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 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.
The Biophysical Society contributed to the information contained in the TV portion of this report.