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October 2004
BREAST CANCER – THE FACTS
PRESS BACKGROUNDER
A Worldwide Epidemic...
 Breast cancer is by far the most common cancer affecting women in Westernised countries – over half of
all global estimated cases of breast cancer occur in North America and Europe, although only 18% of the
world’s women live in these regions.1
 World-wide, breast cancer is one of the most common cancers among women; in developed countries it is
the most common.2
 Breast cancer incidence rates amongst women over 50 years old in North America increased from 227.5
per 100,000 in 1973 to 334.4 in 1994. In women under 50, incidence rates increased only slightly from
27.7 per 100,000 to 32.8 over the same period.3
 According to the World Health Organisation, more than 1.2 million women will be diagnosed with breast
cancer in 2004. This rise has been partly attributed to increased detection and diagnosis associated with
the introduction of national screening programmes. Recent studies also suggest that the current trend for
Western women to start families later in life is an associated risk factor leading to an increase in cases. 4
 5-year survival rates for breast cancer also vary between countries – from 80% in the US, decreasing
across Western European countries to 5-year survival rates below 50% in some Eastern European
countries.5 These differences are in part explained by variations in screening programmes, the availability
of the latest diagnostic techniques and the types of treatment available.
Risk Factors
 A woman’s risk of developing breast cancer doubles if she has a first-degree relative (mother, sister,
daughter) who developed the disease under 50 years of age – the risks more than triple if more than one
relative is affected.6
 Other key risk factors for breast cancer include; early age at first menstruation, late onset of menopause,
nulliparity (no children), late age at birth of first child and the use of artificial hormones in contraception
or hormone replacement therapy (HRT) – all of these relate to the lifetime exposure of breast tissue cells
to oestrogen.3
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 Risk factors for breast cancer also include age (the incidence of breast cancer increases rapidly during
reproductive years, and increases more slowly post-menopause), a history of benign breast disease and
genetic predisposition.7
 The stage at which breast cancer is diagnosed has a significant impact on the type of treatment used and
on the prognosis (the predicted outcome of the disease based on survival).
Symptoms
Most common symptoms include:
 A painless lump in the breast
 Unexplained pain in the breast with no lump
Less common symptoms include:
 A thickened area of skin on the breast
 Swelling or distortion of the skin
 Unexplained discharge from the nipple
 Inversion or retraction of the nipple
 Scaling or erosion of the nipple
NB: Breast pain is not necessarily a symptom of breast cancer. In fact, many healthy women find their
breasts feel lumpy and tender prior to menstruation, and some types of benign breast lumps are painful. On
average, nine out of ten lumps are found to be benign.
Detecting Breast Cancer
1. Breast Self Examination (BSE) – particularly important for younger women. It is recommended that all
women should undertake monthly self examinations.
2. Clinical Breast Examination (CBE) – again particularly important for younger women. In some countries,
it is recommended that a CBE is carried out annually by a physician.
3. Genetic screening and mammography (low-dose x-ray examination of the breast) – screening by
mammography has been shown to reduce breast cancer mortality by 30% in Western women aged 50-69
years, and when combined with CBE, an additional 5-20% of tumours may be detected.8 Mammography
is only suitable for older (postmenopausal) women. In younger (premenopausal) women, the breast tissue
is too dense for tumours to be detected. Instead of routine screening younger women with a suspected
tumour will be offered ultrasound as part of their diagnosis.
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The Stages of Breast Cancer
When a woman is diagnosed with breast cancer, one of the first things that will be established is the ‘stage’
of the cancer – i.e. how far advanced the disease is. Different treatment strategies can be used depending on
the stage of the breast cancer.
Stage
0
Disease Status
Other terms
Cancer cells are confined to the milk ducts in the breast and have not spread
Ductal Carcinoma in Situ
to the surrounding area.
(or DCIS)
Breast tumours are very small, measuring less than 2cm in size. The lymph
1
glands are not affected and the cancer has not spread to other parts of the
Early breast cancer
body.
Breast tumours measure between 2 and 5 cm and the lymph nodes in the
2
armpit may also have become affected. The cancer has not spread to other
Early breast cancer
parts of the body.
Tumours are larger than 5cm and the lymph nodes are usually affected. The
3
underlying tissues of the chest wall may also be affected, but there is still no
sign of the disease having spread to other parts of the body.
Tumours can be any size, but in addition the lymph nodes are affected and
4
the cancer has spread to other parts of the body such as the bone, lungs, liver
and brain.
Locally advanced breast
cancer
Advanced or metastatic
breast cancer
Breast Cancer Treatments
 Stage 1 and 2 cancers are referred to as ‘early’ disease. In early disease, the primary objective of
treatment is cure and in the majority of patients, therapy consists of initial surgery to remove the tumour,
and any affected lymph nodes, with or without local radiotherapy which aims to destroy any remaining
cancerous tissue. This is generally followed by systemic additional (adjuvant) drug treatment, which aims
to prevent both recurrence of the tumour in the breast and the development of metastases, or secondary
cancers, in other areas of the body.
 Stage 3 cancers are referred to as ‘locally advanced disease’ and stage 4 cancers as ‘advanced’ or
‘metastatic’ disease. In both stages 3 and 4, the main aim of treatment is to put the cancer into remission
and is palliative – i.e. helping to relieve the symptoms of the disease, improving patient well-being and
life expectancy.
 In patients with locally advanced disease, endocrine therapy or chemotherapy is now sometimes used as
initial treatment prior to surgery to achieve tumour shrinkage and make surgical intervention
possible/easier (called neo-adjuvant therapy).
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 For patients with inoperable Stage 3 or 4 disease, endocrine therapy, chemotherapy and radiotherapy can
all be used, as appropriate to each individual patient, to put the cancer into remission, maintain quality of
life and prolong survival.
How endocrine therapies work in postmenopausal women
 Many breast tumours, particularly in older women, are ‘hormone sensitive’ (also known as oestrogen
receptor-positive or ER+), i.e. their continued growth is dependent on the female hormone, oestrogen.
 In postmenopausal women, oestrogen is no longer produced by the ovaries, but the hormone is instead
produced, in small quantities, by a process known as ‘aromatisation’. Endocrine therapies work either by
disrupting the process of aromatisation to prevent the production of oestrogen in older women (the
aromatase inhibitors, AIs) or by interfering with the way that oestrogen interacts with the tumour,
blocking access to the tumour cells (tamoxifen). This has the effect of starving the tumour of its main
nutrient and so preventing growth.
 Tamoxifen is an anti-oestrogen and acts primarily to prevent oestrogen binding to its receptor at tumour
sites. Tamoxifen has some partial oestrogenic activity, which may be responsible for the differences in its
side-effect profile compared with AIs.
 AIs are used in the hormonal (endocrine) treatment of breast cancer in postmenopausal women. AIs act
differently to tamoxifen by blocking the production of oestrogen by the aromatase enzyme pathway – the
primary source of oestrogen in postmenopausal women, whose ovaries no longer function.
 Endocrine therapies are now widely used in the treatment of both early and advanced breast cancer. In
addition, they are being investigated for use in the prevention of breast cancer.
-endsReferences:
1. Parkin DM, Stjernsward J, Muir CS. Bull Who 62(2):163-182,1984.
2. Ferlay J, Bray F, Pisani P and Parkin DM. GLOBOCAN 2000: Cancer Incidence, Mortality and Prevalence
Worldwide, Version 1.0. IARC CancerBase No. 5. Lyon, IARCPress, 2001.
3. American Cancer Society Home Page: www2.cancer.org/bcn/information.html.
4. Cancer Research Campaign and Imperial Cancer Research Study, November 2001.
5. Reynolds T. J Nat Cancer Institute 1995;87(16):1209.
6. Studzinski GP, Godyn JJ, in Cancer of the Breast, 4th ed (Donegan WL, Spratt JS eds) WB Sanders, Philadelphia,
1995, p.209-315.
7. ibid.
8. Rimer BK, in Diseases of the Breast (Harris JR et al, eds) Lippinicott-Raven, Philadelphia, 1996, pp307-322.
Notes to editors

The organisation of the ‘Redefining Hope & Beauty’ campaign is supported by AstraZeneca, a
company committed to raising breast cancer awareness.
For further press information, please visit www.hopeandbeauty.org or please contact:
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Rita Martins
Tel: +44 (0) 207 471 1528
Email: [email protected]
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