Unfortunately, weight gain can be a common side effect with the aromatase inhibitors. Counteracting the weight gain is usually a matter of diet and exercise but again, that is often more difficult with age, menopause and aromatase inhibitors. I don't think an endocrinologist would be particularly helpful. I would start with checking back with the oncologist managing your case and see if changing the aromatase inhibitor would help. If not, then it is certainly your decision to continue or discontinue the drug but discuss it with your doctor whatever you decide.
Sherree