I have had kidney problems that were specifically due to my metastisized prostate cancer. I have been into the hospital twice with kidney failure - in early 2011 and then again in mid-2012.
I had a very recent experience ... and wrote about it in the kidney forum ... regarding dehydration while experiencing diarrea side effects from my current chemo ... Jevtana!
The kidney forum moderator did agree with my theory - since he had similar experiences himself.
By the way, in my case, the prostate cancer in its growth, did block both kidneys - affecting the function of both. My left kidney had an internal stent placed in June of 2012 that needs replacement every 4 to 5-months.
My right kidney, which functions slightly better, had a nefrostomy tube placed - also in June of 2012. It also needs to be replaced every 4 to 5-months.
I mention these only because they were, for me, valid options to the thought of dialysis.
I would suggest to either talk to your oncologist about the corresponding tests for the kidney functions ... or possibly to see a nefrologist (spelling?)!
What you eat can be extremely important for the kidneys - by controlling the potassium and possibly phosphorous in your diet. And, of course, water is extremely important.
Maybe 10-days ago, on just one night, I had three small glasses of ice coffee .... and no water that evening. For the next few days, I was very light-headed (similar feeling as when I had kidney failure) ... and started to drink a lot of water while limiting myself to just one large coffee a day. The caffeine can be disastrous with a kidney problem.
After maybe 4-days of fairly heavy water drinking, the light-headed feeling disappeared. As a part of my chemo, my blood tests this past Monday did include my kidneys being checked ... and they were good!!!
I hope the above helps a little - at least in direction.
Rob and Gizzy
Initial Dx of PCa in 2003/2004
Radiation (5x5wks) & Brachytherapy (96 seeds) in 2004
Low PSA for 6-years then Casodex briefly
Lupron from 2011 to current
Zytiga 2012 (5-months) - PSA increase
Prednisone & Xgeva from 2012
Taxotere - August 2012 (30-weeks) - PSA from 54+ to 12+
No chemo (8-wks) - PSA to over 23
Xtandi - June to Aug - 2013 - PSA increase
Jevtana + Lexapro - from October 2013