Journalist Cokie Roberts being treated for breast cancer

WASHINGTON -- Cokie Roberts says she is being treated for breast cancer that was detected in the early stages and that she does not expect any major disruption in her work schedule at ABC News.

She told The Washington Post in Tuesday's editions that her doctor detected a suspicious lump in mid-June and a subsequent mammogram revealed a small tumor in her left breast.

She underwent a successful lumpectomy at Washington's Sibley Hospital two weeks ago, she told the paper.

Roberts, 58, had already announced her departure from "This Week," the Sunday panel show she has co-anchored with Sam Donaldson since 1996, before receiving the diagnosis. She said the cancer was caught early and she expects a clean bill of health after six months of chemotherapy. She said the treatments, scheduled to start this week, won't "cause any major interference with my work" as a political analyst and commentator covering the midterm elections.

A sister of Roberts, Barbara Sigmund, a former mayor of Princeton, N.J., died of cancer in 1990.