Maureen Reagan, 60, eldest child of former President Ronald Reagan and his first wife, actress Jane Wyman, appears to making progress in her fight against malignant melanoma, a ferocious and often deadly type of skin cancer, say her doctors. Dr. Steven O’Day, director of medical oncology at the John Wayne Cancer Institute at St. John’s Health Center in Santa Monica, Calif., near the elder Reagan’s home, said that while Maureen’s progress is still guarded, “her response to the treatment so far is encouraging.” She has so far gone through two cycles of chemotherapy, and will begin a third cycle in a few days, O’Day told the Associated Press. In November, doctors removed a golf ball-sized malignant tumor from her pelvis. It was her second bout with melanoma. The first was diagnosed four years ago.