There are several different types of breast cancer. Ductal carcinoma begins in the cells lining the ducts that bring milk to the nipple and accounts for more than three-fourths of breast cancer.

Lobular carcinoma begins in the milk-secreting glands of the breast but is otherwise fairly similar in its behavior to ductal carcinoma. Other varieties of breast cancer can arise from the skin, fat, connective tissues, and other cells present in the breast.

Risk factors for breast cancer include:

• Age and Gender -- As with most cancers, age is a significant factor. In fact, 77% of new cases and 84% of breast cancer deaths occur in women aged 50 and older. More than 80% of breast cancer cases occur in women over 50. Less than 1% of breast cancers occur in men. The risk of breast cancer is clearly related to hormonal influences, but how these affect the disease and particularly types of the disease is not yet clear.

• Genetic Factors and Family History of Breast Cancer -- Some families appear to have a genetic tendency for breast cancer. Two variant genes have been found that appear to account for this: BRCA1 and BRCA2. The genes p53 and BARD1 also appear to be important. Researchers have identified some other defective genes that may cause breast cancer, including BRCA3 and Noey2 (which is a disease inherited only from the father's side of the family).
  
  These facts suggest that breast cancer is caused by the growth of genetically damaged cells. Such genetic damage is known to gradually accumulate in the cells of the body over time. Women carrying mutated BRCA1 and/or BRCA2 genes have a "head start" in this process.
  
  Hormonal influences are important because they encourage cell growth. High levels of hormones during a woman's reproductive years, especially when they are not interrupted by the hormonal changes of pregnancy, appear to increase the chances that genetically damaged cells will grow and cause cancer.

• Early Menstruation and Late Menopause -- Women who started menstrual periods early (before age 12) or went through menopause late (after age 55) are at higher risk. Also, women who have never had children or who had them only after the age of 30 have an increased risk.

• Oral Contraceptives (birth control pills) -- Birth control pills may slightly increase the risk for breast cancer, depending on age, length of use, and other factors. No one knows how long the effects of the pill last after stopping it.

• Hormone Replacement Therapy -- Use of HRT for more than 5 years has been shown to slightly increase the risk of breast cancer and risk increases with longer use.

• Physical Characteristics -- Obesity is controversial as a risk factor. Some studies report obesity as a risk of breast cancer, possibly associated with higher levels of estrogen production in obese women.

• Alcohol Consumption -- Excessive alcohol use (more than 1-2 drinks a day) has been associated with an increased risk of breast cancer.

• Chemicals -- Some studies have pointed to exposure to estrogen-like chemicals that are found in pesticides and other industrial products as a possible increased risk of breast cancer.

• DES -- Women who took diethylstilbestrol (DES) to prevent miscarriage may have an increased risk of breast cancer.

• Radiation -- People exposed to radiation, particularly during childhood may face an increased risk for breast cancer in adulthood. Especially at risk are those that received chest irradiation for prior cancers.

• Additional Risk Factors -- Some studies show previous breast, uterine, ovarian, colon cancer, and a strong history of cancer in the family may increase the risk for breast cancer.

The Gail Model is a simple breast cancer risk assessment tool that is available online and takes into account the most important risk factors.

• Breast lump or breast mass noted upon breast exam -- usually painless, firm to hard and usually with irregular borders
• Lump or mass in the armpit
• A change in the size or shape of the breast
• Abnormal nipple discharge
  • Usually bloody or clear-to-yellow or green fluid
  • May look like pus (purulent)
• Change in the color or feel of the skin of the breast, nipple, or areola
  • Dimpled, puckered, or scaly
  • Retraction, "orange peel" appearance
  • Redness
  • Accentuated veins on breast surface
• Change in appearance or sensation of the nipple
  • Pulled in (retraction), enlargement, or itching
• Breast pain, enlargement, or discomfort on one side only
• Any breast lump, pain, tenderness, or other change in a man
• Symptoms of advanced disease are bone pain, weight loss, swelling of one arm, and skin ulceration

• X-ray mammography may help identify the breast mass.
• Ultrasound (sonogram) can show whether the lump is solid or fluid-filled.
• Needle aspiration or needle biopsy of breast lumps can demonstrate if they are fluid-filled and provide material to send to the laboratory for analysis. In the case of very small abnormalities visible only on mammography, special techniques are necessary.
• A surgical biopsy or breast lump removal provides a portion or all of a breast lump for laboratory study.

If breast cancer is diagnosed, additional testing is performed, including chest X-ray and blood tests. Surgery, radiation, chemotherapy, or a combination of these may then be recommended, not only for treatment, but also to help determine the stage of disease. Staging is important to help guide future treatment and follow-up, and to give some idea of what to expect in the future.

Stages of Breast Cancer (from the American Joint Committee on Cancer):

• STAGE 0. In Situ ("in place") disease in which the cancerous cells are in their original location within normal breast tissue
• STAGE I. Tumor less than 2 cm in diameter with no spread beyond the breast
• STAGE IIA. Tumor 2 to 5 cm in size without spread to axillary (armpit) lymph nodes or tumor less than 2 cm in size with spread to axillary lymph nodes
• STAGE IIB. Tumor greater than 5 cm in size without spread to axillary lymph nodes or tumor 2 to 5 cm in size with spread to axillary lymph nodes
• STAGE IIIA. Tumor smaller than 5 cm in size with spread to axillary lymph nodes which are attached to each other or to other structures, or tumor larger than 5 cm in size with spread to axillary lymph nodes
• STAGE IIIB. The tumor has penetrated outside the breast to the skin of the breast or of the chest wall or has spread to lymph nodes inside the chest wall along the sternum
• STAGE IV. A tumor of any size with spread beyond the region of the breast and chest wall, such as to liver, bone, or lungs

Many additional factors besides staging can influence the recommended treatment and the likely outcome. These can include the precise cell type and appearance of the cancer, whether the cancer cells respond to hormones, and the presence or absence of genes known to cause breast cancer.

Please discuss any and all treatment options for your condition with your healthcare professional.

• 95% for stage 0
• 88% for stage I
• 66% for stage II
• 36% for stage III
• 7% for stage IV

The axillary (armpit) lymph nodes are the main passageway that breast cancer cells must use to reach the rest of the body. Their involvement at any time strongly affects the prognosis.

Chemotherapy and hormone therapy can improve prognosis in all patients and increase the likelihood of cure in patients with stage I, II, and III disease.

• If you are a woman, 40 years or older, and have not had a mammogram in the last year.
• If you are a woman, 35 years or older, and have a mother or sister with breast cancer, or have already had cancer of the breast, uterus, ovary, or colon.
• If you are a woman, 20 years or older, and do not know how or need help to learn how to perform a breast self-examination.
  

Many risk factors cannot be controlled. Some experts in the field of diet and cancer agree that changes in diet and lifestyle may reduce the incidence of cancer generally.

Efforts have focused on early detection since breast cancer is more easily treated and often curable if it is found early. Breast self-examination (BSE), clinical breast examination (CBE) by a medical professional, and screening mammography are the three tools of early detection.

Most recommend breast self-examinations (BSE) once a month -- the week following your menstrual period if you are age 20 or older.

Regular clinical breast examinations (CBE) by a health professional are recommended for women between ages 20 and 39, at least every 3 years. After age 40, women should have a (CBE) by a health professional every year.

Mammography is the most effective way of detecting breast cancer early. The American Cancer Society recommends mammogram screening every year for all women age 40 and older.

The National Cancer Institute recommends mammogram screening every 1-2 years for women age 40 and older. For those with risk factors, including a close family member with the disease, annual mammograms should begin 10 years earlier than the age at which the relative was diagnosed.

Two drugs are being studied currently that have been shown to reduce the risk of breast cancer: tamoxifen (Nolvadex ®) and raloxifene (Evista ®). Both are anti-estrogens in breast tissue.

Tamoxifen is already widely used to prevent recurrence in women who have been treated for breast cancer. For some women at very high risk of breast cancer, preventive use of these drugs may be appropriate. This should be discussed with a qualified physician.

Preventive Mastectomy, which is the surgical removal of one or both breasts, is an option to prevent breast cancer for women who are at very high risk for breast cancer.

Possible candidates for this procedure are women who have already had one breast removed due to cancer, women with a strong family history of breast cancer and those who have a mutation in genes p53, BRCA1, or have gene BRCA 2.

For additional information on breast cancer, see the website of the American Cancer Society.