Tests for Staging of Breast Cancer
Breast cancer like all cancers has a tendency to spread to other parts of the body. The tumor in the breast not only increases in size, but spreads through blood vessels and lymphatics.
Disease reaches the armpit through lymph vessels and these nodes can be felt as small marbles in the armpit. They can further spread to the neck of the lady. The disease that has entered the blood stream can reach the liver, lungs, bones and so on. The treatment of cancer is decided based on the stage of the disease and this varies from person to person. So, we do various imaging tests as mentioned below to know if the disease has spread to the organ of interest for the test. Modern test like PetCT can scan the whole body in on go, but it comes with certain limitations and hence sometimes our specialists add other tests to the PET CT Scan.
A word of caution is No test is absolute and the findings reported can be because of other causes and when the disease is early the tests may miss to pick up the disease.
Used to evaluate the extent of the tumour and detect metastasis (spread of cancer).
Imaging Tests
a. Mammography
- Assesses the primary tumour and checks for additional abnormalities in the breast.
b. Breast Ultrasound
- Determines whether a mass is solid (potentially cancerous) or fluid-filled (likely a cyst).
- Examines nearby lymph nodes.
d. Chest X-ray
- Checks for cancer spread to the lungs and can be avoided if a CT Scan of Chest is being done or a PET CT Scan is done.
e. Bone Scan
- Detects metastasis in bones, common sites for advanced breast cancer. This test can only address changes in the bones and the images can be mis leading if the patient has bone disease or inflammation from any cause. Hence doctors correlate the imaging findings with clinical history.
c. Breast MRI
- Provides detailed images to assess tumor size and evaluate both breasts.
- Useful for dense breast tissue or when mammography results are unclear.
- Often the test is done after ultrasound or Mammography to clarify the findings picked up in the initial tests.
f. CT Scan (Chest, Abdomen, Pelvis)
- Evaluates whether cancer has spread to the liver, lungs, or other organs. This is the preferred test if available and can be more sensitive than Chest Xray and ultrasound abdomen.
g. PET-CT Scan
- Combines PET and CT imaging to detect cancerous activity throughout the body. Hence it can be superior to CT Scan as it is a functional test as it can detect disease based on blood flow. This same feature can cause mis interpretation if the flow of blood in the target area is more due to other causes like infection. A high degree clinical correlation is required when interpreting medical imaging.
Staging of Breast Cancer:
TNM method of anatomical staging is the most common form of stage representation. The size of the primary tumor in the breast, lymph nodal involvement in the armpit and any distant disease identified by the above imaging methods is used to calculate staging. There are four stages of the disease and the last stage is where the disease becomes incurable.
Modern staging includes information from the Biological markers like ( ER, PR HER2neu) also into consideration.
The earlier the staging of the particular individual, the simpler would be the treatment, less number of treatment modalities need to be used apart from surgery ( like chemotherapy, radiotherapy, hormone therapy and immunotherapy). Further if the disease is detected at an earlier stage, the surgery would be less complicated and the need for removal of the entire breast ( mastectomy) would be less. Breast conservation using oncoplastic techniques would make impact on aesthetic aspects almost negligible. Lastly, the earlier the treatment for cancer starts, the higher is the success outcomes from cancer.
TNM Staging System
Using these test results, the cancer is staged based on the TNM system:
- T (Tumor): Size and extent of the primary tumor.
- N (Nodes): Involvement of nearby lymph nodes
- M (Metastasis): Presence of distant metastasis.
