Women who have more than two alcoholic drinks a day double their risk of endometrial cancer compared with those who drink less, a new study finds.
Researchers examined a multiethnic group of 41,574 postmenopausal women, following them for an average of eight years and using questionnaires about diet and drinking habits. In that time, the team found 324 cases of endometrial cancer, the type that forms in the tissue that lines the uterus. According to the National Cancer Institute, the United States has 40,000 new cases of endometrial cancer a year and 7,400 deaths.
After controlling for variables, including body mass index, age, hormone therapy and whether they had been pregnant, the researchers found that women who had less than two drinks a day had no increased risk of endometrial cancer. But those who had more than two drinks a day had slightly more than twice the risk. It made no difference whether the women drank beer, wine or hard liquor.
The exact mechanism is unknown, but alcohol raises estrogen levels, and it is well established that prolonged exposure to estrogen increases mutations and DNA replication errors, predecessors of cancerous growths.
"Relatively few studies have examined the relationship between endometrial cancer and drinking," said Veronica Wendy Setiawan, the lead researcher and an assistant professor of research at the Keck School of Medicine of the University of Southern California. "If this is a true association, that's one more lifestyle change women can make."