Metaplastic Carcinoma of Breast

According to WHO, Metaplastic Breast Cancer (MpBC) is a unique and very rare subtype of aggressive breast cancer that accounts for less than 1% of all breast cancers. Metastatic breast cancer is a breast cancer is stage-IV disease in which cancer spread to distant parts of the body – bones, lungs and brain. This type of cancer is considered terminal. Metaplastic Breast Cancer is only a type of breast cancer. On this site we refer to metaplastic breast cancer as MpBC.

Understand Metaplastic Breast Cancer:

Histologically, Metaplastic Breast Cancer is biphasic and contains both carcinomatous component and heterogeneous sarcomatous component. Metaplastic Breast Cancer is characterized by the differentiation of neoplastic epithelium into squamous cells and/or mesenchymal-looking elements i.e. squamous cells, spindle cells, cartilage or bone, etc while normal breast cancer will be made up only of the glandular (epithelial) cells. Metaplastic Breast Cancer has many similarities with invasive ductal carcinoma and benign lesions on mammography, which further create misinterpretation and delayed in the diagnosis. Prognosis for Metaplastic Breast Cancer is not as good considering stage and grade. Few studies showed overall survival at 50% and some as high as 75% depending on the subtype and initial stage of the tumor while Johns Hopkins study revealed 5-yr overall survival rates at 65% compared to traditional breast cancer(Invasive Ductal Carcinoma) at 89%.

Triple Negative Breast Cancer:

About 80% of all breast cancers are influenced by the hormones estrogen, progesterone or the protein HER-2neu (or a combination of the three) and hence they are treated by targeted therapy with hormone and/or Anti-HER and it also prevent from cancer recurrence.  Triple negative breast cancers i.e. ER-ve, PR-ve and HER2neu -ve are not influenced by these targeted therapy, therefore these treatment options are not effective against these tumours. The prognosis for triple negative breast cancers (TNBC) is always worse in general than for traditional hormone positive breast cancers.

Metaplastic Breast Cancer is different from other types of Breast Cancers:

There are many things that make Metaplastic Breast Cancers (MpBC) different than other more common traditional forms of breast cancer

• A larger tumor size at the time of presentation,
• Higher grade at time of diagnosis and hence more aggressive.
• Lower rates of nodal involvement but more frequently distance metastasis.
• Higher rates of both local and distant recurrence and in a shorter time disease free interval.
• Higher rates of triple negative i.e. ER, PR and Her-2 negativity.

Treatments for Metaplastic Breast Cancer:

Poor response to systemic therapies as compare with invasive breast cancer, but studies suggest that removal of the tumor and adjuvant radiation therapy has the greatest benefit. Because metaplastic breast cancer is triple negative patients are often offered the standard treatments for triple negative cancers and needs multi modalities treatment according to the disease stage i.e.  Surgical options, Chemotherapy and Radiotherapy.