Archive for the ‘Breast Cancer’ tag
Encouraging data on genetic risk assessment for breast cancer
Appearing today in the New England Journal of Medicine is a stealthily encouraging study for the use of genetic testing to improve the assessment of the risk of the common forms of breast cancer. Stealthily, I say, because the authors seem oddly determined to provide a gloomy interpretation of their own data. The study, entitled ‘Performance of Common genetic Variants in Breast-Cancer (sic) Risk Models,’ by Wacholder et al, uses data from several major breast cancer studies to answer an interesting question: does adding the measurement of common SNPs linked to risk of breast cancer add to the risk assessment provided by the traditional ‘Gail score’ criteria – age, family history, age at menarche, age at first live birth and the number of previous breast biopsies?
The answer is clearly yes, though the authors of the paper seem not to want you to know that. Most importantly, the authors define as elevated risk those women between the ages of 50 and 79 who are at a greater than 0.575% chance of developing breast cancer in any given year. Using the Gail criteria alone, 18.9% of study participants were considered to be at elevated risk. But with the addition of the genetic risk factors – which are ten of the twelve risk factors tested for by deCODE Breast Cancer test – another 9% of participants could be identified as being in the higher risk category. A 50% improvement.
Similarly, using an Area Under the Curve calculation (customarily used to evaluate the accuracy of methods for diagnosing disease) the Gail model yielded an AUC of 58%, and the Gail-plus-genetics model yeilded an AUC of 61.8%. In an AUC model, the amount over 50% (the baseline of a test that is no better than random) is the measure of relative discriminatory power. So an increase from 8 to 11.8 is, yes, a small number, but also an improvement of something in the neighborhood of 45%. The study also shows that compared to each other, the set of genetic risk factors were more accurate predictors of breast cancer than were the Gail factors that are the current mainstay of risk assessment.
So I can see why the authors wouldn’t want to celebrating these results too loudly – because we need to do better. But what this study shows is that genetics is already taking us in the right direction, and that the addition of genetic risk to current clinical practice can – right now, today – provide a substantial improvement in the crucial task: to better risk stratify the population, focus screening on those who should have it, pick up more cancers earlier and save lives. I can’t see anythig but good news in that. Our task is to keep discovering new risk factors that will continue to increase the power of these tests, and we are committed to doing so.
Dr. Kari Stefansson
deCODE Discovers A Major Risk Factor for Type 2 Diabetes Dependent on Parent of Origin
deCODE scientists have discovered a single SNP that confers increased risk if inherited from the father, but is protective if inherited from the mother
Scientists at deCODE genetics, Inc. publish in the journal Nature the discovery of a version of a common single-letter variant in the sequence of the human genome (SNP) with a major impact on susceptibility to type 2 diabetes (T2D). The impact of the T2D variant is not only large, but unusual: if an individual inherits it from their father, the variant increases risk of T2D by more than 30% compared to those who inherit the non T2D-linked version; if inherited maternally, the variant lowers risk by more than 10% compared to the non T2D-linked version. Nearly one quarter of those studied have the highest risk combination of the versions of this SNP, putting them at a roughly 50% greater lifetime risk of T2D than the quarter with the protective combination. This is the second largest effect of any genetic variant for T2D apart from SNPs in TCF7L2, discovered by deCODE in 2006.
“We could make this discovery beacause we are in the unique position of being able to distinguish what is inherited from the mother from what is inherited from the father. This we can do because of the large amount of data we have assembled on the Icelandic population. Read the rest of this entry »
Who’s afraid of genetic testing?
As a deCODEyou reader, you have an active interest in how genetics can help to improve personal health and healthcare. If you are a deCODEme subscriber or have taken one of our DNA-based diagnostic tests, you have already followed up on that interest.
Then again, you may not have had your genome analyzed yet. You may simply be interested in taking part in research, having a scan, or simply in keeping up with the latest discoveries.
But whoever you are, your genome is information about you. And at deCODE, we believe that your genome belongs to you. Over the past decade we have worked with hundreds of thousands individuals who have decided to use their genome to advance our gene discovery work, to understand their risk of a certain disease, or who want to have a broad and constantly updated look at their genome through deCODEme. In every case, we think it is the individual who has the right to decide to use their genome and learn about it as they wish.
The battle against breast cancer gets personalized
A new genetic test assessing a woman's risk of developing the most common forms of breast cancer has arrived. Can the test, developed by the biopharmaceutical company deCODE, improve the way doctors screen for breast cancer?
Breast cancer kills 40,000 people a year in the U.S. This is about the population of Atlantic City, New Jersey. Imagine, each year an entire city wiped out by breast cancer.
To help fight breast cancer, a new test assessing individual risk has just become available. For women without a clear family history of the disease, the deCODE BreastCancerTM test assesses their personal risk of developing the most common forms of breast cancer. The DNA test, launched by the biopharmaceutical company deCODE, makes it possible to identify those women at significantly higher than average risk, helping doctors use new screening technologies and treatments in a more targeted, personalized and effective manner.
The Breast Cancer Network of Strength celebrates 30 years of invaluable support
Breast Cancer Network of Strength was started by Mimi Kaplan and Ann Marcou.
Attitudes towards breast cancer have changed quite a lot over the past three decades, a fact evidenced by the outpouring of response when stars such as Olivia Newton-John, Kylie Minogue, and, most recently, Christina Applegate, went public with their personal struggles with the disease. But this change in attitude is also reflected in many other ways and not least in the adoption of a new name for the patient advocacy and support organization that until now called itself Y-ME? Tomorrow, a gala event held at the Fairmont Hotel in Chicago will celebrate Breast Cancer Awareness Month and the evolution of Y-ME, 30 years on, into the Breast Cancer Network of Strength-a change they hope that will better communicate the organization’s mission to promote a proactive, engaged and positive approach to fighting breast cancer.
Breast cancer gene tests explained
On October 8th MSNBC published an article by Arthur Caplan, Ph.D. on genetic tests for breast cancer.
The following is a response by Jeff Gulcher, M.D., Ph.D, Chief Scientific Officer at deCODE Genetics.
Arthur Caplan stresses caution in the application of the new genetic risk tests for common diseases and I certainly agree that genetic testing should be applied with care. However, he goes too far when he says that the new deCODE BreastCancer genetic risk test is only useful for women who have two or more close relatives with breast cancer, is not based on large enough studies to be accurate, and is not regulated.
There are two major types of breast cancer: the rare, early onset form that occurs in certain families and for the detection (for which the Myriad Genetic test is well suited), and the common form which accounts for 95 percent of breast cancer. The vast majority of women who develop breast cancer do not have the conventional risk factors of family history, pregnancy history or breast density. Unfortunately, many of these women were likely considered to be of average risk before their cancer was found. Therefore, they were not even offered screening with breast MRI which detects two to three times more cancer at an earlier stage than mammography alone, or preventive measures such as tamoxifen treatment which can cut down cancer rates by 40 to 50%.
Read the rest of this entry »
deCODE launches deCODE BreastCancer™, a genetic test to screen for risk of the most common forms of breast cancer
deCODE Breast Cancer enables women to understand whether they may benefit from more intensive screening, monitoring or preventive drug therapy.
Reykjavik, ICELAND, October 8, 2008 – deCODE genetics today announced the launch of deCODE BreastCancer™, a new tool for assessing risk of the common forms of breast cancer. For the first time, a woman concerned about breast cancer can speak with her physician about a genetic test to better understand her lifetime risk of developing the common forms of the disease.
The common forms of breast cancer result from the interplay of genetic as well as environmental and lifestyle factors and represent 95 percent of all breast cancers. These are distinct from the rare and essentially purely inherited forms of the disease due to mutations in the BRCA1 and BRCA2 genes, which cause between 1 and 3 percent of breast cancers. deCODE BreastCancer™ is a DNA-based reference laboratory test performed using a simple blood sample or cheek swab, ordered by physicians on behalf of their patients.
Read the rest of this entry »
deCODE scientists discover another set of common genetic variants linked to risk of breast cancer
Scientists from deCODE genetics today report the discovery of two common single-letter variants (SNPs) associated with risk of estrogen receptor-positive (ER+) breast cancer. More than 60% of the general population carry at least one copy of the risk variant of the most important SNP, and women who have inherited the variant from both parents are at approximately 50% greater risk of developing ER+ breast cancer than women who have not inherited the variant. The second variant is located near the first and occurs only in tandem with it, adding slight risk of the disease. Although these variants confer modest risk, they are so common that they are estimated to account for approximately 11% of breast cancers overall.
With this latest discovery, the genetic factors underpinning a very significant proportion of inherited risk of ER+ breast cancer have now been elucidated. Common variants previously discovered by deCODE are together involved in an estimated 25% of ER+ breast cancers.
deCODE made today’s discovery through the analysis of genotypic data from a total of nearly 40,000 patients and control subjects from five countries. deCODE gratefully acknowledges the participation of the patients and researchers who took part in this study.
