Harvard, MIT teams identify a 'pre-malignant' phase for blood cancers

In cancer treatment, diagnosing and drugging the disease at an early stage has become a key survival strategy. Now two different groups of investigators from Harvard and MIT say they've found a way to identify a large group of patients that are characterized by a very high risk of developing blood cancers--and their discovery could pave the way to a new treatment approach in oncology.

Two research teams made the advance independently of each other. Sequencing DNA samples from patients who had not yet developed cancer, the investigative teams studied the somatic mutations found in cells--mutations that probably begin in blood stem cells and develop over time as they divide and replicate.

The work led them to a group of people with a "pre-malignant" status that becomes more likely to develop into cancer as people age. Because these cells replicate more frequently, the boost increases the chance that subsequent mutations will come along to trigger cancer.

People who carry the mutations bear a 5% chance of developing a blood cancer within 5 years--and for every decade they age past 40, their chances of being diagnosed with cancer grows 10%.

Steven McCarroll

"People often think about disease in black and white--that there's 'healthy' and there's 'disease'--but in reality most disease develops gradually over months or years. These findings give us a window on these early stages in the development of blood cancer," said Steven McCarroll, senior author of one of the papers. McCarroll is an assistant professor of genetics at Harvard Medical School and director of genetics at the Broad's Stanley Center for Psychiatric Research.

"Cancer is the end-stage of the process," said Siddhartha Jaiswal, a Broad associated scientist and clinical fellow from Massachusetts General Hospital. "By the time a cancer has become clinically detectable it has accumulated several mutations that have evolved over many years. What we are primarily detecting here is an early, pre-malignant stage in which the cells have acquired just one initiating mutation."

- here's the release