Six men said they hadn't been told, or had forgotten. Of the other 18, two mistakenly said the test had been negative. Seven did not think the results revealed anything about their own cancer risk. Only five understood they, too, might carry the genes.

Of the six who expressed any interest in being tested themselves, three said they were doing so mostly for their children's sake.

"We try to reach out to the men in these families, particularly men who have little children," Daly said. "If they were to die without being tested, their children would grow up without that information" that they, too, were at risk, she said.

Dr. Steven Vogl, a cancer doctor in private practice in New York, said he recognized that potential when his neighbor was dying of lung cancer and told him how many female relatives had suffered or died of breast and other cancers.

"Being a good doctor, I took a history," and realized the man, an Eastern European Jew, probably had the gene.

"At least it will help his granddaughter" to know of the risk, Vogl said.

Women, too, need to realize they are doing male relatives and their descendants a favor when they reveal their own genetic risk from BRCA genes.

"They don't realize they are at risk," or that their grandchildren may be, Daly said.