Second study confirms data on PSADT and survival post-surgery
Posted Dec 29 2010 12:00am
In 2009, at a presentation at the American Society for Clinical Oncology, Antonorakis et al. initially presented data , from the Johns Hopkins database, demonstrating the prognostic significance of PSA doubling time (PSADT) to long-term survival of men with progressive prostate cancer who were otherwise untreated after surgery.
In a second paper, this time based on data from the Center for Prostate Disease Research (CPDR) National Database, Antonarakis et al. have now been able to replicate the data originally presented at the ASCO meeting. The CPDR National Database is a multi-center data registry that collects data on prostate cancer from one civilian and five military hospitals. Because of its military orientation, the database captures patients from a wide ethnic background.
The research team carried out a retrospective analysis of data from patients in this database who had a biochemical relapse (PSA ≥ 0.2 ng/ml) after an initial radical prostatectomy and who had no additional therapy until the time of radiographically evident metastatic disease.
Results of this study showed the following:
346 men underwent radical prostatectomy between May 1983 and November 2008 and fulfilled the entry criteria.
All 346 patients had information on survival and 190/346 men had information on metastasis.
10-year overall survival was 79 percent at a median follow-up of 8.6 years after biochemical recurrence.
10-year metastasis-free survival was 46 percent at a median follow-up of 7.5 years after biochemical recurrence.
Patient age, Gleason score, pathological stage, time to PSA relapse, and PSA doubling time were all predictive of overall and/or metastasis-free survival in univariate analysis
Only PSA doubling time (≥9.0 months vs 3.0-8.9 months vs < 3.0 months) remained independently predictive of overall and/or metastasis-free survival in multivariate analysis.
The authors note that based on this data set – overall and metastasis-free survival ”can be extensive for men with PSA-recurrent prostate cancer, even in the absence of further therapy before metastasis.”
In other words, men with a PSA doubling time > 9 months after initial biochemical failure have a high probability of long-term metastasis-free survival, which may call into question the value of any form of second-line therapy until there is clear evidence of the presence of metastatic disease.
This data set is the second-largest available data set after the Johns Hopkins cohort. The analysis confirms the original finding that PSA doubling time is the strongest predictor of overall and metastasis-free survival among men with PSA-recurrent disease after first-line surgery alone. It should be noted that, in their original paper, based on 25-year follow-up data in the Johns Hopkins cohort, Anonarakis et al. were able to show an even lower risk for prostate cancer-specific mortality among men with a PSA doubling time of 15 months or longer.