Understanding Breast Cancer
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Understanding Breast Cancer

The structure and function of the breasts

The breasts are made up of fat, connective tissue and glandular tissue that contains lobes. The lobes are where breast milk is produced. A network of milk ducts connects the lobes to the nipple. A woman's breasts are rarely the same size as each other, and may feel different at different times of the menstrual cycle, sometimes becoming lumpy just before a period. Under the skin, an area of breast tissue extends into the armpit (axilla). The armpits also contain a collection of lymph nodes (lymph glands), which are part of the lymphatic system. There are also lymph nodes just beside the breastbone and behind the collarbones.

Understand Breast Cancer

Breast lumps

Most breast lumps are benign and are not cancer. Common causes of benign breast lumps are cysts (sacs of fluid which build up in the breast tissue) or fibroadenomas (solid tumours made up of fibrous and glandular tissue). Benign breast lumps are easily treated. Any different or unusual change in the breast should always be examined by a doctor. This is because even though most breast lumps are benign, they still need to be checked carefully to rule out the possibility of cancer. Also, if it is a cancer, the earlier the treatment is given, the more likely it is to be successful.

If you notice a lump or are aware of any new change in your breast, visit your doctor straight away.

What is cancer?

The organs and tissues of the body are made up of tiny building blocks called cells. Cancer is a disease of these cells. Cells in different parts of the body may look and work differently but most reproduce themselves in the same way. Cells are constantly becoming old and dying, and new cells are produced to replace them. Normally, cells divide in an orderly and controlled manner. If for some reason the process gets out of control, the cells carry on dividing, developing into a lump which is called a tumor.


Tumors can be either benign or malignant. Cancer is the name given to a malignant tumor. Doctors can tell if a tumor is benign or malignant by examining a small sample of cells under a microscope. This is called a biopsy.
In a benign tumor the cells do not spread to other parts of the body and so are not cancerous. However, if they continue to grow at the original site, they may cause a problem by pressing on the surrounding organs.
A malignant tumor consists of cancer cells that have the ability to spread beyond the original area. If the tumor is left untreated, it may spread into and destroy surrounding tissue. Sometimes cells break away from the original (primary) cancer. They may spread to other organs in the body through the bloodstream or lymphatic system. When the cancer cells reach a new area they may go on dividing and form a new tumor. This is known as a secondary cancer or metastasis.

It is important to realize that cancer is not a single disease with a single type of treatment. There are more than 200 different kinds of cancer, each with its own name and treatment.

Magnitude of Breast Cancer

Breast cancer is a global problem and is far more common in the Western world as compared to India. It is expected that about 200,000 new cases of breast cancer will be diagnosed in the USA in 2009 and there will be about 40,000 deaths due to breast cancer during this period. It is estimated that 1 in every 8 women born in the USA will develop breast cancer during her lifetime. The situation in India is not as grim. We do not have precise figures but it is estimated that breast cancer is about 5 times more common in USA as compared to India. In India, it is more common in the urban population as compared to the rural population. In our metros, breast cancer has taken over the number one position for cancer in women.

Risk factors and causes of breast cancer

The causes of breast cancer are not yet completely understood. The risk of developing breast cancer is very small in young women and increases as women get older. Eight out of ten (80%) breast cancers occur in women over the age of 50. Some factors may slightly increase a woman’s risk of developing the disease and these are described below.

Health factors

  • Having had breast cancer before.
  • Having had certain types of benign breast disease (lobular carcinoma in situ or atypical hyperplasia).
  • Being overweight, once you have had your menopause, can increase the risk of breast cancer.

Hormonal factors

  • Women who are taking combined hormone replacement therapy (HRT), or have recently taken it, have a slightly increased risk of breast cancer. Younger women who take HRT because they have had an early menopause, or have had their ovaries removed, do not have an increased risk of breast cancer until after the age of 50.
  • Women who are taking the contraceptive pill, or have recently taken it, have a very slightly increased risk of developing breast cancer.
  • Women who don’t have children are slightly more likely to develop breast cancer than women who have children.
  • Women who start their periods early (early puberty) or have a late menopause have a slightly higher risk of breast cancer.
  • Women who have never breastfed are slightly more likely to develop breast cancer than women who have breastfed for more than a year.

Lifestyle factors

Drinking more than two units of alcohol a day over many years can increase the risk. A unit of alcohol is half a pint of normal strength lager or beer, a small glass (125ml) of wine, or a single measure (25ml) of spirit.
Genetic factors

A very small number – between 5–10% of breast cancers are thought to be related to inherited faulty genes. The two main breast cancer genes are BRCA1 and BRCA2. Other genes connected with breast cancer have been identified but these increase the risk of breast cancer only slightly whereas 40–80% of women with faulty BRCA1 and BRCA2 genes get breast cancer.

If you have any of the following in your family, you might want to speak to your doctor:

  • Three close blood relatives (from the same side of the family) who developed breast or ovarian cancer at any age
  • Two close relatives (from the same side of the family) who developed breast or ovarian cancer under the age of 60
  • One close relative who developed breast cancer under the age of 40
  • A case of breast cancer in a male relative
  • A relative with cancer in both breasts.

Your close relatives are your parents, children, brothers and sisters. These are called your first degree relatives.

Symptoms of breast cancer

In most women, breast cancer is first noticed as a painless lump in the breast.

Other signs may include:

  • A change in the size or shape of a breast
  • Dimpling of the skin of the breast
  • A thickening in the breast tissue
  • A nipple becoming inverted (turned in)
  • A lump or thickening behind the nipple
  • A rash (like eczema) affecting the nipple
  • A bloodstained discharge from the nipple (this is very rare)
  • A swelling or lump in the armpit.

Pain in the breast is usually not a symptom of breast cancer. In fact, many healthy women find that their breasts feel lumpy and tender before a period. Some types of benign breast lumps can be painful.