Breast Cancer Overview

Every year, almost 200,000 women in America are diagnosed with breast cancer, making it the most common cancer diagnosed in women aside from skin cancer. Approximately one in every eight females will develop breast cancer at some point in her life. Only lung cancer claims more lives than breast cancer in women overall, but breast cancer serves as the leading cause of cancer-related deaths among some populations, such as Hispanic women.

There are significant differences between breast cancers that occur before and after menopause. Hereditary factors figure prominently in premenopausal breast cancers, while most breast cancers that develop after menopause have far less family history involvement.

Without an inherited predisposition, many women will look at their health behaviors and lifestyle choices as suggestive of their risks. Drinking alcohol, smoking, eating poorly or being obese, and a lack of exercise may contribute to breast cancer occurrence. Some studies have implicated alcohol consumption and obesity for increasing risk; another found that regular exercise can lower the incidence of breast cancer.

Still, scientists have yet to explain how some women with virtually identical risk factors can have such different outcomes, or why women without any risk factors end up developing breast cancer.

Breast cancer mortality rates have declined in recent years thanks primarily to increased awareness and early detection. Medicines continue to improve and treatment options are expanding, but women still need to be vigilant in order to increase their chances of success should they develop breast cancer. 

Types of Breast Cancer

There are a number of different cancers that can occur in the breast, and treatment and prognosis vary according to the type. Generally, breast cancers are grouped according to where they first develop.

Ductal carcinomas

These types of cancer first develop in the milk-producing ducts of the breast. These types of breast cancer are considered the earliest forms of breast cancer and the most common kinds, and they can be either invasive (invasive ductal carcinoma) or noninvasive (ductal carcinoma in situ, or DCIS). "Invasive" means that the cancer has spread from the original site to nearby breast tissue and/or lymph nodes and other parts of the body.

Lobular carcinomas

 These cancers develop in the cells lining the lobules that produce milk, are the second most common type of breast cancer. These are always considered invasive because they spread to surrounding tissue. (Lobular carcinoma in situ is sometimes referred to as cancer but actually stays confined to the lobules or milk glands. However, this type serves as an indicator that you have a higher chance of developing breast cancer in the future.)

Other breast cancers

Other, rarer types of cancer include:

• Breast sarcomas are cancers that start from connective tissues of the breast, such as muscle, fat, or blood vessels.
• Inflammatory breast cancer blocks the lymphatic vessels in the breast, causing severe inflammation.
• Paget's Disease of the breast is a rare form of breast cancer where cancer cells gather in or around the nipple.
• Male breast cancer is very rare, but can occur. When it does, it is usually ductal carcinoma.