Biopsy

Hi, my husband has just had 2 mri scans which show a lesion on the body of the pancreas and a possible 2 smAll lesions on the liver, which they are not sure if they are cancerous( but probably) he is going fora biopsy.my problem is they say that eve if the biopsy comes back negative it wouldn't necessary mean they are not cancerous and would do another biopsy to make sure. These seems very time wasting to me has anyone else been in this position. Some advice pleaae