Postdiagnosis body mass index and risk of mortality in colorectal cancer survivors: a prospective study and meta-analysis

Cancer Causes Control. 2014 Oct;25(10):1407-18. doi: 10.1007/s10552-014-0435-x. Epub 2014 Jul 19.


Purpose: Aim of this study was to investigate the association between postdiagnosis body mass index (BMI) and all-cause mortality in colorectal cancer (CRC) survivors in a prospective study and meta-analysis.

Methods: We conducted a prospective cohort study on 2,143 CRC survivors in Germany. Participants were recruited to the study on average 4 years after diagnosis, and postdiagnosis BMI was assessed at recruitment using a self-administered questionnaire. CRC survivors were followed up for a mean time of 3.5 years. The association between BMI and all-cause mortality was investigated using multivariable Cox proportional hazards models. Additionally, we performed a meta-analysis of studies on postdiagnosis BMI and all-cause mortality (n = 5, including this study) by applying random-effects models.

Results: In the prospective analysis, 349 participants died. BMI was not statistically significantly associated with all-cause mortality. Compared to normal weight survivors, the hazard ratios (HRs) [95% confidence interval (CI)] for all-cause mortality in underweight, overweight and obese survivors were 1.65 (0.79-3.45), 0.80 (0.62-1.03) and 0.84 (0.62-1.14), respectively. In the meta-analysis, individuals with underweight were at increased risk for all-cause mortality [HR (95% CI) 1.72 (1.18-2.49)], whereas individuals with overweight had a lower risk [HR (95% CI) 0.79 (0.71-0.88)], compared to normal weight subjects. For obesity, the risk of mortality was also reduced with only borderline significance [HR (95% CI) 0.88 (0.77-1.00)].

Conclusions: While the present study as well as single previously published studies showed that overweight was associated with a non-significant reduced risk for all-cause mortality, our meta-analysis indicated a decreased mortality risk among overweight CRC survivors.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alcohol Drinking / epidemiology
  • Body Mass Index
  • Cause of Death*
  • Cohort Studies
  • Colorectal Neoplasms / diagnosis
  • Colorectal Neoplasms / mortality*
  • Comorbidity
  • Female
  • Germany
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Obesity / epidemiology
  • Overweight / epidemiology*
  • Proportional Hazards Models
  • Prospective Studies
  • Risk Factors
  • Smoking / epidemiology
  • Surveys and Questionnaires
  • Survival Rate
  • Survivors / statistics & numerical data*
  • Thinness / epidemiology