In a study reported in JAMA, Wang et al found that individuals with a weight loss of more than 10% during the prior 2 years had a higher risk of cancer diagnosis over the subsequent 12 months vs those with no weight loss.
Study Details
The retrospective cohort analysis included women aged at least 40 years from the Nurses’ Health Study, with follow-up from June 1978 until June 2016, and men aged at least 40 years from the Health Professionals Follow-Up Study, with follow-up from January 1988 until January 2016. Recent weight change was calculated from biennially reported participant weights.
Intentionality of weight loss was categorized as high if both physical activity and diet quality increased, medium if only one of those factors increased, and low if neither increased. The primary objective was to determine rates of subsequent cancer diagnoses over 12 months among participants with vs without weight loss during the prior 2 years.
Key Findings
Among 157,474 participants included in the analysis, 71.1% were female. During 1.64 million person-years of follow-up, 15,809 incident cancer cases were identified (incident rate = 964 cases/100,000 person-years).
During the 12 months after reported weight change, there were 1,362 cancer cases/100,000 person-years among all participants with recent weight loss of greater than 10.0% vs 869 cancer cases/100,000 person-years among those without recent weight loss (between-group difference = 493 cases/100,000 person-years, 95% confidence interval [CI] = 391–594 cases/100,000 person-years, P < .001). The multivariate adjusted relative risk for cancer diagnosis for greater than 10% weight loss vs no weight loss was 1.37 (95% CI = 1.27–1.48).
Among participants categorized with low intentionality for weight loss, there were 2,687 cancer cases/100,000 person-years among those with more than 10% weight loss vs 1,220 cases/100,000 person-years among those without recent weight loss (between-group difference = 1,467 cases/100,000 person-years, 95% CI = 799–2,135 cases/100,000 person-years, P < .001). The adjusted relative risks for cancer diagnosis for more than 10% weight loss vs no weight loss were 1.95 (95% CI = 1.48–2.56) among those with low intentionality, 1.42 (95% CI = 1.23–1.63) among those with medium intentionality, and 1.30 (95% CI = 1.12–1.50) among those with high intentionality for weight loss.
Cancer of the upper gastrointestinal tract (esophageal, stomach, liver, biliary tract, or pancreatic) was notably common among participants with recent weight loss. Overall, there were 173 cancer cases/100,000 person-years among those with more than 10% weight loss vs 36 cases/100,000 person-years for those without recent weight loss (between-group difference = 137 cases/100,000 person-years, 95% CI = 101–172 cases/100,000 person-years, P < .001).
The investigators concluded, “Health professionals with weight loss within the prior 2 years had a significantly higher risk of cancer during the subsequent 12 months compared with those without recent weight loss. Cancer of the upper gastrointestinal tract was particularly common among participants with recent weight loss compared with those without recent weight loss.”
Brian M. Wolpin, MD, MPH, of the Department of Medical Oncology, Dana-Farber Cancer Institute and Harvard Medical School, is the corresponding author for the JAMA article.
Disclosure: The study was supported by the National Institutes of Health, Swedish Research Council, and others. For full disclosures of the study authors, visit jamanetwork.com.
