An Italian group has published an analysis of data from their surgical series suggesting that it is possible to predict the probability of a persistently detectable PSA post-surgery.
Naselli et al. have attempted to identify factors predictive for a detectable, post-surgical PSA level in patients who undergo radical prostatectomy (RP) and to define the prognostic role of these factors post-surgery.
They were able to analyze data from 318 patients who underwent RP at their institution between 2002 and 2007. Appropriate patients for the analysis had to meet the following criteria:
- No neo-adjuvant therapy of any type
- Surgical specimens analyzed and reviewed according to a standardized protocol by two pathologists
- Clinical stage T1, T2, or T3 N0
- Pathological stage T2-3 and N0-1.
Pre- and post-surgical patient characteristics were as follows:
- The median patient age was 65. 22 years.
- All patients had a PSA > 20 ng/ml (6.9%).
- 56 patients (17.6 percent) had poorly differentiated prostate cancer at biopsy
- 77 patients (24.2 patients) had poorly differentiated prostate cancer after pathological examination.
- The patient’s stage was cT2/3 in 128 patients (40.2 percent), pT3 in 79 patients (24.8 percent), and pN1 in 20 patients (6.2 percent)
- Surgical margins were positive in 89 cases (28 percent).
- 33/318 patients (10.3 percent had a persistently detectable PSA post-surgery.
A careful analysis demonstrated that three factors were independent predictors of a persistently detectable PSA level post-RP:
- The patient’s PSA level(odds ratio 3.07; P = 0.0008),
- A pathological stage of pT3a/b (odds ratio 2.72; P = 0.0466)
- The presence of nodal metastasis (odds ratio 5.68; P = 0.0060)
As one might expect, such a persistently detectable PSA post-RP had great impact on prognosis. Twenty-four of these 33 patients experienced PSA progression and needed a second-line treatment.
The authors conclude that in their experience, a detectable PSA after RP can be predicted by the patient’s preoperative PSA, pathological stage, and nodal status.
(Strangely, they also manage to conclude that the use of hormonal therapy is appropriate in cases of progression, even though they present no data to support this conclusion.)
While the ability to predict the probability of a sustained and detectable PSA level immediately post-surgery is probably useful, and suggests the need for immediate adjuvant therapy, The “New” Prostate Cancer InfoLink would suggest that the form of that therapy may need to depend on the nature of the reason for the sustained PSA level. A man with pT3a disease may well be appropriate for immediate adjuvant radiation. A man with a clear case of N1 disease may be most appropriate for some type of clinical trial.
We are also puzzled by the fact that the authors did not consider that the pathologic Gleason score might be highly predictive of an elevated post-RP PSA. They offer limited data on the patient’s cancer grade, mentioning only that some patients had “poorly differentiated” cancer before and after surgery. If this means that they did not break down the pathologic grade into Gleason scores <7, 7 and 8-10, then it may not have been possible to show that high-grade disease was independently predictive of a high risk for an elevated PSA post-surgery.