Kevin M. Slawin

Predicting the Outcome of Salvage Radiation Therapy for Recurrent Prostate Cancer After Radical Prostatectomy

PURPOSE An increasing serum prostate-specific antigen (PSA) level is the initial sign of recurrent prostate cancer among patients treated with radical prostatectomy. Salvage radiation therapy (SRT) may eradicate locally recurrent cancer, but studies to distinguish local from systemic recurrence lack adequate sensitivity and specificity. We developed a nomogram to predict the probability of cancer control at 6 years after SRT for PSA-defined recurrence. PATIENTS AND METHODS Using multivariable Cox regression analysis, we constructed a model to predict the probability of disease progression after SRT in a multi-institutional cohort of 1,540 patients. RESULTS The 6-year progression-free probability was 32% (95% CI, 28% to 35%) overall. Forty-eight percent (95% CI, 40% to 56%) of patients treated with SRT alone at PSA levels of 0.50 ng/mL or lower were disease free at 6 years, including 41% (95% CI, 31% to 51%) who also had a PSA doubling time of 10 months or less or poorly differentiated (Gleason grade 8 to 10) cancer. Significant variables in the model were PSA level before SRT (P < .001), prostatectomy Gleason grade (P < .001), PSA doubling time (P < .001), surgical margins (P < .001), androgen-deprivation therapy before or during SRT (P < .001), and lymph node metastasis (P = .019). The resultant nomogram was internally validated and had a concordance index of 0.69. CONCLUSION Nearly half of patients with recurrent prostate cancer after radical prostatectomy have a long-term PSA response to SRT when treatment is administered at the earliest sign of recurrence. The nomogram we developed predicts the outcome of SRT and should prove valuable for medical decision making for patients with a rising PSA level.

Do margins matter? The prognostic significance of positive surgical margins in radical prostatectomy specimens.

PURPOSE The prognostic significance of positive surgical margins (PSM) in radical prostatectomy (RP) specimens remains unclear. While most studies have concluded that a PSM is an independent adverse prognostic factor, others report that surgical margin status has no effect on prognosis. One reason for these discordant conclusions is the variable number of patients with a PSM who receive adjuvant therapy and the differing statistical methods used to account for the effects of the time course of adjuvant treatment on recurrence. We evaluated the prognostic significance of PSMs using multiple methods of analysis accounting for patients who received adjuvant therapy. MATERIALS AND METHODS We analyzed 1,389 consecutive patients with clinical stage T1-3 prostate cancer treated with RP by 2 surgeons from 1983 to 2000. Of 179 patients with a PSM, 37 received adjuvant therapy (AT), 29 radiation therapy and 8 received hormonal therapy. Because the method used to account for men receiving AT can affect the outcome of the analysis, data were analyzed by the Cox proportional hazards technique accounting for patients receiving AT using 5 methods: 1) exclusion, 2) inclusion (AT ignored), 3) censoring at time of AT, 4) failing at time of AT and 5) considering AT as a time dependent covariate. RESULTS Overall 179 patients (12.9%) had a PSM, including 6.8% of 847 patients with pT2 and 23% of 522 patients with pT3 disease. A PSM was a significant predictor of cancer recurrence when analyzed using methods 1, 3, 4 and 5 (p=0.005, p=0.014, p=0.0005, p=0.002, respectively). However, it was not a predictor of recurrence using method 2 in which AT was ignored (p=0.283). Using method 5 multivariate analysis demonstrated that a PSM (p=0.002) was an independent predictor of 10-year progression-free probability (PFP) along with Gleason score (p=0.0005), extracapsular extension (p=0.0005), seminal vesicle invasion (p <0.0005), positive lymph nodes (p <0.0005) and preoperative serum prostate specific antigen (p <0.0001). Using method 5 the 10-year PFP was 58% +/- 12% and 81% +/- 3% for patients with and without a PSM, respectively (p <0.00005). The relative risk of recurrence in men with a PSM using method 5 was 1.52 (95% confidence interval 1.06-2.16). CONCLUSIONS We confirm that a PSM has a significant adverse impact on PFP after RP in multivariate analysis using multiple statistical methods to account for patients who received AT. While prostate cancer screening strategies have resulted in a majority of men having organ confined disease at RP, surgeons should continue to strive to reduce the rate of positive surgical margins to improve cancer control outcomes.

Comparison of percent free PSA, PSA density, and age-specific PSA cutoffs for prostate cancer detection and staging.

OBJECTIVES Various methods have been proposed to increase the specificity of prostate-specific antigen (PSA), including age-specific PSA reference ranges, PSA density (PSAD), and percent free PSA (%fPSA). In this multicenter study, we compared these methods for their utility in cancer detection and their ability to predict pathologic stage after radical prostatectomy in patients with clinically localized, Stage T1c cancer. METHODS Seven hundred seventy-three men (379 with prostate cancer, 394 with benign prostatic disease), 50 to 75 years old, from seven medical centers were enrolled in this prospective blinded study. All subjects had a palpably benign prostate, PSA 4.0 to 10.0 ng/mL, and a histologically confirmed diagnosis. Hybritechs Tandem PSA and free PSA assays were used. RESULTS %fPSA and age-specific PSA cutoffs enhanced PSA specificity for cancer detection, but %fPSA maintained significantly higher sensitivities. Age-specific PSA cutoffs missed 20% to 60% of cancers in men older than 60 years of age. %fPSA and PSAD performed equally well for detection (95% sensitivity) if cutoffs of 25% fPSA or 0.078 PSAD were used. The commonly used PSAD cutoff of 0.15 detected only 59% of cancers. %fPSA and PSAD also produced similar results for prediction of the post-radical prostatectomy pathologic stage. Patients with cancer with higher %fPSA values (greater than 15%) or lower PSAD values (0.15 or less) tended to have less aggressive disease. CONCLUSIONS The results of this study demonstrated that cancer detection (sensitivity) is significantly higher with %fPSA than with age-specific PSA reference ranges. %fPSA and PSAD provide comparable results, suggesting that %fPSA may be used in place of PSAD for biopsy decisions and in algorithms for prediction of less aggressive tumors since the determination of %fPSA does not require ultrasound.

A multicenter study of [-2]pro-prostate specific antigen combined with prostate specific antigen and free prostate specific antigen for prostate cancer detection in the 2.0 to 10.0 ng/ml prostate specific antigen range

PURPOSE Prostate specific antigen and free prostate specific antigen have limited specificity to detect clinically significant, curable prostate cancer, leading to unnecessary biopsy, and detection and treatment of some indolent tumors. Specificity to detect clinically significant prostate cancer may be improved by [-2]pro-prostate specific antigen. We evaluated [-2]pro-prostate specific antigen, free prostate specific antigen and prostate specific antigen using the formula, ([-2]pro-prostate specific antigen/free prostate specific antigen × prostate specific antigen(1/2)) to enhance specificity to detect overall and high grade prostate cancer. MATERIALS AND METHODS We enrolled 892 men with no history of prostate cancer, normal rectal examination, prostate specific antigen 2 to 10 ng/ml and 6-core or greater prostate biopsy in a prospective multi-institutional trial. We examined the relationship of serum prostate specific antigen, free-to-total prostate specific antigen and the prostate health index with biopsy results. Primary end points were specificity and AUC using the prostate health index to detect overall and Gleason 7 or greater prostate cancer on biopsy compared with those of free-to-total prostate specific antigen. RESULTS In the 2 to 10 ng/ml prostate specific antigen range at 80% to 95% sensitivity the specificity and AUC (0.703) of the prostate health index exceeded those of prostate specific antigen and free-to-total prostate specific antigen. An increasing prostate health index was associated with a 4.7-fold increased risk of prostate cancer and a 1.61-fold increased risk of Gleason score greater than or equal to 4 + 3 = 7 disease on biopsy. The AUC of the index exceeded that of free-to-total prostate specific antigen (0.724 vs 0.670) to discriminate prostate cancer with Gleason 4 or greater + 3 from lower grade disease or negative biopsy. Prostate health index results were not associated with age and prostate volume. CONCLUSIONS The prostate health index may be useful in prostate cancer screening to decrease unnecessary biopsy in men 50 years old or older with prostate specific antigen 2 to 10 ng/ml and negative digital rectal examination with minimal loss in sensitivity.

OPTIMAL COMBINATIONS OF SYSTEMATIC SEXTANT AND LATERALLY DIRECTED BIOPSIES FOR THE DETECTION OF PROSTATE CANCER

PURPOSE The standard sextant protocol for obtaining transrectal ultrasound guided biopsy of the prostate has been shown to underestimate the presence of prostate cancer. Studies have demonstrated an increased cancer detection rate with additional laterally directed biopsies. We compared the sensitivity of individual biopsy cores and evaluated combinations of these cores to identify an optimal biopsy strategy. MATERIALS AND METHODS A total of 396 consecutive patients underwent biopsy of the lateral peripheral zone in addition to standard sextant biopsy. The cancer detection rate for each biopsy core was calculated. The sensitivity of different combinations of biopsy cores was compared with those of standard sextant biopsies and with a 12 core biopsy protocol that combined the standard sextant biopsy with a complete set of laterally directed cores. RESULTS Cancer was detected in 160 of 396 (40.3%) patients. Of the possible combinations of biopsy cores a strategy that included laterally directed cores at the base, mid gland and apex of the prostate with mid lobar base and apical cores detected 98.5% of cancers. The detection rate of this 10 core biopsy regimen was significantly better than that of the standard sextant protocol (p < or =0.001), and was equivalent to that of the 12 core regional biopsy (p > or =0.302). CONCLUSIONS The standard sextant protocol failed to detect a large proportion of cancers located laterally in the peripheral zone. A 10 core biopsy regimen that combined laterally directed cores at the base, mid gland and apex of the prostate with mid lobar biopsy cores at the base and apex maximizes the sensitivity of transrectal ultrasound guided systematic biopsy.

Plasma levels of interleukin-6 and its soluble receptor are associated with prostate cancer progression and metastasis.

OBJECTIVES Elevated circulating levels of interleukin 6 (IL-6) have been associated with cancer metastasis. IL-6 binds either to membrane or to soluble IL-6 receptor (IL-6sR), which then induces homodimerization of gp130 that activates downstream signaling. We tested the hypothesis that preoperative plasma IL-6 and IL-6sR levels are associated with prostate cancer stage, progression, and metastasis after radical prostatectomy. METHODS Plasma levels of IL-6 and IL-6sR were measured in 120 consecutive patients who underwent radical prostatectomy for clinically localized prostate cancer, 44 healthy men without any cancer, 19 men with prostate cancer metastatic to the regional lymph nodes, and 10 men with prostate cancer metastatic to bone. RESULTS Plasma IL-6 and IL-6sR levels were highest in patients with bone metastases (P <0.001). The preoperative IL-6 and IL-6sR levels were associated with the preoperative prostate-specific antigen (PSA) level (P </=0.041), prostatectomy tumor volume (P </=0.048), and final Gleason sum (P </=0.042). The preoperative IL-6 and IL-6sR levels and biopsy Gleason sum were independent predictors of PSA progression (P </=0.029). However, in a model that included both IL-6 and IL-6sR, only IL-6sR and the biopsy Gleason sum predicted progression (P </=0.040). In patients whose disease progressed, the preoperative IL-6 and IL-6sR levels were highest in those with presumed aggressive failure (P </=0.042). CONCLUSIONS Plasma IL-6 and IL-6sR levels were dramatically elevated in the men with prostate cancer metastatic to bone. In patients with clinically localized prostate cancer, the preoperative plasma IL-6 and IL-6sR levels independently predicted biochemical progression after surgery, presumably because of an association with occult metastatic disease present at the time of radical prostatectomy.

The Addition of Interleukin-6 Soluble Receptor and Transforming Growth Factor Beta1 Improves a Preoperative Nomogram for Predicting Biochemical Progression in Patients With Clinically Localized Prostate Cancer

PURPOSE Several preoperative prostate cancer nomograms have been developed that predict risk of progression using pretreatment prostate-specific antigen (PSA) level, clinical stage, and biopsy Gleason grade. We describe the development and performance of a new nomogram. The nomogram adds new markers to the standard clinical predictors that reflect the biologic behavior of prostate cancer: pretreatment plasma levels of interleukin-6 soluble receptor (IL6SR) and transforming growth factor beta1 (TGF-beta1). PATIENTS AND METHODS Between November 7, 1994 and December 22, 1997, 714 patients with stage cT1c to cT3a prostate cancer and no prior therapy were treated with radical prostatectomy at the Methodist Hospital, Houston TX. Plasma levels of IL6SR and TGF-beta1 were measured in banked preoperative plasma. With these data, a nomogram was developed to predict the probability of PSA progression within 5 years of surgery. The nomogram was validated with bootstrapping to assess its discrimination and calibration performance. RESULTS In the multivariable Cox model, PSA (P =.004), IL6SR (P <.001), TGF-beta1 (P <.001), primary Gleason grade (P <.002), and secondary Gleason grade (P =.029) were associated with PSA progression, whereas clinical stage (P =.696) was not. The nomogram seemed to be well calibrated and had a bootstrap-corrected area under the receiver operating characteristic curve (ie, concordance index) of 0.83. For comparison, a nomogram that omitted IL6SR and TGF-beta1 achieved a concordance index of only 0.75. CONCLUSION We found that pretreatment plasma levels of IL6SR and TGF-beta1 improved the ability to predict biochemical progression by a prognostically substantial margin. A nomogram including the pretreatment levels of these molecular markers, along with standard clinical markers, has been developed and internally validated.

Prediction of Response to Salvage Radiation Therapy in Patients With Prostate Cancer Recurrence After Radical Prostatectomy

PURPOSE To identify factors predictive of local recurrence as defined by a complete response to salvage radiation therapy in patients whose disease recurs after radical prostatectomy. PATIENTS AND METHODS Ninety-five patients with recurrence after radical prostatectomy who were evaluated by prostatic fossa biopsies, and a subset of 49 of these patients treated with radiation for control of presumed or biopsy-proven local recurrence, were studied. RESULTS Biopsies were positive in 40 (42%) of the 95 biopsied patients. Multivariate analysis revealed that prebiopsy prostate-specific antigen (PSA) level, postrecurrence PSA doubling time, and positive digital rectal examination (DRE) of the prostatic fossa were all statistically significant predictors of a positive biopsy. For the 49 patients subsequently treated with salvage radiation therapy, the overall actuarial 3- and 5-year PSA relapse-free probabilities were 43% and 24%, respectively. Univariate analysis showed no differences in the PSA relapse-free probabilities associated with any pathologic features of the radical prostatectomy specimen, biopsy confirmation of local recurrence, or DRE of the prostatic fossa. In multivariate analysis, controlling for all other variables, preradiation PSA and postrecurrence PSA doubling time measured before radiation were the only statistically significant predictors of outcome. CONCLUSION DRE of the prostatic fossa, prebiopsy PSA, and postrecurrence PSA doubling time predict which patients will have biopsy-proven local recurrence. However, response to salvage radiation therapy is associated with postrecurrence PSA doubling time and with preradiation PSA level only. DRE of the prostatic fossa and biopsy confirmation of local recurrence are not associated with salvage radiation outcome.

Preoperative Plasma Levels of Transforming Growth Factor Beta1 (TGF-β1) Strongly Predict Progression in Patients Undergoing Radical Prostatectomy

PURPOSE Elevated local and circulating levels of transforming growth factor beta(1) (TGF-beta(1)) have been associated with prostate cancer invasion and metastasis. We tested the hypothesis that preoperative plasma TGF-beta(1) levels would independently predict cancer stage and prognosis in patients who undergo radical prostatectomy. PATIENTS AND METHODS The study group consisted of 120 consecutive patients who underwent radical prostatectomy for clinically localized prostate cancer (median follow-up, 53.8 months). Preoperative plasma levels of TGF-beta(1) were measured and correlated with pathologic parameters and clinical outcomes. TGF-beta(1) levels also were measured in 44 healthy men without cancer, in 19 men with prostate cancer metastatic to regional lymph nodes, and in 10 men with prostate cancer metastatic to bone. RESULTS Plasma TGF-beta(1) levels in patients with lymph node metastases (14.2 +/- 2.6 ng/mL) and bone metastases (15.5 +/- 2.4 ng/mL) were higher than those in radical prostatectomy patients (5.2 +/- 1.3 ng/mL) and healthy subjects (4.5 +/- 1.2 ng/mL) (P <.001). In a preoperative analysis, preoperative plasma TGF-beta(1) level and biopsy Gleason sum both were predictors of organ-confined disease (P =.006 and P =.006, respectively) and PSA progression (P <.001 and P =.021, respectively). In a postoperative multivariate analysis, preoperative plasma TGF-beta(1) level, pathologic Gleason sum, and surgical margin status were predictors of PSA progression (P =.020,P =.020, and P =.022, respectively). In patients who progressed, preoperative plasma TGF-beta(1) levels were higher in those with presumed distant compared with local-only failure (P =.019). CONCLUSION Plasma TGF-beta(1) levels are markedly elevated in men with prostate cancer metastatic to regional lymph nodes and bone. In men without clinical or pathologic evidence of metastases, the preoperative plasma TGF-beta(1) level is a strong predictor of biochemical progression after surgery, presumably because of an association with occult metastatic disease present at the time of radical prostatectomy.

Baseline factors as predictors of clinical progression of benign prostatic hyperplasia in men treated with placebo.

PURPOSE We analyzed data from the placebo arm of the MTOPS trial to determine clinical predictors of BPH progression. MATERIALS AND METHODS A total of 3,047 patients with LUTS were randomized to either placebo, doxazosin (4 to 8 mg), finasteride (5 mg), or a combination of doxazosin and finasteride. Average length of followup was 4.5 years. The primary outcome was time to overall clinical progression of BPH, defined as either a confirmed 4-point or greater increase in AUA SS, acute urinary retention, incontinence, renal insufficiency, or recurrent urinary tract infection. We analyzed BPH progression event data from the 737 men who were randomized to placebo. RESULTS The rate of overall clinical progression of BPH events in the placebo group was 4.5 per 100 person-years, for a cumulative incidence (among men who had at least 4 years of followup data) of 17%. The risk of BPH progression was significantly greater in patients on placebo with a baseline TPV of 31 ml or greater vs less than 31 ml (p <0.0001), a baseline PSA of 1.6 ng/dl or greater vs PSA less than 1.6 ng/dl (p = 0.0009), a baseline Qmax of less than 10.6 ml per second vs 10.6 ml per second or greater (p = 0.011), a baseline PVR of 39 ml or greater vs less than 39 ml (p = 0.0008) and baseline age 62 years or older vs younger than 62 years (p = 0.0002). CONCLUSIONS Among men in the placebo arm, baseline TPV, PSA, Qmax, PVR and age were important predictors of the risk of clinical progression of BPH.