If you have lost weight without trying, you may want to see your doctor as soon as possible. According to a new study by Dana-Farber Cancer Institute, unintended weight loss is associated with an increased risk of cancer diagnosis within the next year.
The study, published in the Journal of the American Medical Association, analyzed data from 157,474 participants in two large longitudinal studies: the Nurses’ Health Study and the Health Professionals Follow-Up Study. The researchers found that compared with participants who did not lose weight, recent weight loss was linked to a higher risk of several types of cancer, including upper gastrointestinal tract, hematological, colorectal, and lung cancers.
However, not all weight loss is harmful. Sometimes weight loss is due to more exercise or a healthier diet, and this can be beneficial to people’s health. The researchers were able to differentiate healthy weight loss from unhealthy weight loss by assessing each participant’s level of weight loss promoting behaviors, such as dietary improvements and increases in physical activity.
“We wanted to differentiate healthy weight loss from unhealthy weight loss,” said Qiaoli Wang, MD, PhD, a research fellow at Dana-Farber and the first author of the paper.
The study suggests that people who experience unintentional weight loss not due to healthier behaviors should see their primary care doctor for further evaluation.
“There are many conditions that can result in unexpected weight loss. Your doctor can determine if there is something that needs evaluation,” said Brian Wolpin, MD, MPH, the lead investigator of the study and the director of the Gastrointestinal Cancer Center and the Hale Family Center for Pancreatic Cancer Research at Dana-Farber.
“Unexpected weight loss can come from cancer or many other conditions. However, when a patient experiences unintentional weight loss not due to healthier behaviors, seeing your primary care doctor is appropriate, so they can determine whether additional evaluation is necessary for other causes of weight loss, including cancer,” he added.
The study also found that similar levels of weight loss occurred before diagnosis of both early and late-stage disease. This means that unintended weight loss could be a sign of a developing cancer even before other symptoms appear.
The researchers hope that their findings will raise awareness among both patients and doctors about the potential link between unintended weight loss and cancer, and encourage timely diagnosis and treatment.