Sorry to hear of your cancer, but you are in a good place here on this blog to receive our collective advice and recommendations ("qualified" of course) on what our experiences were. To that end, I haven't written this in several months, but here is what I discovered/realized after I went with my urologist's recommendation for the DaVinci single-incision, robotic assisted radical prostatectomy:
The Gleason score is just the "tip of the iceberg" called prostate cancer. I too was a Gleason 3 + 4 = 7 with perineural invasion. That is "all" that can usually be accurately observed with biopsy slides. When I asked about Active Surveillance and radiation, my urologist was adamant saying "I never do Active Surveillance...it just gives your cancer two or so years to slowly grow and get worse...it will NOT go away...YOU HAVE CANCER." As for radiation, he said "you never want to do radiation "before" surgery because radiation fries your prostate, turning it into a little walnut size chunk of concrete that is nearly impossible to remove surgically thereafter." So...he flatly told me: "I am taking your prostate." It was a very firm statement. So...
I AM GLAD I HAD THE SURGERY. The hidden, unseen, larger part of that "iceberg" is all of the other pathology - often ominous - that a biopsy can't tell you. I had Extraprostatic Extension ("EPE") where the tumor breaks through the membranous capsule that surrounds and encases the prostate. My cancer spread into my left seminal vesicle (cells, no nodule or tumor, fortunately). Even during the surgery, the urologist can't clearly see "where" the tumor has spread once it breaks through the capsule...he is trying to take as much as he can. That is why they routinely remove both seminal vesicles, and sometimes the local lymph nodes.
Because I had EPE, I was one of the unlucky 10% that had "Surgical Margins", meaning the pathologist identified cancer tissue right up to the edge of what he was given, meaning that some cancer was left in my body. It is not a simple surgery like a skin cancer, where the urologist can rush a sample (the whole prostate) to pathology to have a frozen section done to see if there are those margins. With skin cancer, they phone the surgeon and say "take more surrounding tissue out." You can't do that with a prostatectomy. The urologist just hopes he got all of the cancer.
So, all of that and more can be part of your post-RP surgical pathology report. My urologist was initially thrilled with my biopsy saying "we caught the cancer early." I only had <10% of cells that were graded "4". I was almost a Gleason 3 + 3 =6. When he got my surgical pathology report, my urologist was quite solemn...humbled...saying: "It seems that your cancer is worse and more aggressive than I thought."
Had I done Active Surveillance for two years, my PSA would have likely soared and the cancer would have spread more aggressively into both seminal vesicles and beyond...exactly why my urologist never does Active Surveillance. I would be in a much worse situation. So...bottom line:
I personally recommend having the radical prostatectomy because you don't really know for sure how bad your cancer really is based on just the biopsy. BTW - what percentage of grade "4" cells did you have? Again, I had the lowest you can have at <10%, but my cancer was far worse than the Gleason 3 + 4 = 7 with the <10% would have indicated. Good luck to you.