I Am 69 Yrs Old, Male With Metastatic Renal Cell

I am 69 yrs old, male with Metastatic Renal Cell Carcinoma in my chest and lungs, left kidney removed and Prostate Cancer, prostate removed and after hormone treatments and radiation it is so far undectable. After chemo treatments for the Renal cell with no success then had radiation treatments to the two largest masses on either side of trachea and esophagus. Have also been on medication tyo stabilize my thyroid after it started causing problems while on Opdivo. Ok, now that I got a brief history out there my question is about what would make my feet start turning chalky white and my toes hurt. Feet, ankles and legs swollen.