allergic to the medication. there is an option for cancer patients allergic to team 0 therapy. >> reporter: chemotherapy can be brutal but for anita the experience was utterly terrifying. >> i nearly stopped breathing my blood pressure went extremely low. they had to administer epinephrine and oxygen. >> reporter: anita experienced a serious allergic reaction during her first treatment. for the past year she has been being undergoing a process called chemo desense sayings. the chemo is diluted with saline and given in a more gradual way until the patient gets their full dose. >> the oncologist would say we need to switch you to something else. the problem is that sometimes that something else may not be the optimal treatment. >> reporter: dr. george gottlieb describes three steps patients undergo. >> they would get an ant histamine the night before. has principle second thing may require 12 to 16 steps may require 6 to 8 hours the third thing it has to be under the supervision of a an experienced allergist will step in and administer additional medications as needed. >> reporter: her cancer levels are far down. to to