Half Genetic BC are inherited from woman's father

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Breast cancer genes can come from father
CHICAGO (AP) — A deadly gene's path can hide in a family tree when a woman has few aunts and older sisters, making it appear that her breast cancer struck out of nowhere when it really came from Dad.

A new study suggests thousands of young women with breast cancer — an estimated 8,000 a year in the U.S. — aren't offered testing to identify faulty genes and clarify their medical decisions.

Guidelines used by insurance companies to decide coverage for genetic testing should change to reflect the findings, said study co-author Dr. Jeffrey Weitzel of City of Hope Cancer Center in Duarte, Calif. Testing can cost more than $3,000.

"Interestingly, it's about Dad," Weitzel said. Half of genetic breast cancers are inherited from a woman's father, not her mother. But unless Dad has female relatives with breast cancer, the faulty gene may have been passed down silently, without causing cancer. (Men can get genetic breast cancer, too, but it's not common.)

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Weitzel said doctors often overlook the genetic risk from the father's side of the family.

The study, appearing in Wednesday's Journal of the American Medical Association, looked at the genetic test results from 306 women diagnosed with breast cancer before age 50.

None of the cancer patients in the study had a family history of breast or ovarian cancer.

Among the women with plenty of female relatives, about 5% had BRCA gene mutations. But among those with few sisters and aunts older than 45 (when breast cancer would be likely to appear), almost 14% had mutations of the genes BRCA1 or BRCA2. That suggests that these cancer patients were unaware of their genetic mutations because there were so few women in the family to signal a cancer risk.

The researchers defined few female relatives as fewer than two on either the father's or mother's side of the family.

Women who were adopted and don't know their family medical history should be aware of the findings, Weitzel said. Women whose female relatives died young before breast cancer had time to show up also are affected.

When such a woman gets breast cancer before age 50, she should get a genetic test, said Dr. Noah Kauff, a cancer geneticist at Memorial Sloan-Kettering Cancer Center in New York. That would help her decide whether to have the unaffected breast or her ovaries removed to prevent more cancer. Kauff was not involved in the research, but wrote an accompanying editorial.

"The study allows physicians and patients to make an argument to insurance carriers that, although there's not a family history of breast cancer, it's still reasonable to test and it should be a covered benefit," Kauff said.

Genetic testing helps a woman choose her next medical steps. A woman with breast cancer who has a BRCA gene mutation has a four times greater risk of developing cancer in the other breast and a 10 times greater risk of ovarian cancer than does a woman with breast cancer who has no BRCA gene mutation.

Some women with a family history of breast cancer choose to have a BRCA genetic test so they can decide whether to reduce their cancer risk by removing their ovaries and breasts before any cancer appears. Drug therapy and monitoring with annual MRI tests offer alternatives.

Testing the genes of more women would cost more money, but Weitzel said that won't add significantly to health care costs and will prevent cancer in some of the women.

The study also showed that three commonly used predictive models don't accurately estimate the genetic breast cancer risk for women without a family history of cancer. The American Cancer Society recently based its recommendation for annual MRIs on risk assessments from the predictive models.
Copyright 2007 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.



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Indigoblue

Perhaps it has nothing to do with father or mother. The plastics, fowled environment, pesticides, and screwed up significance of a greedy world who choose to ignore the actual reality of cancer may be out worst enemies.

Perhaps we have a ravaged ensyme, hormone, or unknown corroded cell mutated from the nuclear poisons and toxic soils in which we eat, breath and exist while raising children and pretending the planet is going to heal; just like we pretend the cancer will disappear.

I think there's more to this mess than any of us can imagine. Scientific minds cannot even guess or prove what the ramifications of waste, water, air and nuclear poluted environments will induce. Cancer is a spec; the rest of our pretty planet cries, dies.

Indi

Beesie

Depending on the source you read, anywhere from 75% to 90% of all breast cancers are not inherited. These are 'spontaneous' cancers. I'd guess that many of these cancers probably are triggered by a vulnerable gene meeting up with some environmental toxin.

The article however is simply pointing out that of the women who do have hereditary BC, 1/2 will have inherited the gene from their father's side of the family. The fact that the BC gene can be inherited from either one's mother or one's father is important for everyone to know. In the end though, heredity is not the cause of most BC.

Methusala

Roswell dr. told me at first visit it was a genetic mutation passed down from my father. makes sense to me, ALL cancer in my family is on my father's side. NONE on my mother's.