Fibrocystic breast cancer also called benign breast disease or physiologic nodularity. Fibrocystic disease refers to the presence of nodules or masses in the breast tissue that change during the menstrual cycle in response to fluctuating hormone levels, particular oestrogen. The connective tissue of the breast is gradually replaced by the dense fibrous tissue. Increasing fluid in the breast during the secretory phase of the menstrual cycle accumulates in cysts (a membrane sac or cavity, containing fluid) bound by fibrous tissue, unable to escape. As well, the epithelial cells in the ducts proliferate in response to hormones. The cysts enlarge over time, often causing more lesions (loss of function in the tissues) of normal tissue.
3 categories of lesions (a region in an organ or tissue which has suffered damage through injury or disease, such as wound, ulcer or tumour) have been designated, based on the risk of development of breast cancer.
One category is non-proliferate lesions, which include micro-cysts and fibroadenomas. Fibroadenomas are specific benign tumours that appear as singular, movable masses. These tumours are usually removed.
The second category includes proliferate (to grow or spread) lesions (with epithelial hyperplasia (the enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells, in the ducts) in which there are no atypical cells. The risk in this group increases if there is also a family history of breast cancer.
The 3rd category, a small one, is the one that requires monitoring, particularly if a family history of breast cancer is present. These lesions show proliferate changes with atypical cells. Breast biopsy can detect atypical cells and can differentiate benign from malignant cells.
Carcinoma of the breast is a common malignancy in women and a major cause of death. 10% of all cancers worldwide. Rarely, breast cancer occurs in males. The incidence of breast cancer continues to increase after age 20, and more women are developing the malignancy at a younger age.
The majority of cases occur in women over age 50. A strong genetic predisposition has been supported by the identification of specific genes related to breast cancer. Familial occurrence that is proportional to the numbers affected relatives and the closeness of the relationships has been well documented.
The other major factor in the aetiology of breast cancer is hormones – specifically, exposure to high oestrogen levels. Circumstances such as a long period of regular menstrual cycles (for example, from an early menarche to late menopause), nullipatiry (no children), and delay of the first pregnancy appear to promote cancer development.
The role of exogenous oestrogen (birth control pills, supplements) in oral contraceptives or postmenopausal supplements still remains controversial.
Other factors predisposing to breast carcinoma include fibrocystic disease with atypical hyperplasia, prior carcinoma in the uterus or in the other breast, and exposure of the chest to radiation – particularly in young women.