Breast cancer runs in Kristy Tubiolo's family. When she was diagnosed in 2016, at the age of 35, it wasn’t exactly a surprise, but it wasn’t expected either.

Aretha Graham is Brooklyn-born tough. At age 50, she looks many years younger and exudes a quiet, Zen-like energy, even though she navigates everyday life with a cluster of noncancerous brain tumors.

What if doctors were able to identify, with a simple blood test, when a patient’s cancer was starting to make a return? Or that a person’s disease was so well treated it would not return?