Twenty years ago, Evgenia Cherkasova and Elena Kornilov were doctoral students in their mid-20s, living in the same housing complex at Penn State University. As they pursued their degrees -- Chersakova in philosophy, Kornilov in physics -- both started families, and to take a break from studying they often found themselves meeting for wine or tea, or watching their young children on the playground. As their friendship deepened, their conversations often veered into the Big Questions on their minds: How could they live a "good life" with purpose, happiness and success? What did those words mean?

After graduation, Cherkasova and Kornilov went their separate ways, keeping in touch via letters and weekly phone calls, sharing the details of every aspect of their lives – their kids’ first days of school, their academic research, their relationship hurdles.

On March 4 of this year – Kornilov’s 48th birthday -- her doctor called to tell her she had breast cancer. Even as she hid the diagnosis from other friends and some family members, Kornilov confided in Cherkasova, and the two went over her treatment options. Some, like chemotherapy, were physically intrusive, but would greatly reduce the chance of remission. Others, like hormonal drugs, were easier to handle, but came with a higher risk of a returned tumor.