Stage 0 breast cancer, ductal carcinoma in situ (DCIS) is a non-invasive cancer where abnormal cells have been found in the lining of the breast milk duct.
DCIS (ductal carcinoma in situ) is a non-invasive breast cancer. If DCIS is diagnosed with invasive breast cancer, treatment and prognosis are based on the invasive breast cancer (not the DCIS). . Breast Cancer - Treatment for Stage 0.
So the doctor says you have stage 0 breast cancer, and now you have form of breast cancer in the nipple; Ductal carcinoma in situ (DCIS).