Test gives insight into prognosis in patients with plasma cell malignancies

A new Mayo Clinic study due to be presented at the annual meeting of the American Society of Human Genetics in San Diego this week shows that a chromosome test called "FISH" is better than conventional methods in identifying chromosomal genetic abnormalities associated with plasma cell malignancies.

This improved chromosomal analysis may help physicians better assess a patient's prognosis and likelihood to respond to a given treatment.

Plasma cell proliferative disorders, or PCPD, account for approximately 10 percent of all blood born cancers that range from the very slow-growing smoldering myeloma to a very aggressive plasma cell leukemia.

The study will be presented by Ryan Knudson of the Mayo Clinic Cytogenetics Laboratory at 6:30 p.m., CDT, Wednesday, Oct. 24.

FISH, which stands for fluorescence in situ hybridization, detected chromosomal abnormalities in 67 percent of 1,548 patients with suspected PCPD. Conventional chromosomal analysis detected abnormalities in only 10 percent of the same patients. The FISH test is designed to detect genetic abnormalities in plasma cells whereas other conventional methods typically looks within any cell type that is present, says the lead author of the study, Rhett Ketterling, M.D., a Mayo Clinic pathologist and geneticist who specializes in chromosomes and chromosomal abnormalities.

“This test is a marked improvement over conventional chromosomal analysis and has become readily accepted into the diagnostic algorithm in patients with PCPD at Mayo Clinic and at other leading academic institutions,” Dr. Ketterling says.

The test should be applied to patients diagnosed with PCPD, particularly multiple myeloma, to determine the presence of genetic abnormalities that could offer insight into prognosis, he states.

“Our results show that a targeted plasma-cell specific FISH analysis is an important method for detecting common genetic abnormalities typically seen in patients with multiple myeloma,” Dr. Ketterling says.