A 62-year-old man presents to the OPD for an annual physical examination. After noting a PSA level of 12.3 ng/dL, you refer him to an urologist for fuher workup. Following a prostatic biopsy, the results show the presence of adenocarcinoma of the prostate, which is given a Gleason score of 8. The Gleason score is a measurement of:

Gleason grading system: Developed to provide a measurement of the potential for prostate cancer to grow and spread Prostate biopsies involve sampling of tissue from several different areas of the gland (normally at least six). Two samples that appear to be most heavily involved, then histologically graded on a scale from 1 to 5 numbers are combined to give a Gleason score of 2 to 10 Tumors graded from 2 to 4- Slow growing Tumors graded 5 to 6- Intermediate Tumour graded 7 to 10 considered highly aggressive. Gleason score has nothing to do with the: stage (extent) of the cancer, expression of prostate specific antigen estimated survival time.