. >> reporter: michelle avery diagnosed with breast cancer in september 2013. doctors told her her cancer was aggressive and spreading quickly. >> i had cancer all through my spine and my hipbones and i had too many liver lesions to be able to count. >> reporter: her doctors elected for a treatment found to be successful in women with incurable her2 positive breast cancer, includes one-fifth of patients, avery was overwhelmed. >> and then to learn, okay, for rest of your life you're going -- every three weeks have do these infusions and i thought, my god, who could do that? but it's okay. >> reporter: instead of using just chemotherapy, doctors added two more drugs in herceptin and perjeta. when this method tested in clinical trials it expanded the patient's average life expectancy by more than a year. >> this is the kind of discovery that's unprecedented. we don't see anything like this. >> reporter: uncommon because most breakthroughs have only added a few months to life expectancy. the study also found patients given the cocktail of drugs lived nearly five y