Histological analysis of breast lesions involves the examination of tissue samples taken by the surgeon or radiologist. The analysis is done by a specially qualified anatomopathologist.
The anatomopathologist’s competence is a key element in all treatment decisions.
Breast cancer analysis results can appear full of complicated and overly coded terms that are difficult for the layperson to understand.
Here are the key points that a patient should try to retain and understand:
1-Know if a cancer is in situ or invasive.
- a cancer is in situ if it starts in the milk ducts (ductal carcinoma in situ) or the lobules (lobular carcinoma in situ) and in both cases the cancer is specific to the breast tissue without risk of spreading beyond the breast.
- a cancer is invasive when it has broken through the basal membrane of the ducts or lobules. Uncontrolled cell division forms a mass of cancerous cells that overflow the ducts or lobules and in certain cases risk spreading beyond the breast to the axillary lymph nodes (also known as axillary node metastasis) or even develop other organ metastases such as the bone, the lung, the liver...).
2-Know the characteristics of the tumour.
- The size of the tumour,
- The width of the margins: that is the distance between a tumor and the edge of the surrounding tissue that's removed along with it. In general a width of greater than 10 mm is considered necessary to be confident that all the cancerous cells have been removed.
- The histological type of the tumour: ductal or lobular.
- The histological prognostic grade: this indicates the degree of differentiation of the tumour and the capacity of cell division (the grades rise in seriousness from SBR1 to 2 and then 3 (SBR, Scarff-Bloom-Richardson system).
- the Ki-67 antibody score
- The hormone receptor status: expressed as a percentage of cells indicating the presence of oestrogen receptors (RE) or progesterone receptors (PR), which then indicates the level of sensitivity of the tumour to hormones
- Identification of clusters of HER 2 (or HER 2/NEU ErbB 2) in the cell membranes. ErbB2 is proto-oncogene whose over-expression is detected in the laboratory and when present is given a positive mark
All these elements contribute to an appropriate treatment plan which can encompass:
an indication of need for further surgery,
some hormone treatment,
possibly chemotherapy treatment,
focused therapies such as Trastuzumab (or Herceptin®) which interferes with HER 2
Any treatment decision made is done so within an ICM framework comprising all the relevant fields of the highest level; surgeons, radiologists, pathologists, and oncologists.