Family History Downgraded as Breast Cancer Risk
Study: Chances of getting disease not as great as thought
FRIDAY, Oct. 26, 2001 (HealthDayNews) -- The risk of breast cancer for women with a family history of the disease is not as high as has been thought, and most cases occur in women with no such family history, an international study finds.
"We've brought together a huge amount of information from all over the world which shows that the lifetime risk associated with a family history is much lower than had been thought," says Dr. Valerie Beral, professor of epidemiology at the University of Oxford in England. Beral is the lead author of a report on the finding in the Oct. 27 issue of The Lancet.
Beral and other members of the International Collaborative Group on Hormonal Factors in Breast Cancer analyzed 52 studies to compare the risk for women with a first-degree relative -- mother, sister or daughter who had breast cancer -- with women without a close relative with the disease.
They found women with one affected relative have a 7.8 percent chance of developing breast cancer; women with two affected relatives have a 13.3 percent risk, and women with three affected family members have a 21.1 percent risk.
Beral says, "Much of the risk is evident in older women, over the age of 50. This is quite reassuring for young women with a family history of breast cancer. In the next few years, their risk of cancer is not very high, but over the age of 50, a woman with such a family history should go for regular mammograms."
The study offers a degree of reassurance even for women with a family history. "If you have one relative with the disease, the risk is one in eight. If you have two relatives, the risk is about one in five. So even if a woman has a mother and a sister with breast cancer, the chance that she will not develop breast cancer is four out of five," Beral says.
The study has clear public health implications, Beral says. "A public health official who is trying to think of ways of reducing the incidence of breast cancer will be more interested in the fact that eight out of nine women who develop the disease will not have a family history. If you concentrate on family history, you will miss most cases."
The study should ease fears of women with close relatives who have had breast cancer, says Debbie Saslow, director of breast and cervical cancer for the American Cancer Society. "It's really important for those women to know that their risk is only slightly elevated, so they don't walk around thinking that their risk is 100 percent, which is not true," she says.
The society now recommends annual mammograms for all women starting at age 40, and that "women with a family history should talk to their doctors about possibly starting earlier," Saslow says.
The recommendation for women with a family history of breast cancer, which dates back to 1997, is based on "opinion rather than evidence, because there haven't been that many studies out there," Saslow says. The society plans to review and update its recommendations, she says.
"We would like to make a more specific recommendation than we have now for women with a family history," she says. "It's easy to say that women should talk to their doctors, but we don't know if the doctors they talk to have the information to make the right decision."
The society is forming committees of experts to review its breast cancer recommendations, which should be issued next year, Saslow says.
What To Do
Annual mammograms and breast self-examination are especially important for older women, with or without a family history, since the risk of breast cancer increases with age, Saslow says.