Weighing Down Life Before Colorectal Cancer

Colorectal cancer patients with high BMIs before diagnosis have shorter lifespans

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Obesity is a known risk factor for colorectal cancer. What has not been known, until now, is if and how the timing of the extra weight impacts life after diagnosis.

The body mass index (BMI) before being diagnosed with colorectal cancer has more influence on how someone fares with the disease than the post-diagnosis BMI.  Those are the findings of a recent study.

"Learn what you're weight needs to be to have a healthy BMI."

Researchers, led by Peter T. Campbell, Ph.D. with the Epidemiology Research Program of the American Cancer Society, designed a study to see how BMI affected the outcomes of people diagnosed with colorectal cancer.

Individuals diagnosed with nonmetastatic (had not spread) colorectal cancer answered questions about their weight and other risk factors in surveys distributed between 1992 and 2007. Participants, which eventually included a total of 2,303 people, also completed periodic follow-up surveys during the study period.

Researchers observed and reported the cause of death among participants from the time of original colorectal diagnosis through December 2008.

Here's what they learned:

  • 851 of the participants died during the 16-years of follow-up
  • 380 people died of colorectal cancer
  • 153 cancer patients died from cardiovascular disease
  • People who were obese before and at the time of diagnosis were more likely to die of all causes, including colon cancer and cardiovascular disease
  • Obesity that appeared after diagnosis was not associated with mortality - all cause or specific.

This research suggests that pre-diagnosis obesity is a more important survival predictor than is obesity that develops after the diagnosis of colorectal cancer.

This study was published in the January, 2012 issue of Journal of Clinical Oncology.

Reviewed by: 
Review Date: 
January 2, 2012
Last Updated:
January 3, 2012