Breast cancer is a malignant (cancerous) tumor that starts from cells of the breast. The disease occurs mostly in women, but men can get breast cancer too.

Breast cancer is the most common cancer among women in the United States, other than skin cancer. It is the second leading cause of cancer death in women, after lung cancer.

Statistics

About 182,460 women in the United States will be found to have invasive breast cancer in 2008. About 40,480 women will die from the disease this year. Right now there are about two and a half million breast cancer survivors in the United States.

One-fourth of all breast cancers are diagnosed in women before menopause.

The chance of a woman having invasive breast cancer some time during her life is about 1 in 8. The chance of dying from breast cancer is about 1 in 35. Breast cancer death rates are going down. This is probably the result of finding the cancer earlier and improved treatment.

Symptoms

Common symptoms of breast cancer include:

• A lump or thickening in or near the breast or in the underarm area
  Nipple
• A change in how the breast or nipple feels
• A change in how the breast or nipple looks. The skin of the breast, areola, or nipple may be scaly, red, or swollen. It may have ridges or pitting so that it looks like the skin of an orange.
  Nipple discharge (fluid)  
• A change in the size or shape of the breast
• A nipple turned inward into the breast 

It is important to note that early breast cancer usually does not cause pain. Still, a woman should see her health care provider about breast pain or any other symptom that does not go away.

Diagnosis

There are several tools that aid in diagnosing breast cancer. They include:

• Diagnostic Mammogram. Diagnostic mammograms are x-ray pictures of the breast. They take clearer, more detailed images of areas that look abnormal on a screening mammogram. Doctors use them to learn more about unusual breast changes, such as a lump, pain, thickening, nipple discharge, or change in breast size or shape. Diagnostic mammograms may focus on a specific area of the breast. They may involve special techniques and more views than screening mammograms.
• Ultrasound. An ultrasound device sends out sound waves that people cannot hear. The waves bounce off tissues. A computer uses the echoes to create a picture. Your doctor can view these pictures on a monitor. The pictures may show whether a lump is solid or filled with fluid. A cyst is a fluid-filled sac. Cysts are not cancer. But a solid mass may be cancer. After the test, your doctor can store the pictures on video or print them out. This exam may be used along with a mammogram.
• Magnetic Resonance Imaging. Magnetic resonance imaging (MRI) uses a powerful magnet linked to a computer. MRI makes detailed pictures of breast tissue. Your doctor can view these pictures on a monitor or print them on film. MRI may be used along with a mammogram.
• Biopsy. Your doctor may refer you to a surgeon or breast disease specialist for a biopsy. A biopsy is where fluid or tissue is removed from your breast to help find out if there is cancer. If cancer cells are found, the pathologist can tell what kind of cancer it is. The most common type of breast cancer is ductal carcinoma. Abnormal cells are found in the lining of the ducts. Lobular carcinoma is another type. Abnormal cells are found in the lobules.