Problems with Kidney, renal pelvis and gallbladder

Hi, I had abdominal ultrasounds during routine checkups after having had breast cancer and I was told that my left kidney is 8cm with simple cysts and irritations, the largest cyst being 2.5 cm. The right kidney is 15.5 cm.  So why would the left kidney be so small and are simple cysts a problem.

My gallbladder was shown to have a polipoid lesion with various forms of polyps the largest being 5mm, is this a big problem?

My renal pelvis was shown to be 3.5cm, is this also a problem.?

Could these problems be a result of taking medications?  I am taking Arimidex for breast cancer and Fosavance for osteoporosis which I believe was a side effect from the Arimidex and oopherectomy?  I have also had several bouts of anaesthesia for operations which I think could also play a role.

  I am extremely worried as I seem to have exchanged one life threatening disease for others.  I am seeking medical advise but would like some thoughts before my appontment

Thank you.