If you or your doctor have noticed a breast change — a lump, a skin change, a new nipple symptom, or an abnormality picked up on a screening mammogram — the next step is a structured diagnostic process to determine what is causing it.

Being referred for breast cancer investigations can feel alarming, but it is important to know that the majority of breast abnormalities turn out to be benign. The purpose of the diagnostic process is to establish the cause clearly and definitively so that, whatever the result, you and your specialist can plan the right next steps with confidence.

At Breast & Surgical Oncology at The Poche Centre, our specialist breast surgeons guide patients through every stage of the diagnostic process — explaining what each test involves, what it can tell us, and what the results mean for your care.

The Triple Assessment — The Gold Standard for Breast Diagnosis

Breast cancer diagnosis follows a structured three-part process known as triple assessment. The combination of all three components — clinical examination, imaging, and pathology — provides the most accurate and complete picture of what is happening in the breast. No single test alone is sufficient for a definitive diagnosis.

Step 1 — Clinical History and Breast Examination

The first step is a detailed consultation with your specialist. Your surgeon will ask about:

• When you first noticed the change and whether it has changed over time
• Associated symptoms such as pain, nipple discharge, or skin changes
• Your menstrual history and menopausal status
• Any relevant medications, including hormonal contraceptives or HRT
• Your personal history of breast conditions or previous biopsies
• Your family history of breast, ovarian, or other cancers

This is followed by a thorough physical examination of both breasts, the nipple and areola, the axillary lymph nodes (under each arm), and the supraclavicular lymph nodes (above the collarbone). Examination helps characterise the nature of any lump or change — its size, consistency, mobility, and relationship to surrounding structures — and identifies any associated lymph node involvement.

Clinical examination alone cannot diagnose breast cancer, but it is an essential component that directs what imaging and investigations are required next.

Step 2 — Breast Imaging

Breast imaging is used to characterise an area of concern in more detail — to determine whether a lump is solid or fluid-filled, whether its features appear benign or suspicious, how large it is, and whether there are other areas of abnormality in the breast. The imaging modalities used depend on your age, breast density, and the nature of the concern.

Mammography

A mammogram is an X-ray of the breast and is the primary screening and diagnostic imaging tool for breast cancer. It uses low-dose X-ray to produce detailed images of the breast tissue that can detect abnormalities, including masses, microcalcifications (tiny calcium deposits that can be an early sign of cancer), and areas of architectural distortion.

Mammography is recommended as the first-line imaging for women over 40. Results are reported using a standardised classification system (BI-RADS) that guides the need for further investigation. Some cancers — particularly those in women with dense breast tissue — can be difficult to see on mammogram alone, which is why ultrasound is frequently used alongside it.

Women aged 50–74 in Australia are eligible for free two-yearly mammograms through BreastScreen Australia. If you are outside this age range or have symptoms, a diagnostic mammogram can be arranged through your GP or specialist referral.

Breast Ultrasound

Ultrasound uses high-frequency sound waves to produce real-time images of the breast tissue and is particularly valuable for distinguishing between solid masses and fluid-filled cysts, and for imaging younger women or those with dense breast tissue where mammogram alone may be insufficient.

Ultrasound is also used to guide biopsy procedures, allowing the radiologist or surgeon to precisely target an area of concern. It is painless, does not use radiation, and can be performed quickly in the outpatient setting.

Breast MRI (Magnetic Resonance Imaging)

Breast MRI uses a strong magnetic field and contrast dye to produce highly detailed images of the breast. It is more sensitive than mammogram or ultrasound for detecting certain breast cancers, particularly in women with dense breast tissue, those with a high genetic risk, or those with implants.

MRI is not used routinely for every patient but is recommended in specific situations, including assessing the extent of a known cancer before surgery, evaluating the opposite breast, investigating a suspected cancer where other imaging is inconclusive, or screening high-risk women annually.

Contrast-Enhanced Mammography (CEM)

Contrast-enhanced mammography is a newer imaging technique that combines standard mammography with an intravenous contrast injection, providing enhanced visualisation of areas with increased blood flow — a feature of many cancers. It offers improved sensitivity compared to standard mammogram and can be a useful alternative to MRI in certain situations.

Step 3 — Biopsy and Pathological Analysis

Imaging can indicate whether an abnormality looks suspicious, but it cannot provide a definitive diagnosis. Only a tissue sample — obtained through biopsy and examined by a pathologist under the microscope — can confirm or exclude breast cancer with certainty.

Core Biopsy

Core biopsy is the preferred and most informative method of breast tissue sampling. A small hollow needle is used to remove several cylindrical cores of tissue from the area of concern, under local anaesthetic and guided by ultrasound or mammographic imaging. The procedure takes around 20–30 minutes and is performed in the outpatient or radiology setting — no general anaesthetic or hospital admission is required.

The tissue samples are sent to a pathology laboratory where a specialist pathologist examines the cells. Core biopsy not only confirms whether cancer is present, but also provides critical information about the cancer's characteristics — including its grade (how aggressive it appears), its type (ductal, lobular, etc.), and its receptor status (see below). This information is essential for planning treatment.

After a core biopsy, a small titanium clip is often placed at the biopsy site to mark its location for future reference, particularly important if neoadjuvant (pre-surgery) treatment is planned.

Fine Needle Aspiration Cytology (FNAC)

Fine needle aspiration uses a thin needle to collect a small sample of cells from a lump or lymph node. It is less invasive than core biopsy and can provide a rapid result, making it useful in specific situations — particularly for assessing lymph nodes. However, FNAC provides cells rather than tissue, which means it gives less information about the cancer's characteristics than core biopsy. For this reason, core biopsy is always preferred for diagnosing breast lumps when possible.

Surgical (Excision) Biopsy

In rare cases where a diagnosis cannot be established through image-guided biopsy, a surgical biopsy — removing part or all of the abnormality under general anaesthetic — may be required. This is now less common due to the accuracy and availability of image-guided core biopsy.

What the Pathology Report Tells Us

When a core biopsy confirms breast cancer, the pathology report provides far more than just a yes or no answer. It is a detailed document that characterises the cancer and directly informs treatment planning. Key information includes:

Tumour type — whether the cancer is ductal, lobular, or another type, and whether it is invasive or in situ (contained within the ducts).

Tumour grade — graded 1 (low grade, slow-growing) to 3 (high grade, faster-growing), reflecting how different the cancer cells look from normal cells under the microscope.

Hormone receptor status — whether the cancer cells have receptors for oestrogen (ER) and/or progesterone (PR). Receptor-positive cancers are driven by these hormones and respond to hormonal (endocrine) therapies.

HER2 status — whether the cancer over-expresses the HER2 protein. HER2-positive cancers are more aggressive but respond well to targeted therapies such as trastuzumab (Herceptin).

Ki-67 — a measure of how rapidly the cancer cells are dividing, giving additional information about the tumour's proliferative activity.

Margins — once surgery has been performed, the pathology report on the surgical specimen will indicate whether the cancer has been completely removed with clear margins around it.

This receptor and molecular information, combined with imaging findings and clinical factors, forms the basis of all treatment decisions.

Genomic Testing — Beyond Traditional Pathology

For certain breast cancers — particularly early-stage, hormone receptor-positive, HER2-negative cancers — genomic testing of the tumour tissue can provide additional information that goes beyond what standard pathology can tell us.

Tests such as Oncotype DX and Prosigna analyse the activity of multiple genes within the tumour to predict the likelihood of recurrence and help determine whether chemotherapy is likely to add meaningful benefit for a specific patient. This means some patients who might previously have been recommended chemotherapy can safely avoid it — and others can be more confidently directed toward treatment that will genuinely help them.

Our team incorporates genomic testing into treatment planning where it is clinically appropriate, reflecting our commitment to personalised, evidence-based care.

Staging Breast Cancer

Once breast cancer is confirmed, staging investigations are arranged to determine the extent of the disease — whether it is localised to the breast and lymph nodes, or has spread (metastasised) to other parts of the body. Staging guides treatment planning and provides important prognostic information.

Staging investigations typically include a CT scan of the chest, abdomen, and pelvis, and a bone scan. A PET scan may be recommended in certain situations. These tests are usually only performed when there is a meaningful likelihood of spread — early-stage breast cancers in otherwise well patients do not routinely require staging scans.

Breast cancer is staged from 0 to IV:

Stage 0 — non-invasive cancer (DCIS) confined within the milk ducts, with no spread into surrounding tissue.

Stage I — a small invasive tumour (under 20mm) that has not spread to the lymph nodes, or with only microscopic lymph node involvement.

Stage II — either a tumour up to 50mm with spread to a small number of axillary lymph nodes, or a larger tumour without lymph node involvement.

Stage III — locally advanced cancer, where the tumour has spread to multiple lymph nodes, to the chest wall or skin, or where the disease is extensive in the axilla. Stage III breast cancer has not spread to distant organs.

Stage IV (metastatic) — cancer that has spread beyond the breast and regional lymph nodes to distant sites, most commonly the bones, lungs, liver, or brain.

Staging also takes into account tumour grade, receptor status, and genomic factors — reflecting the modern understanding that breast cancer prognosis is determined by much more than tumour size and lymph node status alone.

What Happens After Diagnosis?

If a diagnosis of breast cancer is confirmed, you will have an appointment with your specialist to discuss the results in full and begin planning your treatment. At Breast & Surgical Oncology at The Poche Centre, your case will be reviewed at a multidisciplinary team (MDT) meeting attended by breast surgeons, medical oncologists, radiation oncologists, radiologists, and pathologists — ensuring your treatment plan reflects the expertise of the full team.

We understand that waiting for results and navigating the diagnostic process can be an anxious and overwhelming time. Our team is here to support you at every step — to explain what each test means, to answer your questions honestly, and to make sure you feel informed and in control of what comes next.