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Breast Cancer

Breast Cancer

Monday, February 27, 2023 - 13:55
Contributors to this article: 

Charles E Cox  MD
Michael Baum  Ch.M.FRCS
S.Eva Singletary MD
Guy Slowik FRCS

If the normal cells of the breast grow out of control they form a lump or tumour. The cells change in appearance and function and become abnormal.  

A breast lump is considered benign if it is limited to a few cell layers and does not invade surrounding tissues or organs. A benign lump is not cancer.  But if the tumor spreads to the surrounding tissues or organs, it is considered malignant, or cancerous

The breasts are, in essence, a collection of fatty tissue and glands that have been adapted to secrete milk after a woman gives birth. The glands that produce milk are called lobules and the tubes that connect them to the nipples are called ducts. Cancer of the breast develops when malignant changes occur in the cells that line the lobules or, more commonly, the ducts.

Carcinoma is the term used to describe the cancers that arise from the surface or lining cells. 

There are two major types of breast cancer:

  • lobular carcinoma, and
  • ductal carcinoma.

Cancer can be either invasive (spreading) or noninvasive (generally known as 'in situ' - confined to the original site). The majority of breast cancers (70% - 80%) arise from the ducts, which make up the bulk of breast tissue. Since lobular and ductal cells are found in the glandular tissues of the upper, central, and outer regions of the breast, this is where most breast cancers occur. Breast tumors rarely arise in the fatty or nonglandular tissues. Such tumors, when they appear, are usually sarcomas.

Cells from the tumor may break away, travel, and grow within other parts of the body. This process is known as metastasis. Breast cancer often metastasizes to sites such as the lung, bone, liver, and brain. If breast cancer is detected at an early stage - for example, before metastasis - it usually can be cured; however, as the disease progresses, the possibility of effective treatment is diminished. Fortunately, though, many breast "lumps" are caused by benign breast diseases that do not spread beyond the breasts and are not life-threatening.

Men can also develop breast cancer.

Facts About Breast Cancer:

A diagnosis of breast cancer is alarming, but the good news is that most women recover from it. Improvements in breast cancer detection have helped to limit the harmful potential of this disease. In fact, during the last decade, the majority of breast cancers reported in the U.S. were small, very treatable, early-stage tumors.

Overall, about 83% of women survive breast cancer, as shown by recent 5-year survival statistics. Although these numbers don't guarantee that a person will be in the 'favorable' statistical group, they do show that the likelihood of beating breast cancer is good. If breast cancer is detected and treated in the early stages, the chances of complete recovery are even better.

With the exception of skin cancer, breast cancer is the most common cancer among American women. Recent findings from the National Cancer Institute (NCI) indicate that an American woman has a one in eight chance of developing breast cancer during her lifetime. The American Cancer Society estimates that about 230,480 new cases of invasive breast cancer were diagnosed in the year 2011, as well as 57,650 new cases of in situ breast cancer. Nearly 40,000 American women died from breast cancer in 2011, making it the second leading cause of cancer death after lung cancer. 

Breast cancer also can strike men, although cancer of the male breast accounts for only 1% of all diagnosed breast cancers. in 2011, more than 2,000 men were diagnosed with breast cancer, and 450 men died from the disease.

Over the last 5 years, patients have benefited from many advances in breast cancer treatment. Breast conservation - the saving of the breast - has increased enormously because of early diagnosis and the widespread use of mammograms (x-rays of the breast). In addition, new anti-cancer drugs such as paclitaxel (Taxol®) and trastuzumab (Herceptin®) have been approved by the Food and Drug Administration (FDA) and show promise in the treatment of people with advanced disease.

The progress made in breast cancer detection and treatment is perhaps best reflected by mortality (death rate) figures. U.S. statistics show that breast cancer mortality decreased significantly between 1990 and 2007, at a rate or 2.2% per year. The largest decline seen in younger women, in whom the mortality rate decreased by 3.2 percent per year. This suggests that, although breast cancer remains a major concern among American women, it can be managed successfully.

However, white non-Hispanic women appear to have benefited the most from advances in screening and treatment. While decreases in mortality were significantly less for all ethnic groups other than whites, the most striking disparity is seen between white and Black women. In 2007, the breast cancer mortality rate for Black women was 41 percent higher than for white women.

The following sections will explain the causes and treatment of breast cancer, as well as some of the methods used to overcome the far-reaching effects of this disease.


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