how long do you have to file a medical malpractice lawsuit in the state of california

my husband died in a california hosp. when he was admitted he had neumonia 3days later was diagnosed with aml he was never treated for cancer was told day by day they were going to transfer him to a hosp. were they treat cancer patients that never happened. I was also told that they weren't able to treat him because of his legal status.his medical records show that when he was younger he was treated for aml, he was never admitted to the hosp. for any cancer, So that has me thinking did they not treat him because on his supposively med records it states that he did indeed have this cancer..before?????