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Entries in Mutations (3)

Thursday
Mar082012

Why a Cancer 'Cure' Is So Elusive

iStockphoto/Thinkstock(NEW YORK) -- In the realm of targeted cancer treatment, Carla Leslie is a success story.

Leslie was diagnosed in September 2010 with Stage 3C breast cancer, a disease that kills 50 to 60 percent of those who have it within five years.  She was treated at MD Anderson Cancer Center in Houston with chemotherapy plus Herceptin, a drug that targets a specific genetic mutation in certain kinds of breast cancer.  The results were remarkable; Leslie is now in remission.

Stories like Leslie's are becoming more common.  Yet, as any doctor will tell you, even today the prospect of a cure for most kinds of cancer is elusive.

Doctors have had some success using drugs like Herceptin, which tailor a patient's treatment to their specific genetic makeup.  This practice, known as "personalized medicine," is an effective approach in some cases.  But the cancers that cannot be treated with these personalized approaches -- in other words, most of them -- are so complex that any simple approach to treating them remains elusive, at least for now.

New research, published Wednesday in the New England Journal of Medicine, reinforced this idea, demonstrating that the tumor cells of a particular kind of cancer can vary not only throughout a particular patient's own body, but even within a single tumor.  Each of these different variations of the same kind of cancer cell is known as a mutation, and each of these mutations can be thought of like a target. So while a given treatment might hit some of these targets, others are left unscathed, and the cancer remains.

In this study, researchers took multiple samples of tumors from four patients with a kind of cancer originating in the kidneys called metastatic renal cell carcinoma.  By analyzing these samples, they found that cancer cells within a single tumor and at places where the cancer had spread showed a large amount of variation, with 60 percent of tumor mutations not uniformly detected in every part of the tumor.

This has implications not only for treatment, but for diagnosis as well.  In some cases, the researchers found mutations associated with both good and bad prognosis in different parts of the same tumor.

The variation among tumor cells might actually help cancer to survive and could explain why some cancers become resistant to chemotherapy.

These findings highlight new challenges in the management of cancer and suggest that, in many cases, the idea of "personalized medicine" might be too simplistic for cancer treatment.

Copyright 2012 ABC News Radio

Tuesday
Nov292011

Scientists Concerned About New Bird Flu Vaccine Research

iStockphoto/Thinkstock(ROTTERDAM, Netherlands) -- Research on the bird flu virus that involved creating a highly contagious strain has some scientists worried that the findings could lead to the development of a bioweapon, according to numerous media outlets.

At a European flu conference in September, Ron Fouchier, a scientist at Erasmus Medical Center in Rotterdam, the Netherlands, doing vaccine research presented his work on H5N1, the virus that causes bird flu.  By infecting ferrets with different altered strains of the virus manufactured in the laboratory, he and his colleagues discovered a form of the virus that was lethal and easily spread through the air.

Fouchier explained it took only five mutations for the virus to become extremely contagious.  The ferrets infected with the new virus died.  Ferrets are often used in flu virus research, experts say, because viruses multiply in these animals in ways similar to humans.

In a conference newsletter, Fouchier called his team's findings "very bad news."

"This virus is airborne and as efficiently transmitted as the seasonal virus," he said.  Fouchier did not respond to ABC News' request for comment.

While thousands of people and millions of birds have died from bird flu worldwide, it never became a global human scourge because H5N1 isn't easily spread among humans, and it's primarily seen in people who are in close contact with infected birds.

But like any virus, H5N1 can mutate, and the possibility of creating such a lethal and transmissible form of the virus caught the attention of scientists in the United States.  Before Fouchier's research is published in a scientific journal, it is undergoing review by the U.S. National Science Advisory Board for Biosecurity (NSABB), a government committee tasked with assessing research known as "dual use," meaning it has scientific value, but could also pose a threat to public health.

The NSABB does not have the power to prevent publication of scientific findings, but it can request that journals not publish certain studies.

One member of the NSABB contacted by ABC News didn't want to comment on Fouchier's research, saying he wants to wait until the board releases its findings.

But one scientist not affiliated with NSABB, Dr. Thomas Inglesby, director of the University of Pittsburgh Medical Center's Center for Biosecurity, told NPR this research should not be made public.

"It's just a bad idea for scientists to turn a lethal virus into a lethal and highly contagious virus, and it's a second bad idea to publish how they did it so others can copy it," Inglesby said.

Copyright 2011 ABC News Radio

Tuesday
Jan182011

New Test Finds 580 Fatal Diseases Before Conception

Photo Courtesy - Getty Images(SANTA FE , N.M.) -- A new DNA test has been developed to detect parents who are carriers of 580 of the most severe inherited childhood diseases, including Batton, muscular dystrophy, and immune deficiencies like the "Bubble Boy" syndrome and Pompe disease, described in the 2010 film Extraordinary Measures.

The test, which was announced in the journal Science in Translational Medicine, uses genetic sequencing to identify recessive mutations before a couple decides to become parents.

The average person carries at least two-to-three gene mutations that can cause diseases.  When both have the same mutation, the chance of having an affected child is one-in-four; the risk of having a child who is a carrier is two-in-four; and the odds of having a normal child is one-in-four.

The carrier screening test is cheap -- less than $400 for hundreds of conditions -- and could be marketed in the near future, according to Dr. Stephen Kingsmore, now a physician-researcher at Children's Mercy Hospital in Kansas City, Missouri, where clinical work will be done.

"The long-term impact could be phenomenal," said Kingsmore, who headed up the research at the National Center for Genome Resources in Santa Fe, New Mexico.

The test will likely be a blood test and later a simple swab of the cheek.  Egg and sperm banks may be the first industry to adopt the testing to screen potential donors. 

Copyright 2011 ABC News Radio







ABC News Radio