I Have Taken Anastrozole For 5 Years And 9 Months

i have taken anastrozole for 5 years and 9 months since my bilateral breast cancer operation. My cancer was estrogen sensitive and I was a stage 1 with low risk factors. I have been told that I could discontinue the drug if I want to or continue for another 5 years. It is my decision. This past year I have experienced significant weight gain. What is your opinion?