No higher risk of breast cancer for women who don't have BRCA mutation but have relatives who do
In the largest study of its kind to date, Stanford University School of Medicine researchers have shown that women related to a patient with a breast cancer caused by a hereditary mutation -- but who don't have the mutation themselves -- have no higher risk of getting cancer than relatives of patients with other types of breast cancer. The multinational, population-based study involving more than 3,000 families settles a controversy that arose four years ago when a paper hinted that a familial BRCA mutation in and of itself was a risk factor.
"The results are encouraging and reassuring," said Allison Kurian, MD, assistant professor of oncology and of health research and policy and first author of a paper that will appear online Oct. 31 in the Journal of Clinical Oncology. She and her colleagues -- including senior author Alice Whittemore, PhD, professor of health research and policy -- said their findings support the current practice of advising so-called non-carriers that there is no increase in risk attributable to their family-specific BRCA1 or BRCA2 mutation.
The study doesn't dispute that women who have relatives with any type of breast cancer have a greater risk of contracting the disease compared to those with no cancer-stricken relatives.
Mutations in the BRCA1 and BRCA2 genes are strongly associated with the development of breast or ovarian cancer: Carriers face a five- to 20-fold increased risk of developing these cancers and are usually subject to intensive screening and risk-reduction strategies. Female relatives who are tested and found not to carry the family-specific mutation have historically been advised that their cancer risks are the same as those of other relatives of breast cancer patients (that is, slightly higher than women in the general population).
The field was shaken up when a 2007 Journal of Medical Genetics paper showed that women who tested negative for a familial BRCA mutation had a two- to five-fold increased risk of developing breast cancer. Several other studies found a two-fold risk for non-carriers who had a relative with the mutation, prompting some to wonder whether ongoing breast cancer surveillance should be recommended for these relatives.
"Our clinic received many calls about it -- it was widely read by people in the field and by patients," said Kurian, a practicing oncologist whose research focuses on breast cancer risks across populations. The study, and the notion that additional screening for non-carriers might be warranted, caused both concern and skepticism among cancer geneticists. "It went against what was being done."
The 2007 study had compared relatives of BRCA carriers with women in the general population, and Kurian and her colleagues thought this might have created high estimates of the non-carriers' risk. For one reason: Women in a family with a known BRCA mutation are more likely to receive more intensive screening, and thus be more likely to be diagnosed with breast cancer than women in the general population.
And also, said Whittemore, "First-degree relatives of breast cancer patients are themselves at higher risk than women in the general population. So some reports of higher risk among non-carriers, as compared to risk in the general population, may have been an inappropriate comparison of apples and oranges."
The researchers sought, then, to compare cancer risk in non-carriers with a control group of relatives of cancer patients without the mutations. For the study they used data from population-based cancer registries provided by co-investigators from the Cancer Prevention Institute of California, the University of Melbourne in Australia and the University of Toronto in Canada to look at 3,047 families. Of the total, 160 families had BRCA1 and 132 had BRCA2 mutations.
When comparing the groups of relatives, they found no evidence of an increased breast cancer risk for non-carriers compared with the control group. The authors note that this finding supports "evidence-based practice guidelines [that] currently recommend that non-carriers be screened according to standard protocols for their age and other risk factors."
The findings should put to rest questions about risk based on a familial BRCA mutation. But Kurian added, "It's important for patients and clinicians to remember this doesn't rule out other risk factors, which might increase a non-carrier's probability of getting breast cancer."
Provided by
Stanford University Medical Center
-
Breast cancer risk varies among women who are carriers of BRCA1 and BRCA2 gene mutations
Jan 08, 2008 |
not rated yet |
0
-
Breast cancer risk amplified by additional genes in combo with BRCA mutation
Apr 16, 2008 |
not rated yet |
0
-
BRCA2 mutations associated with improved survival for ovarian cancer
Apr 04, 2011 |
not rated yet |
0
-
Breast cancer patients with BRCA mutations 4 times more likely to get cancer in opposite breast
Apr 05, 2010 |
not rated yet |
0
-
Ashkenazi ovarian cancer patients with BRCA mutations live longer than those with normal gene
Jan 02, 2008 |
not rated yet |
0
-
Motion perception revisited: High Phi effect challenges established motion perception assumptions
Apr 23, 2013 |
3 / 5 (2) |
2
-
Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update)
Apr 02, 2013 |
4.5 / 5 (11) |
5
-
The visual system as economist: Neural resource allocation in visual adaptation
Mar 30, 2013 |
5 / 5 (2) |
9
-
Separate lives: Neuronal and organismal lifespans decoupled
Mar 27, 2013 |
4.9 / 5 (8) |
0
-
Sizing things up: The evolutionary neurobiology of scale invariance
Feb 28, 2013 |
4.8 / 5 (10) |
14
-
How can there be villous adenoma in colon, if there are no villi there
17 hours ago
-
How can there be a term called "intestinal metaplasia" of stomach
May 21, 2013
-
Pressure-volume curve: Elastic Recoil Pressure don't make sense
May 18, 2013
-
If you became brain-dead, would you want them to pull the plug?
May 17, 2013
-
MRI bill question
May 15, 2013
-
Ratio of Hydrogen of Oxygen in Dessicated Animal Protein
May 13, 2013
- More from Physics Forums - Medical Sciences
More news stories
American cancer society celebrates 100 years of progress
(HealthDay)—The American Cancer Society, which is celebrating on Wednesday a century of fighting a disease once viewed as a death sentence, is making a pledge to put itself out of business.
Cancer
7 hours ago |
not rated yet |
0
CT detects twice as many lung cancers as X-ray at initial screening exam
National Lung Screening Trial (NLST) investigators also conclude that the 20 percent reduction in lung cancer mortality with low-dose computed tomography (LDCT) versus chest X-ray (CXR) screening previously reported in the ...
Cancer
7 hours ago |
not rated yet |
0
Research offers promising new approach to treatment of lung cancer
Researchers have developed a new drug delivery system that allows inhalation of chemotherapeutic drugs to help treat lung cancer, and in laboratory and animal tests it appears to reduce the systemic damage ...
Cancer
11 hours ago |
not rated yet |
0
|
Study details genes that control whether tumors adapt or die when faced with p53 activating drugs
When turned on, the gene p53 turns off cancer. However, when existing drugs boost p53, only a few tumors die – the rest resist the challenge. A study published in the journal Cell Reports shows how: tumors that live even i ...
Cancer
11 hours ago |
not rated yet |
0
|
Small increase in cancer risk following CT scans in childhood and adolescence
Study leader, Professor John Mathews from the University of Melbourne said this small increase in cancer risk must be weighed against the undoubted benefits from CT scans in diagnosing and monitoring disease.
Cancer
15 hours ago |
not rated yet |
0
Rate of bicycle-related fatalities significantly lower in states with helmet laws
Existing research shows that bicyclists who wear helmets have an 88 percent lower risk of brain injury, but researchers at Boston Children's Hospital found that simply having bicycle helmet laws in place showed a 20 percent ...
Slowing the aging process—only with antibiotics
Swiss scientists reveal the mechanism responsible for aging hidden deep within mitochondria—and dramatically slow it down in worms by administering antibiotics to the young.
Researchers complete largest genetic sequencing study of human disease
Researchers from Queen Mary, University of London have led the largest sequencing study of human disease to date, investigating the genetic basis of six autoimmune diseases.
Brain can be trained in compassion, study shows
Until now, little was scientifically known about the human potential to cultivate compassion—the emotional state of caring for people who are suffering in a way that motivates altruistic behavior.
Having both migraines, depression may mean smaller brain
(HealthDay)—Migraines and depression can each cause a great deal of suffering, but new research indicates the combination of the two may be linked to something else entirely—a smaller brain.
Novel approach for influenza vaccination shows promise in early animal testing
A new approach for immunizing against influenza elicited a more potent immune response and broader protection than the currently licensed seasonal influenza vaccines when tested in mice and ferrets. The vaccine ...