What is Breast Cancer?
A mature human female’s breast consists of fat, connective tissue and thousands of lobules – tiny glands which produce milk. The milk of a breastfeeding mother goes through tiny ducts (tubes) and is delivered through the nipple.
The breast, like any other part of the body, consists of billions of microscopic cells. These cells multiply in an orderly fashion – new cells are made to replace the ones that died. In cancer, the cells multiply uncontrollably, and there are too many cells, progressively more and more than there should be.
Breast cancer is an uncontrolled growth of breast cells. The term “breast cancer” refers to a malignant tumor that has developed from cells in the breast. Usually breast cancer either begins in the cells of the lobules, which are the milk-producing glands, or the ducts, the passages that drain milk from the lobules to the nipple. Less commonly, breast cancer can begin in the stromal tissues, which include the fatty and fibrous connective tissues of the breast.
A breast cancer that started off in the lobules is known as lobular carcinoma, while one that developed from the ducts is called ductal carcinoma.
Invasive breast cancer– the cancer cells break out from inside the lobules or ducts and invade nearby tissue. With this type of cancer, the abnormal cells can reach the lymph nodes, and eventually make their way to other organs (metastasis), such as the bones, liver or lungs. The abnormal (cancer) cells can travel through the bloodstream or the lymphatic system to other parts of the body; either early on in the disease, or later.
Non-invasive breast cancer – this is when the cancer is still inside its place of origin and has not broken out. Lobular carcinoma in situ is when the cancer is still inside the lobules, while ductal carcinoma in situ is when they are still inside the milk ducts. “In situ” means “in its original place”. Sometimes, this type of breast cancer is called “pre-cancerous”; this means that although the abnormal cells have not spread outside their place of origin, they can eventually develop into invasive breast cancer.
According to http://www.medicalnewstoday.com some of the causes of breast cancer are explained below,although experts are still not sure about what causes breast cancer. Some risk factors can impact on a woman’s likelihood of developing breast cancer.
Genetics– women who have a close relative who has/had breast or ovarian cancer are more likely to develop breast cancer. If two close family members develop the disease, it does not necessarily mean they shared the genes that make them more vulnerable, because breast cancer is a relatively common cancer.The majority of breast cancers are not hereditary.
Women who carry the BRCA1 and BRCA2 genes have a considerably higher risk of developing breast and/or ovarian cancer. These genes can be inherited. TP53, another gene, is also linked to greater breast cancer risk.
A history of breast cancer – women who have had breast cancer, even non-invasive cancer, are more likely to develop the disease again, compared to women who have no history of the disease.
Having had certain types of breast lumps – women who have had some types of benign (non-cancerous) breast lumps are more likely to develop cancer later on. Examples include atypical ductal hyperplasia or lobular carcinoma in situ.
Alcohol consumption – the more alcohol a woman regularly drinks, the higher her risk of developing breast cancer is. The Mayo Clinic says that if a woman wants to drink, she should not exceed one alcoholic beverage per day.
Height – taller-than-average women have a slightly greater likelihood of developing breast cancer than shorter-than-average women. Experts are not sure why.
HRT (hormone replacement therapy) – both forms, combined and estrogen-only HRT therapies may increase a woman’s risk of developing breast cancer slightly. Combined HRT causes a higher risk.
Cosmetic implants may undermine breast cancer survival – women who have cosmetic breast implants and develop breast cancer may have a higher risk of dying prematurely form the disease compared to other females.
Getting older – the older a woman gets, the higher is her risk of developing breast cancer; age is a risk factor. Over 80% of all female breast cancers occur among women aged 50+ years (after the menopause).
Dense breast tissue – women with more dense breast tissue have a greater chance of developing breast cancer.
Estrogen exposure– women who started having periods earlier or entered menopause later than usual have a higher risk of developing breast cancer. This is because their bodies have been exposed to estrogen for longer. Estrogen exposure begins when periods start, and drops dramatically during the menopause.
Obesity– post-menopausal obese and overweight women may have a higher risk of developing breast cancer. Experts say that there are higher levels of estrogen in obese menopausal women, which may be the cause of the higher risk.