Definitions for "Gleason Grade"
The most often used prostate cancer grading system is called the Gleason system. This system assigns a Gleason grade ranging from 1-5. The grade is based on how closely the arrangement of cancer cells resembles normal cells in a healthy gland. Because prostate cancers often have areas within them of different grades, a grade is assigned to the two areas that make up most of the cancer. These two grades are added together to give a Gleason score between 2 and 10. Tumors graded Gleason score 5-6 behave only slightly worse than tumors with sores of 2-4, but significantly better than tumors graded score 7.
a widely used method for classifying prostate cancer tissue for the degree of loss of the normal glandular architecture (size, shape and differentiation of glands); a grade from 1–5 is assigned successively to each the two most predominant tissue patterns present in the examined tissue sample and are added together to produce the Gleason score; high numbers indicate poor differentiation and therefore more aggressive cancer.
A number from 1 to 5 indicating how different a sample of prostate tissue looks when compared to normal prostate tissue.