KILLIN gene discovery stirs up research on Cowden syndrome cancers.

R esearchers at the Cleveland Clinic have identified what appears to be a powerful gene predictor for cancer among some patients with Cowden syndrome (CS) or Cowden-like syndrome (CLS) — rare, inherited conditions characterized in part by the presence of benign neoplasms throughout the body. Published in the Journal of the American Medical Association in December, the findings show that up to 85% of CS/CLS patients who have breast cancer also have a compromised gene called KILLIN. Moreover, CS/ CLS patients with compromised KILLIN also have much higher risks for kidney cancer than those CS/CLS patients without it. The study’s authors emphasize that other studies must still replicate these fi ndings. But if the results hold up, KILLIN could be one of the strongest genetic cancer risk factors discovered — on par with BRCA1 and BRCA2, albeit for this more limited CS/CLS population, according to the study’s corresponding author, Charis Eng, M.D., Ph.D . “The fi nding has important implications for testing — meaning improved molecular diagnosis of cancer among people with CS/CLS — and also for screening of cancer risk among CS/CLS patients and their relatives,” said Eng, who chairs the Cleveland Clinic’s genomic medicine institute. “If a CS/CLS patient tests positive in a KILLIN assay, we might lower the threshold for prophylactic mastectomy because it can be hard to distinguish breast cancer from the many benign nodules that characterize these conditions.”