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Breast cancer is diagnosed through the triple test. This involves a discussion of the patient’s medical history/clinical breast exam, followed imaging and biopsy. It is positive if the result of any of its components is suspicious, indeterminate or malignant. Further investigation is required when one result is different from the others. Only when all three results are negative can breast cancer be ruled out accurately.
Medical history and clinical breast exam
A medical professional will discuss medical and personal history with patients, such as breast cancers, family history, medication and treatment history. Clinical breast examination (CBE) should also take place.
Imaging
Imaging may take the form of the following:
Diagnostic mammogram and ultrasound
A diagnostic mammogram is the same as screening mammogram, but takes extra views of the breast. Patients under 35 will have an ultrasound performed first, followed by a diagnostic mammogram if an abnormality is found. Tomosynthesis (3D mammography) can be used in conjunction with standard mammograms, but this technology is not yet available in all centres.
MRI
This is often used to evaluate the true size and extent of cancers that are hard to see on mammograms. It is also used in the following scenarios:
- Evaluating lobular cancer, to ensure the cancer is confined to one breast
- Evaluating breast density in younger women
- Viewing lesions that can be felt but aren’t seen on other imaging
- When breast cancer cells have been found in the axillary lymph nodes but no tumour can be seen in the breast on other imaging.
Breast MRI may not be available outside of the main treatment centres.
Biopsy
Biopsies are used to diagnose an area of abnormality. It may be necessary for patients to undergo more than one procedure. Biopsies may be performed at the clinic or radiology rooms, or as part of surgery, depending on the biopsy required.
Fine needle aspiration (FNA)
This method, where a fine needle is inserted into the breast guided by an ultrasound, can identify cancer but not the specific type of cancer. It isn’t able to identify DCIS. Fine needle aspiration can be performed at the doctor’s clinic.
Core biopsy
This biopsy is performed at the breast clinic or radiology rooms, where a device with a spring-loaded hollow needle removes ‘cores’ of tissues from a specimen under ultrasound guidance. The procedure is performed using local anaesthetic. This is the most commonly used technique, as it provides a tissue diagnosis, distinguishes between invasive and pre-invasive cancer and provides information about tumour grade and receptors.
Stereotactic core biopsy
This is used when an abnormality is detected on an ultrasound but cannot be felt during CBE or located on ultrasound (e.g. breast calcifications). The procedure takes place in a radiology clinic, where the breast is compressed in the mammogram machine in order to locate the abnormality. Local anaesthetic is used to numb the breast. Once the area is identified, a biopsy is taken. The specimen is x-rayed to ensure the correct tissue has been collected before it is sent to the laboratory.
Wire localisation biopsy
This is used when an abnormality in the breast needs to be removed, but it can’t be felt by the surgeon or it is too small to take a biopsy in the clinic. A hookwire is used to guide the surgeon to the correct area. The procedure is done using local anaesthetic, where a wire is inserted into the area of concern using mammogram or ultrasound guidance. This is typically done either the day before or the day of surgery, and is likely to be performed at a breast clinic in a main centre.
Excision biopsy
An open surgical biopsy may need to be performed if a conclusive diagnosis cannot be made using the other methods. The procedure is typically performed in a ‘day stay’ hospital, where the abnormality is surgically removed and sent to the laboratory for analysis.
After a biopsy has been completed, a titanium marker clip may be placed in the breast. This enables the exact area to be identified on future imaging or if future surgeries are needed. Adverse reactions are rare.
