Breast cancer is the commonest form of cancer that occurs in women and, behind lung cancer, it is the second leading cause of cancer death among females. In 2004 some 186,772 new cases of breast cancer were reported by the American Cancer Society and this number would seem to be going up on a yearly basis.It should also be noted that breast cancer is not confined solely to women and that some 1,815 men were also diagnosed with the disease in 2004 and that 362 men died of breast cancer that year.Women’s breasts are complex structures consisting of glands, fat and connective fibrous tissue. They have several lobes which are split into lobules ending in the milk glands and there are also a large number of tiny ducts from the milk glands that connect together and end in the nipple.   Eight out of ten breast cancer cases start in these ducts and this condition is called infiltrating ductal cancer. It is also relatively common for cancer to originate in the lobules where it is known as lobular cancer. Other types of cancer are known as inflammatory breast cancer.Pre-cancerous changes (called ‘in situ’) are also common in women and are changes that have not yet spread from the area of the breast where they started. Where these changes take place within the ducts then the condition is known as ductal carcinoma in situ or DCIS and where they occur in the lobules they are called lobular carcinomas in situ or LCIS.The most serious form of breast cancer is metastatic cancer which involves the spread of a cancer from its original site of growth. It commonly metastasizes into the lymph nodes under the arms or above the collarbone on the same side of the body as the cancer which leads to pain and swelling as the lymphatic drainage system is compromised. Other quite common sites for breast cancer metastasis include the liver, brain and bones. Excluding the very obvious factor of gender, age is a critical factor when it comes to breast cancer. Despite the fact that breast cancer can appear at any age the risk of finding it certainly rises with age. A normal woman of 30 will usually have a 1 in 280 chance of getting breast cancer by the time she reaches 40. However, this then increases to a 1 in 70 chance when that same women is in her forties.   Family history is also an important risk factor for breast cancer with the risk being particularly high when you have a close relative (like a mother or aunt) who has developed breast cancer at a young age. There has recently been found what is believed to be a cancer gene that can be passed from mother to daughter.