dense breast tissue
... that more than 40 percent of women have dense breast tissue that increases the risk of breast cancer and makes it difficult for mammograms to identify tumors?
... that more than 40 percent of women have <b id="mwA1Y"><a href="./Dense_breast_tissue" id="mwA1c" rel="mw:WikiLink" title="Dense breast tissue">dense breast tissue</a></b> that increases the risk of <a href="./Breast_cancer" id="mwA1g" rel="mw:WikiLink" title="Breast cancer">breast cancer</a> and makes it difficult for <a href="./Mammography" id="mwA1k" rel="mw:WikiLink" title="Mammography">mammograms</a> to identify tumors?