Women with dense breasts who have breast cancer are not more likely to die than women with less dense breasts who have the disease, according to a study funded by the National Cancer Institute (NCI).

Previous research has suggested that women with dense breasts are at greater risk of developing breast cancer, but it was not clear whether these women also have poorer outcomes. Researchers from the NCI and the Breast Cancer Surveillance Consortium compared outcomes among 9232 women with breast cancer based on breast density and other factors. The women were followed up for 6.6 years on average, and there were 1795 deaths in the group, including 889 cancer-related deaths. The scientists found that women with dense breasts were not more likely than other women to die of cancer or any cause. The authors concluded that risk factors for cancer may not necessarily influence whether women are more likely to die as a result of the disease.