but that is what happened to stephanie lipscomb in 2011, diagnosed with the worst kind of brain tumorioblastoma. she became one of the first patients in duke university's cancer trial to be given, of all things, the polio virus, as a last chance to fight her disease. today, four years later, she is cancer free. and she's not the only one. >> this, to me, is the most promising therapy i have seen in my career, period. >> pelley: "60 minutes" has been following this daring experiment for more than two years. and now the federal government has given it rare "breakthrough

in 2011, stephanie lipscomb was a nursing student with headaches.her she had this glee oh blast oma tumor the size of a tennis >> exactly. >> reporter: in 2012, what did the doctors tell you? >> your cancer is back. >> reporter: with recurrent glioblast oma, there were no options other than the one that was tried. stephanie became the first to experiment with the polio virus. the virus is a creation of molecular biologist mathia mathias bromeyer. he reengineered the virus removing a key genetic sequence. he replaced it with a harmless bit of cold virus. the modified virus can't cause paralysis or death because it can't reproduce in normal cells. in cancer cells, it does. in the process of replicating, it releases toxins that poison the cell. this process also awakens the immune system to the cancer that it had never noticed before. why di react to the cancer to begin with? >> so cancers, all human cancers, they develop a shield, a shroud of protective measures that make them invisible to the immune system. this is precisely what we try to reverse wi

in 2011 stephanie lipscomb was a nursing student with headaches.the size of a tennis ball. >> i looked at the nurse that was sitting there holding my hand and i said i don't understand. what did he just say? it was kind of hard for me to process. >> you had 98% of the tumor removed. >> exactly. >> as much radiation as you can have in a lifetime. and chemotherapy. >> exactly. >> and then in 2012 what did the doctors tell you? >> your cancer's back. >> reporter: with recurrent glioblastoma there were no options. except the one that had never been tried. >> did they tell you that it had never been tried in a human being before? >> they did. but at the same time i had nothing to lose honestly. >> reporter: her polio treatment began in 2012. and from the very beginning it looked like a bad bet. >> so we treated her in the may. then in july the tumor looked bigger, looked really inflamed. i got really concerned, got really worried. >> you thought this wasn't working. >> i thought it wasn't working. >> neuro-oncologist monique desjardins wanted to abandon

in 2011 stephanie lipscomb was a nursing student with headaches.. you had 98% of the tumor removed. >> exactly. >> and then in 2012 what did the doctors tell you? >> your cancer's back. >> reporter: with recurrent glioblastoma there were no options except the one that had never been tried. ep volunteer for duke's experiment with the polio virus. the virus is the creation of molecular biologist mathias gromeier. gromeier reengineered the virus, removing a key genetic sequence. the virus can't survive this way, so he repaired the damage with a harmless bit of cold virus. this new modified polio virus can't cause paralysis or death because it can't reproduce in normal cells. but in cancer cells it does. and in the process of replicating it releases toxins that poison the cell. this process also awakens the immune system to the cancer that it had never noticed before. why didn't the immune system react to the cancer to begin with? >> so cancers, all human cancers, they develop a shield or a shroud of protective measures that make them invisible to the

but that is what happened to stephanie lipscomb in 2011, diagnosed with the worst kind of brain tumor glioblastoma. she became one of the first patients in duke university's cancer trial to be given, of all things, the polio virus, as a last chance to fight her disease. today, four years later, she is cancer free. and she's not the only one. >> this, to me, is the most promising therapy i have seen in my career, period. >> pelley: "60 minutes" has been following this daring experiment for more than two years. and now the federal government has given itar