Your gleason score is made up of two numbers, the first is the majority of cancer cell grade in the sample, the second, is the lesser grade, if different, or in your case, it can be the same.
Yes, as the cancer grows and if it becomes more agressive, it would increase the gleason score. The cancer cells are rated from 1 to 5, 5 being the most agressive, 4's being moderately agressive.
There are still a lot of other variables and factors, of course, we are talking about PC, lol. Nothing is easy. There are men that are gleason 6, and in their lifetime, it never gets higher. And there are other men, who start out low, and over time they become more and more agressive.
Hope this helps. A good book on prostate cancer would explain it much better than I can, but that's the general gist.
David in SC
Age: 57, 56 dx, PSA: 7/07 5.8, 7/08 12.3, 9/08 14.5, 10/08 16.3
3rd Biopsy: 9/08 - 7/7 Positive, 40-90% Cancer, Gleason 4+3
Open RP: 11/08, Rht nerves saved, 4 days in hospt, on catheters for 63 days, 5th one out 1/09
Path Rpt: Gleason 3+4, pT2c, 42g, 20%, Contained in capsule, 1 pos margin
2009 PSA: 2/09 .05,5/09 .1, 6/09 .11. 8/09 .16
Latest: 7/09 met 2 rad. oncl, 7/09 cath #6 - blockage, 8/09 2nd corr surgery, 8/9 cath #7 - out after 38 days