Metaplastic breast cancer is a breast cancer that includes several metaplastic (a phenomenon in which a tissue is converted into a tissue with a completely different shape and function) changes, such as squamous cell metaplasia and spindle cell metaplasia.
It is known to occur in 1% of all breast cancer patients, and according to data in the early 2000s, the 5-year survival rate is 40%.
Among breast cancers, those that occur in the ducts and lobules are divided into ‘invasive breast cancer’ and ‘non-invasive breast cancer’ according to the degree of invasion of cancer cells (penetrating into adjacent cells or tissues).
Metaplastic breast cancer is one of several types of double invasive breast cancer. Types of invasive breast cancer include mucinous cancer, medullary cancer, papillary cancer, tubular cancer, adenoid cystic carcinoma, secretory carcinoma, and apocrine carcinoma in addition to metaplastic carcinoma.
