Blood test

Could a New Blood Test Predict Breast Cancer Risk?

blood test for Breast Cancer

Researchers believe they may have a new way to test a woman’s risk for breast cancer, even if she doesn’t have an inherited genetic mutation.

The test looks not for mutations, but for changes to how DNA functions — in this case, the BRCA1 breast cancer gene.

It’s important because most cases of breast cancer are not caused by inherited DNA mutations. About 40 percent of breast cancer cases can be explained by genetic susceptibility, which leaves most to outside causes such as diet, exercise, smoking and alcohol use.

“Women who carry the signature are at particularly higher risk of developing breast cancer in the future,” said Martin Widschwendter at University College London, who led the study.

The researchers looked for changes made by a process called methylation, which can step up or down a gene’s function.

BRCA1 brakes cell growth, stopping the out-of-control proliferation that turns a healthy cell into a tumor.

Widschwendter and colleagues tested blood from women with and without BRCA1 mutations before they ever developed breast cancer. Both groups had similar changes in the DNA methylation, they report in the journal Genome Research.

“It was able to predict breast cancer risk several years before diagnosis,” Widschwendter said. The changes may be caused by factors that raise breast cancer risk, such as obesity and drinking too much alcohol, he says.

The researchers tested their “signature” in three different groups of women and found it could consistently predict who would develop cancer five to 12 years later.

“I think this is a productive direction,” says Dr. Jeffrey Weitzel, director for clinical cancer genetics at the City of Hope Cancer Center in Duarte, California.

Breast cancer is the most common cancer affecting women. It will be diagnosed in more than 200,000 U.S. women this year and will kill 40,000.

There’s a debate over how best to prevent it and who benefits most from screening. Right now, women get conflicting advice on when to get mammograms — starting at age 40 or age 50, depending on who’s talking. And there’s disagreement over how often women should get one — once a year, every other year or even every three years.

A simple test that could show who’s at the highest risk of the most dangerous types of breast cancer could help women decide. “A test could help us tailor screening and risk reduction for women,” said Weitzel. For instance, recent research suggested that women with the very highest risk should remove their ovaries.

“We know that we can change risk,” Weitzel said.

Women at high risk can also take tamoxifen to reduce that risk and those at the very highest risk can consider having mastectomies to reduce — but not eliminate — the likelihood that they will get breast cancer. “Most of us think the absolute risk should be 50 percent or more before you offer surgical removal,” said Weitzel.

The test is far from ready for prime time. Right now it’s not terribly accurate, says Widschwendter. It was only tried in a few women. And the team tested blood. It might be better to test cervical cells, perhaps as a test alongside the regular Pap smear that many women get, because these cells respond to the same hormones associated with most cases of breast cancer.

Researchers are still working to understand all the underlying causes of breast cancer. Just this month, another team discovered that women with many moles also had a slightly higher-than-usual breast cancer risk.

More than 75 different genes are linked with breast cancer risk. BRCA1 and BRCA2 are the best known.

Source: NBC news

Cheaper blood test to diagnose asthma

Researchers have developed a faster, cheaper and more accurate tool for diagnosing even mild cases of asthma using just a single drop of blood.

The researchers used neutrophil cell function in a clinical study to show accurate asthma diagnosis.

To directly diagnose asthma, David Beebe, a UW-Madison professor of biomedical engineering and co-author on the paper, and his team focused on the cell function of neutrophils. Neutrophils are the most abundant white blood cell in the body and generally are the first cells to migrate toward inflammation.

“Neutrophils are sort of like a dog tracking something. They sense a chemical gradient, like an odor, in the body,” Beebe says.

In other words, the human body emits chemical signals in response to inflammation or wounds and the neutrophils detect those chemical signals and migrate to the site of the wound to aid in the healing process. Researchers can track the velocity at which the neutrophil cells migrate — the chemotaxis velocity — to differentiate nonasthmatic samples from the significantly reduced chemotaxis velocity of asthmatic patients.

UW-Madison students have developed the kit-on-a-lid-assay (KOALA) microfluidic technology, which allows them to detect neutrophils using just a single drop of blood.

The KOALA diagnostic procedure uses simple lids and bases (each being a small, cheap piece of plastic), diagnosticians place a KOALA lid containing a chemical mixture onto the base containing the blood sample. That chemical mixture triggers neutrophil migration — and researchers can automatically track and analyze the neutrophil chemotaxis velocity using custom software.

The team has published online in the journal Proceedings of the National Academy of Sciences

Source: Times of India

 

Egg Timer Test proves unreliable guide to fertility

A popular fertility test designed to tell a woman how long she has left to fall pregnant is providing inaccurate and misleading results, creating a wave of panic among women in their 30s and 40s, Australia’s leading fertility expert, Dr Anne Clarke, said.

Dr Clarke, medical director of Fertility First in Sydney, said a recent British study, plus anecdotal evidence, had found the simple blood test, known as the Egg Timer Test, was unreliable and becoming discredited worldwide. ”I have big concerns about its accuracy,” she said. ”I’m seeing a lot of women turning up at my clinic in an incredibly distressed state and highly depressed because they’ve been told the test showed they had no chance of having a baby. It’s wrong and misleading.”

Among them was a 40-year-old Sydney woman who was told by her GP in April last year that the test, which measures the level of anti-mullerian hormone (AMH) in the blood, showed her ovarian reserve was dangerously low. Further analysis revealed she was very fertile and well within the normal range, Dr Clarke said.

The Egg Timer Test – which costs about $70 – was pioneered by Adelaide clinic Repromed in 2004, to measure the number of eggs a woman had and predict how many child-bearing years she had left. With thousands of women rushing to take the test, other companies entered the market, but Dr Kelton Tremellen, of Repromed, said they were not always reliable. ”[If it’s not done properly] one person’s blood test can be analyzed and get two vastly different results,” he said. Results could be compromised, for example, if a woman had been on the pill. Dr Clarke added that inaccurate readings also occurred when the blood was stored incorrectly or the hormone not analyzed immediately.

 

Asked if women should have the test, she said: ”I’m not sure of the value of the test. If I want to look at ovarian reserves, I do an antral follicle count with an ultrasound.”

The first reported study on the effectiveness of the Egg Timer Test was damning. The Manchester study, published last year, found significant variations in the results – up to 60 per cent.

Head researcher Dr Oybek Rustamov said the study, which looked at the results of 5000 women between 2008 and 2011, found ”commercial AMH or Egg Timer Tests provide erroneous results”.

Dr Clarke said research was increasingly discrediting and devaluing the test as a means of gauging a woman’s biological clock.

Cheriece Harper, 31, from Penrith, had the Egg Timer Test in 2011 and was left depressed when her doctor told her she had little chance of conceiving. Ms Harper consulted Dr Clarke, became pregnant via a sperm donor and gave birth to Bridie in October last year.

”I’m glad I had the test because it pushed me to make a decision and not delay motherhood, but if women get it done, they need to know it’s measuring egg quantity, not quality.”

Source: Sydney Morning Herald