Meanwhile, at the bottom of the world, Nielsen's odds didn't look particularly good. Under the best of circumstances, women with her type and stage of breast cancer have a 50/50 chance of survival. And the Amundsen-Scott circumstances.
In temperatures cold enough to coagulate jet fuel, 41 people were living and working in perpetual exterior darkness under a polar dome designed to house a staff of 17. As the medic, it was Nielsen's job to keep the scientists and onsite construction crew healthy until fresh personnel and supplies would arrive with the coming of the Antarctic spring.
As Nielsen's cancer progressed, though, the doctor increasingly became the patient. Because it was too cold at that point to land an airplane at the Pole, the NSF arranged to have cancer-fighting drugs and other medical supplies airdropped.
To a large degree, Nielsen treated herself after that, while continuing to care for other "Polies" with injuries. She did, though, have plenty of help administering her weekly chemotherapy sessions.