I have graves disease only treated by methimazole and was told methimazole causes cancer is that true?

because i was told that"about causing blood cancer,I am nervous about it and stopped taking the methimazole for fear of cancer..I know that is far more dangerous to be untreated but i dont know if i was told that just to have a surgery or radio iodine pushed on me or if its true that you cannot be on methimazole for more than a year or two...I didnt want the radio iodine because of the signifigant weight gain horror stories,and the surgery because of the possible damage to vocal chords..I am a studio Vocalist and do not want to damage my voice or become enormus in weight.... anyone out there on methimazole or with a dead thyroid and still thin????or a doctor that has non bias facts???