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Cadmium exposure may increase risk for endometrial cancer
Women with high levels of cadmium exposure appeared to have increased risk for endometrial cancer, according to a population-based, case-control study published in PLOS One.
“More than 31,000 new cases of endometrial cancer are expected to be diagnosed in 2017,” Jane McElroy, PhD, associate professor in the department of family and community medicine at University of Missouri School of Medicine, told HemOnc Today. “The majority of cases are discovered upon workup for unusual vaginal bleeding, spotting or other discharge. Diagnosis of endometrial cancer consists of an endometrial biopsy that is painful. Further, as incidence is increasing and women are diagnosed at increasingly younger ages, there is a need to address endometrial cancer risk.”
Cadmium — a toxic, bioaccumulating, nonessential and highly persistent metal with a variety of adverse health effects — mimics estrogen and may increase estrogen-receptor-mediated proliferation, which may contribute to endometrial cancer risk.
McElroy and colleagues conducted the Health and Environmental Exposure Research study to evaluate cadmium exposure associations among women with endometrial cancer.
The analysis included 632 women with a history of endometrial cancer identified through the Arkansas, Iowa and Missouri state cancer registries, as well as 879 age-matched controls identified through voter registration lists.
Trained individuals interviewed participants by telephone about risk factors potentially associated with endometrial cancer. These included physical activity, reproductive history, alcohol consumption, height and weight, use of oral contraceptives and hormone replacement therapy, personal and family medical histories, demographic factors, a limited set of dietary components and smoking history.
Upon completion, investigators sent urine and saliva kits to participants for home collection. Kits were returned to University of Missouri Research Reactor for analysis of cadmium levels.
Multivariable analysis showed a doubling of urine cadmium increased risk for endometrial cancer by 22% (OR = 1.22; 95% CI, 1.03-1.44).
Researchers observed a similar elevated endometrial risk for cadmium exposure among those diagnosed with type I endometrial carcinoma (OR = 1.21; 95% CI, 1.03-1.47).
“Women diagnosed with endometrial carcinoma who were also 50 pounds over ideal weight had an increased endometrial cancer risk for cadmium exposure,” researchers wrote.
Researchers re-ran the model without including current smoking, and results showed cadmium concentration remained statistically significant (OR = 1.19; 95% CI, 1.01-1.41). Investigators observed similarly elevated endometrial risk for cadmium exposure when they re-ran the model and accounted for age of menarche and number of live births.
“For patients who can benefit by hearing more evidence about why their doctor is encouraging them to have a healthy weight and not smoke, this study is one that provides some evidence that the potential endometrial cancer risk might be increased,” McElroy said. “To reduce the exposure, eating foods that are considered more likely to have high cadmium levels in moderation would make sense, as well as not smoking.”
Because cadmium is a metal commonly found in certain foods — such as shellfish, kidney and liver — McElroy recommended women pay more attention to their diets.
“You don’t necessarily need to cut these from your diet, but eat them in moderation,” she said. “This is especially true if you have a predisposition to endometrial cancer, such as a family history, diabetes or obesity.”
The researchers recommended additional studies be conducted that employ urinary cadmium as a biomarker. They also suggested a comprehensive list of suspected and known risk factors should also be collected to fully adjust the regression models.
“We need to continue our research endeavors to understand risk factors for endometrial cancer,” McElroy said. “These insights might facilitate development of a low-cost, noninvasive screening tool. These insights might also play a role in the development of effective treatments for those who are diagnosed with endometrial cancer.” – by Kristie L. Kahl
Disclosures: American Cancer Society and the National Science Foundation funded the study. The researchers report no relevant financial disclosures.