AN initial diagnosis of breast cancer can be devastating.
Waiting to learn the exact subtype of breast cancer can be emotionally difficult for patients and their families, but accurate classification is essential to ensure the best treatment is provided.
After all, breast cancer is not a single entity and has different manifestations that require
tailored management and therapy, says Pantai Hospital Kuala Lumpur consultant breast and endocrine surgeon Dr Nur Aziah Adib Anuar.
Breast cancer is classified both structurally and biologically. Structurally, it is categorised based on where the cancer is located, whether it remains
confined within the breast ducts, has become invasive, or has spread (metastasised) to other parts of the body (Stage 4).
“Uniquely, breast cancer has a Stage 0 category known as ductal carcinoma in situ, in which abnormal cancer cells remain confined within the milk ducts and have not invaded surrounding breast tissue.
“Because it is non-invasive, treatment outcomes are generally excellent and if completely removed, cure rates are extremely high,” says Dr Nur Aziah.
“Breast cancers are also defined by their biological/molecular subtype and this plays a critical role in treatment decisions.
“More importantly, a patient must understand that treatment will differ depending on the subtype of breast cancer,” she explains.
Key biological subtypes that influence treatment and prognosis include:
- Hormone receptor-positive (HR+) cancers grow in response to hormones like oestrogen or progesterone;
- HER2-enriched breast cancer is characterised by high activity of HER2-related genes and growth-signalling pathways (different from HER2-positive), with faster tumour growth, aggressive spread and higher recurrence rates;
- Triple-negative breast cancer (TNBC) lacks hormone receptors (oestrogen and progesterone receptors) and HER2, making it more aggressive and harder to treat.
Hence, two patients with similarly sized tumours may receive completely different treatments because their cancers behave differently at a molecular level.
Differentiating cancer subtypes is essentially precision medicine because treatment can be tailored to each individual patient and such therapy can significantly improve outcomes, says Dr Nur Aziah.
Breast cancer remains the most common cancer among women in Malaysia and ranks among the top three most common cancers affecting women globally.
According to Dr Nur Aziah, approximately “1 in 30 women in Malaysia is estimated to develop breast cancer during her lifetime.”
Although breast cancer is far more common in women, men can also develop the disease – the World Health Organization figures put the number at approximately 1% of all breast cancers.
And unlike in the past, breast cancer is increasingly being diagnosed in younger women.
“We are now seeing cases even among women in their 20s. Breast cancers occurring at a younger age are often biologically more aggressive,” observes Dr Nur Aziah.
Risk factors and recognising signs
Risk factors for breast cancer can be divided into non-modifiable as well as modifiable ones.
Non-modifiable risk factors include age, family history, gender, as well as age of menarche and menopause (this relates to duration of exposure to oestrogen and progesterone).
Modifiable risk factors are weight and lifestyle factors such as food intake, alcohol consumption and chronic stress.
Dr Nur Aziah emphasises the importance of regular breast self examinations (BSEs) in recognising signs of the cancer.
“Besides the obvious, regular BSEs familiarise individuals with what is normal, so when something abnormal develops, it is noticed sooner.”
Most people tend to overlook the nipple when considering possible symptoms of breast cancer, observes Dr Nur Aziah.
“Is there discharge from the nipple? Is it bloody, serous or milky? Is there inversion of the nipple, or is there eczema, excoriation, ulceration? We must not ignore such changes.
“Next, is there a lump? Don’t just check for lumps in the breast, you need to check in the armpits too.
“Are there any skin changes? Is there redness, or hardening of the skin? Such changes to the breast should be assessed promptly,” advises Dr Nur Aziah.
“Even if you are breastfeeding and you feel a lump, do not assume it’s breast engorgement. Get it checked,” she adds.
Diagnosing and treating breast cancer
Breast cancer diagnosis typically involves a combination of imaging tests, such as mammography, ultrasound, or Magnetic Resonance Imaging (MRI), followed by a biopsy.
“If a clinical breast examination reveals a suspicious finding, the patient is usually referred for imaging. The imaging modality used depends on factors such as the patient’s age, symptoms, breast density and clinical suspicion,” explains Dr Nur Aziah.
If imaging findings are concerning, a biopsy is then performed to obtain tissue for laboratory analysis. Pathologists will determine whether cancer is present, the type of breast cancer, tumour grade and important biological markers such as hormone receptor and HER2 status.
If cancer is confirmed, additional investigations may be carried out to determine the stage of the disease and whether it has spread elsewhere in the body.
These may include Computed Tomography (CT) scans, Positron Emission Tomography (PET) scans, or other imaging studies.
Some patients may be recommended for genomic testing, depending on the cancer subtype. Genomic testing can help determine whether chemotherapy would be beneficial or unnecessary as part of the overall treatment plan.
Dr Nur Aziah opines that more patients diagnosed with breast cancer should undergo genetic testing as this can determine whether they carry cancer-related genes that may also affect family members. This allows relatives to undergo appropriate counselling, testing and earlier screening where necessary.
Advances in breast cancer treatment mean that even aggressive cancers such as triple negative and HER2-enriched breast cancer can be managed more effectively.
The main treatment options include surgery, radiotherapy, chemotherapy, hormone therapy, targeted therapy and immunotherapy.
Depending on the cancer sub-type, different combinations are included in the treatment plan. An example is treatment for triple-negative cancer.
This type of cancer is treated with a combination of chemotherapy and immunotherapy upfront to improve survival rates and reduce the risk of recurrence.
Dr Nur Aziah informs that some tumours may even change and evolve during treatment and this needs to be kept in mind so that treatment can be adjusted if this happens.
It’s also important for the patient to be mindful that even after treatment, the cancer may recur, so vigilance is important.
Follow-up and recurrence risk
After treatment, patients will require long-term follow-up. Understanding the breast cancer subtype helps doctors tailor follow-up care and surveillance strategies.
For example, HR+ cancers can recur many years later, requiring prolonged monitoring. Triple-negative and HER2-enriched breast cancers are also more likely to recur within the first few years after treatment. Some breast cancers can even recur in a different form, in that its tumour biology has changed.
Follow-ups typically include regular clinical examinations and periodic imaging and may extend to 10 years or more, especially with higher risk breast cancers.
Dr Nur Aziah advises that patients who have completed treatment need to be wary and check with their doctor if they experience unusually severe headaches, shortness of breath, loss of appetite, and unexplained pain in the body.
Of course, patients will need to continue with their BSEs and notify their doctor immediately if they notice any new lumps or other signs.
Screening remains one of the most effective ways to detect breast cancer early. Performing regular BSEs and undergoing recommended mammogram schedules is vital, notes Dr Nur Aziah.
The Health Ministry recommends a risk-based approach to breast cancer screening:
- Women are encouraged to practise regular BSEs and seek medical attention if they notice changes such as lumps, nipple discharge, or skin changes;
- Clinical breast examination is recommended periodically, especially from age 40 onwards;
- For average-risk women aged 50–74 years, mammograms every two years are recommended;
- Women at higher risk - such as those with a strong family history or BRCA mutations - may require earlier and more intensive screening, including MRI in selected cases.
Awareness elevates protection
There are many misconceptions surrounding breast cancer, says Dr Nur Aziah. Some of the common ones include:
- I don’t want a mammogram because of the radiation risk;
- I don’t want a biopsy because it can ‘seed’ cancer cells elsewhere.
Others may include:
- I don’t have a family history of breast cancer, so I won’t have breast cancer;
- All breast cancers behave the same;
- A small tumour means a mild cancer.
Such misconceptions need to be clarified to avoid unnecessary suffering and pain. These not only delay diagnosis, but also lead to inappropriate expectations about treatment and survival.
While not all breast cancers are preventable, individuals can reduce their risk by maintaining a healthy weight, staying physically active, practising regular BSEs, attending regular screenings, and seeking medical attention early if any changes are noticed.
Dr Nur Aziah emphasises that early detection remains one of the most important tools in improving breast cancer outcomes.
“Women should undergo regular screening and remain aware of breast health throughout the year, not only during Breast Cancer Awareness Month in October.”
