Ductal Carcinoma In Situ: Stage 0 Breast Cancer

4. Diagnosis

About 90 percent of ductal carcinoma in situ cases are detected on a regular mammogram screening. Small calcifications in branching patterns are suspicious for DCIS. If it is suspected, the next step is a diagnostic mammogram and a core needle biopsy to determine if the cancer is non-invasive or invasive. There is a chance that someone presenting with DCIS may already have invasive breast cancer. Even when a needle biopsy shows the former, the chances that the cancer is invasive are between 10 and 20 percent, but this often is not confirmed until after surgery. Large or fast-growing DCIS lesions are more likely to be invasive.