Daily Archives: May 16, 2014

hide captionSex can matter, whether you're looking at drug side effects, the response to treatment, or the progression of a disease.

Many potential new drugs look like they could be big winners at least when judged by how well they work in mice or other lab animals. Over the years, there have been a number of promising cancer "cures," possible Alzheimer's treatments, and candidate drugs for holding back the ravages of various degenerative diseases.

But, time after time, these great promises fade away once the potential treatments are tried in people. There are lots of reasons for that. Humans aren't rodents, for starters.

But now the National Institutes of Health is targeting a more subtle problem in animal studies: Labs often don't consider that the sex of the animal could also influence research findings.

There are obvious sex differences in people when it comes to disease. Low-dose aspirin affects men and women differently. It appears that some of the gene variants that increase the risk of Alzheimer's are more potent in women than in men. And women are more likely than men to have bad reactions to drugs.

It should be no surprise, then, that mice and other lab animals also have sex differences in their response to drugs and diseases. Yet scientists often don't take that into account when planning their laboratory studies. In fact, sometimes they deliberately choose male mice, because scientists worry that the cycling reproductive hormones in female animals might make it harder to interpret the results. It also appears that males are sometimes favored because that's simply the conventional thing to do.

Enough! says Janine Clayton, director of the Office of Research on Women's Health at NIH, and NIH Director Francis Collins. They're starting to roll out new guidelines to make sure that research on animals as well as on tissue samples taken from animals takes into account potential differences between the sexes. Clayton and Collins laid out their plans this week in a Nature commentary.

These days, following an abysmal history of ignoring women in clinical trials in the late 20th century, a bit more than half of all participants in NIH-funded studies are women.

But "there has not been a corresponding revolution in experimental design and analyses in cell and animal research despite multiple calls to action," Clayton and Collins write.

Scientists who do the research often ignore the issue; so do colleagues who review the studies. And scientific journals also don't demand that scientists state the gender of animals used in the studies they publish.

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Medicine Needs More Research On Female Animals, NIH Says

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Newswise PHILADELPHIAWhile large genetic testing panels promise to uncover clues about patients DNA, a team of researchers from Penn Medicines Abramson Cancer Center (ACC) has found that those powerful tests tend to produce more questions than they answer. In a study of 278 women with early onset breast cancer who did not have the BRCA genes, the researchers found that only 2.5 percent of the patients had inherited mutations that were actually clinically actionable. Experts dont yet know how to interpret most of the mutations discovered by the testknown as massively parallel gene sequencing.

Results of the study, led by author Kara Maxwell, MD, PhD, a fellow in the division of Hematology-Oncology in the Perelman School of Medicine at the University of Pennsylvania, will be presented during the annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago in early June (Abstract #1510).

Large genetic testing panels sometimes reveal mutations in genes that are associated with an increased risk in developing cancer. BRCA 1 and BRCA 2 genes are prime examples, where women can opt for mastectomies and ovary removal surgerywhich research shows slashes their risk of developing those cancers. However, there is not yet guidance for clinicians on how to care for patients who exhibit other types of mutations, such as CHEK2 and ATM. These are known as variants of unknown significance (VUS).

Were in a time where the testing technology has outpaced what we know from a clinical standpoint. Theres going to be a lot of unknown variants that were going to have to deal with as more patients undergo large genetic testing panels, said Maxwell. Its crucial that we figure out the right way to counsel women on these issues, because it can really provoke a lot of anxiety for a patient when you tell them, We found a change in your DNA and we dont know what it means.

The team, which includes Susan Domchek, MD, the Basser Professor in Oncology and director of the Basser Research Center for BRCA in Penns ACC, and Katherine Nathanson, MD, an associate professor in the division of Translational Medicine and Chief Oncogenomics Physician for the ACC, studied 278 patients who had been diagnosed with breast cancer under the age of 40, were not carriers of the BRCA1 or BRCA2 mutations, and had no family history of ovarian cancer.

The researchers performed massively parallel gene sequencing to detect 22 known or proposed breast cancer susceptibility genes in each woman. Though the testing did reveal multiple variants of genes that are known to confer increased risk of breast cancer in patients who develop the disease young, only 2.5 percent of patients tested were found to have mutations that are actionable under current treatment guidelines, including TP53, CDKN2A, MSH2, and MUTYH.

In all, the sequencing revealed reportable variants in over 30 percent of the patients.

Knowing there is a mutation may not help us any more than knowing that the person has a positive family history which we already know, Nathanson said. We dont know yet what to do with the information on an individual basis, and there certainly are no clinical standards.

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Large Panel Genetic Testing Produces More Questions than Answers in Breast Cancer