Breast cancer is a cancer that occurs in the tissues of the breast. It involves a group of abnormal cells which start to have abnormal growth patterns. It is a illness which is found primarily in women, although approximately 1% of breast cancer occurs in men.
Breast cancer is the most common type of cancer that occurs in women and following lung cancer, it is the second leading cause of cancer death in females. 184,200 new cases of breast cancer were reported in the year 2000 by the American Cancer Society, and this figure appears to be rising on a yearly basis.
The breasts in women are a complicated piece of machinery which consist of glands, fat and connective fibrous tissue. They have several lobes, divided into lobules which end in the milk glands. There are tiny ducts which from the numerous tiny glands and after connecting together, end in the nipple.
Eighty percent of breast cancer cases occur in these ducts, and this condition is known as infiltrating ductal cancer. Cancer which develops in the lobules is known as lobular cancer and approximately 10-15% of breast cancers are this type of cancer. Other types of cancers are known as inflammatory breast cancer.
Changes such as precancerous changes (known as in situ) are also common in women. These are changes which have not spread from the place in the breast where they started. When these changes do occur within the ducts, the condition is known as ductal carcinoma in situ or DCIS. When they occur in the lobules, they are known as lobular carcinomas in situ or LCIS. Routine mammography routinely diagnoses DCIS.
The most serious types of breast cancer are known as metastatic cancer. This type of cancer involves the spread of the cancer from the place where it began. It most commonly metatasizes into the lymph nodes above the collarbone or under the arms on the same side of the cancer. This results in pain and swelling to the affected area as the lymphatic drainage system is then compromised. Other common sites of breast cancer metastasis include the brain, liver and the bones.
Approximately 50% of women who develop breast cancer do not have any risk factors apart from age and their gender. Due to the fact breast cancer occurs mostly in women, their sex is the biggest risk factor.
Another critical factor is age. Although breast cancer can and does occur at any age, the risk of developing it increases as you get older.
A normal woman aged 30 will usually have a 1 in 280 chance of developing breast cancer during the next ten years of her life. This then increases to a probable 1 in 70 chance of developing breast cancer when she reaches the age of 40 to 50 years.
The risk factor for breast cancer is also affected by family history. This risk is at its highest if a close relative has developed cancer of the breast at a young age. The risk increases further if the relative is close such as a mother, aunt or daughter. There has recently been found what is thought to be a cancer gene which can be passed down from mother to daughter.