@alisha-- @fify is absolutely right. Doctors have not found a link between a dense breast parenchyma and cancer. It is believed to be normal and passed on genetically. More than 25% of women have dense breast parenchyma with no higher risk of developing breast cancer.
A more than usual density of breast parenchyma just means that mammograms might be a bit more difficult for doctors to interpret because the dense tissue sometimes looks like suspicious masses. But there is no reason to jump to negative conclusions about dense breast parenchyma.