Unintentional weight loss may be associated with an increased risk of receiving a cancer diagnosis within the next year, according to a recent study published by Wang et al in JAMA.
Background
Patients with advanced cancer often experience weight loss. However, weight loss is often not thought to occur in those with early-stage disease.
“Sometimes weight loss is due to more exercise or a healthier diet, and this can be beneficial to [individuals’] health. However, when a patient experiences unintentional weight loss not due to healthier behaviors, seeing [their] primary care [physician] is appropriate, so they can determine whether additional evaluation is necessary for other causes of weight loss, including cancer,” recommended senior study author Brian Wolpin, MD, MPH, Director of the Gastrointestinal Cancer Center at Dana-Farber Cancer Institute and Director of the Hale Family Center for Pancreatic Cancer Research. “Unexpected weight loss can come from cancer or many other conditions. [Physicians] can determine if there is something that needs evaluation,” he emphasized.
Study Methods and Results
In the recent study, investigators assessed 157,474 individuals who participated in two large longitudinal studies: the Nurses’ Health Study, which enrolled nurses aged 30 to 55 beginning in 1976, and the Health Professionals Follow-Up Study, which enrolled male health professionals aged 40 to 75 starting in 1986. The participants were followed until 2016.
The participants reported weight every other year in a biennial questionnaire that also included questions about physical activity and requested responses regarding dietary changes every 4 years. The investigators were then able to analyze each participant’s level of weight loss–promoting behaviors—classified as “high” among those making both dietary improvements and increases to physical activity, “medium” among those making only one change, and “low” among those making no changes to diet and exercise.
Compared with the participants who didn’t lose weight, those who experienced recent weight loss had a significantly increased risk of developing upper gastrointestinal tract cancer (esophageal, gastric, hepatic, biliary tract, and pancreatic), hematologic malignancies (non-Hodgkin lymphoma, multiple myeloma, and leukemia), colorectal cancer, and lung cancer. However, recent weight loss wasn’t found to be associated with an increased risk for other cancer types such as breast cancer, genitourinary cancer, brain tumors, or melanoma.
Further, the investigators found that similar levels of weight loss occurred prior to the diagnosis of both early- and late-stage diseases. The investigators noted the mechanisms by which cancer may cause weight loss could vary depending on the type of cancer.
Previous research using weight data collected by physicians from patients seeking care for a possible disease has connected unexpected weight loss with an increased risk for cancer. However, the two studies included in the recent study were focused on health-care professionals, which is not a group fully representative of the U.S. population.
Conclusions
The investigators underscored that unintentional weight loss may be used as a signal of a developing tumor and may help physicians diagnose cancer at an earlier stage, when treatments may be more effective.
“We wanted to differentiate healthy weight loss from unhealthy weight loss,” explained lead study author Qiaoli Wang, MD, PhD, a research fellow at Dana-Farber Cancer Institute. “Healthy weight loss can come from dietary changes or increased exercise, [b]ut unhealthy weight loss that occurs unexpectedly can be due to an underlying cancer,” she concluded.
Disclosure: The research in this study was funded by the National Institutes of Health, the Swedish Research Council, the Project P Fund, the Broman Family Fund for Pancreatic Cancer, the Hale Family Center for Pancreatic Cancer Research, the Lustgarten Foundation Dedicated Laboratory Program, Stand Up To Cancer, the Pancreatic Cancer Action Network, the Noble Effort Fund, the Wexler Family Fund, the Promises for Purple, and the Bob Parsons Fund. For full disclosures of the study authors, visit jamanetwork.com.
