Paperman,
You are correct that this is quite a journey and you have now peaked in the door to where the anxiety level can be very high. As the other guys have stated, a PSA of 6 is no assurance of Pca but the level of rise and speed does cause concern. If you do get to be a member here (hopefully not) there will be alot of research for you to do to figure out who, what, where, etc. regading the situation. Save that for later.
Now, regarding your sore buns, this would be the first that I have heard of anything remotely like that connected to Pca. Since the tenderness is south of the border so to speak you may have associated it with Pca. Such worry is common as we all wondered what else might be affected following the PSA results, biopsy and ultimate treatment. Deep breath...
Ted