Consumption of sugar-sweetened beverages increased endometrial cancer risk

Maurie Markman, MD

The excellent paper by Inoue-Choi and colleagues provides a provocative analysis of a ”potential independent” role of sugar-sweetened beverages (SSB) in the etiology of some endometrial cancers. Utilizing data collected from 23,000 postmenopausal women who participated in the Iowa Women’s Health Study, which was linked with data in SEER, the researchers found that after a statistical adjustment for several relevant co-factors (eg, BMI, physical activity, history of cigarette smoking and diabetes), there appeared to be an impact of self-reported higher level of ingestion of SSB on the subsequent development of estrogen-dependent type I endometrial cancer.

The researchers appropriately noted the important limitations associated with this analysis and, in particular, the difficulty of separating the impact of a single factor that is known to be closely related with other clinical variables. Thus, for example, it is quite clear that the injection of larger quantities of SSB would be highly correlated with obesity, a factor long established to be associated with the development of type 1 endometrial cancer. One additional point is worthy of mention. This study absolutely should not be taken as evidence it is now established that a reduction in the ingestion of SSB will reduce an individual woman’s lifetime risk for endometrial cancer, or that by eliminating SSB from the diet it will be possible to protect an individual against the recognized negative effects of obesity or diabetes (if these two factors persist) in the development of this malignancy.

Andrew M. Kaunitz, MD, FACOG

Endometrial cancer is the most common type of gynecologic cancer in US women, whereas ovarian cancer is much less common but more fatal. Most cases, as we have seen in this report and others, are estrogen-related or type I endometrial cancer. The mean age of women in this article was about 62 years and, of the 592 women, 506 were type-I or common-type cancers.

We have known for many, many years that there is a strong linkage between obesity and endometrial cancers. We understand that this link has what seems to be a clear biologic explanation. By definition, when women are menopausal, their ovaries are no longer making large amounts of estrogen. However, in obese menopausal women, their uterine lining endometrium is still exposed to elevated levels of estrogen. This appears to be the basis for the very clear and demonstrated link between obesity and endometrial cancer.

A very large proportion of these type I endometrial cancers that occur are in obese women, and that’s something that epidemiologists and clinicians have been aware of for decades — there’s nothing new here. But, what was interesting in this article was that, regardless of BMI, the consumption of beverages with sugar is specifically linked with endometrial cancer regardless of body weight. This points out that there are concerns with consumption of sugar-sweetened beverages, even in women who are not overweight.

Sugar-sweetened beverage consumption is rising, as is the prevalence of obesity in the United States among both men and women. This very well done epidemiologic study points out that even women who are not overweight but consume sugar-sweetened beverages have more type-I or estrogen-related endometrial cancer. Perhaps this relates to the rapid increase in blood sugar, as well as in insulin, that occur with consumption of sugar-sweetened beverages.

Interestingly, there was no specific link between juice consumption and endometrial cancer. I'm not sure if juice consumption is associated with less rapid rises in blood sugar than is consumption of sodas with sugar. One additional finding is the important link between BMI and type-I endometrial cancer. Unfortunately, this also extends to ethnic issues, as well. Black women have a higher rate for obesity and, therefore, have a higher rate for endometrial cancers, as well.