The name cancer in situ, refers to a specific diagnosis of cancer. This is a very early type of cancer, which is curable in more than 97% of all women. In situ cancers, when detected and treated early, are rarely life threatening. Non-invasive (or “in situ”) cancers confine themselves to the ducts or lobules and do not spread to the surrounding tissues in the breast or other parts of the body. They can, however, develop into or raise the risk for a more serious, invasive cancer.

Carcinomul mamar in situ după datele literaturii de specialiate constituie 5-40% din numărul total al cancerului mamar primar. Frecvenţa lui în Republica Moldova variază de la 1,9% până la 2,2%. S-a efectuat un studiu a 209 de paciente tratate la Institutul Oncologic din RM în perioada anilor 1993-2006.