The doctor said my granny has breast cancer without carry out a biopsy and asked for the breast to be cut off immediately should i allow it?

NO: There is more to it , with your granny's permission speak to her doctor and get the right information , as all the facts you may not be aware of . No doctor will perform mastectomy with out biopsy , may be a core needle already done in the doctor's office. If doctor is performing mastectomy with out biopsy , it is not too late to take her to different doctor .Good luck.