Expert: Claes-Gustaf Nordquist, M.D. - 8/1/2006

Question
What is the relationship between basal-type (basaloid)and metaplastic breast cancers?

Answer
These are histologic (microscopical) subgroups. Breast cancer usually develop out of the lining of the milk ducts of the milk glands in the breasts (female or male, but there are about 100 female breast cancers for each male one). The milk glands themselves are transformed sweat glands. So most breast cancers are so called adenocarcinomas since they are derived from gland tissue (adeno-). A basaloid type is derived from the basal cells (bottom layer) of the lining of the milk ducts and retain the look of basal cells. Metaplastic cancer is derived from cells higher up in the lining and are transformed (thus the term metaplastic - changing form {your name sounds Greek to me and this is a Greek word}) into squamous formed epithelial cells. So these are microscopic differences. Detection, treatment and prognosis are essentially the same.

After I sent this I did some additional checking. There are reports of worse prognosis associated with the basaloid cancer indicating that it can be more aggressive. With metaplastic cancer there are indications that at least some of them (but this is a rare cancer form already to begin with) may show special immunological features that may offer the possibility of special immunotherapy.