Breast cancer is the most common type of cancer in non-smoking women and the second most common type, after lung cancer, in women who smoke. One woman in every 12 who live to old age will develop breast cancer at some point in her life. Breast cancer can also rarely develop in men. The advancement of techniques for early diagnosis and treatment of breast cancer has improved overall survival rates.
Current theories regarding the causes of breast cancer are focused on hormonal and genetic influences. However, the principal risk factor is age, with a woman’s chances of developing the disease doubling every ten years of her life. The incidence of breast cancer is known to be raised in women whose menstrual periods began at an early age and in those whose menopause was late to commence. The risk is also higher in women who did not have children of those who had their first child late in life.
Women whose mothers or sisters have had breast cancer are also at an increased risk. Diet may also play a part; breast cancer is more common in countries in which the typical diet contains a lot of fat. Studies have shown that hormone replacement therapy (HRT) slightly increases the chances of developing breast cancer; the risk increases with the length of time that HRT has been taken.
Breast cancer in women under the age of 50 may be linked to genetic factors and various genes, including BRCA 1 and BRCA 2, have been identified. These genes seem to account for some of the breast cancers that occur within families. Women with one or more relatives who have developed the disease in their 30’s or 40’s may wish to seek specialist genetic advice.
Signs and symptoms
The first sign of breast cancer is often a painless lump. However, it is important to note that nine out of ten breast lumps are not cancerous. Other symptoms of breast cancer may include a dark discharge from the nipple, retraction (indentation) of the nipple, and an area of dimpled, creased skin over the lump. In the majority of cases, only one breast is affected. An abnormality may sometimes be detected during a mammography.
Investigation and treatment
If a lump is detected in the breast, an imaging procedure, such as mammography or ultrasound scanning, will be carried out. Cells will then be collected from the lump by needle aspiration (withdrawal by suction) or biopsy (surgical removal of a small sample of tissue for analysis). A small cancerous tumor that is not thought to have spread outside the breast is removed surgically, along with a surrounding margin of normal tissue. Lymph nodes in the armpit are usually removed at the same time. Larger cancers may require mastectomy (surgical removal of the whole breast). Surgery can be combined with or followed by mammoplasty (breast reconstruction) to help reduce the psychosexual impact of the disease.
Any further treatment depends on the size of the tumor; whether or not there is evidence of spread to the lymph nodes; and the sensitivity of the tumor cells to hormones, which is assed in the laboratory using a technique known estrogen receptor testing. The women’s age and whether or not she has gone through the menopause are also significant factors in determining appropriate treatment.
After surgery, most women have a course of radiotherapy to any remaining breast tissue and to the armpit, and/or chemotherapy (treatment with anticancer drugs). Tamoxifen, an oral anti-estrogen drug, is commonly prescribed for five years following surgery for breast cancer to reduce the risk of recurrence. Women who are approaching the menopause may be offered treatment to bring on an early menopause if the tumor is estrogen sensitive.
Secondary tumors in other parts of the body, which may be present at the time of the initial diagnosis or may develop years after apparently successful treatment, are treated with anticancer drugs and hormones.
A complete cure or years of good health can usually be expected after treatment for early breast cancer. Regular check ups are required to detect recurrence or the development of a new cancer in the other breast. Mammograms should be performed periodically for this reason. If the cancer recurs, it can be controlled, sometimes for years, by drugs and/or radiotherapy.