I am seeing studies with five year results showing BCR-free percentages of over 97 percent for low-risk men, and 94 percent for intermediate-risk men, who had either SBRT or Proton Therapy (PBT).
Those are amazing results, above (far, far above?) what has been reported for RP.
And, I hear of few, if any side effects from men who had SBRT or HDR-BT, and NONE from men who had PBT.
Yeah, sounds incredible to me also, but both studies and real people on forums are stating it.
The debate and the progress goes forward. All new patients can benefit.
The BCR-free percentages for SBRT are neither "amazing", "far far above" or "incredible". The D'Amico classification of low and intermediate risk are based on clinical stage i.e. biopsy, MRI, guess work etc. In surgery, roughly 30% of these clinical stage low and intermediate risk patients have adverse pathology i.e., ECE, Gleason > 7, surgical margins etc when the pathologist examines the dissected prostate. Patients with adverse pathology have a much higher risk of BCR and may need radiation anyway. The simple conclusion is that based on current technology we are misclassifying patients at the clinical stage. With future genomic testing, better MRI etc, the classification technology will get better and fewer misdiagnosed high risk patients will undergo surgery. But this doesn't answer the difference in 5-yr BCR rates because the studies of SBRT patients were also based on D'Amico classification.
Misdiagnosed surgery patients with adverse pathology have a high probability of BCR and the option of radiation, which theoretically gives them the same chance of not dying from Prostate Cancer as the SBRT patients, albeit with significantly more side effects. The definition of BCR for a surgery patient (e.g., PSA of > 0.2) is different from a SBRT patient, and most undergo radiation only on BCR, Pratoman not withstanding
. Due to these differences, the 5-yr BCR stats for surgery patients are inflated relative to SBRT while their survival rates are not different since most surgery patients with adverse pathology will eventually have radiation after BCR. I hope I've made it clear that comparing 5-year BCR rates for SBRT vs surgery makes zero sense.
Why not do SBRT since survival rates are the same and side effects lower? Don't forget the lucky 80% of surgery patients who didn't have BCR for 5 years. They escaped radiation and almost all conquer bothersome incontinence, while there are no additional urinary or rectal side effects, that sometimes happen during radiation. Erectile Dysfunction rates for surgery are pretty high but the older patients all have rapidly declining potency anyway. Some studies show 25% of AS patients will have ED a few years after PC diagnosis because of naturally worsening potency.
When I say "escaped radiation", its not to say that SBRT is definitively bad for you, but many people don't want any form of radiation and SBRT hasn't been around long enough for us to be sure. The distaste by some from radiation come perhaps from the fact that Brachytherapy and IMRT do have their share of unpleasant side effects or perhaps worry (justified or not) about
other cancers from radiation.
Perhaps SBRT will yet turn out to be a miracle in terms of effectiveness without side effects, but the jury is still out on that one and from what I have read, the definitive studies won't be out until 2022. But it should be made clear that the key advantage for SBRT is the minimal side effects vs current standards of radiation and surgery. It's definitely NOT that SBRT is better at preventing the low and intermediate risk PC patients from dying from Prostate Cancer. The reason for the lower 5-year BCR rates in surgery patients vs SBRT is simply the fact that the pool of D'Amico classified low and intermediate risk surgery patients includes those who will eventually be cured by radiation.