ABC Health & Wellbeing

Fact File

Breast cancer

by Peter Lavelle

Breast cancer is the biggest cause of cancer-related deaths amongst women. About one woman in 11 in Australia will get the condition in her lifetime, but a diagnosis is not a death sentence.

Published 01/09/2005

[Image source: iStockphoto]

• Background
• Causes
• Symptoms
• Diagnosis
• Staging and treatment
• Prognosis
• Screening
• Breast examination
• More info

Background

Breast cancer is the biggest cause of cancer-related deaths amongst women. About one in 11 women in Australia will get the condition in their lifetime.

But while that sounds like bad news, those statistics don't tell the other side of the story. Many more women get breast lumps than breast cancer. The great majority of breast lumps are benign. And in cases where a breast lump is diagnosed as cancer, if it's diagnosed early the cure rate can be 90 per cent or better.

Most breast cancers develop in the glandular tissue of the breast – hence they're called 'adenocarcinomas'. They most commonly arise from the cells lining the milk ducts of the breast, and sometimes from the milk glands themselves.

Most breast cancers arise from the lining of the milk ducts or from the milk glands found within the breast lobes. The upper outer part of the breast is the most common site.

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Causes

You can't predict whether you're going to get breast cancer – we don't know exactly what causes it. But statistically, some women are more likely to get it than others. That could be you (or someone you know) if:

• You're over 50 There's nothing strange about this – cancers are caused by cell mutation, and the older you are, the more chance there is of a cell mutation occurring.
• Someone in your family has had breast cancerThis slightly increases your risk. In most cases there's no family association. But scientists have identified certain genes that are responsible for some cases of breast cancer, and these can be transmitted to offspring. In these cases the cancer tends to occur at a younger age.
• The big ONo, not the late Roy Orbison, we're talking about the hormone oestrogen. High levels of oestrogen for long periods of time increase the likelihood of breast cancer. So do early puberty, late menopause, having your first child at a later age (over 35), not breast feeding, and never having children at all. The oral contraceptive pill is thought to increase the risk slightly, as does hormone replacement therapy (HRT) if taken for more than five years.
• Previous breast cancer Having had breast cancer in the past means you're three to four times more likely to get it again (not a recurrence, but an entirely new cancer somewhere else in either breast).
• Too much booze The link between alcohol consumption and breast cancer has been controversial, but the best available research suggests there is a link. Low levels of consumption – one standard drink a day or less – probably aren't a problem, but three drinks a day definitely increases your risk, maybe fewer if there are other risk factors. A standard drink is 10g alcohol, or about 100ml wine (a small glass).
• SmokingAgain, research results have been mixed, partly because some studies take into account passive smoking while others don't. Those that do are more likely to find that exposure to tobacco smoke – passive or active – is a risk factor. Smoking is also an important risk factor for other cancers, including cervical and vulval cancers. (See Library topic: Cervical and vulval cancers.)

There is NO evidence that underarm antiperspirants, underwire bras, or breast implants affect your risk of breast cancer.

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Symptoms

Lumps are quite common in the breast in women and 95 per cent are benign. Most are due to hormonal effects on the glandular tissue causing areas of lumpy tissue.

Some are fibroadenomas (a fibroadenoma is also called a breast mouse). These are firm breast lumps made up of fibrous and glandular tissue. Fibroadenomas are more common in younger women and may become tender in the days before a menstrual period, or grow bigger during pregnancy. They don't necessarily need treatment, especially if a needle biopsy shows them to be benign (more on biopsies later) although they can be surgically removed if they're large.

Or a lump may be a cyst, a small, firm, fluid-filled sac that many women have in their breasts, especially around menstruation time. Many women have multiple cysts (sometimes called 'lumpy breasts', or fibrocystic disease). Breast cysts don't need treatment either, but they can be aspirated (drained).

A malignant (cancerous) lump is different. It tends to be hard, with an irregular edge. As it grows, it becomes attached to (and can retract) the skin or nipple. If advanced, it can give the skin a pitted appearance, like an orange peel. Sometimes the nipple can secrete a clear or bloodstained fluid, though this very uncommon.

And like other malignant tumours, it can spread beyond the site of origin. Breast cancer spreads first via the lymphatic ducts to the lymph nodes that drain the breast (these are found in the armpit closest to the breast). A malignant lump under the arm tends to be hard and fixed to surrounding tissues.

In advanced cases, cancer cells travel via the bloodstream to other organs, especially the liver, lungs, bone and brain. So there might be symptoms related to secondary cancers (also called metastases) in these organs.

In a few cases, evidence of distant spread may be the first sign that a person has breast cancer. For instance, a person might complain of back pain and be found to have metastases in the spine. The original (or 'primary') breast cancer may only be discovered after tests.

Cells in a malignant tumour multiply faster than normal cells, so it can put a strain on the body's metabolism. The person may be tired, lose weight, and lose their appetite. The more advanced the cancer, the more pronounced these symptoms are.

Of course, many other conditions can cause these symptoms. If you have these symptoms, the chance that they are due to advanced breast cancer is very low, but they should be checked by a doctor.

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Diagnosis

If you notice a breast lump you should see your GP. There is nothing to be gained from waiting; although some people do, often out of an unconscious (and ungrounded) fear that it's cancer. It's usually not, and if it is, the earlier you seek treatment, the better the chance of a cure.

Your GP will feel the lump in the breast and the lymph nodes under the arm, and do a general physical examination of the body. However, it's difficult to be 100 per cent sure whether a lump is benign just by clinical examination, so if there's any doubt, the GP will order further tests.

The simplest tests are imaging tests like mammography (a low-dose X-ray of the breast) and ultrasound (a picture formed by sound waves directed into the breast tissue).

If the lump looks and feels benign to the doctor and these imaging tests don't show anything suspicious, the GP may be content to keep an eye on the lump and ask the patient to come back in three months for a check-up.

If there's still doubt, the GP will usually refer the patient to a surgeon at this point. If the surgeon thinks the lump could be malignant, the next step is to do a breast biopsy. There are several different types:

• Fine needle biopsy Easiest to do and the least painful, this is performed in the surgeon's rooms or at a hospital outpatient clinic. The surgeon guides a needle into the lump and extracts a sample of cells (and/or from the fluid, if the lump is a fluid-filled cyst). These cells are then examined by a pathology laboratory and the result is usually available in one to three days.
• Core biopsy This is the same procedure, but uses a wide-gauge needle in order to extract breast tissue, not just cells, making it more accurate. It is done under local anaesthetic by a radiologist who uses an ultrasound to help guide the needle.
• Open biopsy A sample of breast tissue is taken from the lump via an incision into the breast under general anaesthetic.

If physical examination, imaging and biopsy all fail to show cancer, the condition is diagnosed as benign. This three-pronged approach is accurate in 99.95 per cent of cases.

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Staging and treatment

In about one person in 20, the lump does turn out to be malignant.

Before treatment starts, breast cancers are 'staged' according to how advanced they are. Staging takes into account the size of the tumour, whether and where the cancer has spread, what the cells look like under the microscope, and what sort of breast tissue they've originated from.

Staging helps with prognosis (predicting how the disease will take its course) and also helps determine the most suitable treatment. Stage I or II signifies early breast cancer; Stage III or IV more advanced disease.

There are many treatment approaches, depending not just on the stage of the cancer but on the person's health, age and lifestyle. Treatment decisions involve not just a GP and a surgeon but a team of health professionals, and most importantly of all, the woman herself.

Almost all women – certainly those with early-stage breast cancer – will have some form of surgery recommended to remove the cancer. The chain of lymph nodes under the arm on the side of the affected breast is often also removed. In a new technique called sentinel node biopsy, the affected nodes can be biopsied and removed if cancer is found.

There are basically two options:

• Breast preservation treatment The surgeon removes the cancer, plus some tissue around it, leaving the rest of the breast intact – hence the name. It can also be called lumpectomy, wide excision, partial mastectomy, and quadrantectomy. Afterwards, the breast is always treated with radiotherapy. The treated breast will probably be slightly smaller and the nipple a little higher or lower than before.
• Mastectomy The entire breast, including the cancer, is removed. After surgery, the side of the chest that was operated on is flat and covered with skin with a scar across it. A prosthesis (an artificial breast worn in the bra) can be used if desired, or the breast can be surgically reconstructed using tissue from another part of the body like the abdomen, or a saline-filled bag.

Which is best? Well according to the experts, there's no difference between the two in terms of survival outcomes (though with breast conservation, there's a small chance of later recurrence of cancer in that breast, and it has to be removed by mastectomy). Most women prefer breast preservation treatment because it's less disfiguring. If the cancer is large or involves the nipple, however, breast preservation treatment may not be feasible, so it has to be mastectomy.

In many cases other than very early breast cancer, surgery is followed by a course of chemotherapy or hormone therapy lasting several months.

Regardless of which treatment is chosen, the process is often traumatic. So strong emotional support from partner, family and friends is important. Joining a patient group and using counselling services is also a good idea.

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Prognosis

Doctors talk about a 'five year survival rate' for cancer, which is the chance of a person being alive five years after diagnosis and treatment. The five-year survival rate for cancer confined to the breast is about 80 to 90 per cent. If the cancer has spread to the lymph nodes under the arm, it's 60 to 75 per cent.

Most recurrences occur in the first three to five years after diagnosis. After 10 years the risk of recurrence is very small, although it occasionally happens as late as 30 to 40 years after treatment.

If the cancer recurs or has spread to other organs, the five-year survival rate falls to about 18 per cent. In this case treatment is centred less on a cure, and more on providing quality of life for as long as possible.

Surgery, radiotherapy, chemotherapy and hormonal drugs (like tamoxifen) can be used to reduce the size of the tumour, slow the growth of metastases and relieve complications.

Counselling, relaxation therapy, support groups and occasionally drugs such as antidepressants will help improve mood and wellbeing.

In terminal stages, pain relief should not be spared. The aim is to let the person die as free of pain and with as much dignity as possible, preferably at home.

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Screening

The survival figures given above highlight how important it is to detect breast cancer early. The main strategy for detection is screening mammography. It's not a perfect technology and won't detect all cancers, but it does improve the chances of picking up cancer in its early stages.

A mammogram involves the breast being compressed between two photographic plates, and a low-dose X-ray being taken of the breast tissue. It isn't particularly comfortable ("designed by a man!" is a frequent comment), though it isn't painful. It can be done in a specialised mobile unit, a breast clinic or a radiologist's rooms. Ultrasound examination is sometimes done to give additional information, but on its own it's not a better screening test than a mammogram.

Australia's peak medical advisory body, the National Health and Medical Research Council, recommends that all women aged 50 to 69 have a mammogram every two years. Those aged over 70 and 40 to 49 are also eligible for a free screening mammogram, though the scientific evidence suggests it's less effective in younger age group. Routine mammograms are not recommended for women under 40, because the dense breast tissue in younger women makes mammograms hard to read.

The Commonwealth and State governments jointly fund the national screening program, called BreastScreen Australia. Their booking hotline is 13 20 50.

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Breast examination

Experts used to recommend that women examine their own breasts regularly every month. But studies have failed to show that this reduces overall deaths from breast cancer. Screening by mammography is probably more important in preventing deaths.

Nevertheless, the NHMRC's National Breast Cancer Centre recommends all women be 'breast aware'. That is, they should look and feel their breasts regularly; and if they notice any unusual changes they see their doctor without delay, even if they are having regular mammograms.

Reviewed by Dr Paul Crea, St Vincent's Clinic.

Last modified 31/10/2007