Representing fewer than 0.5% of all breast cancer diagnoses, metaplastic breast carcinoma (MBC) is classified as an uncommon variety of breast cancer. This malignancy is characterized by a unique cellular composition where cancer cells, under a microscope, do not look like usual breast cancer cells.
Understanding Triple-Negative Breast Cancer and Metaplastic Subtypes
Metaplastic breast carcinoma is a rare subtype of triple-negative breast cancer (TNBC), a fast-growing category defined by the absence of estrogen receptors, progesterone receptors, and HER2 protein. According to the Mayo Clinic, TNBC is not a single condition but a broad term encompassing several distinct subtypes, including basal-like, mesenchymal and mesenchymal stemlike, immunomodulatory, luminal androgen receptor, and metaplastic.
Because these tumors test negative for hormone receptors and HER2, standard treatments such as estrogen-blocker therapy or treatments that target the HER2 protein are ineffective. Instead, healthcare professionals may use medicines, such as chemotherapy and immunotherapy, to shrink the cancer to make it easier to remove with surgery. Other treatments might include radiation therapy and targeted therapy.
Recognizing Symptoms and Diagnostic Challenges
Triple-negative breast cancer (TNBC) may not cause signs or symptoms at first. As the cancer progresses, symptoms are usually the same as most other common breast cancer symptoms. According to the Mayo Clinic, patients should monitor for specific physical changes:
- A breast lump or thickened area of skin that feels different from the surrounding tissue.
- A nipple that looks flattened or turns inward.
- Changes in the color of the breast skin, including pink or red on white skin, or darker, red, or purple hues on brown or black skin.
- Change in the size, shape or appearance of a breast.
- Alterations to the breast skin, including textural issues like dimpling or an orange-peel appearance, alongside scaling, flaking, crusting, or peeling skin.
Given that TNBC tends to be a fast-growing cancer, it has a higher likelihood than other forms of breast cancer of developing in the timeframe between scheduled routine mammograms. Healthcare professionals advise patients to report any changes in their breasts even if a recent mammogram showed there was no breast cancer.
Clinical Characteristics and Treatment Protocols
The aggressive nature of metaplastic breast carcinoma requires identification under a microscope. Treatment planning typically involves healthcare professionals. Therapy often incorporates chemotherapy and immunotherapy to manage growth and facilitate surgical removal.
Patients diagnosed with these subtypes are encouraged to discuss treatment options with their healthcare professionals.