Breast Cancer Prevention

Breast cancer may not always cause noticeable symptoms in its early stages. Understanding your personal risk and receiving appropriate screening can help detect breast cancer earlier, allowing timely assessment and treatment before the disease progresses.

Breast cancer screening is not a one-size-fits-all process. In Hong Kong, a risk-based approach is recommended, meaning the type and frequency of screening should be determined according to each woman’s age, family history, medical history and other personal risk factors.

What Is Breast Cancer Screening?

Breast cancer screening refers to the use of tests or procedures to check women who do not have symptoms. Its purpose is to detect breast cancer at an earlier stage or identify women who may be at increased risk of developing the disease.

Screening is different from diagnostic assessment. Women who notice a breast lump, nipple discharge, changes in breast shape or skin, persistent breast or underarm discomfort, or other unusual symptoms should seek medical advice promptly rather than wait for routine screening.

Mammography

Mammography is a commonly used breast cancer screening test. It is a low-dose X-ray examination that can help detect early-stage breast tumours that may be too small to be easily seen or felt.

During the examination, the woman will need to expose her upper body. Each breast is gently compressed between the mammography machine’s flat plastic paddles so that X-ray images can be taken from different angles.

Breast compression may cause temporary discomfort or pain, but it usually lasts only a few seconds. Compression is necessary because it helps:

• produce clearer images;
• reduce movement and image blurring;
• improve the accuracy of the examination; and
• reduce the amount of radiation required.

Two-dimensional mammography, or 2D mammography, is commonly adopted as a principal screening test.

Breast Ultrasound

A doctor may recommend an additional breast ultrasound if it is clinically indicated.

Breast ultrasound uses high-frequency sound waves to visualise structures inside the breast. The reflected sound waves are converted into images for medical assessment. It may provide supplementary information about an area identified during a clinical examination or mammography.

However, breast ultrasound is not automatically required for every woman and should not be regarded as a substitute for mammography unless advised by a doctor.

Screening Recommendations According to Risk

Women should discuss their personal risk profile with a doctor before deciding when and how often to undergo breast cancer screening.

Women at High Risk

A woman may be considered at high risk if she has any of the following factors:

• a confirmed harmful mutation in the BRCA1 or BRCA2 gene;
• a strong family history of breast or ovarian cancer;
• a first-degree female relative with a confirmed BRCA1 or BRCA2 mutation;
• a first- or second-degree female relative who has had both breast and ovarian cancer;
• a first-degree female relative with cancer in both breasts;
• a male relative with a history of breast cancer;
• two first-degree female relatives with breast cancer, with at least one diagnosed at or before the age of 50;
• two or more first- or second-degree female relatives with ovarian cancer;
• three or more first- or second-degree female relatives with breast cancer, or a combination of breast and ovarian cancer;
• a history of radiation therapy to the chest between the ages of 10 and 30;
• a personal history of breast cancer, including ductal carcinoma in situ or lobular carcinoma; or
• a history of atypical ductal hyperplasia or atypical lobular hyperplasia.

Women at high risk should seek medical advice and are generally recommended to undergo mammography every year.

Screening may begin at the age of 35 or 10 years before the age at which the youngest affected relative was diagnosed, whichever is earlier. However, screening would generally not begin before the age of 30.

Confirmed carriers of BRCA1 or BRCA2 mutations, and women who received chest radiation therapy between the ages of 10 and 30, may also be advised to consider annual magnetic resonance imaging, or MRI, in addition to mammography.

Genetic Testing and Counselling

Women who have a first-degree female relative with a confirmed BRCA1 or BRCA2 mutation may be offered genetic testing to determine whether they carry the same mutation.

Women with other strong patterns of breast or ovarian cancer in the family may also discuss referral to a specialist cancer clinic for genetic risk assessment, counselling and management.

Genetic testing should be performed by specialised centres with expertise in genetic counselling. Counselling should be provided both before and after testing so that women understand the possible outcomes, uncertainties and implications for themselves and their families.

Women at Moderate Risk

A woman may be considered at moderate risk if she has:

• one first-degree female relative diagnosed with breast cancer at or before the age of 50; or
• two first-degree female relatives diagnosed with breast cancer after the age of 50.

Women at moderate risk are generally recommended to undergo mammography every two years. Before screening begins, they should discuss its potential benefits and limitations with their doctor.

MRI is not routinely recommended for breast cancer screening in women at moderate risk.

Other Women in the General Population

Women aged 44 to 69 who have certain combinations of personalised risk factors may also have an increased risk of developing breast cancer. These factors include:

• breast cancer in a first-degree relative;
• a previous diagnosis of benign breast disease;
• never having given birth;
• giving birth for the first time at a later age;
• starting menstruation at a younger age;
• having a high body mass index; and
• physical inactivity.

Women in this age group may use a breast cancer risk assessment tool developed for local women to estimate their risk. Depending on the assessment result, women at increased risk may be advised to consider mammography every two years.

The assessment tool estimates risk but does not diagnose breast cancer or predict with certainty whether an individual woman will develop the disease. Women should discuss the result and the appropriate screening arrangement with their doctor.

MRI is not routinely recommended for breast cancer screening among women in the general population.

Understand the Benefits and Limitations of Screening

No breast cancer screening test is 100% accurate. Before undergoing screening, women should understand both its potential benefits and limitations.

Possible limitations and risks include:

• False-positive results: An abnormal result is found even though cancer is not present, leading to additional tests and anxiety.
• False-negative results: A cancer may not be detected by the screening test.
• Overdiagnosis: Screening may identify a cancer that would not otherwise have caused symptoms or affected the woman’s health during her lifetime.
• Unnecessary tests or treatment: Further procedures may be performed to investigate findings that are ultimately non-cancerous.
• Temporary discomfort: Breast compression during mammography may cause brief discomfort or pain.
• Radiation exposure: Mammography involves a small amount of radiation.

Women considering screening should speak with a doctor about these potential benefits and harms. An informed decision should take into account personal risk factors, health condition, preferences and clinical advice.

Screening Does Not Replace Breast Awareness

Even after receiving a normal screening result, women should continue to be aware of the usual appearance and feel of their breasts.

Seek medical advice promptly if you notice:

• a new lump in the breast or underarm;
• changes in the size or shape of a breast;
• redness, thickening, scaling or dimpling of the skin;
• an inverted nipple or a rash around the nipple;
• unusual nipple discharge; or
• persistent pain or discomfort in the breast or underarm.

These changes do not necessarily mean that breast cancer is present, but they should be assessed by a healthcare professional without delay.

Reduce Your Risk Through a Healthy Lifestyle

Although breast cancer cannot always be prevented, a healthy lifestyle may help reduce some modifiable risk factors. Women are encouraged to:

• engage in regular physical activity;
• avoid or limit alcohol consumption;
• maintain a healthy body weight and waist circumference;
• eat a balanced diet;
• avoid smoking; and
• remain aware of their personal and family medical history.

Women taking hormonal medication, including hormone replacement therapy or combined oral contraceptives, should discuss the potential benefits and risks with their doctor. Prescribed medication should not be stopped without medical advice.

Women’s Health Support in Kowloon City

Women who would like to understand their health risks or receive further support may visit the Women’s Health Service Nurse Clinics at the Kowloon City District Health Centre Express.

Healthcare professionals can provide an individual health and nursing assessment, health education and service coordination according to each woman’s needs. Women identified as having health risks may be referred by the Kowloon City District Health Centre Express to Women Wellness Satellite for personalised women’s health services, including cervical cancer and breast cancer screening.

All referrals, screening tests and follow-up arrangements are subject to individual needs and a doctor’s clinical assessment.

 

Important notice: This article is intended for general health education only and does not replace medical consultation, diagnosis or treatment. Women with breast symptoms, a strong family history of cancer or concerns about their screening needs should consult a doctor promptly.