Scott Tomlins, MD, PhD, a pathologist at the University of Michigan, Ann Arbor, was cautiously optimistic about this new test. “Whenever you introduce a new biomarker, you need to demonstrate its ability to impact clinical decision-making, and it needs to improve on what we currently have,” he commented. “It is unlikely that the [cell-cycle progression score] will replace the [prostate-specific antigen (PSA)] value and the Gleason score, so it needs to show benefit when added to models that optimally incorporate these and other parameters.”
Most patients have multifocal disease, and analysis of the cores taken at biopsy may not catch the different foci. In those cases, the clinically relevant tumor focus may not be the one analyzed, he explained.
Unanswered questions remain: Can these scores predict cores that are not sampled? Does incorporating this novel biomarker improve on the accuracy of currently available models that incorporate PSA values and Gleason score? “This has not been shown yet,” Dr. Tomlins cautioned.
“How much does the [cell-cycle progression score] improve on the Cancer of the Prostate Risk Assessment [CAPRA, a 10-point risk-assessment score developed at the University of California, San Francisco] at diagnosis? What would doctors do if the [cell-cycle progression score] showed a lower risk? Adoption of this test will require buy-in from different sectors of the health-care community,” he concluded. ■
Disclosure: Dr. Tomlins reported no potential conflicts of interest.