Tumor Grading

Tumor grade refers to a measure of how abnormal cells from your tumor appear under the microscope. This can refer to the appearance of the cells or to the percentage that appear to be dividing. The higher the grade, the more aggressive and fast growing the cancer. Tumors are typically classified from least to most aggressive as grade I through IV.

The grade is much more important for some kinds of cancers than for others. For most kinds, it is a somewhat secondary factor, but for a few kinds of cancers, notably certain brain tumors, prostate cancer, and lymphomas, it is extremely important. Again your doctor will know how your tumor was graded and how important it is to your type of cancer. The grading will also be found on the pathology report from your biopsy or surgery.

The results of specific molecular tests on your cancer cells may play a significant role in determining treatment and prognosis. For example, breast cancer is often treated differently depending on whether the cancer cells are found to be Estrogen Receptor Positive (ER+) or Negative (ER-). ER+ cells have receptors for estrogen on their surface, and their growth often requires the presence of estrogen. ER+ tumors are more affected by hormonal treatment and tend to be less aggressive.