Ductal carcinoma in situ lesions rarely if ever progress to cause harm nor death.
In 2013, a US National Cancer Institute commissioned expert panel concluded that screening detected lesions known as ductal carcinoma in situ (DCIS), previously considered potentially lethal cancers, were "benign or indolent lesions of epithelial origin".
A 2015 study published in the New England Journal of Medicine revealed that in the previous three decades 1.3 million women in the U.S. were diagnosed with ductal carcinoma in situ (DCIS).