A multiple prognostic index predictive of disease outcome after irradiation for clinically localized prostate carcinoma

Development and Validation of a Clinical Prognostic Stage Group System for Nonmetastatic Prostate Cancer Using Disease-Specific Mortality Results From the International Staging Collaboration for Cancer of the Prostate

Importance

In 2016, the American Joint Committee on Cancer (AJCC) established criteria to evaluate prediction models for staging. No localized prostate cancer models were endorsed by the Precision Medicine Core committee, and 8th edition staging was based on expert consensus.

Objective

To develop and validate a pretreatment clinical prognostic stage group system for nonmetastatic prostate cancer.

Design, Setting, and Participants

This multinational cohort study included 7 centers from the United States, Canada, and Europe, the Shared Equal Access Regional Cancer Hospital (SEARCH) Veterans Affairs Medical Centers collaborative (5 centers), and the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) registry (43 centers) (the STAR-CAP cohort). Patients with cT1-4N0-1M0 prostate adenocarcinoma treated from January 1, 1992, to December 31, 2013 (follow-up completed December 31, 2017). The STAR-CAP cohort was randomly divided into training and validation data sets; statisticians were blinded to the validation data until the model was locked. A Surveillance, Epidemiology, and End Results (SEER) cohort was used as a second validation set. Analysis was performed from January 1, 2018, to November 30, 2019.

Exposures

Curative intent radical prostatectomy (RP) or radiotherapy with or without androgen deprivation therapy.

Main Outcomes and Measures

Prostate cancer-specific mortality (PCSM). Based on a competing-risk regression model, a points-based Score staging system was developed. Model discrimination (C index), calibration, and overall performance were assessed in the validation cohorts.

Results

Of 19 684 patients included in the analysis (median age, 64.0 [interquartile range (IQR), 59.0-70.0] years), 12 421 were treated with RP and 7263 with radiotherapy. Median follow-up was 71.8 (IQR, 34.3-124.3) months; 4078 (20.7%) were followed up for at least 10 years. Age, T category, N category, Gleason grade, pretreatment serum prostate-specific antigen level, and the percentage of positive core biopsy results among biopsies performed were included as variables. In the validation set, predicted 10-year PCSM for the 9 Score groups ranged from 0.3% to 40.0%. The 10-year C index (0.796; 95% CI, 0.760-0.828) exceeded that of the AJCC 8th edition (0.757; 95% CI, 0.719-0.792), which was improved across age, race, and treatment modality and within the SEER validation cohort. The Score system performed similarly to individualized random survival forest and interaction models and outperformed National Comprehensive Cancer Network (NCCN) and Cancer of the Prostate Risk Assessment (CAPRA) risk grouping 3- and 4-tier classification systems (10-year C index for NCCN 3-tier, 0.729; for NCCN 4-tier, 0.746; for Score, 0.794) as well as CAPRA (10-year C index for CAPRA, 0.760; for Score, 0.782).

Conclusions and Relevance

Using a large, diverse international cohort treated with standard curative treatment options, a proposed AJCC-compliant clinical prognostic stage group system for prostate cancer has been developed. This system may allow consistency of reporting and interpretation of results and clinical trial design.

High-Dose Radiotherapy plus Prolonged Hormone Therapy in CT2-3 Prostatic Carcinoma: Is it Useful?

Aims and background

Clinical studies published in the last decade have shown the possible improvement in prognosis of patients with prostatic carcinoma undergoing radiation therapy with dose escalation or in combination with hormone therapy. However, in studies on hormone therapy, moderate doses of radiation therapy have been used, whereas in studies with high-dose radiotherapy, hormone therapy usually was not administered. Therefore, it is not clear whether the concomitant use of high doses and prolonged hormone therapy could determine an additional beneficial effect. The aim of the present study was therefore to evaluate the relative prognostic role of different dose levels (<70 versus >70 Gy) of external beam radiotherapy and of different hormone therapies (neoadjuvant only versus neoadjuvant + adjuvant).

Methods

A total of 426 patients (median age, 71 yrs; range, 51-87 yrs) underwent external beam radiotherapy (70 Gy median dose to prostate volume ± 45 Gy to pelvic lymph nodes) and neoadjuvant hormone therapy (bicalutamide for 30 days; goserelin, 3.6 mg every 28 days starting two months before radiotherapy and for its entire duration). Dose to the prostate was <70 Gy in 44.8% of patients and >70 Gy in 55.2%. A total of 244 patients received adjuvant hormonal therapy. The distribution according to the clinical stage was 48.1% T2 and 51.9% T3. The distribution according to the Gleason score was 14.3% grades 2-4, 66.7% grades 5-7 and 19.0% grades 8-10. The distribution according to pretreatment prostate-specific antigen levels (in ng/mL) was 7.0% for 0-4, 29.3% for 4-10, 30.3% for 10-20, and 33.3% for >20.

Results

With a median follow-up of 35 months (range, 1-151), 81 patients (19.0%) showed biochemical recurrence, 17 patients (4.0%) showed local disease progression, and 12 patients (2.8%) showed distant metastases. Overall, 23 patients (5.4%) showed disease progression. Four patients (0.9%) died. At the time of this writing, no patient has died from prostatic carcinoma. At univariate analysis, the radiation dose delivered to the tumor and the administration of adjuvant hormone therapy were shown to be significantly correlated with biochemical disease-free survival. At multivariate analysis, the single parameter significantly correlated with biochemical disease-free survival was the radiation dose delivered to the tumor. In the subset of patients not treated with adjuvant hormone therapy, there was a significant correlation between radiation dose and biochemical disease-free survival at univariate and multivariate analysis. A similar correlation between adjuvant hormone therapy and biochemical disease-free survival was observed in the subset of stage cT3 patients at univariate and multivariate analysis. In patients undergoing combined treatment without adjuvant hormone therapy, a significant correlation was observed between clinical stage and biochemical disease-free survival, at univariate and at multivariate analysis.

Conclusions

The results of the study confirmed the positive impact of radiotherapy doses >70 Gy and of adjuvant hormone therapy in patients with locally advanced prostatic carcinoma. Owing to the lack of evidence of a correlation between radiation dose and biochemical outcome in patients undergoing prolonged hormone therapy, the role of further dose escalation in patients undergoing combined hormone and radiation therapy is still unclear.

Hormono-Radiotherapy in Prostatic Carcinoma: Prognostic Factors and Implications for Combined Modality Treatment

The aim of this study was to evaluate the prognostic role of several clinical variables in a patient population undergoing neoadjuvant hormonotherapy (NHT) with external beam radiotherapy (ERT) to identify subsets of patients with an unfavorable prognosis who require intensified therapy. Eighty-four patients (mean age, 68.2 +/– 6.1 years; range, 52–81 years) underwent ERT (45 Gy to pelvic volume; 65 Gy mean dose to prostate volume) and NHT (oral flutamide: 250 mg three times daily for 30 days; LH-RH analogue: one vial every 28 days starting two months before radiotherapy and for its entire duration). The distribution according to clinical stage was T2: 46.4%, T3: 50.0%, T4: 3.6%. The distribution according to the Gleason score was grade 2–4: 17.9%; grade 5–7: 53.6%; grade 8–10: 28.5%. The distribution according to pretreatment PSA levels (in ng/mL) was 0–4: 5.9%; 4–10: 26.2%; 10–20: 16.7%; ≥20: 51.2%. With a median follow-up of 36 months, 3.6% of patients died; hematogenous metastases and local disease progression were found in 16.7% and 6% of patients, respectively. Overall, the incidence of disease progression was 17.9%. 32.9% of patients showed biochemical failure during follow-up. Overall, metastasis-free, local progression-free and biochemical failure-free actuarial survival at five years was 89.2%, 66.5%, 85.0% and 41.9%, respectively. At univariate analysis (log-rank) clinical stage (cT) was shown to be significantly correlated with the incidence of metastasis (P = 0.0004), local progression (P <0.0001) and disease-free survival (P = 0.0005). At multivariate analysis (Cox) the correlations between clinical stage and metastasis (P = 0.0175), local progression (P = 0.0200) and disease-free survival (P = 0.0175) were confirmed. Gleason score and pretreatment PSA levels did not show any significant correlation with these endpoints. These results confirm the indications of the recent literature, which, in prostate carcinoma at higher clinical stages, suggest the use of prolonged hormonal therapy after radiotherapy.

Progress and controversies: Radiation therapy for prostate cancer

Radiation therapy remains a standard treatment option for men with localized prostate cancer. Alone or in combination with androgen-deprivation therapy, it represents a curative treatment and has been shown to prolong survival in selected populations. In this article, the authors review recent advances in prostate radiation-treatment techniques, photon versus proton radiation, modification of treatment fractionation, and brachytherapy-all focusing on disease control and the impact on morbidity. Also discussed are refinements in the risk stratification of men with prostate cancer and how these are better for matching patients to appropriate treatment, particularly around combined androgen-deprivation therapy. Many of these advances have cost and treatment burden implications, which have significant repercussions given the prevalence of prostate cancer. The discussion includes approaches to improve value and future directions for research.

Assessment of the American Joint Committee on Cancer staging (sixth and seventh editions) for clinically localized prostate cancer treated with external beam radiotherapy and comparison with the National Comprehensive Cancer Network risk-stratification method

BACKGROUND

The objective of this study was to compare the prognostic value of the sixth and seventh editions of the American Joint Cancer Committee (AJCC) Cancer Staging Manual and the risk-stratification model of the National Comprehensive Cancer Network (NCCN).

METHODS

Two-thousand four hundred twenty-nine men who received definitive radiotherapy with or without androgen-deprivation therapy (median follow-up, 74 months) were analyzed.

RESULTS

There was a migration of stage II patients to stage I with AJCC seventh edition (stage I increased from 1% to 38%, and stage II decreased from 91% to 55%). One pair-wise comparison (4%) of Kaplan-Meier estimates of biochemical failure, distant metastasis, prostate cancer-specific survival, and overall survival between stages was statistically significant for the AJCC sixth edition. Conversely, 16 of 24 comparisons (67%) were significant for the AJCC seventh edition. With the NCCN risk-stratification model, 9 of 12 comparisons (75%) were significant. Concordance probability estimate (CPE) and standard error (SE) analysis indicated uniform and significant improvement in the predictive power of the AJCC seventh edition versus the sixth edition for all outcomes. CPE ± SE values for the AJCC seventh edition versus the sixth edition were 0.51 ± 0.009 versus 0.59 ± 0.02, respectively, for biochemical failure; 0.54 ± 0.02 versus 0.70 ± 0.05, respectively, for distant metastasis; 0.57 ± 0.009 versus 0.76 ± 0.007, respectively, for prostate cancer-specific survival; and 0.52 ± 0.006 versus 0.57 ± 0.01, respectively, for overall survival. CPE ± SE values for the NCCN model were 0.59 ± 0.02 for biochemical failure, 0.72 ± 0.05 for distant metastasis, 0.80 ± 0.01 for prostate cancer-specific survival, and 0.57 ± 0.01 for overall survival.

CONCLUSIONS

The current results indicated that the seventh edition of the AJCC Cancer Staging Manual is a major improvement over the sixth edition, because it distributes patients better among the stages and is more prognostic. However, the NCCN model was superior to the AJCC seventh edition and remains the preferred method for risk-based clinical management of prostate cancer with radiotherapy.

Molecular targets for radiation oncology in prostate cancer

Recent selected developments of the molecular science of prostate cancer (PrCa) biology and radiation oncology are reviewed. We present potential targets for molecular integration treatment strategies with radiation therapy (RT), and highlight potential strategies for molecular treatment in combination with RT for patient care. We provide a synopsis of the information to date regarding molecular biology of PrCa, and potential integrated research strategy for improved treatment of PrCa. Many patients with early-stage disease at presentation can be treated effectively with androgen ablation treatment, surgery, or RT. However, a significant portion of men are diagnosed with advanced stage/high-risk disease and these patients progress despite curative therapeutic intervention. Unfortunately, management options for these patients are limited and are not always successful including treatment for hormone refractory disease. In this review, we focus on molecules of extracellular matrix component, apoptosis, androgen receptor, RUNX, and DNA methylation. Expanding our knowledge of the molecular biology of PrCa will permit the development of novel treatment strategies integrated with RT to improve patient outcome.

Predictive and prognostic models in radical prostatectomy candidates: a critical analysis of the literature

CONTEXT

Numerous predictive and prognostic tools have recently been developed for risk stratification of prostate cancer (PCa) patients who are candidates for or have been treated with radical prostatectomy (RP).

OBJECTIVE

To critically review the currently available predictive and prognostic tools for RP patients and to describe the criteria that should be applied in selecting the most accurate and appropriate tool for a given clinical scenario.

EVIDENCE ACQUISITION

A review of the literature was performed using the Medline, Scopus, and Web of Science databases. Relevant reports published between 1996 and January 2010 identified using the keywords prostate cancer, radical prostatectomy, predictive tools, predictive models, and nomograms were critically reviewed and summarised.

EVIDENCE SYNTHESIS

We identified 16 predictive and 22 prognostic validated tools that address a variety of end points related to RP. The majority of tools are prediction models, while a few consist of risk-stratification schemes. Regardless of their format, the tools can be distinguished as preoperative or postoperative. Preoperative tools focus on either predicting pathologic tumour characteristics or assessing the probability of biochemical recurrence (BCR) after RP. Postoperative tools focus on cancer control outcomes (BCR, metastatic progression, PCa-specific mortality [PCSM], overall mortality). Finally, a novel category of tools focuses on functional outcomes. Prediction tools have shown better performance in outcome prediction than the opinions of expert clinicians. The use of these tools in clinical decision-making provides more accurate and highly reproducible estimates of the outcome of interest. Efforts are still needed to improve the available tools' accuracy and to provide more evidence to further justify their routine use in clinical practice. In addition, prediction tools should be externally validated in independent cohorts before they are applied to different patient populations.

CONCLUSIONS

Predictive and prognostic tools represent valuable aids that are meant to consistently and accurately provide most evidence-based estimates of the end points of interest. More accurate, flexible, and easily accessible tools are needed to simplify the practical task of prediction.

Impact of ultrahigh baseline PSA levels on biochemical and clinical outcomes in two Radiation Therapy Oncology Group prostate clinical trials

PURPOSE

To assess ultrahigh (UH; prostate-specific antigen [PSA] levels ≥50 ng/ml) patient outcomes by comparison to other high-risk patient outcomes and to identify outcome predictors.

METHODS AND MATERIALS

Prostate cancer patients (PCP) from two Phase III Radiation Therapy Oncology Group clinical trials (studies 9202 and 9413) were divided into two groups: high-risk patients with and without UH baseline PSA levels. Predictive variables included age, Gleason score, clinical T stage, Karnofsky performance score, and treatment arm. Outcomes included overall survival (OS), distant metastasis (DM), and biochemical failure (BF). Unadjusted and adjusted hazard ratios (HRs) were calculated using either the Cox or Fine and Gray's regression model with associated 95% confidence intervals (CI) and p values.

RESULTS

There were 401 patients in the UH PSA group and 1,792 patients in the non-UH PSA PCP group of a total of 2,193 high-risk PCP. PCP with UH PSA were found to have inferior OS (HR, 1.19; 95% CI, 1.02-1.39, p = 0.02), DM (HR, 1.51; 95% CI, 1.19-1.92; p = 0.0006), and BF (HR, 1.50; 95% CI, 1.29-1.73; p < 0.0001) compared to other high-risk PCP. In the UH cohort, PSA level was found to be a significant factor for the risk of DM (HR, 1.01; 95% CI, 1.001-1.02) but not OS and BF. Gleason grades of 8 to 10 were found to consistently predict for poor OS, DM, and BF outcomes (with HR estimates ranging from 1.41-2.36) in both the high-risk cohort and the UH cohort multivariable analyses.

CONCLUSIONS

UH PSA levels at diagnosis are related to detrimental changes in OS, DM, and BF. All three outcomes can be modeled by various combinations of all predictive variables tested.

Why are pretreatment prostate-specific antigen levels and biochemical recurrence poor predictors of prostate cancer survival?

BACKGROUND

The value of pretreatment (initial) prostate-specific antigen (iPSA) and biochemical recurrence (BR) as prognostic factors for survival remains unclear. The authors sought to determine why using randomized trial data with 7-year minimum follow-up.

METHODS

In the Trans-Tasman Radiation Oncology Group 96.01 trial, 802 men with T2b, T2c, T3, or T4 N0 prostate cancer (PC) were randomized to radiotherapy alone or with 3 or 6 months neoadjuvant androgen deprivation between 1996 and 2000. Cox modeling was used to identify outcome predictors at follow-up landmark points.

RESULTS

Higher iPSA was found to be a potent predictor of BR-free survival (P < .01) but was not prognostic for prostate cancer-specific survival (PCSS) from randomization. Patients experiencing BR had unfavorable initial prognostic factors compared with patients who did not. After BR, these factors were not prognostic for PC death in models adjusted for time to BR (TTBR). In these models, TTBR predicted PCSS more satisfactorily than the occurrence of BR itself. Survival probability 5 years after BR exceeded 90% for men with TTBR >/=4 years; however, it dropped to 44% +/- 6% for men with TTBR <1 year. After BR, rapid PSA doubling time (DT), low iPSA, and short TTBR were identified as the most important predictors of inferior PCSS.

CONCLUSIONS

When BR occurs, prognostic factors for survival change. Low iPSA, short TTBR, and rapid PSA DT take over at this point, providing reasons why iPSA and occurrence of BR alone predict PCSS unsatisfactorily.

Current Perspectives on the Gleason Grading of Prostate Cancer

Context.—Since its description in 1966 by Donald Gleason, the Gleason grading has remained a cornerstone in the diagnosis and management of prostate cancer. With widespread use of the prostate specific antigen screening, the diagnosis and management patterns of prostate cancers have dramatically changed. In addition, better understanding of the morphologic spectrum of prostate cancer and its subsequent outcome have prompted the refinement of the grading criteria and reporting practices applicable to contemporary practice management.

Objective.—To present contemporary perspectives and approaches to the Gleason grading of prostate cancer.

Data Sources.—Personal practice experience, review of medical literature, and excerpts from the 2005 International Society of Urological Pathology Consensus Statement on Gleason Grading of Prostate Cancer.

Conclusions.—This review addresses the trend in contemporary practice toward a grading shift, with rare utilization of Gleason patterns 1 and 2, and discusses the refinement of histologic criteria for Gleason patterns 3 and 4; approaches to Gleason grading in the setting of unusual variant morphologies of prostate cancer; significance of higher tertiary pattern 5; and practice recommendations for reporting in the setting of extended multiple core biopsies and multifocal prostate cancers in radical prostatectomy. Finally, the impact of consensus recommendations in current practice, its limitations and pitfalls, are also addressed.

Predictive models in external beam radiotherapy for clinically localized prostate cancer

Predictive models are being used increasingly in effort to allow physician and patient expectations to be aligned with outcomes that are based on available data. Most predictive models for men who receive external beam radiotherapy for clinically localized prostate cancer are based on Gleason score, clinical tumor classification, and prostate-specific antigen (PSA) levels. More sophisticated models also have been developed that incorporate treatment-related variables, such as the dose of radiation and the use of androgen-deprivation therapy. Most of the predictive models applied to prostate cancer were derived using PSA recurrence rates as the major endpoint, but clinical endpoints have been incorporated increasingly into predictive models. Biomarkers also are increasingly being added to predictive models in an effort to strengthen them. The Radiation Therapy Oncology Group (RTOG) has completed studies on a wide range of markers using tissue from 2 phase 3 trials (RTOG 8610 and 9202). To date, preliminary assessments of p53; DNA ploidy; p16/retinoblastoma 1 protein; Ki-67; mouse double-minute p53 binding protein homolog; Bcl-2/Bcl-2-associated X protein; cytosine, adenine, and guanine repeats; cyclooxygenase-2; signal transducer and activator of transcription 3; cytochrome P450 3A4; and protein kinase A have been completed. Although they are not ready for widespread, routine use, there are reasons to believe that future models will combine these markers with traditional pretreatment and treatment-related variables and will improve our ability to predict outcome and select the optimal treatment. Cancer 2009;115(13 suppl):3112-20. (c) 2009 American Cancer Society.

Laparoscopic pelvic lymph-node dissection in prostate cancer before external beam radiotherapy: Risk factors of nodal involvement and relapse following intended curative treatment

OBJECTIVE

To report experience with laparoscopic pelvic lymph-node dissection (LPLND) in patients with prostate cancer before radiotherapy. Selection of risk factors for nodal involvement (N1) and recurrence following radiotherapy was made.

MATERIAL AND METHODS

From November 1999 to June 2007, 177 patients with prostate cancer underwent LPLND at this department. The lymphadenectomy was limited to the obturator fossa bilaterally. Patients without nodal involvement were offered external beam radiotherapy with adjuvant hormone treatment.

RESULTS

Complications occurred in 17 patients (9%). The majority of these were minor and were managed by conservative methods. Twenty-six patients (15%) were diagnosed with N1. High Gleason score and a high percentage of positive needle core biopsies were both risk factors of N1 as well as recurrent disease following radiotherapy (p<0.01 and 0.01, respectively). Clinically, T3 disease was associated with a risk of recurrence but not N1. High prostate-specific antigen (PSA) nadir was also a significant predictor of recurrence. Neither pretreatment PSA nor prostate volume was associated with N1 or recurrence.

CONCLUSIONS

LPLND is a safe, well-established staging modality in clinically localized prostate cancer before radiotherapy. Risk factors upon diagnosis may be useful in the estimation of N1 and risk of recurrence.

Major shifts in the treatment and prognosis of prostate cancer due to changes in pathological diagnosis and grading

OBJECTIVE

To examine data on the changes in the accuracy of the diagnosis of prostate cancer and of Gleason grading in the modern era.

PATIENTS AND METHODS

The study comprised a pathological review within a multicentre study of patients with clinically localized prostate cancer diagnosed in the UK from 1991 to 1996 (inclusive) and treated by watchful-waiting or hormonal therapy alone. The clinical follow-up was available, histopathological appearances were reviewed and the Gleason score at diagnosis was compared with the Gleason score as analysed by a panel of genitourinary pathologists using internationally agreed criteria. In all, 1789 patients diagnosed with prostate cancer between 1991 and 1996 were reviewed, with disease-specific survival as the main outcome measure.

RESULTS

In all, 133 patients (7%) were reassigned a nonmalignant diagnosis. There was a significant reassignment in the Gleason score for those with cancer, with increases of Gleason score across a wide spectrum. In multivariate analysis the revised Gleason score was a more accurate predictor of prognosis than the original score.

CONCLUSION

Misdiagnosis and reassignment of Gleason score at diagnosis would have guided clinicians into large-scale changes in the management of patients. Current rates of misdiagnosis are unknown. If applicable nationally, these changes would have profound effects on the workload of prostate cancer management in the UK.

Low Gleason score prostatic adenocarcinomas are no longer viable entities

Gleason scoring is the most powerful predictor of the behaviour of prostatic adenocarcinoma. It was devised more than 30 years ago and is used by pathologists worldwide. However, advances in immunochemistry and the understanding of the biological potential of some tumours have made the diagnosis of tumours of grades 1 and 2, and hence low score (2-4), a rarity. It is suggested that Gleason score 2(1 + 1) tumours, if they do exist, are so rare and so benign that they are a redundant entity and should not be identified as a malignancy. Similar problems revolve around the diagnosis of Gleason score 4(2 + 2) tumours and the criteria for their diagnosis are difficult to evaluate and revolve around reference to the score 2(1 + 1) lesion. The continued presence of low-grade tumours in the Gleason grading system leads to diagnostic confusion, potential error and, more importantly, confusion for patients diagnosed with score 6(3 + 3) tumours. I suggest that Gleason grade 1 (and therefore scores of 2 and 3) should be removed from the Gleason grading system. Gleason grade 2 (and therefore score 4 and 5) tumours require serious re-evaluation if they are to remain clinically useful diagnoses.

Clinical impact of second pathology opinion: A longitudinal study of central genitourinary pathology review before prostate brachytherapy

PURPOSE

To evaluate the clinical impact of pathology review before prostate brachytherapy.

METHODS AND MATERIALS

Original and reviewing pathologists' reports were retrospectively collected from 1323 men treated with prostate brachytherapy between July 1998 and October 2005 at one institution. Statistical analysis was performed pre- and post-January 2002. The clinical impact of pathology review was evaluated.

RESULTS

Gleason Score (GS) change (GS(Delta)) occurred in 25.2% (334) of cases; GS increased in 21.6%, decreased in 2.4%, and diagnosed malignancy in 1.2% of cases. Post-2002, concordance in attributed GS improved, with GS(Delta) of 31.9-20.6%, respectively (p<0.001), and a reduction in the average GS(Delta) (p<0.001). The clinical impact was substantial with management changing in 14.8% of cases.

CONCLUSION

Concordance between the original and reviewing pathologists' GS has improved during the study period. Nevertheless, discordance persists in one of five cases. Pathology review remains essential, if treatment decisions hinge on GS.

Increasing external beam dose for T1-T2 prostate cancer: effect on risk groups

PURPOSE

The aim of this study was to investigate effect of increasing dose on risk groups for clinical failure (CF: local failure or distant failure or hormone ablation or PSA>or=25 ng/ml) in patients with T1-T2 prostate cancer treated with external beam radiotherapy.

METHODS AND MATERIALS

Patients (n=4,537) were partitioned into nonoverlapping dose ranges, each narrow enough that dose was not a predictor of CF, and risk groups for CF were determined using recursive partitioning analysis (RPA). The same technique was applied to the highest of these dose ranges (70-76 Gy, 1,136 patients) to compare risk groups for CF in this dose range with the conventional risk-group classification.

RESULTS

Cutpoints defining low-risk groups in each dose range shifted to higher initial PSA levels and Gleason scores with increasing dose. Risk groups for CF in the dose range 70-76 Gy were not consistent with conventional risk groups.

CONCLUSIONS

The conventional classification of risk groups was derived in the early PSA era, when total doses<70 Gy were common, and it is inconsistent with risk groups for patients treated to doses>70 Gy. Risk-group classifications must be continuously re-examined whenever the trend is toward increasing total dose.

An international multicenter study evaluating the impact of an alternative biochemical failure definition on the judgment of prostate cancer risk

PURPOSE

To evaluate the impact of an alternative biochemical failure (bF) definition on the performance of existing plus de novo prognostic models.

METHODS AND MATERIALS

The outcomes data of 1,458 Australian and 703 Canadian men treated with external-beam radiation monotherapy between 1993 and 1997 were analyzed using a lowest prostate-specific antigen (PSA) level to date plus 2 ng/mL (L + 2) bF definition. Two existing prognostic models were scrutinized using discrimination (Somers Dxy [SDxy]) and calibration indices. Alternative prognostic models were also created using recursive partitioning analysis (RPA) and multivariate nomogram methods for comparison.

RESULTS

Discrimination of bF was improved using the L + 2 definition compared with the American Society for Therapeutic Radiology and Oncology (ASTRO) definition using both the three-level risk model (SDxy 0.30 and 0.22, respectively) or the nomogram (SDxy 0.35 and 0.27, respectively). Both existing prognostic models showed only modest calibration accuracy. Using RPA, five distinct risk groups were identified based primarily on Gleason score (GS) and all subsequent divisions based on PSA. All GS 7-10 tumors were intermediate or high risk. This model and the developed nomogram showed improved discrimination over the existing models as well as accurate calibration against the Canadian data, apart from the 30-50% failure region.

CONCLUSIONS

The L + 2 definition of bF provides improved capacity for discrimination of failure risk. New prognostic models based on this endpoint have overall statistical performance superior to those based on the ASTRO consensus definition but continue to have unreliable discrimination in the intermediate-risk region.

Four year clinical statistics of iridium-192 high dose rate brachytherapy

BACKGROUND

We evaluated the efficacy and complications of high dose rate (HDR) brachytherapy using iridium-192 (192Ir) combined with external beam radiotherapy (EBRT) in patients with prostate cancer.

METHODS

Ninety-seven patients underwent 192Ir HDR brachytherapy combined with EBRT at our institution between February 1999 and December 2003. Of these, 84 patients were analysed in the present study. 192Ir was delivered three times over a period of 2 days, 6 Gy per time, for a total dose of 18 Gy. Interstitial application was followed by EBRT at a dose of 44 Gy. Progression was defined as three consecutive prostate-specific antigen (PSA) rises after a nadir according to the American Society for Therapeutic Radiology and Oncology criteria. The results were classified into those for all patients and for patients who did not undergo adjuvant hormone therapy.

RESULTS

The 4-year overall survival of all patients, the nonadjuvant hormone therapy group (NAHT) and the adjuvant hormone therapy group (AHT) was 87.2%, 100%, and 70.1%, respectively. The PSA progression-free survival rate of all patients, NAHT, and AHT was 82.6%, 92.0%, and 66.6%, respectively. Of all patients, the 4-year PSA progression-free survival rates of PSA<20 and PSA>or=20 groups were 100%, and 46.8%, respectively. According to the T stage classification, PSA progression-free survival rates of T1c, T2, T3, and T4 were 100%, 82.8%, 100%, and 12.1%, respectively. Prostate-specific antigen progression-free survival rates of groups with Gleason scores (GS)<7 and GS>or=7 were 92.8% and 60.1%, respectively. Of NAHT, PSA progression-free survival of PSA<20 was 100% vs 46.8% for PSA>or=20, that of T1c was 100% vs 75% for T2, and that of GS<7 was 100% vs 75% for GS>or=7. No significant intraoperative or postoperative complications requiring urgent treatment occurred except cerebellum infarction.

CONCLUSIONS

192Ir HDR brachytherapy combined with EBRT was as effective as radical prostatectomy and had few associated complications.

Prognostic and predictive factors and reporting of prostate carcinoma in prostate needle biopsy specimens

The information provided in the surgical pathology report of a prostate needle biopsy of carcinoma has become critical in the subsequent management and prognostication of the cancer. The surgical pathology report should thus be comprehensive and yet succinct in providing relevant information consistently to urologists, radiation oncologists and oncologists and, thereby, to the patient. This paper reflects the current recommendations of the 2004 World Health Organization-sponsored International Consultation, which was co-sponsored by the College of American Pathologists. It builds on the existing work of several organizations, including the College of American Pathologists, the Association of Directors of Anatomic and Surgical Pathologists, the Royal Society of Pathologists, the European Society of Urologic Pathology and the European Randomized Study of Screening for Prostate Cancer.

External beam radiotherapy as curative treatment of prostate cancer

External beam radiotherapy (RT) has been used as a curative treatment of prostate cancer for more than 5 decades, with the "modern" era emerging more than 3 decades ago. Its history is marked by gradual improvements punctuated by several quantum leaps that are increasingly driven by advancements in the computer and imaging sciences and by its integration with complementary forms of treatment. Consequently, the contemporary use of external beam RT barely resembles its earliest form, and this must be appreciated in the context of current patient care. The influence of predictive factors on the use and outcomes of external beam RT is presented, as is a selected review of the methods and outcomes of external beam RT as a single therapeutic intervention, in association with androgen suppression, or as a postoperative adjunct. Thus, the "state of the (radiotherapeutic) art" is presented to enhance the understanding of this treatment approach with the hope that this information will serve as a useful resource to physicians as they care for patients with prostate cancer.

Gleason grading of prostate cancer in needle biopsies or radical prostatectomy specimens: contemporary approach, current clinical significance and sources of pathology discrepancies

The Gleason grading system is a powerful tool to prognosticate and aid in the treatment of men with prostate cancer. The needle biopsy Gleason score correlates with virtually all other pathological variables, including tumour volume and margin status in radical prostatectomy specimens, serum prostate-specific antigen levels and many molecular markers. The Gleason score assigned to the tumour at radical prostatectomy is the most powerful predictor of progression after radical prostatectomy. However, there are significant deficiencies in the practice of this grading system. Not only are there problems among practising pathologists but also a relative lack of interobserver reproducibility among experts.

What pretreatment prostate-specific antigen level warrants long-term androgen deprivation?

PURPOSE

Several large randomized prospective studies have demonstrated a survival benefit with the addition of long-term androgen deprivation to definitive radiotherapy for patients with Gleason score 8-10 or T3-T4 prostate cancer. However, these studies were performed before the routine use of prostate-specific antigen (PSA) measurement. The purpose of this study was to determine what pretreatment (initial) PSA (iPSA) level, if any, warrants the addition of long-term androgen deprivation in the PSA era.

METHODS AND MATERIALS

The data set evaluated consisted of 1003 prostate cancer patients treated definitively with three-dimensional conformal radiotherapy between May 1, 1989 and November 30, 1999 (median follow-up, 61 months). Specifically excluded were patients with T3-T4 disease or Gleason score greater than 7 or those who had undergone androgen deprivation as a part of their initial therapy. The median radiation dose was 76 Gy. Patients were randomly split into two data sets, with the first (n = 487) used to evaluate the optimal iPSA cutpoint for which a statistically significant difference in outcome was noted. The second data set (n = 516) served as a validation data set for the initial modeling. The analysis of the optimal iPSA cutpoint was based on a recursive partitioning approach for censored data using the log-rank test for nodal separation of freedom from biochemical failure (FFBF) as defined by the American Society for Therapeutic Radiology and Oncology definition. Cox multivariate regression analysis was used to confirm independent predictors of outcome among the clinical and treatment-related factors: iPSA (grouped as defined by the recursive partitioning analysis), Gleason score (2-6 vs. 7), T stage (T1c-T2a vs. T2b-T2c), and total radiation dose (continuous).

RESULTS

The recursive partitioning analysis data set resulted in an optimal iPSA cutpoint of 35 ng/mL, such that the 5-year Kaplan-Meier estimate of FFBF was 80%, 69%, and 19% for iPSA groups of 0-9.9, 10-35, and >35 ng/mL, respectively. The validation data set demonstrated the optimal iPSA cutpoint to be 30 ng/mL. Conservatively choosing 30 ng/mL as the optimal cutpoint, the 5-year FFBF estimate for the entire 1003 patients was 82%, 69%, and 20% for iPSA groups 0-9.9 (n = 630), 10-30 (n = 329), and >30 (n = 44) ng/mL, respectively. On multivariate regression analysis, with the iPSA grouped as above, the Gleason score and radiation dose were independent predictors of outcome in this patient group (all p < 0.001). On univariate analysis, a higher radiation dose improved FFBF when the iPSA level was between 10 and 30 ng/mL (p = 0.001) but not when the iPSA level was >30 or <10 ng/mL.

CONCLUSION

Recursive partitioning techniques defined an iPSA cutpoint of 30 ng/mL for delineating intermediate vs. high risk. Patients with a PSA level >30 ng/mL in the absence of Gleason score >7 or T3 disease do poorly when treated with radiotherapy alone and should be considered for long-term androgen deprivation or other aggressive systemic therapy.

Optimal treatment of intermediate-risk prostate carcinoma with radiotherapy

The clinical heterogeneity of intermediate-risk prostate carcinoma presents a challenge to urologic oncology in terms of prognosis and management. There is controversy regarding whether patients with intermediate-risk prostate carcinoma should be treated with dose-escalated external beam radiotherapy (EBRT) (e.g., doses > 74 gray [Gy]), or conventional-dose EBRT (e.g., doses < 74 Gy) combined with androgen deprivation (AD). Data for this review were identified through searches for articles in MEDLINE and in conference proceedings, indexed from 1966 to 2004. Currently, the intermediate-risk prostate carcinoma grouping is defined on the basis of prostate-specific antigen (PSA), tumor classification (T classification), and Gleason score. Emerging evidence suggests that additional prognostic information may be derived from the percentage of positive core needle biopsies at the time of diagnosis and/or from the pretreatment PSA doubling time. Novel prognostic biomarkers include protein expression relating to cell cycle control, cell death, DNA repair, and intracellular signal transduction. Preclinical data support dose escalation or combined AD with radiation as a means to increase prostate carcinoma cell kill. There is Level I evidence that patients with intermediate-risk prostate carcinoma benefit from dose-escalated EBRT or AD plus conventional-dose EBRT. However, clinical evidence is lacking to support the uniform use of AD plus dose-escalated EBRT. Patients in the intermediate-risk group should be entered into well designed, randomized clinical trials of dose-escalated EBRT and AD with sufficient power to address biochemical failure and cause-specific survival endpoints. These studies should be stratified by novel prognostic markers and accompanied by strong translational endpoints to address clinical heterogeneity and to allow for individualized treatment.

Radiotherapy in cT3 prostatic carcinoma: retrospective comparison between neoadjuvant and adjuvant hormonotherapy

INTRODUCTION

The aim of this study was to retrospectively compare the clinical outcomes achieved in 2 groups of patients with cT3 prostatic carcinoma undergoing neoadjuvant hormonotherapy and neoadjuvant hormonotherapy plus adjuvant hormonotherapy with external beam radiotherapy.

PATIENTS AND METHODS

One hundred patients with cT3N0M0 prostatic carcinoma underwent radiotherapy to pelvic lymph nodes (45 Gy, 1.8 Gy/fraction) with a booster dose (65-70 Gy) to the prostatic cavity. Forty-four patients received neoadjuvant hormonotherapy (goserelin, starting 2 months before radiotherapy and continuing until the end of irradiation); 56 patients received neoadjuvant hormonotherapy plus adjuvant goserelin until disease progression, if present.

RESULTS

Patients undergoing adjuvant hormonotherapy as compared to those who received exclusive neoadjuvant therapy showed a higher reduction in PSA level below 1.0 ng/ml (p = 0.0211), a lower incidence of biochemical failures (p = 0.0170), a lower incidence of hematogenous metastases (p = 0.0320) and a trend suggestive of a better disease-free survival (p = 0.0660). At univariate analysis (logrank), Gleason score did not show a significant correlation with any of the end points analyzed. To the contrary, patients with tumor <15 mm showed a better local control (p = 0.0347) and biochemical failure-free survival (p = 0.0102). Furthermore, a trend between initial PSA level and incidence of hematogenous metastases was observed (p = 0.0519). Patients with a posttreatment PSA level <1.0 ng/ml had a lower incidence of metastases (p = 0.0237) and a better survival (p = 0.0178); patients with complete clinical response showed a lower incidence of biochemical failures (p = 0.0469). Radiotherapy doses >70 Gy showed a trend with biochemical failure-free survival (p = 0.0554). At multivariate analysis, a correlation between Gleason score and incidence of metastases (p = 0.0232), and between tumor diameter and local control (p = 0.0178) and biochemical failure-free survival (p = 0.0290) was recorded.

CONCLUSIONS

In patients with cT3N0M0 prostate carcinoma, prolonged hormonotherapy was shown to be significantly correlated with biochemical failure-free survival and distant metastasis-free survival. Furthermore, tumor size had a significant impact on biochemical failure-free survival as well as on local control.

What defines intermediate-risk prostate cancer? Variability in published prognostic models

PURPOSE

To assess the efficacy of a variety of prognostic models in the definition of intermediate-risk prostate cancer and to compare them to our own empiric model.

METHODS AND MATERIALS

Two hundred fifty-six consecutive men with prostate adenocarcinoma treated with external beam radiotherapy alone were studied. Biochemical failure (defined as 3 consecutive PSA rises or the initiation of androgen deprivation therapy) was examined using univariate, multivariate, and recursive partitioning analyses. The risk classification model used in our department was then compared to a number of published models to assess the relative performance of each in discriminating risk groups.

RESULTS

At a median follow-up of 62.4 months, the 5-year Biochemical failure-free survival (bFFS) was 46.8% for the overall group. This relates to 5-year bFFS of 77.8%, 51.1%, and 33.8% based on our institutional criteria for low-, intermediate-, and high-risk features, respectively. All the models examined showed an outcome group with a comparatively similar poor outcome when applied to our data. Large variation was seen in the intermediate-risk groups, with 5-year bFFS ranging from 38.1% to 51.1%. Good risk categories had similar large variations. All published models showed inability to delineate three significantly different outcome groups. Recursive partitioning analysis derived categories based on combinations of PSA (with cutpoints at 42.4, 20, and 10.6 ng/mL) and Gleason score (with cutpoints at 2-6 and 7-10) only.

CONCLUSIONS

Large variations in the relative performance of a number of prognostic models are shown when applied to our local data. The prognostic efficacy of PSA and biopsy Gleason score is reiterated, although other factors will need to be explored to further improve the performance of prognostic models, particularly in defining the intermediate-risk subset of prostate cancer.

Utility of the percentage of positive prostate biopsies in predicting PSA outcome after radiotherapy for patients with clinically localized prostate cancer

PURPOSE

To determine the utility of the percentage of positive prostate biopsies (PPPB) in predicting prostate-specific antigen (PSA) outcome after external beam radiotherapy alone.

METHODS AND MATERIALS

The records of 750 clinical Stage T1 and T2 patients treated by external beam radiotherapy alone with a median follow-up of 80 months were reviewed. Of the 750 patients, 345 were eligible for analysis; 255 (74%) had undergone sextant biopsies, 28 (8%) <6 biopsies, and 62 (18%) >6 biopsies. The pretreatment PSA level (<10, 10-20, >20 ng/mL), biopsy Gleason score (2-6, 7, 8-10), and clinical stage (T1-T2a, T2b, T2c), uni- or bilateral positive biopsy, radiation dose, and PPPB were analyzed as potential predictors of PSA outcome. The PPPB data were analyzed as a continuous and as a categorical variable.

RESULTS

PPPB was a significant predictor of the time to PSA failure on univariate analysis as a continuous (p = 0.0053) and as a categorical (<50% vs. >or=50%, p = 0.0077) variable. In multivariate analysis, a trend was noted for worse 5-year PSA failure-free survival based on PPPB >or=50% vs. <50% (p = 0.082). Sixty-four patients experienced biochemical failure according to the American Society for Therapeutic Radiology Oncology definition. The 5-year PSA failure-free survival rate was 79% vs. 69% (p = 0.02) and the clinical disease-free survival rate was 97% vs. 86% (p = 0.0004) for patients with <50% vs. >or=50% PPPB. PPPB was not a significant predictor for the time to PSA failure within the traditional risk groups (low, intermediate, and high) on multivariate analysis.

CONCLUSION

PPPB was a predictor of post-external beam radiotherapy PSA outcome in clinically localized prostate cancer; but in this cohort it did not provide additional information beyond the traditional risk stratification schema.

Use of neoadjuvant and adjuvant therapy to prevent or delay recurrence of prostate cancer in patients undergoing radiation treatment for prostate cancer

Multiple oncologic treatment modalities are often integrated into the curative treatment approach for the patient with a newly established diagnosis of cancer. The combination of neoadjuvant and adjuvant therapies with radiotherapy for the care of the patient with prostate cancer is no exception. There is clear evidence that neoadjuvant androgen suppression reduces the volume of tumor in preparation for radiotherapy, and it is an effective addition to conventional-dose external radiotherapy in patients with large-volume primary prostatic tumors. Adjuvant androgen suppression improves local and systemic tumor control and improves survival duration compared with radiotherapy alone for patients with locally advanced or node-positive prostate cancer, particularly in those with high-grade disease. The role of neoadjuvant and adjuvant therapies is under intense scrutiny as several randomized clinical trials seek to optimize the combination of androgen suppression, chemotherapy, and radiotherapy. The historical precedent for combining androgen suppression with radiotherapy is described, as are the results of prior definitive trials and ongoing studies in this setting.

Long-term multi-institutional analysis of stage T1–T2 prostate cancer treated with radiotherapy in the PSA era

PURPOSE

To report the long-term outcome for patients with Stage T1-T2 adenocarcinoma of the prostate definitively irradiated in the prostate-specific antigen (PSA) era.

METHODS AND MATERIALS

Nine institutions combined data on 4839 patients with Stage T1b, T1c, and T2 adenocarcinoma of the prostate who had a pretreatment PSA level and had received >or=60 Gy as definitive external beam radiotherapy. No patient had hormonal therapy before treatment failure. The median follow-up was 6.3 years. The end point for outcome analysis was PSA disease-free survival at 5 and 8 years after therapy using the American Society for Therapeutic Radiology and Oncology (ASTRO) failure definition.

RESULTS

The PSA disease-free survival rate for the entire group of patients was 59% at 5 years and 53% at 8 years after treatment. For patients who had received >or=70 Gy, these percentages were 61% and 55%. Of the 4839 patients, 1582 had failure by the PSA criteria, 416 had local failure, and 329 had distant failure. The greatest risk of failure was at 1.5-3.5 years after treatment. The failure rate was 3.5-4.5% annually after 5 years, except in patients with Gleason score 8-10 tumors for whom it was 6%. In multivariate analysis for biochemical failure, pretreatment PSA, Gleason score, radiation dose, tumor stage, and treatment year were all significant prognostic factors. The length of follow-up and the effect of backdating as required by the ASTRO failure definition also significantly affected the outcome results. Dose effects were most significant in the intermediate-risk group and to a lesser degree in the high-risk group. No dose effect was seen at 70 or 72 Gy in the low-risk group.

CONCLUSION

As follow-up lengthens and outcome data accumulate in the PSA era, we continue to evaluate the efficacy and durability of radiotherapy as definitive therapy for early-stage prostate cancer. Similar studies with higher doses and more contemporary techniques will be necessary to explore more fully the potential of this therapeutic modality.

Association between CYP2E1 polymorphisms and susceptibility to prostate cancer

Several genetic alterations have been associated with sporadic prostate cancer (PCa). In this study, the association between RsaI and DraI polymorphisms of CYP2E1 and PCa risk was analysed in a case-control study of 227 individuals using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Regarding DraI polymorphisms, the DD genotype is over-represented in PCa cases when compared with the control group (odds ratio (OR) 2.12; 95% confidence interval (CI) 1.11-4.05; P=0.022). Regarding the RsaI polymorphism, no significant differences were found. The results of this study indicate that DraI polymorphisms of the CYP2E1 gene may be associated with a twofold increased risk for the development of PCa.

Quality-of-care indicators for early-stage prostate cancer

PURPOSE

Decisions regarding treatment for early-stage prostate cancer are frustrated not only by inadequate evidence favoring one treatment modality but also by the absence of data comparing quality among providers. In fact, the choice of provider may be as important as the choice of treatment. We undertook this study to develop an infrastructure to evaluate variations in quality of care for men with early-stage prostate cancer.

METHODS

We enlisted several sources to develop a list of proposed quality-of-care indicators and covariates. After an extensive structured literature review and a series of focus groups with patients and their spouses, we conducted structured interviews with national academic leaders in prostate cancer treatment. We then convened an expert panel using the RAND consensus method to discuss and rate the validity and feasibility of the proposed quality indicators and covariates.

RESULTS

The panel endorsed 49 quality-of-care indicators and 14 covariates, which make up our final list of candidate measures. Several domains of quality are represented in the selected indicators, including patient volume, pretreatment referrals, preoperative testing, interpretation of pathology specimens, and 10-year disease-free survival. Covariates include measures of case-mix, such as patient age and comorbidity.

CONCLUSION

This study establishes a foundation on which to build quality-of-care assessment tools to evaluate the treatment of early-stage prostate cancer. The next step is to field-test the indicators for feasibility, reliability, validity, and clinical utility in a population-based sample. This work will begin to inform medical decision-making for patients and their physicians.

Mindless or mindful? Radiation oncologists' perspectives on the evolution of prostate cancer treatment

The evolution of radiation therapy treatment for prostate cancer has been striking over the last 10 years. Advances in brachytherapy (BT), external beam radiotherapy (EBRT), and the combination of EBRT + BT have led to improved biochemical and clinical results. This article describes these advances in the context of the treatment decision process. Key to this process is the assignment of patient risk, which is based on the results of conventional radiation dose and techniques. Using the 1992 AJCC palpation staging system, Gleason score, and pretreatment prostate-specific antigen, two different risk assessment algorithms were compared. Both gave comparable approximations of risk, although the single factor high-risk model was superior in differentiating those patients with the highest probability of failing treatment after radiotherapy. Such criteria are the foundation for treatment selection. Objective findings support BT alone or EBRT alone for low-risk patients, high-dose EBRT or EBRT + BT for intermediate-risk patients, and EBRT + androgen deprivation for high-risk patients. In summary, advances in radiation oncology have led to significant gains in prostate cancer control. Clinical prognostic factor-based patient selection is central to the optimization of outcome.

Serum prostate-specific antigen and survival after external beam radiotherapy for carcinoma of the prostate

OBJECTIVES

To evaluate the significance of pretreatment prostate-specific antigen (pPSA) levels as a predictor of overall survival simultaneously with previously established prognostic factors. The pPSA level is a major predictor of treatment failure after radiotherapy and surgery, but to date has not been shown to predict survival.

METHODS

This analysis was based on data from 927 patients with clinically localized prostate cancer treated with radiotherapy alone between 1987 and 1998. These patients were stratified into four prognostic risk groups, and multivariate analysis was used to determine the independent impact of pPSA level on PSA failure, progression-free survival (death from any cause after PSA failure), and overall survival (death from any cause).

RESULTS

In a multivariate analysis simultaneously considering the prognostic risk group, a pPSA level greater than or equal to 20 ng/mL was associated with a higher risk of PSA failure and worse progression-free and overall survival.

CONCLUSIONS

The pPSA level is an independent predictor of survival in patients initially treated with radiotherapy alone.

Prostate-specific antigen in prostate cancer: a case study in the development of a tumor marker to monitor recurrence and assess response

The serum marker known as prostate-specific antigen (PSA) has established itself as the most important tool for the early detection of prostate cancer. However, more recent data indicate that (post-treatment) PSA and PSA kinetics can be used to predict the outcome of a variety of therapeutic interventions including radical prostatectomy, radiation therapy, androgen deprivation, and treatment of hormone-refractory prostate cancer. PSA recurrence after radiation therapy is now accepted as a harbinger of developing metastatic disease. The American Society for Therapeutic Radiation Oncology (ASTRO) consensus definition is the most widely accepted definition of failure after radiation therapy. Rather than using a specific PSA cutoff, three consecutive PSA rises was felt to be a more reliable indicator of biochemical failure. The PSA nadir (the lowest PSA level achieved after therapeutic intervention) also appears to correlate with the likelihood of remaining disease-free. Similarly, a rapid doubling time is a significant predictor of developing distant metastases. The most appropriate definition for biochemical (PSA) failure following radical prostatectomy is usually considered to be a non-zero value. As is the case after radiotherapy, there appears to be a relationship between the rate of rise of the PSA and the risk of distant failure following radical prostatectomy. In patients with metastatic disease, multiple studies appear to indicate that a fall in PSA, however measured, appears to be predictive of improved outcome in prostate cancer patients treated with androgen deprivation. Multiple reports of trials in the treatment of hormone-refractory prostate cancer (HRPC) appear to substantiate the observation that patients who have a greater than 50% decline in PSA have an improved survival. Correlation of PSA declines with other markers of clinical benefit, including clinically significant "subjective" end points such as pain control, have strengthened the argument that a PSA decline can serve as an intermediate endpoint in clinical trials involving HRPC patients.

Efficacy of vaccination with plasmid DNA encoding for HER2/neu or HER2/neu-eGFP fusion protein against prostate cancer in rats

Despite early diagnosis and improved therapy, 31,500 men will die from prostate cancer (PC) this year. The HER2/neu oncoprotein is an important effector of cell growth found in the majority of high-grade prostatic tumors and is capable of rendering immunogenicity. The antigenicity of this oncoprotein might prove useful in the development of PC vaccines. Our goal is to prove the principle that a single DNA vaccine can provide reliable immunity against PC in the MatLyLu (MLL) translational tumor model. The parental rat MatLyLu PC cell line expresses low to moderate levels of the rat neu protein. To simulate in vivo human PC, MatLyLu cells were transfected with a truncated sequence of human HER2/neu cDNA cloned into the pCI-neo vector. This HER2/neu cDNA sequence encodes the first 433 amino acids of the extracellular domain (ECD). MatLyLu cells were also transfected with the same HER2/neu cDNA sequence cloned into the N1-terminal sequence of EGFP reporter gene to produce a fusion protein. The partial ECD sequence of HER2/neu includes five rat major histocompatibility (MHC)-II-restricted peptides with complete human-to-rat cross-species homology. The HER2/neu protein overexpression was documented by Western Blot analysis, and the expression of fusion protein was monitored by confocal microscopy and fluorimetry. Vaccination with a single injection of HER2/neu cDNA protected 50% of animals against HER2/neu-MatLyLu tumors (P < 0.01). When the tumor cells were engineered to express HER2/neu-EGFP fusion protein, the antitumor immunity was enhanced, as following vaccination with HER2/neu-EGFP cDNA, 80% of these rats rejected HER2/neu-EGFP-MatLyLu (P<0.001). Both vaccines induced HER2/neu-specific antibody titers. Rats vaccinated with EGFP-cDNA rejected 80% of EGFP-MatLyLu tumors and, interestingly, 40% of HER2/neu-MatLyLu tumors. None of the cDNA vaccines induced immunity against parental MatLyLu cells. Our data clearly demonstrate that a single injection of HER2/neu-EGFP cDNA is a very effective vaccine against PC tumors expressing the cognate tumor-associated antigen (TA). The antitumor immunity is significantly more pronounced if the tumors express xenogeneic HER2/neu-EGFP fusion protein as opposed to only the syngeneic HER2/neu oncoprotein. Our data suggests that the HER2/neu-EGFP-MatLyLu tumor is a potential animal tumor model for investigating therapeutic vaccine strategies against PC in vivo and demonstrates the limitations of a cDNA vaccine only encoding for MHC-II-restricted HER2/neu-ECD sequence peptides.

Preoperative parameters for predicting early prostate cancer recurrence after radical prostatectomy

OBJECTIVES

To determine whether easily measurable prostate biopsy features could complement Gleason score, prostate-specific antigen (PSA), or clinical stage in predicting recurrence-free survival after prostatectomy. Information relating preoperative parameters to recurrence-free survival is needed to counsel patients with newly diagnosed prostate cancer regarding expectations for postprostatectomy cancer control.

METHODS

The data of a cohort of 588 consecutive prostatectomy patients (median age 61 years, range 39 to 83) with ascertained preoperative data and up to 4 years of postprostatectomy follow-up were analyzed. Bivariate and multivariate Cox proportional hazards analysis evaluated preoperative factors (clinical stage, PSA, biopsy Gleason score, greatest percentage of a biopsy core involved by cancer [GPC], number of biopsy cores containing cancer, perineural invasion) to identify those relating significantly to recurrence-free survival. Functional forms of these factors were evaluated to optimize accuracy in predicting cancer control.

RESULTS

The baseline parameters significantly affecting PSA-free survival included PSA level (P <0.01), biopsy Gleason score (P = 0.04), and GPC (P <0.01). Although clinical stage and perineural invasion had a marginal association with PSA-free survival as univariate factors, this association was not independently significant in multivariable analysis. The multivariate Cox model using PSA, Gleason score, and GPC was highly predictive of PSA free-survival (chi-square = 48.2, P = 0.0001). A set of plots representing these data can be used to identify the risk of early postoperative PSA recurrence on the basis of specific preoperative PSA, Gleason score, and GPC values.

CONCLUSIONS

These findings provide a highly significant model and a simple tool for assisting preoperative patient counseling regarding predicted cancer control after radical prostatectomy.

[What systematic work-up should be required for the patient with localized adenocarcinoma of the prostate?]

The systematic work-up for patient with clinically localised prostate cancer must allow a reconciliation of all the necessary elements to propose one or several therapeutical options. The evaluation must take into account the life's expectancy, and must precise the cancer progression and prognostic factors. The life expectancy depends out age, performance status and comorbidities. Digital rectal exam, PSA and Gleason score analysis are systematic. These tests allow the specialist to decide whether or not to complete the progression work-up by bone scan and pelvic CT. This first work-up should define if a patient will benefit from some curative local treatment. In case of palliative treatment or deferred treatment, the work-up highlights the specialist to decide the medical supervision. Some exams, systematic or not, are very specific from each therapeutic modality considered; they allow to precise individually the efficacy and toxicity prognostic factors for each therapeutic strategy. The final therapeutic decision is based at first on this objective data even if they are probabilistic, and finally on informed patients preferences.

[Clinical and biological surveillance after radiotherapy for localized prostate cancer]

Serum PSA is an excellent marker of disease status after external beam radiotherapy or brachytherapy for patients with prostate carcinoma. A low PSA nadir < or = 1 even < or = 0.5 ng/mL has been shown to be as a surrogate end point for disease control. Three successive increases of this marker after achieving the nadir defines recurrence as recommended by the American Society for Therapeutic Radiology and Oncology. The biochemical relapse or PSA failure after treatment precedes clinical disease relapse by several months. PSA profile or kinetics may have implications for patterns of failure and prognosis. Prostate post-radiotherapy biopsies should not be part of routine follow-up as its interpretation is frequently problematic. Other exams should not be performed unless clinical symptoms are present. Post-radiotherapy relapse treatment has generally no curative intent.

Artificial neural network model to predict biochemical failure after radical prostatectomy

BACKGROUND

Biochemical failure, defined here as a rise in the serum prostate specific antigen (PSA) concentration to >0.3 ng/mL or the initiation of adjuvant therapy, is thought to be an adverse prognostic factor for men who undergo radical prostatectomy (RP) as definitive treatment for clinically localized cancer of the prostate (CAP). We have developed an artificial neural network (ANN) to predict biochemical failure that may benefit clinicians and patients choosing among the definitive treatment options for CAP.

MATERIALS AND METHODS

Clinical and pathologic data from 196 patients who had undergone RP at one institution between 1988 and 1999 were utilized. Twenty-one records were deleted because of missing outcome, Gleason sum, PSA, or clinical stage data. The variables from the 175 remaining records were analyzed for input variable selection using principal component analysis, decision tree analysis, and stepped logistic regression. The selected variables were age, PSA, primary and secondary Gleason grade, and Gleason sum. The records were randomized and split into three bootstrap training and validation sets of 140 records (80%) and 35 records (20%), respectively.

RESULTS

Forty-four percent of the patients suffered biochemical failure. The average duration of follow up was 2.5 years (range 0-11.5 years). Forty-two percent of the patients had pathologic evidence of non-organ-confined disease. The average area under the receiver operator characteristic (ROC) curve for the validation sets was 0.75 +/- 0.07. The ANN with the highest area under the ROC curve (0.80) was used for prediction and had a sensitivity of 0.74, a specificity of 0.78, a positive predictive value of 0.71, and a negative predictive value of 0.81.

CONCLUSION

These results suggest that ANN models can predict PSA failure using readily available preoperative variables. Such predictive models may offer assistance to patients and physicians deciding on definitive therapy for CaP.