Did my fiance's family lie to him about his Dad's cancer?

I started dating my boyfriend a little over a year ago. Shortly after, he told me about some health problems his father had been having. First, I learned about a major surgery that no doctor would touch save for a surgical team at Johns Hopkins. From that moment forward, I suspected his father had cancer based on many factors. First, the fact that in order to kill "benign" tumors, the doctors had injected some sort of poison. This "poison" caused his father, an avid drinker, to develope psorosis of the liver. They fly out to Johns Hopkins every couple of months for his dad to get a check up. He has weekly appointments with the local doctor. I umed it was from radiation therapy as his dad had not lost a lot of hair. In the past month, his dad began going through Chemotherapy. At that point, I knew he had cancer. Last week, my boyfriend came home really upset. He looked at me and said, "my dad has cancer." I told him that I knew and I was sorry. Then, he proceeded to explain to me that he had just figured it out by directly asking his mother. She told him they had only known for a few months. Is it just me, or is this about the same thing as lying?