Breast cancer is the most common cancer affecting women in Malaysia. Almost half of cases are diagnosed at a late stage—stage III or IV—when the disease may have spread to nearby tissues, lymph nodes or distant organs.

For many women, hearing the words “you have breast cancer” can bring immediate fears of surgery, chemotherapy and an uncertain future. However, breast cancer care has changed considerably. Advances in screening, diagnosis, surgery, radiotherapy, targeted medicines and supportive care now allow doctors to plan treatment more precisely.

Breast cancer is not one single disease. Its biological features, stage and response to treatment can vary widely from one patient to another. Treatment decisions must therefore consider both the cancer and the person receiving care.

Breast cancer can behave differently from patient to patient

Breast cancer begins when abnormal cells in the breast grow uncontrollably. However, different breast cancers can grow at different speeds and respond differently to treatment.

Doctors assess several features, including:

• The size of the tumour
• Whether cancer has spread to lymph nodes or other organs
• Whether the cancer has oestrogen or progesterone receptors
• Whether it produces excess HER2 protein
• The tumour grade, which describes how abnormal the cells look
• The patient’s age, general health and menopausal status
• The patient’s personal preferences and treatment priorities

Dr Nisha Shariff, Consultant Clinical Oncologist at Sunway Medical Centre, Sunway City, says identifying the cancer subtype is an important part of treatment planning.

“Breast cancer is a group of different subtypes, and each behave very differently. Some are responsive to hormones or overproduce a protein called HER2 which drives cancer cell growth. Some have none of these markers which is known as triple negative breast cancer,” she said.

The three broad categories commonly discussed are hormone receptor-positive, HER2-positive and triple-negative breast cancer.

Hormone receptor-positive breast cancer

These cancers have receptors for oestrogen, progesterone or both. These hormones can stimulate the cancer to grow, so hormonal treatment may be used to block this effect or reduce hormone levels.

Hormonal treatment is often prescribed after surgery, sometimes for several years. It may also be used before surgery or to control advanced disease, depending on the patient’s circumstances.

HER2-positive breast cancer

HER2 is a protein that can encourage cancer cells to grow. Some breast cancers produce too much of it. HER2-targeted medicines are designed to block this growth signal.

HER2-positive cancers may grow more quickly, but targeted treatments have changed the outlook for many patients.

Triple-negative breast cancer

Triple-negative breast cancers do not have oestrogen receptors, progesterone receptors or excess HER2. As a result, standard hormonal treatment and HER2-targeted treatment are not suitable.

Depending on the stage and other features, treatment may involve chemotherapy, immunotherapy or other medicines.

Similar-sized tumours may need different treatment

Two women may have tumours of a similar size and still receive different treatment plans.

Dr Nisha gives the example of two women in their 50s with similar-sized, hormone receptor-positive tumours. A woman with a HER2-negative tumour may be treated with surgery, radiotherapy and hormonal therapy. Another woman with HER2-positive disease may also need chemotherapy and HER2-targeted treatment.

“What may look similar on paper can behave very differently. Understanding what is driving the cancer helps us determine which treatment is most appropriate for each patient. We are not simply treating breast cancer; we are treating the person and their specific type of cancer,” Dr Nisha explains.

Age, general health, other medical conditions, menopausal status and personal preferences can all influence treatment decisions.

Patients should not compare their treatment too closely with that of a friend or relative, because even apparently similar cancers may have important biological differences.

What does ‘aggressive’ breast cancer mean?

The word ‘aggressive’ can be frightening. In medical discussions, it usually refers to how quickly a cancer may grow or spread. It does not, on its own, determine how an individual patient will respond to treatment.

Some HER2-positive and triple-negative cancers can grow more quickly than certain other breast cancers. However, they may also respond well to treatments specifically designed for them.

“In the past, HER2-positive breast cancer used to carry a poor prognosis. With targeted therapy, outcomes have transformed dramatically and improved survival in many women with breast cancer,” Dr Nisha says.

Tumour stage, grade, receptor status and response to treatment provide more useful information about a patient’s situation than the word ‘aggressive’ alone.

Early detection remains essential

Treatment advances are important, but finding breast cancer early remains one of the best ways to improve the chances of successful treatment.

Dr Kiran Kaur d/o Amer Singh, a general surgeon with a special interest in breast surgery at Columbia Asia Hospital Klang, who previously spoke to PP Health Malaysia (PPHM) about breast cancer screening.

She said screening can identify breast changes before symptoms develop.

“Early detection remains our most effective tool against breast cancer. Regular screening allows us to identify changes long before symptoms appear, when treatment is most effective and outcomes are best,” she said.

Screening is intended for people who do not have symptoms. It is different from diagnostic testing, which is carried out when a woman notices a lump or another breast change.

A screening mammogram can detect small abnormalities that cannot be felt during a physical examination. Dr Kiran said mammography remains the main screening test because it can identify changes before they become noticeable.

She added that ultrasound can be useful, particularly for younger women with dense breast tissue.

“Because the most appropriate screening depends on age, breast density and risk factors, consulting a healthcare professional is essential,” she said.

Which screening tests are used?

In the previous discussion with PPHM earlier, Dr Kiran explained that different imaging tests have different roles.

“Breast cancer screening for women at average risk is centred on mammography, including 3D mammography where available. Ultrasound is not generally used as a stand-alone screening tool; rather, it helps assess a breast lump, clarify an abnormal mammogram, evaluate selected women with dense breasts, or guide a biopsy. Breast MRI is not routinely needed for average-risk screening, but may be used alongside mammography for women at high risk or individuals require more clinical investigation.”

This distinction is important because no single test is suitable for every woman.

Mammography

Mammography uses low-dose X-rays to examine breast tissue. It remains the main screening test for women at average risk because it can identify small abnormalities, including some calcifications, before they can be felt.

Three-dimensional mammography, also called digital breast tomosynthesis, creates images from different angles and may be available in some centres. Its suitability depends on local availability, patient factors and clinical advice.

Ultrasound

Ultrasound uses sound waves to create images of the breast. It can be useful for assessing a lump, distinguishing some fluid-filled cysts from solid areas, clarifying an abnormal mammogram and examining selected women with dense breast tissue.

However, ultrasound is not generally a replacement for mammography in average-risk screening. It can also identify findings that are not cancer and may lead to additional imaging or biopsies.

Magnetic resonance imaging

Breast MRI uses magnetic fields and contrast in many cases to produce detailed images. It is not routinely needed for average-risk screening.

Doctors may recommend MRI alongside mammography for women at substantially increased risk, such as some women with inherited cancer-risk gene changes or a strong family history. MRI may also be used when other imaging is inconclusive or when more detailed assessment is needed.

Women should ask their doctor which screening approach is appropriate based on age, breast density, family history, previous breast conditions and other risk factors.

Screening guidelines depend on individual risk

There is no single screening schedule suitable for every woman. Recommendations may differ according to:

• Age
• Family history
• Previous breast cancer or high-risk breast lesions
• Breast density
• Inherited gene changes
• Previous radiation treatment to the chest
• Other personal risk factors

Women at average risk should follow current local guidance and discuss the timing of mammography with a healthcare professional. Women at higher risk may need earlier, more frequent or additional screening.

A normal mammogram does not rule out every breast cancer. Women should seek medical advice if they notice a persistent change, even if their most recent screening result was normal.

Breast changes that need assessment

Women should arrange a medical assessment if they notice:

• A new lump in the breast or armpit
• A change in breast size or shape
• Skin dimpling or thickening
• Persistent redness or swelling
• A newly inverted nipple
• Unusual nipple discharge, particularly if bloody or occurring without squeezing
• A persistent rash or sore on the nipple
• Localised pain that does not settle
• Any breast change that is new or becoming more noticeable

Most breast changes are not cancer, but only proper assessment can identify the cause.

“Don’t let fear make the decision for you. A lot of the fear is in the unknown. Knowledge is power,” urges Dr Nisha.

For women who feel anxious about screening, bringing a friend or family member may make the experience more comfortable. Patients can also ask imaging staff to explain what will happen before the examination.

How breast cancer is diagnosed

A breast cancer assessment may involve several stages.

Clinical examination

A doctor examines the breast and nearby lymph nodes, including those in the armpit and around the collarbone.

Imaging

Depending on the patient’s age, symptoms and risk, doctors may recommend mammography, ultrasound or MRI.

Biopsy

A biopsy removes a small tissue sample for laboratory examination. A biopsy is usually needed to confirm whether an abnormality is cancerous.

Laboratory testing

The tissue may be tested for hormone receptors, HER2 and other markers. These findings help guide treatment.

Staging

Additional scans may be recommended to establish whether the cancer has spread beyond the breast and nearby lymph nodes.

Understanding breast cancer stage

Stage describes how extensive the cancer is. It generally considers:

• The size of the primary tumour
• Whether lymph nodes are affected
• Whether the cancer has spread to distant organs

Broadly:

• Stage 0 refers to non-invasive disease confined to ducts or lobules.
• Stages I and II generally describe earlier invasive breast cancer, although the exact features vary.
• Stage III usually indicates more extensive disease involving nearby tissues or lymph nodes.
• Stage IV means the cancer has spread to distant parts of the body, such as the bones, liver, lungs or brain.

Stage is important, but it is not the only factor influencing treatment or outlook. The subtype, grade, response to treatment and general health also matter.

Treatment is tailored to the diagnosis

Many patients receive more than one type of treatment. The sequence depends on the stage and biology of the cancer. “We used to ask which treatment can give the best outcome. Now, the question is which treatment is most appropriate for my patient and our focus has also shifted to patient survivorship,” says Dr Nisha.

Surgery

Surgery may remove the tumour while preserving much of the breast, or it may involve removal of the entire breast. Lymph nodes under the arm may also be assessed or removed.

The choice depends on tumour size and location, whether there is more than one tumour, other clinical findings and the patient’s preferences.

Some patients may also discuss breast reconstruction.

Radiotherapy

Radiotherapy uses high-energy radiation to destroy cancer cells in a specific area. It is commonly recommended after breast-conserving surgery and may be advised after mastectomy in selected patients.

Modern planning techniques help target the area at risk while limiting exposure to nearby healthy tissue.

Chemotherapy

Chemotherapy uses medicines that travel through the bloodstream to destroy cancer cells or stop them from dividing.

It may be given before surgery to shrink a tumour, after surgery to reduce the risk of recurrence or to control advanced disease.

Side effects can include tiredness, nausea, hair loss, mouth ulcers and temporary changes in blood cell counts. Supportive medicines can help manage many side effects.

Hormonal therapy

Hormonal therapy is used for hormone receptor-positive breast cancer. Treatment may include medicines such as tamoxifen or aromatase inhibitors, depending on the woman’s age, menopausal status and other factors.

Possible side effects include hot flushes, joint discomfort, mood changes and menstrual changes. Patients should tell their healthcare team if side effects interfere with daily life.

Targeted therapy

Targeted medicines act on particular features of cancer cells. HER2-targeted treatment is one example. Other targeted medicines may be considered when testing identifies specific features in the tumour.

Immunotherapy

Immunotherapy helps the immune system recognise and attack cancer cells. It is suitable only for selected patients, including some people with particular forms of triple-negative or advanced breast cancer.

Patients should ask why a particular treatment is being recommended and how its possible benefits compare with its risks.

Genomic testing may help some patients decide about chemotherapy

Some patients with early-stage, hormone receptor-positive and HER2-negative breast cancer may be offered a genomic test. These tests examine the activity of selected genes in the tumour.

The results may help estimate the likelihood of recurrence and whether chemotherapy is likely to provide enough additional benefit to justify its side effects. Such testing is not appropriate for every patient or every subtype of breast cancer.

Genomic tumour testing should not be confused with inherited genetic testing. Genomic testing examines the cancer itself, while inherited genetic testing looks for gene changes that may increase a person’s risk of developing cancer and may have implications for relatives.

Knowing personal risk

Some factors can increase the likelihood of developing breast cancer, including:

• Increasing age
• A close relative with breast or ovarian cancer
• An inherited gene change, such as BRCA1 or BRCA2
• A personal history of breast cancer or certain high-risk breast conditions
• Dense breast tissue
• Being overweight or obese after menopause
• Limited physical activity
• Regular alcohol consumption
• Some forms of prolonged hormonal exposure

Having a risk factor does not mean that a woman will develop breast cancer. Conversely, women without obvious risk factors can still develop the disease.

Women with several affected relatives, cancer occurring at a young age in the family, male breast cancer in the family or a known inherited gene change should ask about genetic counselling.

Steps that may support breast health

Not every breast cancer can be prevented, but certain measures can support general health and may lower risk:

• Maintain a healthy weight, particularly after menopause.
• Be physically active on most days of the week.
• Limit alcohol consumption.
• Avoid smoking.
• Eat a balanced diet with vegetables, fruit, wholegrains and sources of protein.
• Breastfeed where possible and appropriate.
• Discuss the benefits and risks of hormonal medicines with a doctor.
• Follow recommended screening guidance.

These actions may reduce risk for some women but do not guarantee that breast cancer will be prevented.

Care beyond the cancer

Breast cancer treatment can affect physical health, emotional wellbeing, appearance, relationships, fertility and work.

A multidisciplinary team may include:

• Breast surgeons
• Medical or clinical oncologists
• Radiologists and pathologists
• Specialist breast care nurses
• Physiotherapists
• Dietitians
• Psychologists or counsellors
• Fertility specialists
• Palliative care professionals when needed

Support may be available for recovery after surgery, arm swelling, shoulder movement, nutrition, fertility preservation, menopausal symptoms, intimacy, body image, breast reconstruction, returning to work and anxiety.

Patients should tell their medical team about side effects or emotional distress rather than trying to manage them alone. “Cancer doesn’t define you. It is one chapter of your life, not the whole story,” assured Dr Nisha.

Questions to ask after a diagnosis

Patients may find it helpful to bring someone they trust to appointments, take notes or request a written treatment plan. Useful questions include:

1. What type and subtype of breast cancer do I have?
2. What is the stage and grade?
3. Has it spread to any lymph nodes or other organs?
4. What treatment do you recommend first, and why?
5. Will I need surgery, chemotherapy, radiotherapy, hormonal therapy or targeted treatment?
6. Would genomic or inherited genetic testing be relevant to me?
7. What side effects should I expect?
8. How can side effects be managed?
9. Could treatment affect fertility, menstruation, intimacy or work?
10. Should I consider a second opinion?
11. Who should I contact if I develop a problem during treatment?

The key messages from PP Health Malaysia (PPHM)

Breast cancer is a serious diagnosis, but it does not have one standard treatment path or one fixed outcome. The cancer’s subtype, stage, grade and response to treatment all matter, as do the patient’s age, health, circumstances and preferences.

For women at average risk, mammography remains the main screening test. Ultrasound and MRI are used selectively, depending on symptoms, breast density and individual risk.

As Dr Kiran explained in her previous discussion with PPHM, the most appropriate screening approach should be determined with a healthcare professional. Early assessment can help patients understand their diagnosis and consider suitable treatment options.

“Early detection remains our most effective tool against breast cancer. Regular screening allows us to identify changes long before symptoms appear, when treatment is most effective and outcomes are best,” said Dr Kiran.

“If you notice a lump or unusual breast change, do not wait. Most lumps are not cancer, but getting checked can provide answers. Fear is understandable, but don’t let it stop you from taking that first step for your health,” urges Dr Nisha.