High AFP level, edema/ascites, elevated liver enzymes (in the blood), hyper/hypoglycemia, jaundice...
My father's first sign of liver cancer was extreme weight loss and a little bit a bloating. We took him to the hospital, thinking it wasnt serious but the CT scan showed stage 3 liver cancer (due to hepatitis B).
If your father has any concerns, it always to get a diagnostic test and blood work checked to make sure. There is alot of good treatment if the disease is caught in the early stages.
For other symptoms of liver cancer, refer to this link: Good luck.