Wednesday, October 14, 2009

Chromosomal Test By Molecular Biologists Determines Cancer Spread

A new biopsy test, created by molecular biologists, can tell ocular melanoma patients if theirs is the kind that will spread. Using very thin needles, surgeons collect cells from tumors and analyze them. If tumors are missing a copy of chromosome three, patients are at high risk of having their cancer spread. While there's no cure for ocular melanoma, patients who are at higher risk can be followed more closely and put on experimental treatments.

Ocular melanoma, or eye cancer, is a serious disease that affects about 2,000 Americans each year. Roughly half of patients will die from the cancer because their tumor spreads to other areas of the body. Now, a new test can tell patients if they're looking at life ... or death.

Just like everyone, Susan Izanstark-Rosenthal relies on her eyes every second of every day. "I'm an attorney, and I read and write all day long," she says.

But about a year ago, she didn't know if she'd be able to see out of her left eye ever again. Rosenthal was diagnosed with ocular melanoma. Surgery followed.

"It was very scary, and I didn't know when I woke up if I'd be able to see in the other eye," she says. Even scarier -- she found out she could die if her cancer spread. Ocular oncologist Tara Young, says a new biopsy test can tell patients if their tumor is the kind that will spread.

"It represents the first step that we've been able to make in a long time with this cancer," Young, of the Jules Stein Eye Institute at UCLA, tells DBIS.

Using very thin needles, surgeons collect cells from tumors and analyze them. If tumors are missing a copy of chromosome three, patients are at high risk of having their cancer spread. If tumors are normal, they have a very low risk.

"If someone could tell you that you were gonna go and die of your cancer, I think that most people want that information and that knowledge, so that they can just take a little bit more control over their lives," Young says.

Only a handful of medical centers across the country are performing the eye biopsy technique. While there's no cure for ocular melanoma, patients who are at higher risk can be followed more closely and put on experimental treatments. She says so far, all of her patients have wanted to know the results of their biopsy.

Rosenthal wasn't missing a copy. It's a great relief for her -- and her daughter. "It's given me, once again, a reminder that you need to appreciate every day and be very grateful for what you have," Rosenthal says.

BACKGROUND: The Jules Stein Eye Institute at the University of California, Los Angeles, is the first center in the country to practice analyzing rare eye cancers at a level as small as a molecule. The new biopsy technique looks for a certain chromosome within the tumor that can predict which tumors have a high risk of spreading. Physicians can determine this earlier, and thereby recommend much more aggressive treatment, resulting in longer survival rates for their patients. Since 2005, JSEI has performed more than 70 procedures.

ABOUT THE DISEASE: Ocular melanoma -- eye cancer -- is a particularly rare and aggressive form of cancer that attacks the pigment cells in the retina. There are essentially two types of intraocular melanoma: low-grade tumors, which grow slowly and rarely metastasize, and high-grade tumors, which grow more quickly and metastasize at a very early stage. Once a tumor metastasizes, the cancer spreads quickly to the liver and other organs, and a patient has only 6 to 12 months to live in most cases, although some can survive for as long as 5 years. The National Eye Institute reports some 2000 newly diagnosed cases of ocular melanoma per year in the US and Canada's roughly seven in one million people. It affects people of all ages and races, and is not hereditary. Ocular melanoma kills nearly half of those who develop it

IT'S ALL IN THE GENES: Doctors understand very little about the molecular changes that result in this aggressive behavior, but they now know that patients who are missing one copy of chromosome 3 in their tumor tissue are more likely to have highly aggressive cancers. For the first time, UCLA surgeons have demonstrated that it is feasible and safe to perform a biopsy on a living eye. They use an ultra-fine needle to collect cells from the cancer before surgery and send the sample to the lab for culture. After growing the tumor cells, a geneticist analyzes them to determine which are missing a copy of chromosome 3. This genetic marker tells them which patients require more aggressive treatment for their cancer.

WHAT ARE CHROMOSOMES? A chromosome is a single large macromolecule of DNA, and constitutes a physically organized form of DNA in a cell. It is a very long, continuous piece of DNA (a single DNA molecule), which contains many genes, regulatory elements and other intervening nucleotide sequences. A broader definition of "chromosome" also includes the DNA-bound proteins which serve to package and manage the DNA. The word chromosome comes from the Greek chroma ('color') and soma ('body') due to its capacity to be stained very strongly with dyes.

Courtesy:ScienceDaily

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