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Breast Cancer

Breast cancer is the most common cancer of women in Hong Kong. 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. The median age at diagnosis was 58 years. The crude annual incidence rate per 100 000 women was 138. Breast cancer was the third leading cause of cancer deaths among females in Hong Kong. In 2021, a total of 791 women died from this cancer, accounting for 12.4% of all cancer deaths in women.

With medical advances, the cure rate of breast cancer has been improving in the last decade. Still, early detection and treatment are critical for improving the survival rate of patients. According to the Cancer Registry statistics, the overall five-year relative survival rate of patients with breast cancer was 84%. Stage I breast cancer had a five-year relative survival rate of 99.3%, which means that these individuals had almost the same chance of surviving more than five years as the general population. The five-year survival rate for stage II was 94.6%, and that for stage III was 76.2%. Stage IV breast cancer still had a five-year relative survival rate of about 30%.

What is Breast Cancer?

The breasts are made up of glandular tissues comprising mammary gland tissues, fat and connective tissues. During pregnancy, mammary glands will produce and excrete milk for babies.

However, when cells in the mammary gland divide and proliferate in an uncontrolled way, they may eventually develop into tumours which may be benign or malignant. Breast cancer is a malignant tumour developed in the breast.

Who have higher chance of having Breast Cancer?

High risk factors of breast cancer include:

  • Gender: although some men may also suffer from the disease, nearly all breast cancers are found in women.
  • Age: in general, the risk of breast cancer increases with age.
  • Family history and genetics: a woman is more likely to have breast cancer if her mother, sister or direct relative had suffered from the disease. According to clinical studies, around 5-10% breast cancers may be related to genetic changes.
  • Menstrual cycle: women having first menses before 12 or menopause after 55 may have higher risk.
  • Childbirth: women with no kid or having their first child after 35.
  • Diet: prolonged intake of diet with high animal fat.
  • Lifestyle: smoking, drinking and lack of exercise will increase the risk.
  • Drugs: prolonged intake of contraceptives or having hormonal replacement therapy for more than 5 years.
  • Personal history of cancer: history of certain malignancy especially with irradiation to the breast region like Hodgkin’s Disease, lung cancer, bowel cancer, or history of cancer in childhood.

What are the symptoms of Breast Cancer?

If you have the following symptoms, you may get breast cancer:

  • Breast
    • Lump of any size*.
    • Changes in shape or size.
    • Dimpling on skin.
    • Vein congestion or orange-peel appearance on skin.
  • Nipple
    • Blood-stained discharge.
    • Retraction (sinks into the breast).
  • Armpit
    • Swollen lymph nodes.

* Bloated or lumpy breasts are normal physiological reactions caused by cyclic hormonal changes, which are common among women before menstrual cycles. There is no need to worry about it. If you are in doubt about the existence of lumps, please consult your doctor to check if they are benign or malignant. Many of these lumps are benign cysts (fluid-filled sacs or pockets in tissues) or fibroma (non-cancerous tumours composed of fibrous tissue) which are harmless to human body.


Most of the risk factors for female breast cancer are related to lifestyle, which include –
  • Lack of physical activity;
  • Alcohol consumption;
  • Obesity after menopause;
  • Advancing age;
  • No childbirth, late first live birth (after the age of 30) or no breastfeeding;
  • Early menarche (before the age of 12) or late menopause (after the age of 55);
  • History of breast cancer or ovarian cancer;
  • History of benign breast conditions or lobular carcinoma in situ;
  • Receiving hormonal replacement therapy; and
  • Using combined oral contraceptives.

Further, women with family history of breast cancer or ovarian cancer, especially with first-degree relative (i.e. mother, sister or daughter) diagnosed with breast cancer before the age of 50, or those with confirmed carrier (or family history) of certain gene (e.g. BRCA1 or BRCA2) mutations and a history of receiving radiation therapy to the chest before the age of 30 are considered at increased risk of breast cancer.

To reduce the chance of getting breast cancer, members of the public, with women in particular, are recommended to have regular physical activities, avoid alcohol drinking and maintain a healthy body weight and waist circumference. If possible, they are advised to have childbirth at an earlier age and breastfeed each child for a longer duration.

Every woman should be breast aware and familiar with the normal look and feel of their breasts at all time. Be aware of any unusual changes of their breast. If women notice unusual changes in the breast, they should see a doctor as soon as possible.


Based on available international and local scientific evidence, the Government’s Cancer Expert Working Group on Cancer Prevention and Screening (CEWG) makes the recommendations on breast cancer screening for women at different risk profiles as follows:

(a) For women at high risk

Local definition - with any one of the risk factors:
  1. Carriers of BRCA1/2 deleterious mutations confirmed by genetic testing.
  2. Family history of breast cancer /ovarian cancer, such as
    • any first-degree female relative is a confirmed carrier of BRCA1/2 deleterious mutations;
    • any first- or second-degree female relative with both breast cancer and ovarian cancer;
    • any first-degree female relative with bilateral breast cancer;
    • any male relative with a history of breast cancer;
    • 2 first-degree female relatives with breast cancer AND one of them being diagnosed at age ≤50 years;
    • ≥2 first- or second-degree female relatives with ovarian cancer;
    • ≥3 first- or second-degree female relatives with breast cancer OR a combination of breast cancer and ovarian cancer.
  3. Personal risk factors
    • history of radiation therapy to chest for treatment between age 10 and 30 years, e.g. Hodgkin’s disease;
    • history of breast cancer, including ductal carcinoma in situ (DCIS); lobular carcinoma;
    • history of atypical ductal hyperplasia or atypical lobular hyperplasia.
Recommendation on screening
  1. Should seek advice from doctors; and
    • have mammography screening every year;
    • begin screening at age 35 or 10 years prior to the age at diagnosis of the youngest affected relative (for those with family history), whichever is earlier, but not earlier than age 30.
    • for confirmed carriers of BRCA1/2 deleterious mutations or women who had radiation therapy to chest for treatment between age 10 and 30 years (e.g. for Hodgkin’s disease), consider additional annual screening by magnetic resonance imaging (MRI).
Recommendation on genetic testing
  1. Women who have any first-degree female relative with confirmed BRCA1/2 deleterious mutations should be offered genetic testing to confirm or refute their carrier status.
  2. For women at high risk due to other types of family history who wish to clarify their genetic risk or that of their family, referral to a specialist cancer clinic for advice, counselling and management should be discussed and considered.
  3. Genetic testing should be performed by specialised cancer centres with expertise in genetic counselling, which should be provided before genetic testing. Healthcare professionals should discuss with their clients in detail about the uncertainties and implications of the test results. Confirmed carriers of BRCA1/2 deleterious mutations who wish to consider prophylactic surgery / chemoprevention should also be referred to a specialist cancer clinic for advice and counselling.

(b) For women at moderate risk

  1. Women at moderate risk (i.e. family history of only one first-degree female relative with breast cancer diagnosed at ≤50 years of age; or two first-degree female relatives diagnosed with breast cancer after the age of 50 years) are recommended to have mammography every two years and should discuss with their doctors the potential benefits and harms of breast cancer screening before starting screening.
  2. MRI is not recommended for breast cancer screening in women at moderate risk.

(c) For other women at general population

  1. Women aged 44-69 with certain combinations of personalised risk factors (including presence of history of breast cancer among first-degree relative, a prior diagnosis of benign breast disease, nulliparity and late age of first live birth, early age of menarche, high body mass index and physical inactivity) putting them at increased risk of breast cancer are recommended to consider mammography screening every two years.  They should discuss with their doctors on the potential benefits and harms before undergoing mammography screening.
  2. A risk assessment tool for local women (e.g. one developed by The University of Hong Kong, accessible at ) is recommended to be used for estimating the risk of developing breast cancer with regard to the personalised risk factors described above.
  3. MRI is not recommended for breast cancer screening in women at general population.

Of note, all screening tests have their limitations and they are not 100% accurate. There are false-positive and false-negative results. All women who consider breast cancer screening should discuss with doctors on the potential benefits and harms before undergoing screening.

How to investigate and make diagnosis of Breast Cancer?

After taking the medical history and physical examination, the doctor will arrange the following check-ups for suspicious cases:

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    Tissues of the lump are taken out through a fine needle for further microscopic examination to determine the nature of cells in the lump. The procedure is usually performed with local anaesthesia. Ultrasound, X-Ray or MRI may be needed to localise the breast lesion for biopsy.

    Patients should provide information concerning the current medications used especially antiplatelet and anticoagulation drugs and any allergic history.

    Complications are uncommon. These include bruising, hematoma and wound infection.

    Some other tests will also be arranged if necessary:

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    Hormone receptor test and HER2 tests on tumour tissues

    These may help to determine whether a patient should receive hormonal treatment or targeted therapy.

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    Chest x-ray

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    Computed tomography (CT) scan; bone scan; or PET scan

    Especially for patients with high risk of tumour spreading to other organs.

What is the treatment for Breast Cancer?

Once the diagnosis has been confirmed, one or more of the following treatments will be recommended to patients:

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    There are two main types of surgery:

    1. Breast conservation therapy

      The surgeon removes only the breast tumour and its surrounding tissues; patients should require radiotherapy afterwards to reduce the risk of recurrence. This approach is most suitable for smaller lumps located away from the nipple and there is less undesirable effect on the cosmesis.

    2. Mastectomy (removal of whole breast)

      When the breast tumours are too large or found in different parts of breasts, the whole breast has to be removed surgically.

    In either procedure, the lymph nodes in the armpit of the affected side has to be sampled or removed for further microscopic examination. Nowadays suitable patients would be offered sentinel lymph node biopsy. If no tumour cells are detected in the sentinel lymph node, patients could be spared the operation of axillary dissection. This will reduce the chance of post-operative lymphoedema of the upper limb.

    For patients undergoing mastectomy, the patient may choose to have breast prosthesis or breast reconstructive surgery. The reconstructive surgery generally uses the fat from the belly or specially made saline implant to restore the contour and shape of breasts. It is recommended to seek further advice from experienced surgeons and nurse specialists before and after breast surgery.

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    For more aggressive tumours or potential residual tumour cells around the surgical wound (e.g. in breast conservation therapy), radiotherapy (treatment using high energy X-ray beams) may also be needed as an adjuvant treatment to reduce the risk of recurrence.

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    Neoadjuvant or adjuvant chemotherapy is often provided before or after surgery. Anti-cancer drugs will be used to destroy and disrupt the growth of cancer cells, shrink the tumour to facilitate surgery (in the neoadjuvant setting), and reduce the risk of recurrence. For patients with advanced breast cancer, chemotherapy can also be used in the palliative setting.

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    Hormonal treatment

    Estrogen will stimulate the growth of breast cancer cells. Therefore, doctors may prescribe drugs to block the effect of female hormones to stop the growth of breast cancer cells. However, this approach is only effective in tumours with positive hormonal receptors. The drug can be used alone or started after chemotherapy.

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    Targeted therapy

    For HER2-positive breast cancers, targeted therapy drugs will further improve the effectiveness of adjuvant chemotherapy.

What are the complications of Breast Cancer and its treatment?

Breast cancer may turn out to be fatal if it spreads to other parts of the body, such as lungs, liver, and brain, etc. Treatments may also lead to side effects or complications, including:

  • Wound infection after surgery.
  • Patients with their armpit lymph nodes removed may suffer from arm swelling, soreness, discomfort and stiffness around shoulders.
  • Mastectomy patients with their chest wall muscles removed may have slight limitation in movement of their arms.
  • Radiotherapy may cause reddening and soreness of the skin. These symptoms may last a few weeks after radiotherapy.
  • During chemotherapy, patients are more vulnerable to bacterial infections due to the weakened body defense system. The treatment will also cause short-term hair loss, vomiting and tiredness, etc.
  • Targeted therapy usually has mild side effects, but may affect cardiac function in uncommon situation.

Although treatments may induce some side effects with variable degree of severity, modern treatment has been improved to reduce the associated discomfort and side-effects. Nursing care, medications as well as support from relatives and friends can help to relieve discomfort caused by treatments.

How to take care of Breast Cancer patients?

Patients should keep in mind the following before and after surgery and during recovery::

  1. Regular follow-up

    Regular follow-up and examinations are required after treatment. If patient experience persistent bone pain, shortness of breath or numbness of the limbs with weakness, she should inform doctor immediately. In general, the risk of relapse will decrease with longer disease-free period.

  2. Avoid lifting heavy objects with the affected arm

    This will also decrease the risk of arm swelling after surgery.

  3. Simple exercise

    With instructions from doctors and physiotherapists, patients should have simple arm exercise for upper limbs training so as to maintain the mobility of shoulder joints and reduce the risk of arm swelling.



  1. Introduction

    Mammography is an x-ray imaging procedure to screen for cancer and suspected pathology in the breast.

  2. Preparation before the procedure

    • Please inform medical staff before the examination if you think you are or may be pregnant.
    • Abstaining from coffee or postponing the procedure to post-menstrual period may decrease the discomfort.
  3. The procedure

    • Two views are performed for each breast:
      • Body relaxed with head rotates to one side.
      • Back straight with tummy in and lean forward.
      • Breast rests on bucky.
      • Whole breast pulled out with force.
      • Breast flattened by plastic paddle.
    • It involves compression of the breast by a flat plastic paddle. Patient may feel pain or discomfort during compression of the breasts, especially when performed in pre-menstrual period. This process is absolutely important because it can improve image quality, increase the diagnostic accuracy and reduce radiation dose.
    • Patient may feel discomfort or pain during compression of the breasts. If the pain is intolerable, patient can ask to stop the procedure immediately.
    • The examination takes approximately 1 to 2 hours, though occasionally the time required may be longer.
  4. After the procedure

    After the examination, patient may have pain for a short period of time. In rare situation, bruise may occur in some patients. The examination report will be sent to the referring doctor. If further investigations are needed, the doctor will conduct further examination or arrange ultrasound scanning with or without needle biopsy.

  5. Remarks

    For further information please contact your doctor.


Surgery for Breast Cancer

  1. Introduction

    Axillary Dissection

    Breast cancer may spread from the breast to involve the lymph nodes in the axilla. Axillary dissection is frequently included in the operation for breast cancer. This operation can make a definite diagnosis and treatment for axillary lymph node metastasis.

    Lumpectomy/Partial Mastectomy

    The extent of resection in lumpectomy/partial mastectomy includes the primary tumour with adequate margins. In selected cases the nipple areolar complex will be removed with the primary tumour. This operation conserves the breast. This operation results in less deformity when compared with mastectomy.

    This operation is usually performed at the same time of axillary dissection or sentinel lymph node biopsy. Radiotherapy to the breast is usually required after the operation. Not every patient is suitable to undergo this operation and adequate removal is not guaranteed. Re-operation may be necessary for some patients.

    Modified Radical Mastectomy

    The extent of resection in modified radical mastectomy includes the involved breast together with the nipple areolar complex and the lymph nodes in the axilla. This operation results in significant deformity with a linear scar on the chest wall. This operation is sometimes performed in conjunction with immediate reconstruction.

    Simple Mastectomy

    Simple mastectomy will remove all the breast tissue. This operation results in significant deformity with a linear scar on the chest wall. This operation is sometimes performed in conjunction with immediate reconstruction.

  2. Preparation before the procedure

    • Procedures are performed as elective operation. Admit 1 day before or on same day for operation.
    • If operation is performed under general anaesthesia, keep fast for 6 to 8 hours and require anaesthetic assessment before operation.
    • Before undergo lumpectomy / partial Mastectomy, patient may need to go to X-Ray Department for preoperative imaging and localization with the injection of isotope / guidewire /or equivalent.
    • Change to operation room uniform before transfer to operating room.
    • Empty bladder before surgery.
    • May need pre-medications and intravenous drip.
    • Antibiotic prophylaxis or treatment may be required.
    • Inform doctors about drug allergy, regular medications or other medical conditions.
  3. The procedure

    • Axillary Dissection
      • The operation is performed under general anaesthesia. Incision is made in the skin crease in the axilla.
      • The fat and the lymph nodes in the axilla will be removed as defined by anatomy. Drainage tube is left for drainage of body fluid. Wound closed with suture.
    • Lumpectomy / Partial Mastectomy
      • The operation is performed under general or local anaesthesia. Incision is made on the skin of the breast.
      • The exact site of lesion can be determined by palpation, ultrasound localization or stereotactic localization. If preoperative localization is done in the Radiology Department, a skin marker/ guidewire/ isotope/ or equivalent will be injected into the breast. These will be removed together with the specimen during the operation.
      • The tumour is removed with adequate healthy margin.
      • Ultrasound or specimen mammogram may be performed to confirm accurate removal of the lesion and adequate margin.
      • Small metal clips may be put in the wound to localize the tumour bed. Drainage tube may be needed.
      • Wound closed with suture.
    • Modified Radical Mastectomy
      • The operation is performed under general anaesthesia.
      • An elliptical incision is made to include the nipple areolar complex and the skin overlying the primary tumour. All the breast tissue, level 1 & 2 axillary lymph nodes are removed
      • Drainage tube is left for drainage of body fluid. Wound closed with suture.
    • Simple Mastectomy
      • The operation is performed under general anaesthesia.
      • An elliptical incision is made to include the nipple areolar complex and the skin overlying the primary tumour. All the breast tissue is removed.
      • Drainage tube is left for drainage of body fluid. Wound closed with suture.
  4. After the procedure

    • Usually after operation
      • May feel mild throat discomfort or pain because of intubation.
      • Mild discomfort or pain over the operative site. Inform medical staff if pain severe.
      • It is common that general anaesthesia may cause nausea or vomiting. Inform medical staff if the symtoms severe.
    • Normally, patient can mobilize and get out of bed 6 hours after operation and usually go home day 2 after the operation.
    • Wound care
      • In the first day after operation, patients can have shower with caution, keep wound dressing dry.
      • Stitches or skin clips (if present) will be taken off around 10-14 days.
      • The drainage tube is removed when drainage decreases. Patients usually go home before the removal of drainage tube and return to hospital / clinic to remove the drainage tube.
    • Resume diet when recover from anaesthesia.
  5. Risk and complication

    • Anesthesia related complications
      • Cardiovascular complications: myocardial infarction or ischaemia, stroke, deep vein thrombosis, pulmonary embolism, etc.
      • Respiratory complications atelectasis, pneumonia, asthmatic attack, exacerbation of chronic obstructive airway disease.
      • Allergic reaction and shock.
    • Common procedural related complications
      • Wound pain or infection.
      • Flap necrosis.
      • Patient may require re-operation to evacuate the blood clot.
      • Seroma collection. This may need prolonged drainage or needle aspiration.
      • Hypertrophic scar and keloid formation may result in unsightly scar.
    • Complications related to Axillary Dissection / Modified Radical Mastectomy
      • Lymphoedema.
      • Nerve injury including long thoracic nerve, thoracodorsal nerve and rarely brachial plexus.
      • Injury to blood vessels.
      • Frozen shoulder and chronic stiffness.
      • Numbness over axilla.
    • Complications related to Lumpectomy / Partial Mastectomy
      • Deformity of the breast.
      • Deviation of nipple.
      • Incomplete excision of tumour.
  6. Things to take note on discharge

    • Contact your doctor or the Accident & Emergency Department for the following events occurs:
      • Increasing pain or redness around the wounds.
      • Discharge from the wound.
    • Take the analgesics prescribed by your doctor if required
    • Resume your daily activity gradually (according to individual situation). Avoid lifting heavy objects over the operated arm.
    • Protect the arm of operated side from infection or injury. Wear protective grove when washing or horticulture.
    • Remember the dates of taking off stitches/clips in the clinic, and follow-up in the specialist clinic.
  7. Follow-up

    • If pathology report shows positive margin, further surgery (e.g re-excision or mastectomy) may be required.
    • Radiotherapy is usually necessary. Adjuvant therapy such as chemotherapy, hormonal therapy and target therapy may be necessary according to the final pathology and will be advised by the doctor once this is available after the operation.
    • Despite surgical clearance of the cancer, there is still a chance of recurrence of the disease and death. This is dependent on the initial stage of disease at the time of presentation and subsequent progression.
  8. Remarks

    For further information please contact your doctor.