Pathology
The pathology report describes the tumour (e.g. size, grade, lymph node and hormone receptor status) and is used to determine treatment.
Description of terms
Macro (gross) description: A description and measurement of the specimen as seen without a microscope.
Micro (microscopic) description: A description and measurement of the specimen when viewed under a microscope.
The description will include the following:
Type of breast cancer: Whether the breast cancer is invasive (classified as ductal, lobular, or a special type) or in-situ (classified as ductal carcinoma in-situ/DCIS).
Tumour size: Expressed in millimetres.
Number of tumours in the breast: If there is more than one tumour in the breast, it will be either multi-focal (confined to one-quarter of the breast) or multicentric (in different quarters of the breast).
Grade of the tumour: This describes how abnormal the cells are and how rapidly they are dividing. The grades are as follows:
- Grade 1 – low grade, well differentiated, slow growing
- Grade 2 – intermediate grade, moderately differentiated, faster growing
- Grade 3 – high grade, poorly differentiated/undifferentiated, fast growing.
DCIS is classified separately as low, intermediate or high grade.
Lymph node status: This describes how many lymph nodes were removed during surgery, and whether any contained cancer cells.
Hormone receptor status: Cancer cells with hormone or HER2 receptors receive growth signals from these hormones. A positive receptor status for any of these hormones indicate that endocrine or anti-HER2 therapy may be effective to block hormonal signals for cancer cell growth. Hormone receptor status may change over time, so any recurrences of breast cancer will be retested.
- Oestrogen and progesterone receptor (ER and PR) status: Oestrogen or progesterone-positive (ER+ or PR+) breast cancer is likely to respond to endocrine therapy that blocks these hormones.
- HER2 receptor status: HER2-positive (HER2+) breast cancer has an aggressive growth pattern and a higher risk of recurrence compared to HER2- cancers. Early HER2+ cancer is treated with the antibody treatment Herceptin.
Lymphovascular/vascular space invasion: The presence of lymphovascular invasion indicates that cancer cells were found in blood or lymphatic vessels surrounding the tumour.
Surgical margins: These are reported as:
- negative (margins surrounding the surgical specimen are clear of cancer cells)
- close (cancer cells are close to the edge(s) of the specimen)
- positive (cancer cells present at edge(s) of specimen).
