Is it possible to have liver cancer with no symptoms?
Yes, it is possible, and even probable to have no symptoms of liver cancer. Or, a patient could have non-specific symptoms -- like your father's weakness and pain that could be attributed to something else. This is one of the reasons that when discovered diseases like liver cancer, pancreatic cancer, and ovarian cancer are often late stage. Patients think they are feeling these things because of other maladies, or they are just regular aches and pains. Your father probably couldn't remember exactly when he felt a little weak or a little pain, which makes it difficult to know when his cancer-related symptoms started.