Final answer:
Ductal carcinoma in situ (DCIS) is often a precursor to invasive ductal carcinoma, a type of breast cancer that invades surrounding tissues. DCIS is a pre-malignant condition confined to the milk ducts and early treatment is pivotal.
Step-by-step explanation:
Ductal carcinoma in situ (DCIS) is often considered a pre-malignant or non-invasive tumor, meaning that it has not spread beyond the milk ducts into the surrounding breast tissue. DCIS is classified as a precursor to invasive ductal carcinoma, which is a type of breast cancer that invades the surrounding tissues.
Cancer classification is generally based on the type of cell that resembles the tumor, indicating the tissue that is presumed to be the origin of the tumor. Carcinomas are tumors that originate in the epithelial cells, such as those in the breast, prostate, lung, and colon.
Being the most common type of cancer in females, breast cancer cells can sometimes grow out of control forming a tumor. Early detection and treatment are critical and can often lead to a cure, especially in cases like DCIS where the cancer is still contained within the ducts.