Surprisingly or not, genetic studies have shown that breast cancer doesn’t strike out of the blue in a family where no females have had breast cancer in the past. It’s usually the father’s genes.

Up until now, genetic tests were performed only to spot the presence or absence of the famous BRCA1 or BRCA2 gene mutations, which usually increase the risk of developing breast cancer. Such tests are “prescribed” when doctors notice that the patient’s family history includes females who have had breast cancer.

However, a new study published in the June 20 issue of Journal of the American Medical Association, shows that genetic predictions for women suspected of having the aforementioned mutations could be improved if the father’s family history is taken into account.

"In some circumstances, we have to qualify what family history can tell us," explained lead researcher Dr. Jeffrey Weitzel, director of the department of clinical cancer genetics at City of Hope Comprehensive Cancer Center in Duarte, Calif. He pointed out that family history data isn't always available to women, and "if there's no family, then you can't have a family history, if you don't have older women in either lineage."

Genetic breast cancer tests are quite expensive so not all women can afford it, and the insurance companies also weigh their options thoroughly before recommending them to women. Testing can cost more than $3,000.

Following the recent discoveries, guidelines used by insurance companies in going forward with recommendations should change, according to study co-author Dr. Jeffrey Weitzel of City of Hope Cancer Center in Duarte, Calif.

"Interestingly, it's about Dad," Weitzel said. He added that half of genetic breast cancers are inherited from a woman's father, not her mother.

Nearly 216,000 U.S. women have been diagnosed with breast cancer in 2005, and about 40,000 of them have died according to the American Cancer Society (ACS).