Robin Roberts has 'shed more tears' watching her partner fight cancer than she did during her own battles

Robin Roberts is still smiling.

The ABC broadcaster, who still feels the thrill of saying "Good Morning America" after 20 years with the program, has battled breast cancer and myelodysplastic syndromes. With MDS, "the blood-forming cells in the bone marrow become abnormal," which results in "low numbers of one or more types of blood cells," according to cancer.org. Roberts learned that without a successful transplant, her life expectancy would be one to two years.

"You're just numb when you when you hear something like that," she says. (In 2012, she underwent a bone marrow transplant, receiving healthy blood-forming cells from her sister Sally-Ann Roberts.)

She writes of her health crises and more in her new book, "Brighter by the Day: Waking Up to New Hopes and Dreams," (Grand Central, 240 pp., out now), which is divided into three parts: The Joy Mindset, Positive on Purpose and Stronger Than You Know. Most chapter titles encourage readers to believe in their own greatness: "Make Your 'One Day' Your Day One," "Dream Big, Focus Small," "Vulnerability Is Strength."

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"I know people feel that I'm always upbeat, I'm always happy," says Roberts, 61. "That's not the case. It is the majority of the time because I've gotten in a habit of being optimistic. It's a muscle that gets stronger with use."

Roberts, who most weekdays greets 765,000 Instagram followers with an uplifting video message, found inspiration from her fans to preserve her wisdom in writing. She wants her book to instill hope in its readers.

"Hope and then underline it!" she emphasizes. "People have heard me share different mantras and different mommy-isms. I show in the book how I apply that in my life."

Roberts writes about the tenacity with which she chased the dream of working at ESPN – a goal she wrote on a white board as a senior in high school – which came true 11 years later. She shares what helps preserve her optimistic attitude: leaning into her faith, Transcendental Meditation and practicing gratitude.

Roberts reached for "Brighter by the Day" when her longtime partner, Amber Laign, was diagnosed with breast cancer in late 2021, news the journalist went public with on social media in February. Laign had surgery in January and began chemotherapy on Feb. 24, Roberts told followers, adding, "Thankfully, the prognosis is good."

"I cannot even begin to tell you what I was feeling," Roberts says of Laign's diagnosis. "I was like, 'Are you kidding me?'"

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"I had to refer to my book, because it's one thing when it's happening to me," Roberts says. "I have shed more tears and have been in a state with Amber that I wasn't with myself my two times combined. It's something when you watch a loved one go through something like this."

The pair exchanges tips gathered when roles were reversed. Roberts gives her insight about chemotherapy; Laign helps Roberts with the role of caregiver. She says Laign's cancer "was caught in the early stages" and knows her love "is going to be fine." But a disruption in Laign's treatment plan when she wasn't responding well to the chemotherapy gave the couple, who met in 2005, a scare.

"It was a little frightening when she was not reacting well to the chemo, but the fact that she is doing better now, we are in really, really good spirits," Roberts says. "But it was a little daunting there, for a time. People who go through this, they know. Cancer, it's not a straight line – cancer treatment. It's peaks and valleys, and thankfully, we're at a peak right now after being in a valley for a bit."

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Roberts' own bouts with cancer taught her to be fully present, she says. In "Brighter by the Day," she writes of "the opportunity to reinvent ourselves with every sunrise."

The morning we speak in late March, Roberts says she woke up and chose to be "the person that God created."

"I've had a really hectic time with my schedule, with Amber, with covering the war. You name it, all those things," she says. "And I made a choice today, as I often do. I choose happiness. I choose joy."

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This article originally appeared on USA TODAY: Robin Roberts' Brighter by the Day book helps amid love's cancer fight