What is grading of cancer?

After the determination is made as to the type of cancer, the cancer is graded – a measurement of how aggressive the tumor is. Most cancer cells are graded by how much they look like normal cells. Grading is done in the lab using cancer cells taken during biopsy.

Cancers are usually graded from low to high. Low-grade cancers look more like normal tissue under the microscope. High-grade tumors look very abnormal and are generally more aggressive with a poor outcome.

Source:  Univ. of Kansas Cancer Center