How is the stage decided
from the Histo Pathology Report?
The one report which determines everything! The single most important document in the journey of breast cancer - The Histo Pathology Report. After surgery, the tumour and the nodes which were removed, are sent for examination to the pathology lab (People commonly refer to this as 'biopsy') and the report which the lab prepares after studying the tumour and the lymph nodes is called the Histo Pathology Report. This report determines the Final Stage of cancer for the patient. And according to this stage, and all the features written in the report, the decisions on further treatment - Chemotherapy, Radiation Therapy, Targeted Therapy, Hormonal (Endocrine) therapy, are taken.
How does a Pathologist write the histopathology report?
The 'specimen' of surgery (all that was removed in surgery - the breast or the tumour, along with the nodes) reaches the pathologist in a preservative solution. The Pathologist performs the assessment in three steps:
1. Gross Examination: The Pathologist first examines the specimen with 'naked eyes'. He notes the 'size' of the tumour, checks if there is a single tumour or multiple tumours, whether tumour is close to the skin / nipple / base etc. He will slice the breast tissue in detail to check for smaller tumours and other nearby breast tissue. He then checks the arm pit tissue, finds out all the lymph nodes from the fat, and see how those nodes are looking - how many nodes are there, are they looking enlarged in size, are they stuck to each other? etc.
2. Microscopic Examination: The Pathologist prepares 'slides' from all the above tissues - the tumour, the nodes, the normal breast tissue and then studies those slides under microscope. Under microscope, one can see 'typical' cancer cells. The Pathologist examines all the slides in detail. We will definitely see cancer cells in the slides from tumour. In the slides from nodes, if we see those same cancer cells, it means the cells had 'travelled' from tumour in the breast to that lymph node in the arm pit. The more the number of nodes which show cancer cells, the higher the stage.
3. Immuno Histochemistry and other special tests: Breast cancer is of several different types. And each type has its own treatment protocols and also has similar outcomes within a type. So, for further planning, we need to know the type of Breast Cancer. This is known by certain tests called Immuno Histo Chemistry (IHC)
So finally, we get to know a lot of details about the tumour, the surrounding breast, whether the tumour was actively spreading or not, the nodes and other information and from that, we finally denote which stage it is. The staging is laid down by AJCC (American Joint Committee on Cancer) along with UICC (Union Internationale Contre Cancer), the latest is the 8th Edition. A good explanation about staging is given on the - Cancer.org Website.
It would be too vast and distracting to write in detail about the stage determination here. So I have focussed only on explanation of certain important points in the report. Please leave the staging part for your Oncologist. When it comes to 'pathologic' staging, we focus on three things in the report, each of which is discussed below:
The Tumour: This is denoted by 'T'.
The Lymph Nodes: This is denoted by 'N'.
The Type of Cancer: This is determined by IHC.
After reading the report, we assign a number (1 to 4) to 'T' and one number (1 to 3) to 'N' - for example, T2N1, or maybe T3N0, which will gives us the final pathological stage. This is only for a rough understanding. A request to please do not try to stage the report on your known, as the latest staging according to AJCC 8th Ed. is very complex, and I have not added all the points needed for staging here since discussing all that is beyond the scope here.