The link between obesity and the risk of endometrial cancer has been well documented. Now a new study, published online in Menopause, the journal of The North American Menopause Society (NAMS), an even lower body mass index (BMI) than previously thought can signal an increased risk in Asian women with postmenopausal bleeding.
Endometrial cancer is the sixth most common form of cancer in women worldwide and is a leading cause of cancer death. Because there is currently no routine screening for endometrial cancer in asymptomatic women, it is important for healthcare professionals to be aware of added risk factors so that they can effectively intervene.
In this study, researchers using the Asian BMI standard for obesity (BMI < 25 kg/m2) sought to determine the relationship between BMI and a subsequent diagnosis of endometrial cancer in Asian women. The threshold for being defined as obese in Asian women is lower than that used for classifying white women. Because roughly 90% of postmenopausal women with endometrial cancer have postmenopausal bleeding, the study specifically looked at women who had experienced postmenopausal bleeding.
This study included 4,164 Asian women referred for treatment for postmenopausal bleeding from 2002 to 2013. For all women, a medical history was taken, and physical examination, BMI measurement, transvaginal pelvic ultrasonography, and endometrial sampling were performed. Additional investigations were performed as clinically indicated. The presence of risk factors for endometrial cancer and histological diagnoses were compared among groups defined by the standard Asian BMI cut-off values.
Within the cohort study participants, 868 (20.8%) women were overweight (BMI 23-24.9 kg/m2) and 1,611 (38.7%) were obese (BMI ≥25 kg/m2). A total of 162 (3.9%) women were diagnosed with endometrial cancer. The prevalence of endometrial cancer correlated with BMI category (P < 0.001). On multivariate analysis, BMI ≥25 kg/m2 was independently associated with 1.57 times risk of endometrial cancer (95% CI 1.13-2.20, P = 0.008) compared with BMI less than 25 kg/m2.
On the basis of the results of the study and the Asian BMI standard for obesity at 25 kg/m2, the researchers identified 51% of endometrial cancers in this group. The researchers also observed that women with a BMI of more than 25 kg/m2 were 1.57 times (57%) more likely to develop endometrial cancer. These results should alert healthcare professionals to be especially vigilant when treating Asian women with postmenopausal bleeding who are obese.
“This study highlights the known relationship between BMI and endometrial cancer and suggests that the Asian BMI standard for obesity (< 25 kg/m2) helps to identify endometrial cancer in Asian women with postmenopausal bleeding. Key takeaways are that all women with postmenopausal bleeding should undergo evaluation, and obesity remains an important and modifiable risk factor for endometrial cancer, with a linear relationship between BMI and endometrial cancer risk,” concluded Stephanie Faubion, NAMS medical director.
 Liu F, Cheung ECW, Lao TT. Obesity increases endometrial cancer risk in Chinese women with postmenopausal bleeding. Menopause. 2021 Jun 28. doi: 10.1097/GME.0000000000001822. Epub ahead of print. PMID: 34183566.