Danielle Fishel was diagnosed with ductal carcinoma in situ (DCIS), which is a very early form of breast cancer where the cancer cells are confined inside a milk duct in the breast. She specifically had "high-grade DCIS with micro- invasion," which means the cancer had begun to breach the duct membrane, classifying it technically as stage 1 cancer. Fishel underwent lumpectomy surgery followed by radiation treatment and hormone therapy to reduce the risk of recurrence. She publicly shared her diagnosis and treatment journey to raise awareness about the importance of regular mammograms for early detection.