Facts about Breast Cancer
What is Breast Cancer?
A cancerous tumour arises when control is lost of cell division
and cells continue to multiply unnecessarily. Breast cancer is not
a single disease. Ductal carcinoma (cancer in the milk ducts) accounts
for over 70% of breast cancers, followed by carcinoma of the breast
lobules at about 10% -15%. The rest are rare forms of cancer, for
example of the connective tissues. Both ductal and lobular carcinomas
can be localized, and, if untreated may or may not progress to invasive
cancer (extending beyond the duct or lobule into surrounding tissue).
Incidence
 Each
year in the UK around 41,000 new cases of breast cancer were diagnosed,
and about 13,000 patients die of breast cancer. Breast cancer is
the commonest single cause of death among women aged 35-54 years.
Each year 1 or 2 women in every thousand will be newly diagnosed
with breast cancer. 75% of these will be post-menopausal women.
1 in 9 women in the UK will develop the disease.
Incidence Worldwide
There are striking differences in the incidence of breast cancer
throughout the world. Breast cancer accounts for 24.3 deaths per
one hundred thousand in England and Wales, but only 18.9 in Italy,
and 8.3 in Japan. There are many possible reasons for these differences,
for example climate, diet, genetic inheritance, environmental toxins,
patterns of birth control or breast feeding and age at first pregnancy.
Women moving from low incidence to high incidence countries seem
to acquire the higher risk of their new country. This could suggest
that environmental factors, such as diet and lifestyle, play a large
role.
Known Causative Factors
5-10% of breast cancers are believed to involve a hereditary factor.
Women with no children or late first pregnancies (aged 30 years+)
are more likely to develop breast cancer. Risk increases with early
onset of menstruation and late menopause. Exposure to significant
doses of radiation increases breast cancer incidence. Most of the
factors affecting breast cancer development are still unknown.
Breast Lumps
A lump or thickening in the breast or armpit tissue is the first
symptom in 80-90% of breast cancers. Other symptoms include dimpling
or flaking skin, nipple discharge or bleeding, pain in the breast,
change in breast size or shape, or any new difference in appearance
or feel of the breast. If any of these symptoms are found medical
advice should be sought. Only about 1 in 9 breast lumps seen by
a breast cancer specialist will prove to be cancerous. For every
9 women with cancerous lumps, 5 or 6 can be treated initially without
removal of the breast.
Mammographic Screening
Mammograms are simply X-rays of the breast. They are most successful in detecting breast cancer in women over 50 years. Breast tissue of younger women is usually too dense to allow cancers to be seen. All women aged 50-70 years are offered a 3-yearly mammogram. Women aged over 70 years are also entitled to screening, but must request it when their appointment is due.
Surgery
Conservative surgery removing only the lump or segment of breast
is now offered to up to two thirds of women with one small tumour.
If the tumour is too big or has spread too far mastectomy is more
suitable. Also some women choose mastectomy because it brings them
greater peace of mind. Surgery is often followed up by adjuvant
therapy (see examples below) to kill stray cancer cells. Every woman
who has a mastectomy is entitled to a suitable breast prosthesis
on the NHS.
Radiotherapy
Radiotherapy is usually given post-operatively to the breast and
sometimes armpit regions. Courses range from 3-6 weeks or more,
with patients usually receiving one dose a day, five days a week.
The side effects of radiation can be slight reddening or discomfort
in the treated area, tiredness and nausea. Most patients can expect
to remain pretty well throughout treatment.
Tamoxifen
Tamoxifen is a hormonal therapy that works mainly by depriving
residual cancer cells of the oestrogen they require for growth.
It is especially effective in protecting post-menopausal patients,
however recent evidence suggests it may also be useful in pre-menopausal
patients. Side effects are few, but may include vaginal irritation,
occasional nausea, and symptoms similar to those of the menopause,
eg. hot flushes and irregular menstruation. Tamoxifen is usually
prescribed for 2 or 5 years.
If you are a patient, or a friend or relative of a patient, this
site offers easy-to-understand facts about HER2 and breast cancer,
what an HER2-positive diagnosis means, and what questions you could
ask a doctor about your HER2 status. This site will allow you to
find out about the activity of HER2, its effect on the prognosis
of breast cancer, its use in predicting the outcome of therapy and
exciting new targeted therapies that improve the survival of HER2-positive
breast cancer patients.
Chemotherapy
Anti-cancer drugs (chemotherapy) aim to track down and kill cancer
cells anywhere in the body. Most pre-menopausal patients under 50
years are routinely offered chemotherapy, usually with 6 courses
of a standard drug regime known as CMF(cyclophosphamide, methotrexate,
flouracil) given on an out-patient basis over a period of around
six months. Chemotherapy increases the survival of patients whose
cancer has spread to the lymph nodes, as well as increasing disease-free
survival in patients without any node involvement. Possible side
effects include the disruption or cessation of menstrual periods,
with possible onset of the menopause. Also tiredness, nausea, loss
of hair, mouth ulcers, loss of appetite and diarrhoea.
Breast Reconstruction
Techniques have been developed enabling surgeons to produce a
breast that looks attractive and matches the other side. In most
cases a cosmetic result that pleases the woman can be produced.
25-50% of women who have had a mastectomy will request breast reconstruction.
Recurrence
All women who have had breast cancer should be monitored for recurrences,
usually with an annual check up for at least five years. Recurrences
occur in 20-30% of women who have undergone surgery aimed at cure
of the disease. With early diagnosis and treatment 85% of women
will survive at least 5 years.
Secondary Spread
Cancer cells are carried from the breast to other areas of the
body by the blood supply and lymphatic system. Breast cancer most
commonly spreads to the lymph nodes, bones, liver, brain, lungs
and ovaries. Surgeons will often remove some lymph nodes to tell
whether the cancer has spread and to stage the development of the
disease. The main problem with breast cancer is not related to local
control of the disease, but rather the distant recurrence elsewhere
in the body that may prove fatal.
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