Oct 6 (Reuters) – Starting breast cancer screening as early as age 25 may help women who carry a genetic mutation linked to a higher risk of cancer live longer, according to a U.S. study.
Researchers, whose findings were reported in the journal Cancer, looked at which breast cancer screenings — mammogram or magnetic resonance imaging (MRI) — were effective in women who carry the gene mutations BRCA1 and BRCA2, known to increase the risk of breast and ovarian cancer. They looked at women aged 25, 30, 35 and 40 years old.
Compared to no screening at all, annual screening starting at age 25 extended life by 1.3 to 1.8 years. Screening with a breast MRI every six months extended life by 1.5 to 1.7 years.
"Results indicate that breast cancer deaths will decrease because of screening," said study co-author Janie Lee, who specializes in breast imaging at Massachusetts General Hospital, by email.
The tests were not perfect. Over the course of their lives, women with BRCA1 who began having mammograms at the age of 25 would have two false positives. Women with BRCA1 who had an annual mammogram and breast MRI would have four false positives.
For BRCA2 carriers, the corresponding numbers of false positives were three and eight.
In addition, the authors based their findings on a computer model that may not translate into real life, said Carol Fabian, a specialist in breast cancer research at the University of Kansas, who was not part of the study.
In women 40 years old or younger with breast cancer, about 1 in 10 are likely to have a BRCA mutation, according to the National Cancer Institute.
The United States Preventive Services Task Force, a government-funded agency, recommends breast cancer screening for all women beginning at age 50. BRCA carriers are encouraged to start screening at a young age by groups such as the American Cancer Society, which recommends screening at age 30.
"Starting at 25 years may have a slight benefit, but for most women 30 is good too," said Debbie Saslow, director of breast and gynecologic cancer for the American Cancer Society.
"For women who have a BRCA mutation in their family, they tend to get diagnosed at age 40 or younger so they should consider screening at age 25," she added.
Annual screenings can add up in cost. Another concern is repeated radiation exposure, especially among those at increased risk of breast cancer.
When researchers factored in the radiation risk, they found fewer than 5 out of every 100 women who were BRCA carriers were diagnosed with breast cancer due to exposure to radiation.
"The risk of getting breast cancer from radiation is small compared to the risk of dying from breast cancer if you don't get screening," said Fabian. "It's an acceptable tradeoff."
Source: bit.ly/pN50Qt
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Reporting from New York by Linda Thrasybule at Reuters Health; editing by Elaine Lies, Thu Oct 6, 2011 1:00am EDT