Robin Roberts taking medical leave from Good Morning America

After announcing a new battle with a side-effect from chemotherapy, Good Morning America co-anchor, Robin Roberts, is now taking a leave of absence.

Roberts, who beat breast cancer in 2005, was recently diagnosed with myelodysplastic syndromes, a disease of the blood and bone marrow. Robin’s sister is preparing to become a bone marrow donor, doctors indicated that she was nearly a perfect match. “It’s fascinating-slash-scary how to prepare yourself for something like this,” Roberts said.

Robin says that GMA’s jump to number one has been the “best medicine” and has helped raised her spirits during this difficult time. Barbara Walters, Diane Sawyer, Katie Couric and, perhaps, Kelly Ripa will serve as a guest host alongside George Stephanopoulos in her absence.