Specialist Pathologists from Concord Hospital Pathology Department, Healthscope Pathology and Douglass Hanly Pathology provide a comprehensive pathology and cytology service for patients attending the Strathfield Breast Centre. This service is provided by means of written reports and also by attendance at weekly Multidisciplinary Team Meetings. The aim of the Pathologist is to provide information to the Multidisciplinary Team that will assist in providing treatment that is tailored specifically to the individual patient.
An important step in the evaluation of patients with a breast lesion is fine needle aspiration biopsy (FNAB) or core needle biopsy (CNB). These techniques may be used to diagnose both benign and cancerous lesions in the breast. A sample of breast tissue is provided to the Pathologist so that any abnormality can be diagnosed and if necessary a treatment plan discussed with the Surgeon. If the diagnosis is breast cancer then it is likely that wide local excision or mastectomy will be performed with or without lymph node sampling, so that all the features of the cancer can be assessed by the Pathologist. There are many subtypes of breast cancer and it is not just one disease. Correctly categorizing the cancer of each patient is important so that the best treatment can be given. The Pathologist will examine the cancer microscopically to evaluate features that are of ‘prognostic’ importance such as the size and grade of the cancer as well as information concerning possible spread of the cancer cells to local lymph nodes in the armpit. In addition there are features of the cancer that the Pathologist assesses and that are used to determine any further treatment. These ‘predictive’ factors include the presence of oestrogen and progesterone receptors (ER and PR)on the cancer cells. When these are present there is likelihood that the growth of any remaining cancer cells in the patient may be controlled by endocrine therapy. Some breast cancer cells may overexpress HER2 a receptor that is on the surface of the cells and that is associated with a poor prognosis. Patients with this form of cancer would be considered for specific anti-HER2 therapy.
Newer classifications of the different subtypes of breast cancer have been proposed that employ analysis of the genes that control the growth of individual cancer cells. The main breast cancer subtypes identified in this way are called luminal A, luminal B, HER2-enriched and basal-like. These subtypes have been shown to be prognostically significant and their use may also help us to provide more specific treatment targeted to the individual patient; so called “targeted therapy”. Other tests examining the genes that are found in breast cancer cells are also available. Two of these are Mammaprint and Oncotype DX and they can be used to divide patients into various prognostic groups thereby assisting in making an informed decision on chemotherapy choices. So far the gene tests providing this information are available only in specialist laboratories and breast cancer samples may have to be sent to specific laboratories in centres most of which are in the USA. However the Pathologist reporting on any breast cancer can apply a “surrogate” set of tests to the cancer sample that simulates the gene testing and using the combination of the 4 markers ER,PR, HER2 and Ki-67. The latter is a measure of the growth of the cancer cells.