Hello, I am confused on the capitalization rules for Leukemia. It seems it might follow the rules as Mom and Dad, when alone is capitalized, but at times is lowercase (my mom). 
The specific cases simplified: Annie was diagnosed with Leukemia. Then it morphed into adult leukemia. With the new leukemia, the old treatments no longer worked.

any help you have would be great! Also, if there is a place where I can research more topics like this that would be helpful.
Diseases, unless they are named after a person, are not capitalized. It is always leukemia.

You only write it leukemia. It isn't capitalized.