Richard Bloch, 78, who co-founded H&R Block and helped build the company into the world's largest tax preparer, died of a heart ailment July 21 at his home in Kansas City, Mo.

Mr. Bloch founded the company in 1955 with his brother, Henry, to take advantage of the vacuum left after the Internal Revenue Service stopped providing free income tax return service. Kansas City-based H&R Block now has 21 million clients in 11 countries.

In 1978, doctors diagnosed terminal lung cancer, but he was cured after two years of aggressive treatment.

Inspired by that experience, he and his wife, Annette, founded the R.A. Bloch Cancer Foundation in 1980 in Kansas City and donated heavily to programs for cancer patients and survivors of the disease.

They also founded one of the first cancer hotlines in the United States in 1980, which has since logged more than 125,000 calls from patients whose cancer was newly diagnosed. The Blochs also founded the R.A. Bloch Cancer Management Center and the R.A. Bloch Cancer Support Center at the University of Missouri at Kansas City.

The centers have become models for a national network of more than 100 similar organizations across the United States that provide medical, moral and other support for cancer patients and their families.

Mr. Bloch served on the advisory board of the National Cancer Institute and was a member of the Institute of Medicine and the President's Circle of the National Academy of Sciences. Late in life, he pushed for laws making second opinions mandatory for patients with a diagnosis of cancer.