What are the odds?

3 1/2 years ago I was diagnosed with stage 4 RCC. Had my right kidney removed and I am on 800 mg Votrient for just over a year now. So far so good. I am 54 years old. Last week my sister found out she had a 5cm x 4cm mass on her right kidney. They took the kidney out 2 days a go. Her right kidney. The pathology report is due in toady or Monday. But they are prettty sure. It's RCC. She is 65. i think it's enviromental. When we were kids we got our water from. Town wells. less than 1/2 mile from the wells was Rocco's dump. I grew up in tewksbury MA. Rocco's dump is a super fund site. They have found all kinds of nasty chemicals in the ground water. The wells have been closed since the mid 70's. A friend of mine that passed away 10 or so years ago from cancer who is my sisters age and I sat down and listed all the people we knew who have cancer or died from cancer. We were over 90 that was over 13 years ago.