Types of Breast Cancer

Should a diagnosis of cancer be made, one of the first determinations is a confirmation of its type and stage of development. Common types of breast cancer include carcinoma (the vast majority), sarcoma and inflammatory. Carcinomas account for nearly 85 percent of all malignancies, while the number of inflammatory cases may be less than one percent. Carcinomas affect the lobes and ducts of the breast.

Hormone Receptor Positive (HR+) Breast Cancer

When it comes to diagnosing breast cancer, doctors must identify whether or not a patient’s case is hormone receptor positive, meaning that the tumors grow in the presence of estrogen and/or progesterone. Most cases of breast cancer, about 70 percent in fact, are hormone receptor positive.

If a patient suffers from hormone receptor positive breast cancer, keeping the estrogen/progesterone from reaching the hormone receptors on the tumor can stop the cancerous tumors from growing in size and potentially spreading to other areas of the body.

In these cases, doctors may prescribe tamoxifen, a type of antiestrogen drug that can negate or minimize the effects of estrogen on hormone receptor cells. This can significantly slow or even stop the growth of these tumors in the breast. Some clinical trials have proven Faslodex® to work as a breast cancer treatment when tamoxifen fails to combat hormone receptor positive breast cancer.

Post-menopausal women with breast cancer may be prescribed Faslodex® following an antiestrogen regimen if the metastatic breast cancer continues to grow. Faslodex® should only be taken by post-menopausal women.

Administered once a month through injection, Faslodex® (also known as fulvestrant) targets and attaches itself to the hormone receptors on cells to block the estrogen from attaching. Similarly, Faslodex® also alters the shape of the cells so that, once the Faslodex® is gone, the cells’ receptors are no longer compatible with estrogen nor progesterone.

In Situ Breast Cancer

Few cases are diagnosed as carcinoma in situ (ductal or lobular carcinoma), meaning that the tumor is localized and subject to complete removal. At the in situ stage, ductal carcinoma or lobular carcinoma are described as non-invasive or pre-malignant. The majority of carcinomas, however, have already begun to spread (metastasize) by the time they are detected.
 
The in situ condition is sometimes referred to as Stage 0 because the spread has not begun. Patients with this condition have at least a 25 percent chance of developing breast cancer in the next 25 years, although some differences exist between the ductal type and the lobular type. Most often, both types are considered a 'marker' for increased risk.

Sarcoma and Inflammatory Breast Cancer

A sarcoma is a malignant tumor that develops in fatty and connective tissue of the mammary gland. Sarcoma, meaning "fleshy growth,” may or may not metastasize. Alternately, inflammatory breast cancer is an advanced stage tumor that gives the breast skin an orange peel appearance.

Metastatic Breast Cancer

Breast cancer cells may originate in a breast or elsewhere in the body. (Cancer that has metastasized from another part of the body is referred to by the original organ, i.e. lung cancer that has spread to the breast is "lung cancer with metastasis to the breast," or "secondary lung cancer.")
 
When cells from the breast spread and course towards lymph nodes in the periphery of the gland, they are labeled invasive. These cells may leave the nodes and drain laterally towards armpit nodes. From there, they can spread to the nodes in regions of the collar bones, shoulders, ribs and throughout the body where they may take up residence and proliferate as secondary tumors.
 
Blood leaving the mammary glands in veins may carry cancer cells to the lungs, liver, bone and skin.

Less Common Types of Breast Cancer

Paget's disease of the breast is indicative of a less common type characterized by a scaly lesion of the nipple that does not heal or by persistent scaly bumps around the areola. About 75 percent of individuals with Paget's disease have a cancer lying beneath a nipple. Paget's disease requires an immediate mammogram and biopsy.
 
Inflammatory breast cancer is a rare type in which the breast looks as if it is inflamed because of its warmth and orangey-red appearance. The skin may show ridges and dimples similar to an orange peel. This type of breast cancer has the worst prognosis, with a survival rate of only 35 percent.
 
Cystosarcoma phylloides is the only cancer of the mammary glands that originates in the "soft" tissues beyond the lobes and ducts. It has the feel of a benign tumor. Cystosarcoma phylloides is much less common than a ductal carcinoma or lobular carcinoma.
 
Resources
 
Breast Cancer Answers (2007). What is Hormone Receptor Positive Breast Cancer? (2007). Retrieved June 30, 2007 from: http://www.breastcancer-answers.com/webcast_transcript.asp?
f=breast_cancer&c=breast_hormrecept&b=breastcanceranswers.
 
Inflammatory Breast Cancer Research Foundation. (nd). What is inflammatory breast cancer?
 
Susan G. Komen Breast Cancer Foundation. (2004). Carcinoma in situ. Facts for Life [806-385 5/04].
Susan G. Komen Breast Cancer Foundation. (2004). Types of breast cancer. Facts for Life [806-369 5/04].