Creighton Medical Laboratories First To Offer New Cancer Test

Main Category: Cancer / Oncology
Also Included In: Genetics
Article Date: 16 May 2009 - 1:00 PDT

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Creighton Medical Laboratories, based at Creighton University School of Medicine in Omaha, announced today that it has become the first clinical laboratory worldwide to offer a new and more effective testing method for cancer.

The method, called SNP array karyotyping, has been successfully used in research laboratories to study cancer for several years. However, Creighton Medical Laboratories, using AffymetrixTM SNP arrays, is the first laboratory to validate the test in a clinical setting and make it available for routine clinical use.

The method can help doctors make more accurate cancer diagnoses and tailor patient management based on the DNA profiles of each person's cancer.

Array-based karyotyping is a 21st century spin on older genetic testing methods that have helped guide patient care for decades. DNA is bundled inside cells as chromosomes; a karyotype is a representation of all of the chromosomes in a cell. Normal human cells have two copies of each chromosome. Cancer cells will often duplicate or lose pieces of chromosomes, and these chromosomal changes can help physicians categorize a tumor, determine its aggressiveness, and/or determine which tumors will respond to specific drugs.

With the new method being used at Creighton Medical Laboratories, DNA from tumor cells is applied to the arrays and scanned into a computer. The chromosomes are reconstructed by the computer to provide a genome-wide view of the cancer cells at unprecedented resolution; physicians then 'surf' the cancer genome using web-based genome browsers.

"SNP array karyotyping is a powerful new tool in our molecular tool box," said Jill Hagenkord, M.D., a pathologist and director of molecular pathology and clinical genomics at Creighton Medical Laboratories. "We can detect genetic abnormalities that previously would have been missed."

The SNP (single nucleotide polymorphism) array used by Creighton allows the detection of a very common genetic abnormality or lesion in cancer cells - called copy neutral loss of heterozygosity (LOH) - that often goes undetected with conventional diagnostic methods as well as standard array-based karyotyping.

"As an example, with SNP-array virtual karyotypes, we have detected copy neutral LOH at important regions of the cancer genome, like the p53 gene in chronic lymphocytic leukemia. If the tumor has no functional copies of this important gene, it tends to behave aggressively, and the treating physician may want to treat it more aggressively," Hagenkord said. "This genetic lesion would not have been detectable with the current testing methods, which really underscores the importance of having this new testing method available clinically."

Roger Brumback, M.D., chair of the Department of Pathology at Creighton University School of Medicine, said, "We feel that SNP array karyotyping will become the standard of care for the diagnosis and management of many cancers. Creighton Medical Laboratories is excited to be at the forefront of this technology and proud to provide progressive medical care for our patients."

"We are very fortunate to have Dr. Hagenkord at the helm in clinical genomics, since she is currently the only pathologist worldwide with fellowship training in both molecular genetic pathology and pathology/oncology informatics. She has been performing SNP array karyotyping of tumors since the technology emerged and she is truly an expert in the field."

Source: Creighton University