Unintentional Weight Loss Could Signal Elevated Risk of Cancer in Next 12 Months

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Study with 150,000 adults reveals 10% or more of unintentional weight loss associated with an elevated rate of cancer diagnosis within the next 12 months.

Results of a new study are sending a clear message for patients: unintentional weight loss may be reason enough to prompt a visit to their care provider.

The study, which assessed the association of unintentional weight loss with subsequent cancer diagnoses in more than 150,000 adults, found those with a recent weight loss of greater than 10.0% of body weight was associated with a doubling in the rate of cancer during the next 12 months.1

“If you are losing weight and you aren’t trying to lose weight by making changes in your exercise routine or diet, people should see their doctor to consider possible causes,” said lead investigator Brian Wolpin, MD, MPH, director of the Gastrointestinal Cancer Center at Dana-Farber and director of the Hale Family Center for Pancreatic Cancer Research.2 “There are many conditions that can result in unexpected weight loss. Your doctor can determine if there is something that needs evaluation.”

Citing the commonality of weight loss in primary care and a lack of information on characteristics of weight loss requiring further evaluation for a cancer diagnosis are poorly defined. To examine these associations, investigators designed the current study as analysis of data from the Nurses’ Health Study and the Health Professionals Follow-up Study. From the studies, investigators obtained information from 157,474 participants. Investigators pointed out weight change was assessed using biennial questionnaires and weight change within the past 2 years was calculated as a percentage between each consecutive pair of questionnaires.1

Overall, 1,049,077 reported no weight change. Among the 591,639 who reported any weight loss. For the purpose of analysis, the intentionality of weight loss was categorized as high if both physical activity and diet quality increased, medium if only 1 increased, and low if neither increased.1

Among the 157,474 included in the study, the median age was 62 years (Interquartile Range [IQR], 54-70 years) and 71.1% were female. When examining race/ethnicity, 1.7% self-identified as Asian, Native American, or Native Hawaiian, 1.7% self-identified as Black, and 95.2% self-identified as White participants. This cohort had 1.64 million person-years of follow-up, and, during this time, 15,809 incident cancer cases were identified—yielded an incidence rate of 964 cases per 100,000 person-years.1

Upon analysis, results suggested there were 1362 cancer cases per 100,000 person-years during the 12 months following a reported weight change among all participants with recent weight loss of 10% or greater compared with 869 cancer cases per 100,000 person-years among those without recent weight loss (between-group difference, 493 cases per 100,000 person-years [95% Confidence Interval [CI], 391-594]; P < .001).1

When assessing those with a low intentionality of weight loss, there were 2687 cancer cases/100 000 person-years for those with weight loss of greater than 10.0%of body weight compared with 1220 cancer cases per 100,000 person-years for those without recent weight loss (between-group difference, 1467 cases per 100,000 person-years [95% CI, 799-2135]; P < .001). Further analysis demonstrated cancer of the upper GI tract appeared to be more common among participant with recent weight loss. Specifically, there were 173 cancer cases per 100,000 person-years for those with a weight loss of 10% or greater relative to 36 cancer cases per 100,000 person-years for those without recent weight loss (between-group difference, 137 cases per 100,000 person-years [95% CI, 101-172]; P < .001).1

“Unexpected weight loss can come from cancer or many other conditions,” Wolpin added.2 “Sometimes weight loss is due to more exercise or a healthier diet, and this can be beneficial to people’s health. 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.”


  1. Wang Q, Babic A, Rosenthal MH, et al. Cancer Diagnoses After Recent Weight Loss. JAMA. 2024;331(4):318–328. doi:10.1001/jama.2023.25869
  2. Dana-Farber Cancer Institute . Study suggests that unintentional weight loss is a signal to see a doctor. Dana-Farber Cancer Institute . January 23, 2024. Accessed January 26, 2024.