The Different Types of Breast Cancer, Explained

Breast Cancer Hormone Status

Cells from breast cancer will be extracted during surgery to remove the tumor or during a biopsy so they can be sent to a laboratory and examined by a pathologist under a microscope and tested to see if they contain progesterone or estrogen receptors. These receptors on cancerous breast cancer cells provide a way for progesterone and estrogen to fuel the growth of the tumor. Malignant breast tumors containing estrogen receptors are referred to as ER-positive breast cancers. Malignant breast tumors with progesterone receptors are referred to as PR-positive breast cancers.

The term hormone receptor-positive breast cancer refers to any malignancy with one or both receptors for progesterone and estrogen. The term hormone receptor-negative breast cancer refers to a malignancy with no receptors for estrogen or progesterone. Information regarding breast cancer hormone status is extremely helpful when determining how to treat a patient's breast cancer. Certain hormone therapy drugs can be utilized to reduce the estrogen levels or block the estrogen from acting on breast cancer cells in most hormone receptor-positive tumors.

Phyllodes Tumor

Phyllodes tumor describes rare tumors that develop in breast tissue that grow in a leaf-like arrangement and account for less than one percent of all diagnosed breast tumors. Phyllodes tumors differ from other types of breast tumors because they do not develop from the cells of an individual's milk ducts or in the cells making up the milk-producing glands or lobules of the breast. Phyllodes tumors develop in the cells that make up the connective tissues inside the breast (stroma), which include the ligaments and fatty tissues that encapsulate and surround the lobules, blood vessels, milk ducts, and lymph vessels in the breast.

The most common indication of a phyllodes tumor is a palpable lump or mass that can be felt during a breast examination. Phyllodes tumors tend to grow rapidly, reaching a size of between two and three centimeters in just a matter of weeks or months. Phyllodes tumors can be more challenging to diagnose than other types of breast cancer because they are so rare. A physical exam, mammogram, ultrasound, MRI scan, and tissue biopsy are used to make a phyllodes tumor diagnosis.