How Common Is Breast Cancer?
Breast cancer is the most common type of cancer affecting women in Hong Kong, with a crude annual incidence rate of 138 per 100,000. The incidence rate of breast cancer starts to rise after the age of 40 and continues to rise with increasing age even up to 85 or above. In 2021, there were 5,565 new cases of breast cancer, accounting for 28.5% of all new cancer cases in women in Hong Kong.
Hong Kong women stand a lifetime risk of 1 in 21 in
developing breast cancer (1 in 8 in USA). As men
also have a small amount of breast tissue, they can
occasionally develop breast cancer.
What Are The Causes And Risk Factors?
In most cases, we cannot determine why one individual
gets breast cancer while the other does not. However,
we do know that some factors are associated with the
development of breast cancer:
- Family history of breast cancer particularly in firstdegree relatives
- Early onset of menstruation or late menopause,
which results in prolonged exposure to the breaststimulating female sex hormone, oestrogen
- Diets high in fat
- Extended hormone replacement therapy (HRT) after
menopause
- Personal history of breast cancer or precancerous
conditions such as papillomatosis or ductal atypia
also increases the chance of breast cancer
Prolonged breastfeeding by a mother is now known to
reduce her chance of developing breast cancer later
in life, especially if repeated in several pregnancies.
Full-term pregnancy early in life is also associated
with a somewhat lower risk than later pregnancy or no
pregnancy.
What Are The Common Symptoms?
Most breast cancers are first noticed as a painless
lump in the breast that enlarges over time. It is
important to remember that most breast lumps are
not cancerous, but the only way to be sure is to seek
advice from your doctor.
How Does The Doctor Make The
Diagnosis?
The following procedures are indicated for patients who
are suspected to have breast cancer:
- Once breast tumours have grown to a certain size
- typically exceeding 5 mm - most may be detected
using diagnostic examinations called mammograms.
This test involves compressing the whole breast for a
few seconds (which may cause some discomfort) and
then taking a “photograph” of the breast tissue using
X-rays. The dose of X-rays delivered is considered
safe by regulatory authorities.
- Breast lumps may also be examined using
ultrasound, which shows whether a lump is cystic
(fluid-filled) or solid, or whether it has benign or
cancerous features.
- Biopsy may be indicated for those with a suspicious
lump or mammographic abnormality. This procedure
permits microscopic examination of cells or tissues by
a highly trained pathologist. Such biopsies are often
carried out using a fine needle (called fine needle
aspiration, or FNA). In other occasions, a more formal
biopsy procedure may be indicated, which may
require either a local or general anaesthetic.
How Is Breast Cancer Treated?
The following types of treatment may be given alone or
together, depending on the patient’s condition:
- Surgery is the mainstay of treatment for breast
cancer. The most common surgery is called
“lumpectomy” in which the tumour together with some
surrounding normal breast tissue is removed. For
large tumours, the entire breast will be removed by
“mastectomy”. Small mammographic abnormalities
which cannot be felt may be removed using a
procedure called “needle
localisation” or “stereotactic
surgery” in which the precise
position of the mammographic
abnormality is initially confirmed
by inserting a fine wire into the
breast and repeating the X-ray.
- Radiotherapy is usually given
to reduce the risk of local
recurrence after surgery.
- Hormone therapy is often used in breast cancers that
are stimulated by the female hormone oestrogen.
The most common hormone therapy is the daily
“anti-oestrogen” tablet tamoxifen, but there are other
hormonal interventions that work with a different
mechanism.
- Chemotherapy may be given before surgery to shrink
the tumour or after surgery to reduce the risk of
tumour recurrence or metastasis.
- Biological drugs may be given to activate the immune
system or specific human growth factor receptors or
enzymes that are important for cancer cell growth.
Doctors will plan the most appropriate treatment
according to the patient’s condition.
Is There Any Method to Screen for
Breast Cancer?
Mammography is a very effective tool to screen
for breast cancer. Apart from monthly breast self
examination, it is recommended that women above the
age of 40 should undertake regular mammography.
Women with a family history of breast cancer should
start having regular mammography at the age of 35.
We provide a breast cancer screening package which
consists of demonstration of breast self examination,
basic physical examination, medical history taking,
breast examination by doctor, mammography and
follow-up. Please contact us for details.
How Can Breast Cancer Be
Prevented?
The risks of developing breast cancer can be minimised
by avoiding over-eating fatty food and by engaging in
regular exercise on a lifelong basis.
For individuals who are advised by their doctors that
they are at high risk of familial breast cancer, more
aggressive preventive interventions including taking
daily tamoxifen tablets, inducing an early menopause
by removing the ovaries, or else prophylactic surgical
removal of breast tissue may be considered.