Weekend prostate cancer news update: Saturday, July 26
Posted Sep 28 2008 1:49pm
Articles summarized in this weekend news update include information about:
The value of endorectal MRI imaging in staging patients with respect to whether they have cancer confined to the prostate or extracapsular disease
Patterns of disease recurrence after salvage radical prostatectomy for patients with radiation-recurrent disease
The potential of PSA kinetics to improve prediction of likelihood for survival in men with hormone-refractory prostate cancer, and
The appropriateness of testosterone replacement therapy in men with hypogonadism after curative treatment for prostate cancer
Brown et al. have studied the potential value of preoperative staging with endorectal MRI (eMRI) on decisions about nerve sparing and the resulting rates of positive margins following radical prostatectomy (RP). They reviewed data from 62 patients who underwent RP (46 laparoscopic and 16 open retropubic) between March 2002 and February 2005 and who had preoperative eMRI staging to determine the impact of apparent extracapsular extension upon surgical decisions about nerve sparing and the subsequent risk for positive surgical margins. Among men found to have pathologic stage T2 tumors, 34/41 (83 percent) were accurately classified by eMRI. Among men with pathologic stage T3 tumors, only 8/21 (38 percent) were accurately classified by eMRI. Of the men classified as stage T2 with eMRI preoperatively, 83 percent underwent bilateral nerve sparing; by comparison, of the men classified as stage T3 with eMRI preoperatively, 55 percent of those treated laparoscopically and 75 percent of those treated with an open RP had bilateral nerve sparing. The overall post-surgical rate for margin-positive disease was 30 [percent for those treated by laparoscopic surgery and 25 percent for those trweated with open RPs. Pathologic T3 tumors erroneously classified as T2 had a trend toward greater positive margin rate (54 vs. 13 percent for open RPs; 63 vs. 14% percent for laparoscopic RPs). Eighty percent of patients with clinical stage T1c, Gleason 6, pathologic T3 tumors classified erroneously as T2 by eMRI had positive margins. The authors conclude that the value of endorectal MRI in detecting extracapsular extension is limited. Patients with eMRIs suggesting no extracapsular extension were more liable to have bilateral nerve-sparing procedures attemptedbut also had an increased rate of positive surgical margins following laparoscopic RP.
Paparel et al. have carried out a retrospective analysis of the patterns of disease recurrence in carefully selected patients treated by salvage radical prostatectomy (SRP) for post-radiation recurrent prostate cancer by (mainly) two surgeons at a singlke institution (Memorial Sloan-Kettering Cancer Center). Data from 146 patients with biopsy-proven local recurrence were evaluated. Biochemical recurrence (BCR) after SRP was defined as a serum PSA level of ≥ 0.2 ng/mL or by the initiation of androgen deprivation therapy. All predictors analyzed were determined after radiotherapy, before SRP, and included PSA level, clinical stage, biopsy Gleason score, age at SRP, and time interval from radiotherapy to SRP. A total of 65/146 patients (44.5 percent) developed BCR. The median follow-up period for recurrence-free patients was 3.8 years; 43 patients (29 percent) were followed for > 5 years. Overall, the 5-year recurrence-free probability was 54 percent. Clinical local recurrence occurred in only one patient, who also had bone metastases. Overall, there were 16 prostate cancer-specific deaths and 19 deaths from other causes. Pre-SRP serum PSA levels and biopsy Gleason scores were significantly associated with death due to prostate cancer (p<0.0005 and p=0.002, respectively). The authors state that SRP “provides excellent local cancer control” and that “Earlier identification of patients with persistent, viable local cancer despite radiation therapy” will assist in the appropriate selection of candidates for SRP.
The Scandanavian Prostate Cancer Group has attempted to assess the value of PSA kinetics in predicting survival and to relate this to the baseline variables in men with metastatic hormone-refractory prostate cancer (HRPC). Data from 417 men with HRPC were analyzed using a carefully constrcted statistical model. Baseline data included hemoglobin, PSA, and alkaline phosphatase levels, Soloway score, performance status, and pain analgesic score. Post-treatment variables included the PSA level halving time after the start of treatment, PSA level at nadir, interval to nadir, PSA velocity (PSAV), PSA doubling time after reaching a nadir, patient age, and treatment. The authors demonstrate that, of all variables related to PSA kinetics, the PSAV was the best predictor. They conclude that PSAV alone gave a better prediction of survival value than all other PSA kinetics variables and that by combining PSAV with the variables available at baseline, a better treatment decision-making can be accomplished for men with HRPC.
Rhoden et al. have conducted a detailed review of the available literature on testosterone replacement therapy (TRT) after prostate cancer treatment with curative intent. They state that with the recent increase in life expectancy and prostate cancer survival times, growth may be anticipated in the numbers of men with hypogonadism (decreased production of normal gonadal hormones like testosterone) who have undergone presumably curative treatment for prostate cancer. Historically, testosterone replacement has been contraindicated in men with known or suspected prostate cancer, but Rhoden et al. state that there is no convincing evidence that the normalization of testosterone serum levels in men with low but non-castrate levels is deleterious. Furthermore, they say that in the few available case series describing testosterone replacement after treatment for prostate cancer, no case of clinical or biochemical progression was observed. They conclude that, “the available evidence suggests that TRT can be cautiously considered in selected hypogonadal men treated with curative intent for prostate cancer and without evidence of active disease.”