I had partial nephrectomy on my right kidney for the same reason with 80% remaining. No fun at all... Kidney cancer usually goes unnoticed because by the time you have symptoms it has spread. Only about 8% of kidney cancer victims survive 5 years because of that. She and I were lucky it was found early. For me it was because I had a CT scan for diverticulitis and it inadvertently revealed a complex cyst on my right kidney that over the course of a few years turned into clear cell renal carcinoma. A 3.2 cm full blown malignant tumor. So not being super healthy saved my life...