The prognostic value of CTCs in low-volume prostate cancer
Posted Oct 11 2010 12:00am
Circulating tumor cell (CTC) levels have clearly been shown to have relevance to the prognosis of men with metastatic, castration-resistant prostate cancer, but we still know little about their potential importance in men with early stage disease.
Ali et al. have attempted to assess the incidence of circulating tumor cells (CTCs) after radical prostatectomy (RP) in a cohort of prostate cancer patients with low-volume tumors (< 0.5 cm3).
After radical prostatectomy, they took blood samples from 64 patients to assess their CTC levels. Only 9/64 patient actually met criteria for low-volume prostate cancer, and among these 9 patients:
7 had detectable levels of CTCs.
PSA elevation was evident in 2/7 patients with detectable CTCs.
The detection of CTCs did not predict biochemical failure.
It is possible that if one tested such men for CTC levels regularly over time, one could correlate rising CTC levels with rising PSA levels, but this would likely not add a great deal to our ability to project risk for men who were already at evident risk from biochemical failure.
Many men showing CTCs in blood soon after radical prostatectomy may be sufficiently immunologically competent to eliminate such cells naturally within a relatively brief period of time after surgery. This does raise the question whether men with early stage disease and suppressed immune systems are at any greater risk from CTCs immediately post surgery.