© CBS PHOTO ARCHIVE/GETTY IMAGES
No two cancers are alike. But tumors, across the myriad permutations of the disease, share one characteristic: unpredictability. That unpredictability includes how the tumor will react to treatment. Because of the toxicity of chemotherapy, no patient wants to find out by trial and error how his or her particular tumor will respond to a given drug. So doctors have long sought ways to identify which therapies will be most beneficial—before actually treating the patient.
In the early 1980s, researchers commonly tested drug efficacy against patient tumor cells in a petri dish, but the method often failed to predict treatment success. At the University of Freiburg in Germany, oncologist Heinz-Herbert Fiebig had a different idea. Fiebig had been implanting pieces of human tumors into mice with ...
