Proximal PSA levels of 10 ng/mL or higher in men with biochemically recurrent prostate cancer (PCa) after radical prostatectomy and a PSA doubling time (PSADT) less than 12 months independently predicts imminent development of metastasis, according to study findings presented at the European Society for Medical Oncology 2017 Congress in Madrid.
A team led by Mark C. Markowski, MD, PhD, of Johns Hopkins University in Baltimore, studied 513 men with biochemically recurrent PCa—defined as a PSA level higher than 0.2 ng/mL after radical prostatectomy—and a PSADT less than 12 months. They defined proximal PSA as the most recent PSA value at least 6 months prior to the development of metastatic disease.
Results showed that a proximal PSA of 10 ng/mL or higher versus less than 10 ng/mL was associated with a significant 2.7-fold increased risk of metastasis.
“These data allow clinicians to counsel their patients regarding risk of metastasis and treatment considerations,” Dr Markowski told Renal & Urology News. “Most important, these data provide critical information for selecting patients for clinical trials.”
The median metastasis-free survival (MFS) times differed significantly by PSADT subgroups. Among patients with a PSADT of 6.01 to 12 months, the median MFS was 20 years for those with a proximal PSA less than 10 ng/mL compared with 5 years for men with a proximal PSA of 10 ng/mL or higher. The corresponding median MFS for men with a PSADT of 3.01 to 6 months was 7 and 3 years, respectively. The median MFS for men with a PSADT of 3 months or less did not differ significantly by proximal PSA value.
The study was a collaboration of Johns Hopkins, the Center for Prostate Disease Research, and the Department of Surgery at the Uniformed Services University of the Health Sciences. At enrollment, the study participants had not received adjuvant or salvage androgen deprivation therapy or radiotherapy. The investigators prospectively followed up the men until radiologic evidence of metastasis. Metastases developed in 218 men (42.5%) during a median follow-up of 9 years. Shorter PSADT was associated with an elevated risk for distant metastasis. Compared with a PSADT of 10.5 to 12 months, a PSADT of 4.01 to 7.5, 4.51 to 6.0, 3.01 to 4.51, and 3 months or less was associated with a 2.2, 2.6, 3.9, and 4.8-fold increased risk of distant metastasis, respectively.
Markowski MC, Chen Y, Feng Z et al. PSA doubling time (PSADT) and proximal PSA predict metastasis-free survival (MFS) in men with biochemically recurrent prostate cancer (BRPC) after radical prostatectomy (RP): Implications for patient counseling & clinical trial design. Data presented at the European Society for Medical Oncology 2017 Congress in Madrid, Spain. Poster 818P.