[health] Family history can trump breast cancer gene test

Family history can trump (超过，胜过，打赢) breast cancer gene test

关于女性身体健康

乳腺、卵巢、子宫等部位的疾病正在袭击越来越多的女性。这些疾病和基因有关系吗？如果有一定关系，母亲有病史的情况下，女儿患该类疾病的可能性是多少？

焦虑的小编

By LAURAN NEERGAARD, AP Medical Writer Lauran Neergaard, Ap Medical Writer

– Mon Nov 17, 5:32 pm ET

WASHINGTON – If breast cancer runs in the family, women can be at high risk even if they test free of the disease's most common gene mutations (转变，突变), sobering (使人清醒的) new research shows. The genes BRCA1 and BRCA2 are linked with particularly aggressive hereditary (遗传的，世袭的) breast cancer, and an increased risk of ovarian (卵巢的) cancer, too.

When a breast cancer patient is found to carry one of those gene mutations, her relatives tend to breathe a sigh of relief if they test gene-free.

But those headline-grabbing genes account for only about 15 percent of all breast cancer cases. Even in families riddled with breast cancer, a BRCA gene is the culprit (罪魁祸首) only in roughly one family of every five that gets tested, said University of Toronto cancer specialist Dr. Steven Narod.

So clearly members of those families remain at risk from other yet-to-be-found genes, but how much risk?

Narod tracked (跟踪，调查) nearly 1,500 women from 365 breast cancer-prone families, who tested negative for BRCA1 and BRCA2 mutations.

After five years, those women had a fourfold (四倍) higher risk than average women of developing breast cancer, Narod reported Monday at a meeting of the American Association for Cancer Research.

This is crucial information for women considering gene testing, said Georgetown University genetics counselor Beth Peshkin, who wasn't part of the study.

"This is contrary to what I think the common perception is," Peshkin said. "Unless a mutation is identified in the family, a negative test result doesn't provide reassurance (放心."

The good news: Narod's study showed these women didn't have an increased risk of ovarian cancer, like BRCA1- and BRCA2-carriers do.

While the $3,000 BRCA tests are well-accepted, newer tests for other genes linked to breast cancer are coming on the market.

But "the family history is a much stronger predictor (predict:  预言)," stressed Narod. He recommends that such women take the anti-cancer drug tamoxifen [它莫西芬(一种抗雌激素,用于治疗妇女乳腺癌或不育症)] and undergo MRI ( magnetic resonance imaging 核磁共振成像) cancer checkups instead of easier mammograms "regardless of what other gene tests showed."

Readers

What do you think are the causes of breast cancer and ovarian cancer? What can females do to prevent them from occurring?

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