Risk factors
The main risk factor for getting breast cancer is age. The older you are, the greater your risk. In the UK about 80 per cent of women with breast cancer are over 45.
The risk is slightly higher if you:
- Have a personal or family history of breast cancer
- Started having periods early (12 or younger)
- Have a late menopause (55 or older)
- Never had children or you had your first baby at a late age
- Used oestrogen and progesterone hormone replacement therapy, although it is believed that the health benefits of HRT outweigh the risks, at least in the first 10 years
- Some studies have suggested that you are at a greater risk of getting breast cancer if you have taken the oral contraceptive pill, but it is now thought that this risk, if real, is very low
- High alcohol intake and obesity may also be linked to a slightly increased risk of getting breast cancer
A majority of women will have one or more risk factors for breast cancer. However, most risks are at such a low level that they only partly explain the high frequency of the disease in the population. Although women cannot alter some of their personal risk factors, maintaining an ideal body weight and reducing alcohol consumption may result in some reduction in breast cancer risk. Early detection, however, provides the best opportunity to reduce your chances of death by this disease.
Hereditary breast cancer
Hereditary breast cancer makes up approximately five per cent of all breast cancer cases. The genes in cells carry the hereditary information that is received from a woman's parents. Several genes have been found to be defective in some breast cancer patients. Relatives of breast cancer patients who carry these defective genes are more likely to develop breast or ovarian cancer.
In breast cancer, the two genes that doctors know about are BRCA1 and BRCA2. If these genes are mutated, there is a stronger than average chance of getting breast cancer. If you are concerned that you may have an increased risk of developing breast cancer because of your family history, your doctor may refer you to a clinic that specialises in such situations.
List of Contents
Overview
Risk factors
Staging of Breastcancer
Prognostic Factors
Early detection of breast cancer
The earlier that cancer can be detected, the better the response to treatment. The main ways of detecting breast cancer are by self-examination and regular mammograms.
Regular self-examination is an important way to detect the early signs of breast cancer and should be performed regularly by all adult women. The self-examination should take about 15 minutes, once a month, about a week after your period starts. Ask your doctor how to do this or pick up a leaflet at the surgery. It may take several months for you to become familiar with the routine and to learn what to expect to feel but with practice, self-examination of your breasts will become a natural part of your routine.
If you find a suspicious lump, see your doctor as soon as possible. He or she will perform an examination and may well suggest a mammogram. The vast majority of breast lumps found by women who perform self-examination regularly are not cancer. However, since about 20 per cent will turn out to be malignant, self-examination can be life saving.
Mammography
Mammography refers to an X-ray examination of the breast that is of most use in older, post-menopausal women. In some cases mammography can pick up cases of breast cancer before physical symptoms develop. The UK has a National Health Service breast-screening programme in which women between the ages of 50 and 64 are offered mammography at three yearly intervals. Beyond the age of 64 these examinations can be continued upon request.
Mammograms can detect a breast lump up to two years before it can be felt during a physical examination. However, this test can miss up to 10 per cent of breast cancers, so it is important to continue to perform regular self-examination.
A mammogram is simply an X-ray of your breasts from various angles. Although it doesn't hurt, it can be uncomfortable for some women or even a little embarrassing, because a radiographer will move and flatten your breasts on the X-ray machine into the best positions for taking pictures. Usually, the whole procedure takes less than 15 minutes. If something abnormal is detected in a mammogram, the next step is to take additional X-ray views or an ultrasound.
A recent study by the World Health Organisation concluded that screening would save the life of 1in every 500 women over 50 who attended appointments.
List of Contents
Overview
Risk factors
Staging of Breastcancer
Prognostic Factors
If your doctor still believes the area is suspicious, he or she will arrange for a sample to be taken to determine if it's cancer, either by needle biopsy, aspiration or another type of biopsy. Both tests remove a sample of the tissue that will then be examined by a pathologist.
Staging of breast cancer
As well as detecting breast cancer, or confirming the doctor's initial diagnosis, the tests are also useful in showing the extent (stage) of the cancer. The stage of a cancer is a term used to describe its size and whether it has spread beyond its original site. Knowing the extent of the cancer and the grade helps the doctors to decide on the most appropriate treatment.
Generally breast cancer is divided into 4 stages, from small and localised (stage 1) to spread to other parts of the body (stage 4). If the cancer has spread to distant parts of the body this is known as secondary cancer (or metastatic cancer).
A commonly used staging system is described below:
Ductal carcinoma in situ (DCIS): DCIS is when the breast cancer cells are completely contained within the breast ducts (the channels in the breast that carry milk to the nipple), and have not spread into the surrounding breast tissue. This may also be referred to as non-invasive or intraductal cancer, as the cancer cells have not yet spread into the surrounding breast tissue and so usually have not spread into any other part of the body. DCIS is almost always completely curable with treatment.
Lobular carcinoma in situ (LCIS) means that cell changes are found in the lining of the lobules of the breast. It can be present in both breasts. It is also referred to as non-invasive cancer as it has not spread into the surrounding breast tissue.
The following stages of breast cancer are known as invasive breast cancer.
Stage 1 tumours: these measure less than two centimetres. The lymph glands in the armpit are not affected and there are no signs that the cancer has spread elsewhere in the body.
Stage 2 tumours: these measure between two and five centimetres, or the lymph glands in the armpit are affected, or both. However, there are no signs that the cancer has spread further.
List of Contents
Overview
Risk factors
Staging of Breastcancer
Prognostic Factors
Stage 3 tumours: these are larger than five centimetres and may be attached to surrounding structures such as the muscle or skin. The lymph glands are usually affected, but there are no signs that the cancer has spread beyond the breast or the lymph glands in the armpit.
Stage 4 tumours: these are of any size, but the lymph glands are usually affected and the cancer has spread to other parts of the body. This is secondary breast cancer.
Grading of breast cancer
Grading refers to the appearance of the cancer cells under the microscope. The grade gives an idea of how quickly the cancer may develop. There are three grades:
- grade 1 (low grade),
- grade 2 (moderate grade) and
- grade 3 (high grade).
Low grade means that the cancer cells look very like the normal cells of the breast. They are usually slowly growing and are less likely to spread. In high grade tumours the cells look very abnormal. They are likely to grow more quickly and are more likely to spread.
Treatment of breast cancer
The mainstay of treatment for breast cancer is surgery. The type of surgery you will receive will depend upon many considerations, including your own preferences. The most common for invasive cancer are lumpectomy with axillary lymph node dissection and modified radical mastectomy.
Types of surgery include:
- Lumpectomy is known as a breast-conserving surgery, and it has become more common in the last 10 years as a means of treating early-stage cancer. In this procedure, a surgeon removes just the tumour along with a margin of healthy tissue, leaving the remainder of the breast intact. An axillary lymph node dissection should be performed for invasive forms of the disease. Radiotherapy is almost always given following lumpectomy for an invasive cancer.
- Simple mastectomy - this is where the entire breast is removed
- Modified radical mastectomy - the most common breast cancer surgery whereby the entire breast is removed along with the underarm lymph nodes
- Radical mastectomy - once the only surgical procedure for breast cancer, this extremely invasive surgery is rarely performed today
- Reconstruction - this is often an option after a mastectomy, either immediately or at some later date, but in some cases immediate reconstruction during the same operation as the mastectomy is appropriate
List of Contents
Overview
Risk factors
Staging of Breastcancer
Prognostic Factors
In addition to surgery, adjuvant therapy ( therapy given in addition to surgery to reduce the chances of the cancer recurring or spreading) may be used to kill any cancer cells that may have spread. In deciding whether adjuvant treatment is necessary, your doctor takes into account the extent (stage) of your disease, your general health and other prognostic factors. The choice of the type of adjuvant therapy that is given depends on many factors, such as whether the cancer cells contain hormone receptors (oestrogen and progesterone), the grade and size of tumour and lymph node involvement.
Most women receive some form of adjuvant therapy, and it usually begins 2-12 weeks after surgery. Two types of systemic adjuvant therapy are used for breast cancer, either alone or in combination:
Chemotherapy involves a combination of anti-cancer drugs, which are powerful and can have many side effects. Anti-cancer drugs are given by mouth or by injection into a blood vessel. Either way, the drugs enter the bloodstream and travel throughout the body. Chemotherapy is given in cycles: a treatment period followed by a recovery period, then another treatment period, and so on. Most patients receive treatment as an out-patient in hospital, and the therapy usually lasts for three-six months.
The second type of treatment involves hormone therapy, which deprives cancer cells of the female hormone oestrogen that the cancerous cells need to grow. For most women, hormone therapy is treatment with the drug tamoxifen. Some pre-menopausal patients may have surgery to remove their ovaries, which are a woman's main source of oestrogen, or they may be treated with a medication to reduce ovarian function.
Similar to anti-cancer drugs, tamoxifen enters the bloodstream and travels through the body. Recently, two studies confirmed benefits for breast cancer patients taking adjuvant tamoxifen for five years, but saw no added benefit and noted potentially negative effects for patients taking tamoxifen longer than five years.
Radiation therapy is another option, and it should be used as a local adjuvant treatment in patients having a lumpectomy. It is also occasionally used after a mastectomy. Such treatment can help destroy breast cancer cells that have spread to nearby parts of the body, such as the chest wall.
List of Contents
Overview
Risk factors
Staging of Breastcancer
Prognostic Factors
Prognostic factors
So, how do you know if the chosen treatment is the right one? Your doctor will try to determine your prognosis - the likely outcome after treatment. Prognostic indicators are characteristics that may help predict whether the disease will recur.
The prognostic indicators most commonly used are:
- Lymph node involvement. Lymph nodes in the underarm or chest are a common site where breast cancer spreads. Doctors usually remove at least 10 of the underarm lymph nodes to determine whether they contain cancerous cells. If cancer is found, the woman is said to be 'node positive.' If the lymph nodes are free of cancer, the patient is said to be 'node negative.' Women who have positive nodes are more likely than those with negative nodes to have a recurrence of breast cancer.
- Tumour size - in general, patients with small tumours have a better prognosis than patients with large tumours.
- Histologic grade. This term refers to how much the tumour cells resemble normal cells when viewed under the microscope. The grading scale usually ranges from one to three. Grade one tumours are composed of cells that closely resemble normal ones; grade three tumours contain very abnormal-looking and rapidly growing cancerous cells.
- Hormone receptors. Cells in the breast contain receptors for the female hormones oestrogen and progesterone. These receptors allow the breast tissue to grow or change in response to changing hormone levels. Research has shown that about two-thirds of all breast cancers contain significant levels of oestrogen receptors. These tumours are said to be oestrogen receptor positive (ER+). About two-thirds of ER+ tumours also test positive for receptors to progesterone (PR+). Tumours that are hormone receptor positive are more likely to respond to hormone therapy, and they also tend to grow less aggressively, resulting in a better prognosis for patients with ER+ tumours.
- Proliferative capacity of a tumour. This characteristic refers to the rate at which cancer cells in a tumour divide to form more cells. Cancer cells that have a high proliferative capacity divide more often and are more aggressive (fast growing) than those in tumours with a low proliferative capacity.
- Oncogene expression and amplification. An oncogene is a gene that causes or promotes unrestrained growth of a cell. The activation of an oncogene can convert a normal cell into a tumour cell. Research has shown that patients whose tumour cells contain certain oncogenes may be more likely to have a recurrence. Tests for oncogenes are experimental.