Robin Roberts Leaving 'Good Morning America' for Bone Marrow Transplant on Friday

UP: Robin Roberts

The "Good Morning America" anchor lands a huge scoop with President Obama's same-sex-marriage interview, adding to GMA's recent momentum in its ratings battle with NBC's "Today."

Robin Roberts will take a medical leave of absence from Good Morning America following Friday's broadcast.

Her last week will pay special tribute to the 51-year-old anchor with a segment called "Robin's Journey," the show said Monday. Roberts revealed in June that she had been diagnosed with myelodisplastic syndrome, a rare form of leukemia.

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"I'll begin the [transplant] process," Roberts explained to viewers on the air. "It still takes about 10 days after being admitted because there are some things you have to go through before the [bone marrow] transplant actually occurs."

Roberts will be receiving marrow from her sister.

Fatigued and in need of a rest, Roberts -- already a breast cancer survivor -- took a several-week leave of absence from GMA starting at the end of July; she returned Aug. 20.

Good Morning America has surged and at times overtaken its rival Today this summer. Following the NBC show's string of victories during the Olympics, GMA retook the lead Aug. 16.