(HealthDay News) — The probability of nonlocalized upstaging on prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) may be prognostic of long-term outcomes in high-risk prostate cancer, according to a study published in JAMA Network Open.
Michael Xiang, MD, PhD, from the University of California in Los Angeles, and colleagues examined the prognostic significance of a nomogram that models an individual’s risk for nonlocalized upstaging on PSMA PET/CT and compared its performance with existing risk-stratification tools in a cohort study of 5,275 patients diagnosed with high-risk or very high-risk prostate cancer. The biopsy Gleason score, percentage positive systematic biopsy scores, clinical T category, and prostate-specific antigen level were included in a nomogram to calculate PSMA upstage probability.
The researchers found that 36% of the patients had biochemical recurrence (BCR), 16% developed distant metastasis (DM), and 5% died of prostate cancer during a median follow-up of 5.1 years. PSMA upstage probability significantly predicted all clinical end points, with eight-year C-indices of 0.63, 0.69, 0.71, and 0.60 for BCR, DM, prostate cancer-specific mortality (PCSM), and overall survival, respectively. Compared with other risk-stratification tools, the nomogram performed favorably.
“The PSMA nomogram was designed to predict the positivity of PSMA PET/CT at initial diagnosis, without regard to eventual clinical outcomes, but interestingly, this PSMA PET/CT-based tool provided better risk discrimination than existing tools that were designed specifically to predict clinical outcomes,” Dr Xiang said in a statement.
Several authors disclosed financial ties to the biopharmaceutical industry.