (exposures); relative risk, which is a statistical measure of probability, for new early onset CRC (outcome)

Study Design: This was an observational study. Researchers were not intervening for purposes of the study and cannot totally control for all the natural differences that could explain the study results.

Authors: Yin Cao, M.P.H., Sc.D., of the Washington University School of Medicine, St. Louis, Missouri, and coauthors

Results: There were 114 cases of early onset CRC among the 85,256 women studied. Higher current BMI, BMI at age 18 and weight gain since early adulthood were associated with increased risk of early onset CRC. Obesity, which is a BMI of 30 or above, was associated with highest risk.

Limitations: The study included mainly white women so the findings need to be validated among other races/ethnicities and among men.

Study Conclusions: Obesity and weight gain since early adulthood were associated with increased risk of early onset CRC. This study highlights the importance of weight control throughout life and the potential role of body weight in complementing CRC screening for the early detection of early onset CRC.


Editor’s Note: The article contains conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

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