DIAGNOSIS OF BREAST CANCER: CORE BIOPSY
WHat does 'Tissue diagnosis' mean?
Tissue Diagnosis: Tissue diagnosis means establishing the presence of cancer by observing the involved tissue under microscope. This is the single most important investigation (for any cancer, for that matter) and is a must before any form of treatment can be carried out.
How is tissue diagnosis achieved?
Tissue diagnosis can be achieved by the following means:
FNAC (Fine needle Aspiration Cytology): In this procedure, a fine needle attached to a syringe is inserted into the tumour, and moved in and out multiple times (multi pass), and while the in out movement is done, aspiration by the syringe is continued. This will result in some cells from the tumour coming into the needle, due to 'suction' action of the syringe. Immediately, the material is collected on a slide and 'fixed', and then the slide is viewed under the microscope. By observing the features of the aspirated cells under the microscope, we can establish the diagnosis of cancer in most cases.
On clinical examination, if the tumour is not locally advanced and if we are contemplating surgery as the first form of treatment , FNAC can be done for diagnosis.
Core Biopsy: In this procedure, a special instrument, called as the 'core biopsy gun' is used. The skin over the tumour area is infiltrated with a local anesthetic, a small nick is taken, and the needle is inserted into the tumour and the gun is fired. This will give us linear bits of tissues from the tumour. The advantage of this method is, we are deriving a proper tissue of the tumour, and so apart from histopathology, other tests to espitmate the hormonal receptor status and HER2 receptor stauts can also be done on this. Hence, for any form of breast cancer, where we intend to give chemotherapy first, a core biopsy is compulsory, since in many patients, the tumour may completely disappear after chemotherapy, and then we will not have any tumour to assess for other details. This implies that for large operable cancers where we intend to give chemotherapy first, for locally advanced cancer,s and for metastatic breast cancers, core biopsy has to be done first. Also, in some cases of operable breast cancer, an FNAC may be equivocal, and may not achieve diagnosis. In such cases too, a core biopsy is indicated.
Open biopsy: In open biopsy, the patient is anesthetised in the operating room, and a formal surgery is done, where tumour is excised completely and sent for histopathology. This is rarely, if ever, needed today.