One standard approach to curing cancer is to kill off malignant cells, and doctors consider their treatment a success when no cancerous cells remain. However, many patients whose test results show no malignancy have their cancer reappear years later. New research suggests an explanation.
Scientists working with mice find that when they crank up production of a protein called Myc, they spur liver-tumor growth, and stopping Myc manufacture halts it. Although the cancer then regresses, not all the tumor cells die, the researchers find. Some differentiate into what appear to be normal liver cells. But their cancerous proclivity reawakens when the cells are given the right cue—a new jolt of Myc, the researchers report in an upcoming Nature.
A dormant cancer might not be so bad, says study coauthor Dean W. Felsher of Stanford University School of Medicine. "If we can make cancer sleep for a lifetime, maybe that's good enough," he says.