A drug maker has decided to release a still-unapproved cancer medication to a woman with terminal breast cancer, after being inundated with phone calls from people who wanted to help the woman try to live a little longer.

Florida mom Darlene Gant, 46, has Stage 4, terminal breast cancer that has spread to her liver, which she says is "engulfed" in tumours. When she was told there were no other treatment for her and she didn't have long to live, she begged her doctor to try a new drug currently under development, called pertuzumab.

Three phases of study have been completed on the drug, which has been shown to extend life expectancy in some cancer patients. The U.S. Food and Drug Administration is expected to approve it in early June. But Gant had been told she didn't have that long to wait.

So two weeks ago, her husband helped her load a 20-minute video to YouTube in which she asked that the drug be released early for her, on compassionate grounds.

In the video, she holds up a slew of cards that she wants to be given to her 11-year-old son on his 12th birthday, his 18th birthday, his wedding day, and the countless other milestone moments that she doesn't expect to be around for.

"It's pretty sad that cancer has taken my life to this point that I have to plan what I'm going to do for my son so he remembers me," she says, dissolving into tears.

"We're planning out cards and videos and books and passing on our final words and trying to raise our kids from beyond," Gant says, as the tears stream down her face. "How sad is that?"

Gant says in the video that while she doesn't expect pertuzumab to cure her, she hopes it can buy her a little more time.

"It could stabilize me and extend my time here on earth with my 11-year-old son and my family," Gant says.

The video has had almost 40,000 views since it was loaded and after a number of U.S. media outlets picked up on the story, it led to dozens of strangers calling up the head office of pertuzumab's developer, Genentech, begging them to release the drug.

It worked. Genentech, a subsidiary of drug giant Roche, has agreed and Gant began her first dose last week.