Chromosomal Translocations & Personalized Cancer Care

There's some promise in identifying the specific translocations and targeting for personalized care.  The article points to one problem...how to know which translocation is causative and which is correlative.  Another problem, is if cancer has developed, those cells mutate pretty uncontrollably, so that by the time you identify a personalized therapy, some cells have evolved and may not be a suitable target.