Understanding Triple Negative Breast Cancer at the National Cancer Centre Singapore

Triple negative breast cancer is a less common but important subtype of breast cancer that behaves differently from other forms of the disease. At the National Cancer Centre Singapore (NCCS), specialists use detailed imaging, pathology and molecular testing to diagnose and manage this condition with precision. This page provides an overview of what triple negative breast cancer is, how it is diagnosed, treatment options available and the support patients can expect throughout their care.

What Is Triple Negative Breast Cancer

Triple negative breast cancer refers to breast cancers that do not have receptors for oestrogen, progesterone or the HER2 protein. These three receptors usually guide treatment decisions for most breast cancers, as many tumours rely on hormones or HER2 signalling to grow. When all three are absent, the cancer is described as “triple negative”.

How Triple Negative Breast Cancer Differs from More Common Breast Cancers

Most breast cancers are driven by hormone receptors (oestrogen or progesterone) or by high levels of the HER2 protein. These cancers respond well to targeted treatments such as hormonal therapy or HER2-directed medicines. In contrast, triple negative breast cancer lacks all three receptors, which means these targeted treatments are not effective. As a result, treatment relies on other approaches such as chemotherapy, surgery, radiotherapy and, in selected cases, immunotherapy.

Triple negative breast cancer can behave differently from hormone-positive or HER2-positive breast cancers. It is more likely to occur in younger women, may grow or spread more quickly and can require more intensive treatment at the start. Even so, many patients respond well to chemotherapy, especially when the cancer is detected early and managed promptly.

How Triple Negative Breast Cancer Is Diagnosed

Diagnosis involves several steps to understand the nature of the tumour, confirm whether it is triple negative breast cancer and determine the extent of disease. Each component of the diagnostic process provides different information that guides treatment planning.

Breast imaging

Breast imaging is usually the first step in evaluation.

• Mammograms use low-dose X-rays to identify abnormal areas or calcifications that may suggest cancer. 
• Ultrasound helps assess whether a lump is solid or fluid-filled and can evaluate the lymph nodes in the armpit. 
• MRI scans may be recommended for more detailed imaging, especially in younger patients, dense breast tissue or when a clearer picture of the tumour’s size and extent is needed.

These imaging techniques help specialists assess the characteristics of the tumour, determine if there are multiple areas of concern and identify whether surrounding tissues or lymph nodes may be involved.

Biopsy and pathology testing

A biopsy is essential to confirm the diagnosis. A small sample of the tumour is taken using a needle or during a minor procedure and examined under a microscope by a pathologist. The sample is tested for:

• Oestrogen receptors (ER) 
• Progesterone receptors (PR) 
• HER2 protein expression

If all three tests are negative, the cancer is classified as triple negative breast cancer. Pathology testing also provides information about the tumour’s grade, appearance under the microscope and other features that influence how it may behave and respond to treatment.

Staging investigations

Once triple negative breast cancer is confirmed, staging tests may be performed to understand the full extent of the disease. These may include:

• CT scans or MRI scans to examine the chest, abdomen or other areas 
• PET scans to check for spread beyond the breast 
• Bone scans if there is concern about symptoms affecting the bones 
• Ultrasound of lymph nodes to determine if cancer has spread locally

These investigations help determine the stage of the cancer, which is crucial for selecting the most appropriate treatment plan and understanding prognosis.

Stages of Triple Negative Breast Cancer

Triple negative breast cancer uses the same staging system as other breast cancers, but understanding the stage is especially important because treatment approaches may differ from hormone-positive or HER2-positive cancers. Staging describes how far the cancer has developed, whether lymph nodes are involved and whether the disease has spread beyond the breast.

Stage I (early stage)

The tumour is small and confined to the breast, with little or no lymph node involvement. Triple negative breast cancers at this stage are often treated with surgery followed by chemotherapy, as they respond well to systemic treatment.

Stage II (early to intermediate stage)

The tumour may be larger or have spread to a small number of nearby lymph nodes. Treatment usually involves a combination of chemotherapy, surgery and radiotherapy. Many triple negative breast cancers show a strong response to chemotherapy at this stage.

Stage III (locally advanced)

The cancer may involve the skin, chest wall or several lymph nodes in the armpit or around the breastbone. Although more advanced, triple negative breast cancer at this stage is still treatable. Treatment commonly begins with chemotherapy to shrink the tumour before surgery and radiotherapy.

Stage IV (metastatic)

The cancer has spread beyond the breast and nearby lymph nodes to other parts of the body, such as the bones, lungs or liver. Treatment focuses on controlling the disease, managing symptoms and supporting quality of life. Chemotherapy, immunotherapy and targeted approaches may be used depending on the individual case.

What Triple Negative Breast Cancer Treatments Aim to Do

Treatment aims depend on the size and stage of the cancer, its behaviour and the patient’s overall health. Common goals include:

• Removing the cancer completely when localised 
• Reducing tumour size so that surgery is possible 
• Lowering the risk of recurrence after surgery 
• Controlling the cancer if it has spread 
• Managing symptoms and improving quality of life

Patients may receive one type of treatment or a combination of therapies to achieve the best outcome.

Main Treatment Options for Triple Negative Breast Cancer

At NCCS, treatment plans are personalised and discussed by multidisciplinary teams to ensure coordinated care.

Chemotherapy

Chemotherapy is a key treatment for triple negative breast cancer. It may be given before surgery to shrink the tumour (neoadjuvant therapy) or after surgery to reduce the risk of recurrence (adjuvant therapy). Because triple negative tumours often respond well to chemotherapy, early treatment can be effective in improving long-term outcomes.

Surgery

Surgery removes the tumour and may involve breast-conserving surgery or mastectomy, depending on the size and location of the cancer. Lymph nodes in the armpit may also be removed or sampled to determine whether cancer has spread.

Radiation Therapy

Radiotherapy is commonly recommended after breast-conserving surgery and in selected cases after mastectomy. It helps reduce the risk of cancer returning in the breast or nearby lymph node areas.

Immunotherapy

Some patients with triple negative breast cancer may benefit from immunotherapy. This treatment boosts the body’s immune system to recognise and attack cancer cells. Immunotherapy is often combined with chemotherapy for certain stages of the disease, depending on tumour characteristics.

Clinical trials and emerging treatments

Because research in triple negative breast cancer is rapidly evolving, selected patients may be considered for clinical trials involving targeted therapies, novel drug combinations or advanced immunotherapies. Your care team will discuss suitability if appropriate.

What Patients Can Expect During Treatment

Throughout treatment, patients undergo regular reviews to monitor progress, assess side effects and adjust plans as needed. These reviews may include imaging, blood tests and physical examinations. Support may also include:

• Guidance on managing side effects such as fatigue or nausea 
• Nutritional advice to maintain strength and energy 
• Rehabilitation support if treatment affects physical function 
• Emotional and psychological support to help patients cope with stress, uncertainty or body image changes

Clear communication with the care team ensures concerns are addressed early and patients feel supported throughout their treatment journey.

Support at NCCS

NCCS provides comprehensive support for patients diagnosed with triple negative breast cancer. Care may include symptom management, survivorship guidance and long-term monitoring to watch for recurrence or late effects of treatment. Multidisciplinary teams work together to provide coordinated care, focusing on both medical and emotional wellbeing.

Patients are encouraged to take an active role in their health, ask questions and share any concerns with their care team. Education, counselling and practical advice are available to help patients manage treatment and recovery with confidence.

Guidance and Support

Understanding triple negative breast cancer helps patients feel more prepared as they navigate diagnosis and treatment. At NCCS, specialists are committed to providing clear explanations, personalised recommendations and ongoing support at every stage of care.

For more information about triple negative breast cancer or to discuss your treatment plan, please speak with your NCCS care team or visit www.nccs.com.sg.