Breast Cancer

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 (Source: Cancer Online Resource Hub).

Hong Kong women stand a lifetime risk of 1 in 21 in developing breast cancer (vs. 1 in 8 in the USA). As men also have a small amount of breast tissue, they too 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 another does not. However, we do know that some factors are associated with the development of breast cancer: 

• A family history of breast cancer, particularly in first degree relatives
• Early onset of menstruation or late menopause, which results in prolonged exposure to the breast-stimulating 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 Some 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.
• A 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). On 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 a patient’s condition. 

How Do You 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 a regular mammography at the age of 35. 

We provide a breast cancer screening package which consists of a demonstration of breast self-examination, basic physical examination, medical history taking, breast examination by a doctor, mammography and follow-up. 

How Can Breast Cancer Be Prevented?
The risks of developing breast cancer can be minimised by avoiding over-eating fatty foods and by engaging in regular exercise on a lifelong basis. 

For individuals who are advised they are at high risk of familial breast cancer, more aggressive preventive interventions can be taken. These included prescribing daily tamoxifen tablets, inducing an early menopause by removing the ovaries, or prophylactic surgical removal of breast tissue.