The BBC's anchor and presenter Rachel Bland, who is suffering from incurable cancer, said she was "in a race against time" to publish her memoirs to her two-year-old son, Freddy.
"I have less than a year," Bland, 40, wrote in the Sunday Telegraph.
She said her book would include "all the stories and advice I should give Freddy, but I will not be with him to do it myself."
Bland, news anchor and presenter of Radio Five Live, a BBC platform, was diagnosed with breast cancer in November 2016.
In May of this year, Bland was told that her illness was incurable and that her hopes were based on clinical experience.
But two months later, a check revealed that cancer had spread more.
"Now we do not have any treatment, but we refuse to surrender," she wrote in the Telegraph.
Bland, who lives in Cheshire, said that whole parts of her life would not be known about her son, so her memoirs, which will come in a book called Freddy, would be "a love speech to my beautiful son. I hope to leave my mark and love forever around him. "He said.
She wrote her book making her laugh and cry.
"I'm looking forward to publishing it before I die, but at the moment I feel like I'm racing against time."
Many praised Bland's honesty and courage.
"In the face of your illness, you offer great courage, information and honesty to others," wrote Tracy Excel, a Twitter user.
Other users shared their own experiences.
Breast cancer is a type of mobile or secondary type that occurs when cancer cells spread from the primary breast cancer through the lymphatic system or circulatory system to other parts of the body.
"I am not afraid of death," she wrote. I am only afraid of those I will leave behind. "
"But I have to restrain a lot of bad ideas, which are in my head, when I imagine Freddie grow up without his mother."
Bland has recorded a second series of her "UMe & BigC" program and said she hopes to return to the show "Drive" on Radio Five Live on Friday.