Unexplained weight loss can be a sign of cancer: Study
Losing weight without trying can be an early sign of cancer, according to a new study. The research raises questions about significant weight loss without changes to diet, exercise or lifestyle, as well as when people should seek medical care.
Experts stress that unexplained weight loss doesn't always signal that something is off with your health — but it can be an indicator. Here's what you need to know about the latest findings, as well as when to speak to your doctor about your weight loss.
What the study says
The study, which was published in JAMA, found that recent weight loss was linked with a significantly higher rate of being diagnosed with cancer over the next 12 months, compared with people without recent weight loss.
What are the key findings
For the study, researchers from several health organizations and cancer centers analyzed data from nearly 160,000 people in the Nurses’ Health Study, a longitudinal study that looks for risk factors for major chronic diseases.
The researchers found that people who lost more than 10% of their body weight were diagnosed with cancer within a year at a rate of 1,362 per 100,000 person-years compared to 860 per 100,000 person-years who didn't recently lose weight. (Person-years combines the number of years someone is in a study with the length of the study.)
People with cancer of the upper gastrointestinal tract — cancer of the esophagus, stomach, liver, biliary tracts or pancreas — were the most likely to have significant weight loss before their diagnosis. The researchers also found that people with breast and brain cancer and melanoma had no significant weight loss beforehand.
Overall, the risk of being diagnosed with cancer after significant unexplained weight loss was low — it was 3.2%. But compared with the 1.3% of people diagnosed with cancer who didn't have significant weight loss, it was notable.
What experts think
Experts say that the findings back up what they see in the field. "This is a well-known phenomenon with cancer," Dr. Wael Harb, a hematologist and medical oncologist at MemorialCare Cancer Institute at Orange Coast and Saddleback Medical Centers in Orange County, Calif., tells Yahoo Life. "We always have to think about cancer as a potential cause when we see these patients."