Diagnosis of breast cancer is consists of three main aspects, called as the 'triple test'. The aims of these investigations are as follows:
Clinical Examination: Clinical Examination by an experienced medical professional is the first step of assessment. Palpation of the tumour in the breast will give a reasonably good idea whether we are dealing with a cancer or not. If there is even a slightest doubt of cancer, it must be investigated further as is mentioned below.
Mammography: 'Mammoography' are special X rays of the breast. Mammography of both the breasts is mandatory. Mammography will give more details about the tumour in the breast, and in more than 85% to 90% of cases, features on mammography will point towards a breast cancer. But the use of mammography is not only limited to this, it is important to see whether the rest of the affected breast is normal, and whether the other breast is normal. There are some typical features of cancer on a mammogram (microcalcification, architectural distortion etc.). If such features are not limited to the involved area only and if they are present in the quadrant different to the quadrant bearing the tumour, or thorughtout the breast; it may indicate a 'multicentric' breast cancer, and breast conservation surgery cannot be done in such cases.
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. 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 may 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.
Thus, after clinical examination, the surgical oncologist will assess first, whether he is going to go ahead with surgery first, or is the patient likely to need a chemotherapy first?
If he plans to operate first, he will do a mammography and then he will perform an FNAC, and after confirming diagnosis, go ahead with a breast conserving surgery or mastectomy, depending on mammography findings.
If he plans chemotherapy first, he will do a core biopsy, send the specimen for histopathology and receptors, and after confirming diagnosis, start chemotherapy.