Partin’

Partin’s Predictions: What Do They Really Mean ?

J.R. Oppenheimer, MD, FCAP

Medical Director and Chief Pathologist, Prostate Lab

The most recent edition of the so-called Partin tables (1) represents a remarkable joint effort of three major academic centers of prostate cancer excellence. Data from 4133 men who had undergone radical prostatectomy (RP) were collected from Johns Hopkins Hospital, the University of Michigan, and the Baylor College of Medicine. These data were analyzed to determine the value of combining readily obtainable pre-operative information (PSA, Clinical Stage, Gleason score) in predicting the extent of the actual tumor as determined by post-surgical pathological exam. The large amount of data collected and tabulated in several charts allows patients and their physicians to more accurately estimate the probability that surgical intervention will result in complete removal of the tumor.

The application of these tables allows the patient and physician to arrive at a more informed treatment decision and encourages more frank discussion regarding the benefits and risks of possible treatments. In order to appreciate the relevance of the Partin tables, however, it is important to understand what they predict rather than what they are assumed to predict.

A major misconception in the minds of many is that the Partin tables predict whether or not RP will be curative. Leaving aside the semantic argument of whether or not "cure" is an acceptable term for a disease that can recur many years after having been apparently successfully treated, the Partin tables predicts the results obtained on pathologic exam of the prostate and lymph nodes after surgery. While there is a logical and scientifically proven correlation between the results of pathologic evaluation and the patient’s prognosis, these two "end-points" are quite different. The divergence between the pathology and prognosis can be attributed to several factors:

Some tumors which are "organ-confined" on pathologic exam are not organ confined in reality. In spite of the main mass of the tumor having been removed, metastatic deposits of tumor may have already been deposited in other parts of the body. Alternatively, since the pathologic examination of the prostate entails the review of multiple planes of tissue taken from a roughly spherical organ, the point of capsular penetration by the tumor may be missed on microscopic examination.

Some tumors which demonstrate "capsular penetration" on pathologic exam are taken from patients who do not show signs of biochemical (detectable PSA) or clinical (symptomatic) recurrence many years after surgery. In a study of 721 men at Johns Hopkins, 58% of men with clear-cut capsular penetration had no evidence of biochemical recurrence ten years after surgery (2). Post-surgical manipulation of the RP specimen may induce tissue changes (artifacts) that are mistaken by the pathologist as evidence of disease extension. Perhaps inflammation or loss of local blood supply induced by the surgery may somehow induce the regression of a small amount of tumor left inside the patient. In view of the above, it is understandable why some surgeons may not wish to deny their patients an attempt at possible "curative" therapy even when faced with a substantial probability of predicted non-organ confined disease.

Patients may benefit from the removal of the great majority of their tumor (so-called tumor debulking) and achieve longer life and decreased symptoms even though not all of the cancer was removed. It has been shown that in patients with no high-grade disease on biopsy, radical prostatectomy can be beneficial even in the presence of locally invasive disease or seminal vesicle invasion(3). The value of tumor debulking is controversial and must be weighed against the benefits of treatment alternatives with less detrimental effect on the patient’s quality of life.

It must be kept in mind that Partin et al assume that it is the post-operative pathologic stage which is of foremost importance in assessing prognosis. Other investigators (4) have found pre-operative PSA, Gleason grade , and DNA ploidy to be better predictive of eventual outcome than pathologic stage.

Although the Partin tables can help to better evaluate therapeutic options, it must always be remembered that these tables use statistical data to predict probable outcome in an individual. Utilizing these tables may lead to the acquisition of more "knowledge" that may leave one with the feeling of even more uncertainty. We should also take into account other pre-operative prognostic data derived from the individual patient: the number and laterality of biopsy cores involved with cancer, the percentage of high grade cancer in biopsies (5), pathologic staging (6), DNA ploidy analysis, microvessel density (7), tumor proliferative markers, endorectal coil (8) and spectroscopic MRI imaging (9), radionuclide (Prostascint) studies (10), etc. The efficacy and cost-effectiveness of the above-mentioned tests are unfortunately not known at present. Nevertheless, the Partin tables remain an extremely useful tool for empowering the thoughtful patient and physician dealing with prostate cancer.

Jonathan R. Oppenheimer, MD, FCAP

September 29, 1997

1) Partin AW, Kattan MW, Subong ENP, et al. Combination of prostate-specific antigen, clinical stage, and Gleason score to predict pathological stage of localized prostate cancer: a multi-institutional update. JAMA 1997;277:1445-1451.

2) Epstein JI, Partin AW, Sauvageot J, Walsh PC. Prediction of progression following radical prostatectomy. Am J Surg Path 1996; 20:286-292.

3) Naitoh J. PSA recurrence pattern following radical prostatectomy for stage pT3c disease. J Urol. 1997;157:803A.

4) Lerner SE, Blute ML, Bergstrahl EJ, Bostwick DG, et al. Analysis of risk factors for progression in patients with pathologically confined prostate cancers after radical retropubic prostatectomy. J of Urology 1996; 156:137-143.

5) Stamey TA, McNeal JE, Yemoto CM, et al. Gleason sums of 7 lose prognostic information in comparison to estimates of percent grade 4 and 5 cancer. J. Urology 1997;157:794A.

6) Narayan P, Gajendran V, Taylor SP, et al. The role of transrectal ultrasound-guided biopsy-based staging, pre-operative serum PSA, and biopsy Gleason score in prediction of final pathologic diagnosis in prostate cancer. Urology 1995; 46:205-212.

7) Bostwick DG, Wheeler TM, Blute M, et al. Optimized microvessel density analysis improves prediction of cancer stage from prostate needle biopsies. Urology 1996; 48:47-57.

8) D’Amico AV, Whittington R, Malkowics SB, et al. A multivariate analysis of clinical and pathological factors that predict for PSA failure after radical prostatectomy. J of Urology 1995; 154:131-138.

9) Kurhanewicz J, Vigneron DB, Hricak H, et al. Three dimensional H-1 spectroscopic imaging of the in situ human prostrate with high spacial resolution. Radiology 1996;198:795-805.

10) Burgers JK, Hinkle GH, and Haseman MK. Monoclonal antibody imaging of recurrent and metastatic prostate cancer. Seminars in Urology, 1995; 13:103-112.