Helen B. Shaffer, 69, a Washington journalist for more than 45 years, died of cancer Tusday at George Washington University Hospital.

Mrs. Shaffer wrote for newspapers, magazines, and for the government during World War II. She joined the staff of Editorial Research Reports in 1952 as a senior writer. She retired from ERR in 1974.

She began her journalism career in the early 1930s with the old Washington Daily News, where she worked as a culture critic and assistant city editor. She later spent two years on the staff of the Washington bureau of Look magazine.

During World War II she served as a writer with the Office of War Information.

After the war, Mrs. Shaffer worked for a time as an editor for radio commentator Raymond Gram Swing before joining ERR. She also was the Washington correspondent at the Women's National News Service, which had just been established then.

Editorial Research Reports, a division of Congressional Quarterly, supplies research reports on current news topics to subscribing publications across the country.

During her years with ERR, Mrs. Shaffer's articles appeared in more than 320 different newspapers. She continued to work for ERR on a part-time basis following her retirement. Her last report, entitled "Right to Dealth" appeared last January.

Hoyt Gimlin, the editor of ERR, said in a tribute to Mrs. Shaffer, "The clarity of her reports and the depth of thought they conveyed made them models for other ERR writers to emulate. Her last report (was) subject to which Mrs. Shaffer brought consideration insight."

Mrs. Shaffer was born in Washington. She earned two bachelor's degrees at George Washington University and studied at the Art Students League in New York before joining the Daily News. Apart from her work, she was an accomplished pianist and harpsichordist.

Her husband, Samuel Shaffer, is the retired chief congressional correspondent of Newsweek.

She was a member of the Washington Press Club.

In addition to her husband, and a daughter, Joan, both of the home in Washignton, Mrs. Shaffer is survived by two other daughters, Karen Baskin, of New York City, and Susan Clarke, of Strasbourg, France; a brother, David Buchalter, of Washington, and a sister, Miriam Lisner, of Silver Spring.