A report this week in Urologic Oncology has confirmed the importance of PSA doubling times in understanding risk for prostate cancer progression among men with non-metastatic, castration-resistant prostate cancer (nmCRPC).
The paper by Freedland et al. in Urologic Oncology reviewed data from just over 12,000 men with nmCRPC being treated within the Veterans Administration health system between January 2007 and August 2017.
The patients’ PSA doubling times were divided into five groups, as follows:
- Less than 3 months
- 3 to 9 months
- 9 to 15 months
- 15 or more months
- Unknown
and the patients were then assessed for metastasis-free survival (MFS) and overall survival (OS) times in correlation with the PSA doubling times.
The core findings of the study were that:
- Shorter PSA doubling times were associated with shorter MFS and OS.
- Patients who developed metastasis had a three times higher risk of death compared to those without metastasis (hazard ratio [HR] = 2.933).
Unfortunately the abstract of the paper does not provide detailed information about the variations in MFS and OS by PSA doubling time group, which might be helpful. The full text of this paper is not available on mline.
The study also reported that onset of nmCRPC and mCRPC was associated with a substantial increase in use of health care services and costs — which is hardly a surprise.
Several years ago now, researchers at John’s Hopkins had shown that PSA doubling times of < 3 months were prognostic for early risk for progression and mortality in men with advanced forms of prostate cancer, so this is not a “new” piece of information. However, it is a valuable piece of information in that it tells us that despite the availability of several new forms of therapy in recent years the basic idea that a short PSA doubling time if prognostic for earlier onset of metastasis and a briefer peiod of overall survival has not changed significantly.
According to a report on this paper in Renal & Urology News, Freedland et al. state that their findings of a pronounced increase in health care costs following progression to mCRPC suggest that
delaying the onset of metastasis with newly approved antiandrogens may lead to savings, or at least delays, in medical costs, although this has yet to be formally tested.
Filed under: Uncategorized | Tagged: castration-resistant, doubling, mCRPC, metastasis, nmCRPC, non-metastatic, PSA, survival |
THE "NEW" PROSTATE CANCER INFOLINK 
There is a certain amount of circular logic in statements about PSA doubling time (PSA-DT) and cancer progression.
Most calculations of PSA-DT are derived from the last 3 PSA test results as recommended in the published literature. PSA progression is a commonly recognized surrogate measure of tumor progression. Accordingly, it would be virtually impossible for PSA progression not to be correlated with tumor progression, except in those cases of neuroendocrine tumors where PSA is recognized as a poorer indicator of tumor activity.