My mom may have cancer. What should I do?

If you are familiar with me, you’ll know that I’m a Chinese gay guy and just came out to my parents half a year ago.
They said that it’s okay. I’m the son of them and nothing will change. They said,“Who wouldn’t love his son? Even if the son was put into prison or something, every dad will love his son. Always. ”
The day before yesterday was the day when dad told me that my mom found a tumor at her thyroid. The doctor said it didn’t look optimistic, and she should take a further test to make sure. The test will be taken in one or three weeks.
What should I tell myself if she really gets a cancer?
And what should I do?
How should I face them…
My dad was totally calm when he told me this. He said,“Every difficult thing will work out. Don’t worry about her. ” I said “You think you can handle this?” He said “Yes. So can your mom, I think.” His voice was slightly low, though. Of course.
My mom was a women like Claire in Modern Family. She seems to get a little angry usually, she’s innocent and kind, and she loves deeply.
My dad does great in getting along with people, and, though it seems that he listen to my mom a lot, actually he has his firmly or decisive opinion upon things. And he loves deeply, too.