Breast Cancer Overview

For more details, please refer to:

American Cancer Society
National Cancer Institute

• Breast cancer is an uncontrolled growth of abnormal breast cells.
  
  
• Metastatic cancer cells can break away from the tumor and enter the bloodstream or the lymphatic system spreading to other organs.
  
  
• There are two major types of breast cancer: ductal carcinoma, which originates in the epithelial cells of the ducts; and lobular carcinoma, which begins in the terminal lobules of the breast. If the cancer spreads beyond the layer of tissue in which it developed, it is called invasive or infiltrating cancer.
  
  
• Ductal carcinoma in situ (DCIS) is the most common type of noninvasive breast cancer, with a nearly 100% cure rate by surgery alone. The cancer cells are contained in the ducts and do not have the ability to spread.
  
  
• Lobular carcinoma in situ originates in the milk-producing glands but does not penetrate through the wall of the lobule. It is often classified as a non-invasive cancer and is considered a marker for an increased risk of invasive cancer.
  

Breast Cancer Incidence Rates

• Breast cancer is the most frequently diagnosed cancer among women, excluding skin cancers. Approximately 1 out of every 8 women will develop the disease during her lifetime.
  
  
• Breast cancer is the leading cause of death among women ages 35 - 54 and the second leading cause of cancer death in women of all ages.
  
  
• Over 180,000 new cases of invasive breast cancer are diagnosed annually among U.S. women resulting in nearly 44,000 deaths per year.
  
  
• 80% of women diagnosed with breast cancer have no known risk factors.
  
  
• Approximately 80% of the women with breast cancer are over the age of 50.
  

Breast Cancer Risk Factors

The risk of breast cancer increases gradually as a woman gets older. However, the risk of developing breast cancer is not the same for all women. The following factors are known to increase a woman's chance for developing this disease: 

• Personal history of breast cancer.
  Women who have had breast cancer are more likely to develop a second breast cancer. 
  
  
• Family history.
  A woman's chance of developing breast cancer increases if her mother, sister, daughter, or two or more other close relatives, such as cousins, have a history of breast cancer (especially if they were diagnosed before the age of 50).
  
  
• Genetic alterations.
  Specific alterations in certain genes (BRCA1, BRCA2, and others) make women more susceptible to breast cancer. These alterations are rare; they are estimated to account for no more than 10 percent of breast cancers.
  
  
• Certain breast changes.
  Having a diagnosis of atypical hyperplasia or lobular carcinoma in situ (LCIS), or having had two or more breast biopsies for other benign conditions, increases a woman's risk for developing breast cancer.
  

Other factors associated with an increased risk for breast cancer include:

• Breast density.
  Women who have at least 75 percent dense tissue on a mammogram are at elevated risk. (This not only because tumors in dense breasts are more difficult to "see," but because, in older women, dense breast tissue itself is related to an increased chance of developing breast cancer.)
  
  
• Radiation therapy.
  Women whose breasts were exposed to radiation during their childhood, such as those treated for Hodgkin's disease, are at an increased risk for developing breast cancer throughout their lives. Studies show that the younger a woman was when she received her treatment, the higher her risk for developing breast cancer later in life.
  
  
• Reproductive and menstrual history.
  Women who had their first child after age 30 have a greater chance of developing breast cancer than women who had children at a younger age. Women who started menstruating at an early age (before age 12), experienced menopause late (after age 55), or never had children are also at a somewhat increased risk for developing breast cancer.
  
  Women who take hormone replacement therapy for an extended period of time (more than 5 years) may also have an increased chance of developing breast cancer. The results of studies examining the use of oral contraceptives as a risk factor for breast cancer are inconsistent.

The risk of breast cancer increases with age.
The older a woman is, the greater her chance of getting breast cancer.

A woman's chance of being diagnosed with breast cancer is:

Breast Cancer Diagnosis

• Mammography is the best-known method of early detection.
  
  
• Annual or biennial mammograms routinely performed on women between 50 and 69 reduce the chances of dying from breast cancer by approximately 30%; results are inconclusive as to whether mammography will increase survival for women 40 to 49.
  
  
• Monthly breast self-examination is recommended.
  
  
• Currently available blood tests are clearly inadequate for detection.

Current Diagnostic Limitations:

Mammography

National Cancer Institute Information Resources (reviewed on 11/21/00):

False Negatives: False negatives occur when mammograms appear normal even though breast cancer is actually present. Overall, mammograms will miss approximately 20 percent of the breast cancers that are present at the time of screening. False negatives occur more often with younger women than with older women. The dense breasts of younger women contain many glands and ligaments, which make breast cancers more difficult to spot in mammograms. As women age, breast tissues become more fatty and breast cancers are more easily "seen" by screening mammograms.  

False Positives: False positives occur when mammograms are read as abnormal, but no cancer is actually present. Between 5 percent and 10 percent of mammograms are abnormal and are followed up with additional testing (a diagnostic mammogram, fine needle aspiration, ultrasound, or biopsy). Most abnormalities will turn out not to be cancer.

About 30 percent of women ages 40 to 49 have a false positive mammogram, as compared with about 25 percent for women age 50 and older. However, all women must undergo follow-up procedures when they have an abnormal mammogram. Some will require breast biopsies.

Once a potential tumor mass is identified, a breast biopsy is usually performed. The average positive confirmation of cancer through a breast biopsy is estimated to be less than 20% as outlined by the information below:  

When mammography or palpation indicates a mass is present, the most common next step is to perform a breast biopsy.

Even with the high expense of the biopsy and subsequent pathology, results are far from conclusive. Surgeons may actually miss the mass and yield a healthy tissue sample or may overlook the possibility of bilateral disease.

Breast Cancer Treatment

• Lumpectomy - surgical removal of only the tumor and a small amount of surrounding tissue
  
  
• MastectomyKastrup cheap hotels - surgical removal of the breast tissue
  
  
• Axillary node dissection - removal of the lymph nodes of the armpit
  
  
• Radiation therapy - the use of high-energy x-rays to treat cancer
  
  
• Chemotherapy - treatment with drugs to kill or slow the growth of cancer cells
  
  
• Hormonal therapy - treatment with drugs to inhibit hormonal actions on cancer cells
  
  
• Biological or immunotherapy - stimulation of the bodys own immune system to treat cancer
  
  
• Sentinel node biopsy - biopsy of this lymph node may obviate the need for axillary node dissection

Breast Cancer Research

Advances in the understanding of the molecular and cellular biology of breast cancer have the potential to identify both new tools for early detection and new therapeutic agents. New directions in prevention, detection and therapy:

• Risk reduction for women at high risk with agents such as selective estrogen receptor modulators (SERM's).
  
  
• Tumor marker test:
  

  	-Blood tests to identify bioactive lipid growth factors present in blood of breast cancer patients with -active disease;
  	-Serum blood tests to increase the efficacy of screening techniques.

• Advances in screening technology:
  

  	-Digital mammography;
  	-Magnetic resonance imaging (MRI);
  	-Positron emission tomography (PET).

• Chemotherapeutic:
  

  	-New agent development;
  	-Drug combinations;
  	-Less toxic delivery systems;
  	-High-dose chemotherapy with autologous bone marrow transplantation (ABMT).

  
  
• Immunotherapy
  
  
• Anti-angiogenesis drug development