Invasive Cancer Grading - Making The Diagnosis: Breast Cancer

Content provided by the Faculty of the Harvard Medical School

Invasive cancer grading

The pathologist grades invasive breast cancer cells based on their appearance during a laboratory examination in which the cells are examined under a microscope. This determination can indicate how aggressive a cancer may be.

The histologic grading system (sometimes called the Elston-Ellis modification of the Scarff-Bloom-Richardson grading system) takes into account the arrangement of cells in relation to one another as well as the features of individual cells. The system assesses the appearance of cancer cells as compared to normal cells.

The cells are given a certain number of points on a scale based on their characteristics and then graded accordingly. If the cells are recognizable because they look a lot like the cells of the tissue in which they originated, they're called "well differentiated" (usually Grade I). If they no longer resemble breast cells, they're said to be "poorly differentiated" and have a higher grade (usually Grade III). Generally, the higher the grade, the more aggressive the cancer.

Lymphatic-vessel invasion

Another part of the pathologist's evaluation determines whether the cancer has invaded any blood or lymphatic vessels. This is a particularly important characteristic in helping determine the likelihood of whether the cancer has spread or metastasized. Cancer cells can leave the breast (egress) by traveling inside the linings of small lymphatic channels or blood vessels. The pathologist will determine whether this has happened. Some experts feel that if there is the presence of cancer cells within the the channel (lumen) of a blood vessel or lymphatic channel, there is a greater chance that cancer spread may have occurred. This spread may occur to lymph nodes or to the liver, bones, lungs or brain.

Last updated:	April 23, 2007