Prostate-specific antigen and radiation therapy for clinically localized prostate cancer

Joint partially linear model for longitudinal data with informative drop-outs

In biomedical research, a steep rise or decline in longitudinal biomarkers may indicate latent disease progression, which may subsequently cause patients to drop out of the study. Ignoring the informative drop-out can cause bias in estimation of the longitudinal model. In such cases, a full parametric specification may be insufficient to capture the complicated pattern of the longitudinal biomarkers. For these types of longitudinal data with the issue of informative drop-outs, we develop a joint partially linear model, with an aim to find the trajectory of the longitudinal biomarker. Specifically, an arbitrary function of time along with linear fixed and random covariate effects is proposed in the model for the biomarker, while a flexible semiparametric transformation model is used to describe the drop-out mechanism. Advantages of this semiparametric joint modeling approach are the following: 1) it provides an easier interpretation, compared to standard nonparametric regression models, and 2) it is a natural way to control for common (observable and unobservable) prognostic factors that may affect both the longitudinal trajectory and the drop-out process. We describe a sieve maximum likelihood estimation procedure using the EM algorithm, where the Akaike information criterion (AIC) and Bayesian information criterion (BIC) are considered to select the number of knots. We show that the proposed estimators achieve desirable asymptotic properties through empirical process theory. The proposed methods are evaluated by simulation studies and applied to prostate cancer data.

ACR Appropriateness Criteria® definitive external beam irradiation in stage T1 and T2 prostate cancer

PURPOSE

: External beam radiation therapy is a standard of care treatment for men who present with clinically localized (T1-T2) prostate cancer. The purpose of this review was to provide clarification on the appropriateness criteria and management considerations for the treatment of prostate cancer with external beam radiation therapy.

METHODS

: A panel consisting of physicians with expertise on prostate cancer was assembled and provided with a number of clinical scenarios for consensus treatment and management guidelines. Prostate cancer patient vignettes were presented along with specific management recommendations based on an extensive review of the modern external beam radiotherapy literature. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances, where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

RESULTS

: Modern external beam radiation therapy series demonstrate favorable biochemical control rates for patients with localized prostate cancer. Morbidity profiles are also favorable and it is clear that this is enhanced by modern techniques like 3-dimensional conformal radiation therapy and intensity-modulated radiation therapy. An active area of investigation is evaluating the use of hypofractionated dosing.

CONCLUSIONS

: Continued investigation to refine patient selection, external beam radiation technology application, and alternative dosing schedules should result in further improvements in biochemical outcome and decreased morbidity with external beam radiation treatment for localized prostate cancer.

Low-dose rate brachytherapy for men with localized prostate cancer

BACKGROUND

Localized prostate cancer is a slow growing tumor for many years for the majority of affected men. Low-dose rate brachytherapy (LDR-BT) is short-distance radiotherapy using low-energy radioactive sources. LDR-BT has been recommended for men with low risk localized prostate cancer.

OBJECTIVES

To assess the benefit and harm of LDR-BT compared to radical prostatectomy (RP), external beam radiotherapy (EBRT), and no primary therapy (NPT) in men with localized prostatic cancer.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (from 1950), and EMBASE (from 1980) were searched in June 2010 as well as online trials registers and reference lists of reviews.

SELECTION CRITERIA

Randomized, controlled trials comparing LDR-BT versus RP, EBRT, and NPT in men with clinically localized prostate cancer.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, treatment regimens, observation period and outcomes were recorded by two reviewers independently.

MAIN RESULTS

We identified only one RCT (N = 200; mean follow up 68 months). This trial compared LDR-BT and RP. The risk of bias was deemed high. Primary outcomes (overall survival, cause-specific mortality, or metastatic-free survival) were not reported. Biochemical recurrence-free survival at 5 years follow up was not significantly different between LDR-BT (78/85 (91.8%)) and RP (81/89 (91.0%)); P = 0.875; relative risk 0.92 (95% CI: 0.35 to 2.42).For severe adverse events reported at 6 months follow up, results favored LDR-BT for urinary incontinence (LDR-BT 0/85 (0.0%) versus RP 16/89 (18.0%); P < 0.001; relative risk 0) and favored RP for urinary irritation (LDR-BT 68/85 (80.0%) versus RP 4/89 (4.5%); P < 0.001; relative risk 17.80, 95% CI 6.79 to 46.66). The occurrence of urinary stricture did not significantly differ between the treatment groups (LDR-BT 2/85 (2.4%) versus RP 6/89 (6.7%); P = 0.221; relative risk 0.35, 95% CI: 0.07 to 1.68). Long-term information was not available.We did not identify significant differences of mean scores between treatment groups for patient-reported outcomes function and bother as well as generic health-related quality of life.

AUTHORS' CONCLUSIONS

Low-dose rate brachytherapy did not reduce biochemical recurrence-free survival versus radical prostatectomy at 5 years. For short-term severe adverse events, low-dose rate brachytherapy was significantly more favorable for urinary incontinence, but radical prostatectomy was significantly more favorable for urinary irritation. Evidence is based on one RCT with high risk of bias.

Differential expression of MSX2 in nodular hyperplasia, high-grade prostatic intraepithelial neoplasia and prostate adenocarcinoma

One of the common features in advanced prostate cancer is bone metastasis. In this study, we investigated the clinical relevance of a bone factor, MSX2, in predicting the metastatic ability of prostate adenocarcinoma. Evaluation of MSX2 expression was performed using prostate cell lines as well as patient specimens. A sharp decrease in MSX2 was found in primary prostate cancer cells, 22Rv1, when compared with the non-malignant counterparts, followed by a gradual increase in more aggressive prostate cancer cell lines. Interestingly, the MSX2 protein was upregulated and predominantly expressed in the nucleus in aggressive prostate cancer cell line, C4-2b, compared with the less aggressive 22Rv1. Consistent with the in vitro results, MSX2 nuclear expression was significantly higher in nodular hyperplasia when compared with high-grade prostatic intraepithelial neoplasia (PIN), while MSX2 nuclear expression in prostate adenocarcinoma was higher than that in high-grade PIN. Importantly, MSX2 expression was increased significantly in tumors with metastasis compared with those without metastasis. Finally, MSX2 nuclear scores were significantly increased in patients with preoperative serum PSA >20 ng/mL. No correlation between MSX2 nuclear score and Gleason score was found. Taken together, MSX2 may serve as a potential biomarker in predicting primary prostate tumors with higher metastatic capability.

Suppression of androgen-independent prostate cancer cell aggressiveness by FTY720: validating Runx2 as a potential antimetastatic drug screening platform

PURPOSE

Previously, FTY720 was found to possess potent anticancer effects on various types of cancer. In the present study, we aimed to first verify the role of Runx2 in prostate cancer progression and metastasis, and, subsequently, assessed if FTY720 could modulate Runx2 expression, thus interfering downstream events regulated by this protein.

EXPERIMENTAL DESIGN

First, the association between Runx2 and prostate cancer progression was assessed using localized prostate cancer specimens and mechanistic investigation of Runx2-induced cancer aggressiveness was then carried out. Subsequently, the effect of FTY720 on Runx2 expression and transcriptional activity was investigated using PC-3 cells, which highly expressed Runx2 protein. Last, the involvement of Runx2 in FTY720-induced anticancer effects was evaluated by modulating Runx2 expression in various prostate cancer cell lines.

RESULTS

Runx2 nuclear expression was found to be up-regulated in prostate cancer and its expression could be used as a predictor of metastasis in prostate cancer. Further mechanistic studies indicated that Runx2 accelerated prostate cancer aggressiveness through promotion of cadherin switching, invasion toward collagen I, and Akt activation. Subsequently, we found that FTY720 treatment down-regulated Runx2 expression and its transcriptional activity, as well as inhibited its regulated downstream events. More importantly, silencing Runx2 in PC-3 enhanced FTY720-induced anticancer effects as well as cell viability inhibition, whereas overexpressing Runx2 in 22Rv1 that expressed very low endogenous Runx2 protein conferred resistance in the same events.

CONCLUSION

This study provided a novel mechanism for the anticancer effect of FTY720 on advanced prostate cancer, thus highlighting the therapeutic potential of this drug in treating this disease.

Prognostic factors in metastatic prostate cancer

OBJECTIVE

Aim of this study is to determine the prognostic value of age, serum alkaline phosphatase, pretreatment PSA level, Gleason score, and number of bone metastasis focuses.

PATIENTS AND METHODS

One hundred fifty-one patients who had been followed in our clinic between years 1989 and 2006 were investigated retrospectively.

RESULTS

As a result of this study, it has been detected that serum alkaline phosphatase, Gleason score, and intensity of bone metastasis are important and statistically significant prognostic factors, and affects time to progression and life time. But pretreatment PSA level, and age have been detected not to be effective in predicting time to progression and life time.

CONCLUSION

Metastatic prostate cancer provides a wide spectrum for risk of death from the disease, and clinicians have long sought methods to predict the outcome accurately in individual patients. In our study, we found that high serum alkaline phosphatase, high Gleason score, and intense bone metastasis (>6) has negative impact on progression and survival.

Radioterapia externa conformada 3D para o carcinoma de próstata: experiência do Instituto do Radium de Campinas com 285 pacientes

OBJETIVO: Reportar resultados de tratamentos do câncer de próstata com radioterapia conformada 3D realizados em uma única instituição. MATERIAIS E MÉTODOS: De julho de 1997 a janeiro de 2002, 285 pacientes consecutivos com câncer de próstata foram submetidos a radioterapia conformada 3D com dose mediana de 7.920 cGy na próstata e analisados retrospectivamente. A distribuição segundo o grupo de risco foi a seguinte: baixo risco - 95 (33,7%); risco intermediário - 66 (23,4%); alto risco - 121 (42,9%) pacientes. RESULTADOS: Em seguimento mediano de 53,6 meses (3,6-95,3 meses), sobrevidas atuariais global, causa específica, livre de metástases a distância e livre de recidiva bioquímica em cinco anos foram de 85,1%, 97,0%, 94,2% e 75,8%, respectivamente. Sobrevidas atuariais livre de toxicidade retal e urinária tardias em cinco anos foram de 96,4% e 91,1%, respectivamente. Ressecção transuretral pré-radioterapia conformada 3D e doses > 70 Gy em 30% do volume da bexiga implicaram maior toxicidade urinária tardia grau 2-3 em cinco anos (p = 0,0002 e p = 0,0264, respectivamente). CONCLUSÃO: A primeira experiência relatada de radioterapia conformada 3D no Brasil permitiu altas doses de radiação, com toxicidades retal e urinária aceitáveis. A existência de ressecção transuretral de próstata pré-radioterapia conformada 3D pode sinalizar maior risco de toxicidade urinária tardia grau 2-3 após irradiação. Restrição da dose < 70 Gy em 30% do volume da bexiga à tomografia de planejamento pode reduzir complicações urinárias tardias.

Determinants of change in prostate-specific antigen over time and its association with recurrence after external beam radiation therapy for prostate cancer in five large cohorts

PURPOSE

To assess the relationship between prognostic factors, postradiation prostate-specific antigen (PSA) dynamics, and clinical failure after prostate cancer radiation therapy using contemporary statistical models.

METHODS AND MATERIALS

Data from 4,247 patients with 40,324 PSA measurements treated with external beam radiation monotherapy in five cohorts were analyzed. Temporal change of PSA after treatment completion was described by a specially developed linear mixed model that included standard prognostic factors. These factors, along with predicted PSA evolution, were incorporated into a Cox model to establish their predictive value for the risk of clinical recurrence over time.

RESULTS

Consistent relationships were found across cohorts. The initial PSA decline after radiation therapy was associated with baseline PSA and T-stage (p < 0.001). The long-term PSA rise was associated with baseline PSA, T-stage, and Gleason score (p < 0.001). The risk of clinical recurrence increased with current level (p < 0.001) and current slope of PSA (p < 0.001). In a pooled analysis, higher doses of radiation were associated with a lower long-term PSA rise (p < 0.001) but not with the risk of recurrence after adjusting for PSA trajectory (p = 0.63). Conversely, after adjusting for other factors, increased age at diagnosis was not associated with long-term PSA rise (p = 0.85) but was directly associated with decreased risk of recurrence (p < 0.001).

CONCLUSIONS

We conclude that a linear mixed model can be reliably used to construct typical patient PSA profiles after prostate cancer radiation therapy. Pretreatment factors along with PSA evolution and the associated risk of recurrence provide an efficient and quantitative way to assess the impact of risk factors on disease progression.

PSA Nadir Is a Significant Predictor of Treatment Failure after High-Intensity Focussed Ultrasound (HIFU) Treatment of Localised Prostate Cancer

OBJECTIVES

To assess if prostate-specific antigen (PSA) nadir is an independent predictor of treatment failure and disease-free survival after high-intensity focussed ultrasound (HIFU) therapy for localised prostate cancer as defined by the new ASTRO criteria.

METHODS

One hundred three patients after HIFU treatment (Ablatherm, EDAP, Lyon, France) for localised prostate cancer without previous hormonal therapy were evaluated retrospectively. Patients attended regular follow-up visits every 3 mo. Treatment failure was defined by the revised ASTRO criteria (PSA >or=2 ng/ml above nadir PSA, positive biopsy, if salvage treatment was administered). Patients were divided into three PSA nadir subgroups (group 1, <or=0.2 ng/ml; group 2, 0.21-1 ng/ml; group 3, >1 ng/ml). The disease-free survival rate (DFSR) was calculated by using life table methods. The log-rank test was used to compare the curves based on Kaplan-Meier models.

RESULTS

The median follow-up was 4.9 (3-8.6) yr. Mean time to PSA nadir was 6.4+/-5.1 mo. A PSA nadir of <or=0.2 ng/ml, 0.21-1 ng/ml, and >1ng/ml was reached by 64%, 22.3%, and 13.6% of patients, respectively. Treatment failure rates during follow-up were 4.5%, 30.4%, and 100%, respectively, for the three groups (p<0.001). The actuarial DFSRs at 5 yr were 95%, 55%, and 0%, respectively, for the 3 groups (p<0.001).

CONCLUSIONS

The PSA nadir after HIFU correlates highly significantly with treatment failure and DFSR, and can be applied in daily clinical practice. Promising oncological outcome is obtained if a PSA nadir of <or=0.2 ng/ml is reached.

Prostate-specific antigen nadir within 12 months of prostate cancer radiotherapy predicts metastasis and death

BACKGROUND

The nadir prostate-specific antigen (PSA) at 1 year (nPSA12) was investigated as an early estimate of biochemical and clinical outcome after radiotherapy (RT) alone for localized prostate cancer.METHODS.From May 1989 to November 1999, 1000 men received 3D conformal RT alone (median, 76 Gy) with minimum and median follow-up periods of 26 and 58 months, respectively, from the end of treatment. The calculation of PSA doubling time (PSADT) was possible in 657 patients. Multivariate analyses (MVAs) via Cox proportional hazards regression were used to determine the association of nPSA12 to biochemical failure (BF; ASTRO definition), distant metastasis (DM), cause-specific mortality (CSM), and overall mortality (OM). Dichotomization of nPSA12 was optimized by evaluating the sequential model likelihood ratio and P-values.RESULTS.In MVA, nPSA12 as a continuous variable was independent of RT dose, T-stage, Gleason score, pretreatment initial PSA, age, and PSADT in predicting for BF, DM, CSM, and OM. Dichotomized nPSA12 (2 versus >2 ng/mL) was independently related to DM and CSM. Kaplan-Meier 10-year DM rates for nPSA12 2 versus >2 ng/mL were 4% versus 19% (P<.0001).CONCLUSIONS.nPSA12 is a strong independent predictor of outcome after RT alone for prostate cancer and should be useful in identifying patients at high risk for progression to metastasis and death.

Influence of obesity on biochemical and clinical failure after external-beam radiotherapy for localized prostate cancer

BACKGROUND

Several reports have shown that obesity is associated with increased risk of biochemical failure after radical prostatectomy. However, limited information is available regarding the impact of obesity on prostate cancer progression after radiotherapy. The current study sought to determine whether obesity was an independent predictor of biochemical failure (BF) and clinical recurrence (CF) among patients treated with external-beam radiotherapy (EBRT).

METHODS

A retrospective analysis was performed on 873 patients receiving EBRT as the sole treatment for localized prostate cancer between 1988 and 2001. The Kaplan-Meier method, log-rank test, and Cox proportional hazards analyses were performed.

RESULTS

Of the 873 patients, 18% were mildly obese and 5% were moderately to severely obese. Obesity was related to younger age at diagnosis (P < .001), more recent year of diagnosis (P = .03), and race (P = .03), with African-American men having the highest obesity rates. During a mean follow-up of 96 months, 295 patients experienced BF and 127 had CF. On multivariate analysis, controlling for clinical and treatment characteristics, increased body mass index (BMI) significantly predicted BF (hazards ratio [HR] = 1.04; 95% confidence interval [95% CI], 1.02-1.07) with a positive trend by BMI category (P = .001). Similar results were found when the outcome was CF; BMI remained an independent predictor of progression (HR = 1.05; 95% CI, 1.01-1.09), with a statistically significant trend by increased BMI category (P = .03).

CONCLUSIONS

The current findings validate the important role of obesity, not only on BF but also on CF, and suggest a link to the biologic basis of tumor progression that can be therapeutically exploited.

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.

Minimally invasive surgery in prostate cancer: current and future perspectives

Prostate cancer is a leading cause of death for men. Its prevalence increases substantially with advancing age, which coincides with increased incidence of comorbidities. The mainstay therapy for early prostate cancer remains radical surgery and radiotherapy. In the era of prostate-specific antigen and the newly emerging highly specific screening tests, more men are diagnosed earlier in their life and with confined disease. The application of minimally invasive approaches, such as the laparoscopic/telerobotic approach and focal treatments, is becoming more popular, yielding shorter hospital stays and faster recovery, with minimal complications. In part, this is possible due to groundbreaking advances in laparoscopic equipment, prostate imaging modalities, and gained urologic expertise in minimally invasive treatment. In this review we critically discuss the current knowledge and future perspectives of minimally invasive treatment in prostate cancer.

Sustained long-term immune responses after in situ gene therapy combined with radiotherapy and hormonal therapy in prostate cancer patients

PURPOSE

To explore long-term immune responses after combined radio-gene-hormonal therapy.

METHODS AND MATERIALS

Thirty-three patients with prostate specific antigen 10 or higher or Gleason score of 7 or higher or clinical stage T2b to T3 were treated with gene therapy that consisted of 3 separate intraprostatic injections of AdHSV-tk on Days 0, 56, and 70. Each injection was followed by 2 weeks of valacyclovir. Intensity-modulated radiation therapy was delivered 2 days after the second AdHSV-tk injection for 7 weeks. Hormonal therapy was initiated on Day 0 and continued for 4 months or 2.3 years. Blood samples were taken before, during, and after treatment. Lymphocytes were analyzed by fluorescent antibody cell sorting (FACS).

RESULTS

Median follow-up was 26 months (range, 4-48 months). The mean percentages of DR+CD8+ T cells were increased at all timepoints up to 8 months. The mean percentages of DR+CD4+ T cells were increased later and sustained longer until 12 months. Long-term (2.3 years) use of hormonal therapy did not affect the percentage of any lymphocyte population.

CONCLUSIONS

Sustained long-term (up to 8 to 12 months) systemic T-cell responses were noted after combined radio-gene-hormonal therapy for prostate cancer. Prolonged use of hormonal therapy does not suppress this response. These results suggest the potential for sustained activation of cell-mediated immune responses against cancer.

PSA nadir predicts biochemical and distant failures after external beam radiotherapy for prostate cancer: a multi-institutional analysis

PURPOSE

To determine the significance of prostate-specific antigen (PSA) nadir (nPSA) and the time to nPSA (T(nPSA)) in predicting biochemical or clinical disease-free survival (PSA-DFS) and distant metastasis-free survival (DMFS) in patients treated with definitive external beam radiotherapy (RT) for clinical Stage T1b-T2 prostate cancer.

METHODS AND MATERIALS

Nine participating institutions submitted data on 4839 patients treated between 1986 and 1995 for Stage T1b-T2cN0-NxM0 prostate cancer. All patients were treated definitively with RT alone to doses > or =60 Gy, without neoadjuvant or planned adjuvant androgen suppression. A total of 4833 patients with a median follow-up of 6.3 years met the criteria for analysis. Two endpoints were considered: (1) PSA-DFS, defined as freedom from PSA failure (American Society for Therapeutic Radiology and Oncology definition), initiation of androgen suppression after completion of RT, or documented local or distant failure; and (2) DMFS, defined as freedom from clinically apparent distant failure. In patients with failure, nPSA was defined as the lowest PSA measurement before any failure. In patients without failure, nPSA was the lowest PSA measurement during the entire follow-up period. T(nPSA) was calculated from the completion of RT to the nPSA date.

RESULTS

A greater nPSA level and shorter T(nPSA) were associated with decreased PSA-DFS and DMFS in all patients and in all risk categories (low [Stage T1b, T1c, or T2a, Gleason score < or =6, and PSA level < or =10 ng/mL], intermediate [Stage T1b, T1c, or T2a, Gleason score < or =6, and PSA level >10 but < or =20 ng/mL, or Stage T2b or T2c, Gleason score < or =6, and PSA level < or =20 ng/mL, or Gleason score 7 and PSA level < or =20 ng/mL], and high [Gleason score 8-10 or PSA level >20 ng/mL]), regardless of RT dose. The 8-year PSA-DFS and DMFS rate for patients with nPSA <0.5 ng/mL was 75% and 97%; nPSA > or =0.5 but <1.0 ng/mL, 52% and 96%; nPSA > or =1.0 but <2.0 ng/mL, 40% and 91%; and nPSA > or =2.0 ng/mL, 17% and 73%, respectively. The 8-year PSA-DFS and DMFS rate for patients with T(nPSA) <6 months was 27% and 66%; T(nPSA) > or =6 but <12 months, 31% and 85%; T(nPSA) > or =12 but <24 months, 42% and 94%; and T(nPSA) > or =24 months, 75% and 99%, respectively. A shorter T(nPSA) was associated with decreased PSA-DFS and DMFS, regardless of the nPSA. Both nPSA and T(nPSA) were significant predictors of PSA-DFS and DMFS in multivariate models incorporating clinical stage, Gleason score, initial PSA level, and RT dose. The significance of nPSA and T(nPSA) was supported by landmark analysis, as well as by analysis of nPSA and T(nPSA) as time-dependent covariates. A dose > or =70 Gy was associated with a lower nPSA level and longer T(nPSA) in all risk categories, and a greater dose was significantly associated with greater PSA-DFS and DMFS in multivariate analysis. Regression analysis confirmed that higher clinical stage, Gleason score, and initial PSA were associated with a greater nPSA level.

CONCLUSION

The results of this large, multi-institutional analysis of 4833 patients have provided important evidence that nPSA and T(nPSA) after definitive external beam RT are not only predictive of a predominantly PSA endpoint (PSA-DFS), but are also predictive of distant metastasis in all clinical risk categories. Greater RT doses were associated with lower nPSA, longer T(nPSA), and improved PSA-DFS and DMFS.

Is patient age a factor in the occurrence of prostate-specific antigen bounce phenomenon after external beam radiotherapy for prostate cancer?

OBJECTIVES

To evaluate the effect of patient age on the occurrence of prostate-specific antigen (PSA) "bounce" after external beam radiotherapy (EBRT) for prostate cancer.

METHODS

In this study, 964 patients received EBRT alone for prostate cancer between April 1987 and January 1998 who had been followed for at least 12 months. Prostate-specific antigen values were obtained every 3 to 6 months after radiotherapy. Median overall follow-up was 48 months. Prostate-specific antigen bounce was defined as an initial increase in serum PSA of at least 0.5 ng/mL, followed by a decrease to prebounce baseline serum PSA values, all within 60 months after EBRT. Biochemical failure was defined as three consecutive increases in posttreatment PSA concentration after achieving a nadir. Multivariate Cox regression analysis was performed to evaluate the influences of age, pretreatment PSA concentration, Gleason score (determined at biopsy), clinical T stage classification, and radiation dose on PSA bounce-free survival and biochemical disease-free survival, with P < 0.05 considered statistically significant.

RESULTS

Twelve percent of the patients developed a PSA bounce. Age was not associated with the occurrence of a PSA bounce (P = 0.63), the magnitude of the PSA bounce (P = 0.90), or the duration of the PSA bounce (P = 0.39). Patients who had PSA bounce had a statistically significant higher biochemical disease-free survival than those who did not (P = 0.00004).

CONCLUSIONS

In our study, age was not predictive of PSA bounce. However, younger patients with a rising PSA after radiotherapy should be followed closely for evidence of biochemical failure.

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.

Long-term outcome of high dose rate brachytherapy in radiotherapy of localised prostate cancer

BACKGROUND AND PURPOSE

High dose rate brachytherapy (HDR-BT) in prostate cancer (PC) is receiving increasing interest. The steep dose gradient gives a possibility to escalate the dose to the prostate. If the alpha/beta ratio is low for PC, hypofractionation will be of advantage. A retrospective analysis of outcome in patients (pts) consecutively treated with combined HDR-BT and conformal external beam radiotherapy (ERT) was performed.

MATERIAL AND METHODS

Data from 214 pts treated consecutively from 1988 to 2000 were analysed. The median age was 64 years (50-77). Median follow up was 4 years (12-165 months). Pre-irradiatory endocrine therapy was given to 150 pts (70%). The pts were divided into low-, intermediate- and high (80/87/47 pts) risk groups according to the occurrence of none, one, or more risk factors defined by T-classification, PSA and histopathology. ERT was given with 2 Gy fractions to 50 Gy. HDR-BT consisted of two 10 Gy fractions.

RESULTS

Overall 5-year biochemical no evidence of disease (bNED) was 82%, and for the low-, intermediate-, and high-risk group bNED was 92, 88 and 61%, respectively. PSA-relapse was found in 17, local recurrence in 3 and distant metastases in 13 pts. Five pts died of PC. No recurrences were observed after 5 years. Severe late complications were few. Urethral stricture (13 pts) was the most frequent. No severe rectal complications were seen.

CONCLUSION

Dose escalation with HDR-BT is safe and effective in radiotherapy of localised PC.

Radiotherapy in prostate cancer treatment

Prostate cancer is a complex disease, with many controversial aspects of management in almost all stages of disease. The natural history of this tumor is variable and is influenced by multiple prognostic factors. Radical prostatectomy and radiotherapy are standard treatment options for disease limited to the prostate. The data in literature does not provide clear- cut evidence for the superiority of any treatment. Neo- adjuvant or adjuvant hormonal therapy improves local control and survival in locally advanced disease. The patients treated with radiotherapy would have a relatively long life expectancy, not great risk factors for radiation toxicity and a preference for radiotherapy. The advantages of radiotherapy are that it has a significant potential for cure, it is well tolerated in the majority of men especially when the modern techniques of conformal radiotherapy and intensity modulated therapy are used and it is non-invasive therapeutic options with no anesthesia risk. Expected complications like radiation cystitis, impotence and proctitis are registered in about 1% of patients.

Rise in serum psa of 1.5 ng/mL above 24-month nadir after external beam radiotherapy is predictive of biochemical failure

OBJECTIVES

To determine whether a rise in the serum prostate-specific antigen (PSA) concentration 24 months or later after completion of external beam radiotherapy (EBRT) for prostate cancer could predict for biochemical failure.

METHODS

We evaluated the records of 1006 patients who had undergone full-dose EBRT alone as primary treatment for T1-T4NxM0 prostate cancer at our institution between April 1987 and January 1998. Patients who had biochemical failure--as determined by the American Society for Therapeutic Radiology and Oncology (ASTRO) definition--prior to 24 months after EBRT were excluded. PSA increases of four different magnitudes (0.5, 0.8, 1.0, and 1.5 ng/mL above the 24-month nadir) were evaluated for their ability to predict ASTRO-defined biochemical failure.

RESULTS

A total of 745 patients met the analysis criteria. The rate of ASTRO-defined biochemical failure in patients with a PSA increase of 0.5, 0.8, 1.0, and 1.5 ng/mL above the 24-month nadir was 56%, 64%, 66%, and 71%, respectively. An increase of 1.5 ng/mL or more had a sensitivity of 80% and a specificity of 88% in the prediction of biochemical failure, with an accuracy of 86%.

CONCLUSIONS

A PSA increase of 1.5 ng/mL or more above the 24-month nadir can be used to predict for ASTRO-defined failure after EBRT and may be used to identify patients at risk early-on.

Prostate-specific antigen and related isoforms in the diagnosis and management of prostate cancer

Despite its unparalleled merits for prostate cancer detection and staging, prostate-specific antigen (PSA) is not a marker for prostate cancer only, but also is expressed in benign conditions. For early detection, limitations of PSA are obvious. Its widespread use has led to an extensive amount of expensive and often unnecessary diagnostic procedures associated with significant morbidity. Total PSA derivatives may enhance the accuracy of prostate cancer diagnosis. The ratio of free-to-total PSA improves specificity while maintaining a high sensitivity for prostate cancer detection for men with a total PSA of 2.5 to 10 ng/mL. Human glandular kallikrein also has the potential to be a valuable tool in combination with total and free PSA for early diagnosis of prostate cancer. Complex PSA seems to be a reliable tool to improve specificity at high sensitivity levels in men with suspected prostate cancer (mainly in PSA levels below 4 ng/mL). Newly discovered isoforms of free PSA also may impact early detection of prostate cancer with encouraging preliminary results that warrant further clinical investigation.

High-dose rate iridium-192 brachytherapy and external beam radiation therapy for prostate cancer with or without androgen ablation

AIM

To report the results of our feasibility study incorporating iridium-192 high-dose-rate (HDR) afterloading brachytherapy and external beam radiation therapy (EBRT) for the treatment of prostate carcinoma and to assess the role of androgen ablation in conjunction with this treatment option.

METHODS

From July 2000 to June 2002, 42 patients with clinically localized or locally extensive prostate carcinoma were treated with HDR iridium-192 brachytherapy and EBRT with or without androgen ablation. The median follow up was 16.5 months.

RESULTS

The technique of HDR brachytherapy and EBRT proved to be feasible with acceptable morbidities. Continuous prostate-specific antigen (PSA) reduction was noted in all patients and no PSA failure was noted during follow up. Within 1 year, the decline of PSA nadir values less than 1 ng/mL was faster in patients with the addition of androgen blockade (P = 0.001). However, within 1 year, PSA nadir values less than 1.0 ng/mL can be achieved in all patients whose initial PSA is less than 20 ng/mL, with or without hormone blockade.

CONCLUSIONS

The need for hormonal therapy in favorable-risk brachytherapy patients (PSA < 20 ng/mL) might be less than the need for intermediate- or high-risk patients. The use of hormonal therapy in intermediate-risk patients (PSA >/= 20 ng/mL) treated with HDR brachytherapy and pelvic EBRT is appealing, considering the favorable results. High dose rate brachytherapy appears to be an effective treatment for clinically localized and locally extensive prostate cancer, with minimal morbidity.

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.

Clinical features and treatment outcome of Hispanic men with prostate cancer following external beam radiotherapy

PURPOSE

We retrospectively analyzed the clinical characteristics and outcomes of Hispanic men compared with other groups who underwent radiotherapy alone for localized or locally advanced prostate cancer.

MATERIALS AND METHODS

Between April 1987 and January 1998, 964 men who underwent full dose external beam radiotherapy alone for localized or locally advanced prostate cancer were included in the study. Patient medical records were reviewed for pertinent information.

RESULTS

Of the 964 men 810 were non-Hispanic white, 54 were Hispanic and 86 were black Americans. The most significant difference among the groups was in the proportion of patients who presented with initial prostate specific antigen (PSA) greater than 20 ng/ml (22% of Hispanic vs 11% of white men, p = 0.0012). In addition, 17% of Hispanic men had a Gleason score of 8 or greater compared with 11% of white men (p = 0.0265). A greater proportion of Hispanic patients also had a less favorable posttreatment PSA nadir of greater than 1 ng/ml compared with white patients, (44% vs 26%, p = 0.0214), which may have translated into a trend toward a lower 5-year disease-free survival rate in Hispanics vs white men (52% vs 65%, p = 0.07).

CONCLUSIONS

Hispanic men presented with higher PSA and higher grade prostate cancer than white men. Furthermore, a higher percent of Hispanic men had a PSA nadir of 1 ng/ml or greater after radiotherapy, which may have been responsible for their trend toward a decreased 5-year disease-free survival rate compared with white men. Improved screening and early detection may improve disease-free survival in Hispanic men with localized prostate cancer.

Hazard rates of disease progression after external beam radiotherapy for clinically localized carcinoma of the prostate

PURPOSE

We established hazard rates for disease progression at different intervals after external beam radiotherapy alone in patients with clinically localized prostate cancer. We determined the likelihood of biochemical failure in those free of disease 5 years after radiotherapy and identified those at risk for early versus late biochemical failure.

MATERIALS AND METHODS

We reviewed the records of 964 patients treated with full dose external beam radiotherapy alone for T1 to T4, NxM0 prostate cancer. Followup prostate specific antigen (PSA) was measured 3 months after the completion of radiotherapy and every 3 to 6 months thereafter. Yearly hazard rates for biochemical failure were calculated each followup year.

RESULTS

Median followup of the whole study group was 48 months. Overall 5 and 10-year biochemical disease-free survival rates were 63.7% and 53.6%, respectively. Patients had a peak overall hazard rate 2 years after treatment. The hazard rate then decreased until year 6, when it increased slightly and remained elevated even at year 10. This late increase in the overall hazard rate was associated with late increases in the hazard rate in men with favorable prognostic factors, namely pretreatment PSA less than 10 ng./ml., Gleason score less than 5, clinical T stage T1 or T2, posttreatment PSA nadir less than 0.99 ng./ml. or radiation dose less than 68 Gy. In 13 of the 307 patients (3.9%) with biochemical failure the failure occurred more than 5 years after initial treatment.

CONCLUSIONS

The peak risk of biochemical failure is 2 years after radiotherapy. Patients are at slight but persistent risk for biochemical failure more than 5 years after treatment. Hazard rate calculations beyond the median followup of 4 years can underestimate the true hazard.

Combining radiotherapy with gene therapy (from the bench to the bedside): a novel treatment strategy for prostate cancer

Combined radiotherapy and gene therapy is a novel therapeutic approach for prostate cancer. There are various potential benefits in combining ionizing radiation with gene therapy to achieve enhanced antitumor effects: A) ionizing radiation improves transfection/ transduction efficiency, transgene integration, and possibly, the "bystander effect" of gene therapy; B) gene therapy, on the other hand, may interfere with repair of radiation-induced DNA damage and increase DNA susceptibility to radiation damage in cancer cells, and C) radiotherapy and gene therapy target at different parts of the cell cycle. Preclinical data have demonstrated the enhanced antitumor effects of this combined approach in local tumor control, prolongation of survival, as well as systemic control. This combined radio-gene therapy is under study in an ongoing clinical trial in prostate cancer. Our study adds gene therapy to the standard of care therapy (radiotherapy). These treatment modalities have different toxicity profiles. The goal of this combined approach is to enhance cancer cure without an increase in treatment-related toxicity. This approach also offers a new paradigm in spatial cooperation, whereby two local therapies are combined to elicit both local and systemic effects. Early clinical results showed the safety of this approach.

Prostate specific antigen bounce phenomenon after external beam radiation for clinically localized prostate cancer

PURPOSE

We characterize the prostate-specific antigen (PSA) bounce in patients who underwent external beam radiation therapy for prostate cancer and correlate the PSA bounce with the development of biochemical disease progression.

MATERIALS AND METHODS

In this study 964 patients received full dose radiation therapy alone. Followup PSA values were obtained 3 months after completion of radiotherapy and every 3 to 6 months thereafter. Median followup of the entire study group was 48 months. All time intervals were calculated from the completion date of radiation therapy. PSA bounce was defined as an initial increase in serum PSA of at least 0.5 ng./ml., followed by a decrease to pre-bounce baseline serum PSA values no more than 60 months after external beam radiation therapy.

RESULTS

Of the 964 patients 119 (12%) had a PSA bounce. PSA bounce was unrelated to age, race, pretreatment PSA, Gleason score, clinical T stage or radiation dose. Mean time to PSA bounce was 9 months from the time of therapy. The respective 1 and 5-year biochemical disease-free survival rates were 100% and 82.1% for patients with PSA bounce and 93.9% and 57.7% for those without PSA bounce (p = 0.0001).

CONCLUSIONS

Of men with prostate cancer treated with external beam radiation therapy 12% experienced a transient increase in PSA (PSA bounce) followed by a return to pre-bounce levels after radiation. The PSA bounce phenomenon was not predictive of time to biochemical recurrence.

Prospective trial of cryosurgical ablation of the prostate: five-year results

OBJECTIVES

To determine in a prospective pilot study the safety and efficacy of cryosurgical ablation for localized prostate carcinoma.

METHODS

A total of 87 cryosurgical procedures were performed on 76 consecutive patients between December 1994 and February 1998. All patients had histologically proved adenocarcinoma of the prostate, with prostate-specific antigen (PSA) readings of less than 30 ng/mL. Clinical evaluations, PSA determinations, and patient self-reported quality-of-life questionnaires (functional assessment of cancer treatment-prostate; FACT-P) were used to determine biochemical and clinical disease-free status and complications. Patients had a mean follow-up of 50 months (minimum 36).

RESULTS

Follow-up biopsies were performed in 73 patients, and 72 were negative for malignancy after one or more treatments. Ten patients required two treatments and 1 patient required three treatments. The 5-year overall and cancer-specific survival rate was 89% (95% confidence interval, 83% to 97%) and 98.6% (95% confidence interval, 96% to 100%), respectively. The undetectable PSA rate (less than 0.3 ng/mL) for low-risk patients (n = 13) was 60% at 5 years; for moderate-risk patients (n = 23), it was 77%, and for high-risk patients (n = 40), 48%. The corresponding percentage of patients with a PSA level less than 1.0 ng/mL at 5 years was 75%, 89%, and 76%. Sloughing occurred in 3 patients (3.9%), incontinence in 1 (1.3%), and testicular abscess in 1 (1.3%). At 3 years, 18 (47%) of 38 patients capable of unassisted intercourse at the time of cryosurgery had resumed sexual intercourse, 5 spontaneously and 13 with sildenafil or prostaglandin.

CONCLUSIONS

The results of this prospective evaluation show cryosurgery to be both a safe and an effective option in the treatment of localized prostate cancer.

Relationship between prostate volume, prostate-specific antigen nadir, and biochemical control

PURPOSE

In patients treated with definitive three-dimensional conformal radiotherapy (3D-CRT) for localized prostatic adenocarcinoma, we sought to evaluate the relationship between pretreatment prostate gland volume and posttreatment prostate-specific antigen (PSA) nadir, as well as the relationship of prostate volume and PSA nadir with biochemical control (bNED). Two subgroups were studied: favorable (PSA <10 ng/mL, Gleason score 2-6, and T1-T2A) and unfavorable (one or more: PSA >/=10 ng/mL, Gleason score 7-10, T2B-T3).

MATERIALS AND METHODS

A total of 655 men (n = 271 favorable and 384 unfavorable) were treated with 3D-CRT alone between May 1989 and November 1997. All patients had information on prostate volume and a minimum follow-up of 24 months (median 56, range 24-126). Of the 655 men, 481 (n = 230 favorable and 251 unfavorable) remained bNED at time of analysis, with biochemical failure defined in accordance with the American Society for Therapeutic Radiology and Oncology consensus definition. Factors analyzed for predictors of bNED included pretreatment prostate volume, posttreatment PSA nadir, pretreatment PSA, palpation T stage, Gleason score, center of the prostate dose, and perineural invasion (PNI). We also analyzed pretreatment prostate volume and its correlation to prognostic factors. For bNED patients, the relationship between PSA nadir and prostate volume was evaluated.

RESULTS

On multivariate analysis, prostate volume (p = 0.04) and palpation T stage (p = 0.02) were the only predictors of biochemical failure in the favorable group. On multivariate analysis of the unfavorable group, pretreatment PSA (p <0.0001), Gleason score (p = 0.02), palpation T stage (p = 0.009), and radiation dose (p <0.0001) correlated with biochemical failure, and prostate volume and PNI did not. For all 481 bNED patients, a positive correlation between pretreatment volume and PSA nadir was demonstrated (p <0.0001). Subgroup analysis of the favorable and unfavorable patients also demonstrated a positive correlation between prostate volume and PSA nadir (p = 0.003 and p = 0.0002, respectively). Using multiple regression analysis, the following were found to be predictive of PSA nadir in all bNED patients: prostate volume (p <0.0001), pretreatment PSA (p <0.0001), palpation T stage (p = 0.0002), and radiation dose (p = 0.0034). Gleason score and PNI were not predictive. For the favorable group, palpation T stage (p = 0.0006), pretreatment PSA (p = 0.0083), prostate volume (p = 0.0186), and Gleason score (p = 0.0592) were predictive of PSA nadir, and PNI and radiation dose were not predictive. In the unfavorable group, prostate volume (p = 0.0024), radiation dose (p = 0.0039), pretreatment PSA (p = 0.0182), and palpation T stage (p = 0.0296) were predictive of PSA nadir, and Gleason score and PNI were not predictive.

CONCLUSION

This report is the first demonstration that prostate volume is predictive of PSA nadir for patients who are bNED in both favorable and unfavorable subgroups. PSA nadir did not correlate with bNED status in the favorable patients, but it was strongly predictive in the unfavorable patients. Prostate gland volume was also predictive of bNED failure in the favorable but not the unfavorable group.

Predicting prostate specific antigen outcome preoperatively in the prostate specific antigen era

PURPOSE

We evaluated the ability of previously defined risk groups to predict prostate specific antigen (PSA) outcome 10 years after radical prostatectomy in patients diagnosed with clinically localized prostate cancer during the PSA era.

MATERIALS AND METHODS

Between 1989 and 2000, 2,127 men with clinically localized prostate cancer underwent radical prostatectomy, including 1,027 at Hospital of the University of Pennsylvania (study cohort) and 1,100 at Brigham and Women's Hospital (validation cohort). Cox regression analysis was done to calculate the relative risk of PSA failure with the 95% confidence interval (CI) in patients at intermediate and high versus low risk. The Kaplan-Meier actuarial method was used to estimate PSA outcome 10 years after radical prostatectomy.

RESULTS

Compared with low risk patients (stages T1c to 2a disease, PSA 10 ng./ml. or less and Gleason score 6 or less) the relative risk of PSA failure in those at intermediate (stage T2b disease or PSA greater than 10 to 20 ng./ml. or less, or Gleason score 7) and high (stage T2c disease, or PSA greater than 20 ng./ml. or Gleason score 8 or greater) risk was 3.8 (95% CI 2.6 to 5.7) and 9.6 (95% CI 6.6 to 13.9) in the study cohort, and 3.3 (95% CI 2.3 to 4.8) and 6.3 (95% CI 4.3 to 9.4) in the validation cohort. The 10-year PSA failure-free survival rate in the 1,020 patients in the low, 693 in the intermediate and 414 in the high risk groups was 83%, 46% and 29%, respectively (p <0.0001).

CONCLUSIONS

Based on 10-year actuarial estimates of PSA outcome after radical prostatectomy 3 groups of patients were identified using preoperative PSA, biopsy Gleason score and 1992 clinical T category.

High-dose-rate brachytherapy in the treatment of carcinoma of the prostate

BACKGROUND

Although radical prostatectomy for localized disease is considered as a standard of care, external-beam radiotherapy and brachytherapy are equally effective. We report on the technique and preliminary results of high-dose-rate (HDR) brachytherapy using a temporary iridium-192 implant technique.

METHODS

The authors reviewed the literature on the techniques, treatment protocols, and results of HDR brachytherapy in the treatment of carcinoma of the prostate, and they report their own protocols, technique, and results.

RESULTS

The combination of HDR brachytherapy and external irradiation has been well tolerated by all 200 patients in our series, with less than 3% grade 3 late complications and with 95% PSA relapse-free survival with a median follow-up of 24 months.

CONCLUSIONS

HDR brachytherapy may be the most conformal type of irradiation in the treatment of carcinoma of the prostate regardless of tumor size, anatomical distortion, and organ mobility.

Phase I/II trial evaluating combined radiotherapy and in situ gene therapy with or without hormonal therapy in the treatment of prostate cancer--a preliminary report

PURPOSE

To report the preliminary results of a Phase I/II study combining radiotherapy and in situ gene therapy (adenovirus/herpes simplex virus thymidine kinase gene/valacyclovir) with or without hormonal therapy in the treatment of prostate cancer.

METHODS AND MATERIALS

Arm A: low-risk patients (T1-T2a, Gleason score <7, pretreatment PSA <10) were treated with combined radio-gene therapy. A mean dose of 76 Gy was delivered to the prostate with intensity-modulated radiotherapy. Arm B: high-risk patients (T2b-T3, Gleason score >or=7, pretreatment PSA >or=10) were treated with combined radio-gene therapy and hormonal therapy. Hormonal therapy was comprised of a 4-month leuprolide injection and 2-week use of flutamide. Arm C: Stage D1 (positive pelvic lymph node) patients received the same regimen as Arm B, with the additional 45 Gy to the pelvic lymphatics. Treatment-related toxicity was assessed using Cancer Therapy Evaluation Program common toxicity score and Radiation Therapy Oncology Group (RTOG) toxicity score.

RESULTS

Thirty patients (13 in Arm A, 14 in Arm B, and 3 in Arm C) completed the trial. Median follow-up was 5.5 months. Eleven patients (37%) developed flu-like symptoms (Cancer Therapy Evaluation Program Grade 1) of fatigue and chills/rigors after gene therapy injection but recovered within 24 h. Four patients (13%) and 2 patients (7%) developed Grade 1 and 2 fever, respectively. There was no patient with weight loss. One patient in Arm B developed Grade 3 elevation in liver enzyme, whereas 11 and 2 patients developed Grade 1 and 2 abnormal liver function tests. There was no Grade 2 or above hematologic toxicity. Three patients had transient rise in creatinine. There was no RTOG Grade 3 or above lower gastrointestinal toxicity. Toxicity levels were as follows: 4 patients (13%), Grade 2; 6 patients (20%), Grade 1; and 20 patients (67%), no toxicity. There was 1 patient with RTOG Grade 3 genitourinary toxicity, 12 patients (40%) with Grade 2, 8 patients (27%) with Grade 1, and 9 patients (30%) with no toxicity. No patient dropped out from the trial or had to withhold treatment because of severe toxicity.

CONCLUSIONS

This is the first trial of its kind in the field of prostate cancer that aims to expand the therapeutic index of radiotherapy by combining in situ gene therapy. Initial experience has demonstrated the safety of this approach. There is no added toxicity to each therapy used alone. Long-term follow-up and larger cohort studies are warranted to evaluate long-term toxicity and efficacy.

A retrospective analysis of the results of p(65) + Be neutrontherapy for the treatment of prostate adenocarcinoma at the cyclotron of Louvain-la-Neuve. Part I: Survival and progression-free survival

PURPOSE

To retrospectively evaluate survival, progression-free survival (PFS) and biological response in a series of patients irradiated with mixed neutron/photon beams for locally advanced prostate cancer in our institution.

PATIENTS AND METHODS

Three hundred and eight patients were treated between January 1990 and December 1996. Fifty-five of these were recruited for pT3 or pN1 tumors after radical prostatectomy. Neoadjuvant androgen deprivation was given in 106 patients. The treatment protocol consisted of a mixed photon/neutron irradiation in a two-to-three proportion, up to a total equivalent dose of 66 Gy (assuming a clinical RBE value of 2.8). Pre- and post-treatment PSA determinations were available in practically all cases. Study endpoints were overall survival (OAS) and progression-free survival (PFS). The Cox proportional hazard regression model was used to investigate the prognostic value of baseline characteristics on survival and progression-free survival were a progression was defined as local, regional, metastatic or biological progression. Mean age was 69 years (49-86); mean pretreatment PSA was 15 (0.5-330) in all patients and 14 (0.5-160) in those receiving neoadjuvant hormonotherapy; seven patients only had an initial PSA < or = 4 ng/mL; 15% were T1, 46% were T2, 28% were T3 or pT3 and 4% were T4 (7% unspecified); WHO grade of differentiation was I in 38%, II in 38% and III in 14% (5% unspecified).

RESULTS

The median follow-up was 2.8 years (0-7.8). Five-year overall survival (OAS) was 79% (95% CI: 71-87%) and 5-year progression-free survival (PFS) was 64% (95% CI: 54-74%) for the entire series. PFS in patients with an initial PSA > or = 20 ng/mL was the same. PFS could be predicted by two optimal Cox regression models, one including histological grade (p = 0.003) and initial PSA (p = 0.0009) as cofactors, the other including histological grade (p = 0.003) and T stage (p = 0.02). The main prognostic factors for overall survival were PSA and age. Biological responses with PSA < 1.5 ng/mL, < 1 ng/mL and < 0.5 ng/mL at any time after treatment were documented in 70%, 61% and 47% of the patients, respectively.

CONCLUSION

Five-year OAS was 79%, PFS was 64%, and biological response was 70% for prostate cancer patients treated with mixed photon/neutron beams as applied at Louvain-la-Neuve, which are good results as compared with the literature. The usual prognostic factors were confirmed.

In vivo surgical resection plus adjuvant gene therapy in the treatment of mammary and prostate cancer

Adenoviral-mediated gene therapy delivery, combining the herpes simplex virus thymidine kinase gene (Ad-tk) with gancyclovir, has been evaluated as a treatment modality for numerous tumors in the laboratory and in the clinics. As a single modality, gene therapy has shown some promising local and systemic results but no curative success. Surgery is the standard of care for many solid tumors. However, minor residual tumor following surgical resection can lead to local recurrence, and surgery is neither efficient nor plausible for metastatic disease. In this study, two tumor models were used to evaluate the effects of Ad-tk gene therapy as an adjuvant to surgery. Subcutaneous mammary- and prostate-derived tumors were produced in syngeneic mice. To evaluate systemic effects, tumor cells were injected intravenously, with subsequent formation of lung nodules. The subcutaneous tumors were surgically resected and the tumor bed was bathed with saline or Ad-tk. The animals were evaluated for toxicity, local tumor recurrence, survival, and lung nodule formation. No evidence of additional toxicity was observed. In the less aggressive mammary model, the time to recurrence was increased from 11.7 (+/-1.0) days to 22.7 (+/-5.5) days. In the prostate model, recurrence went from a mean of 17.3 (+/-5.6) to 22.6 (+/-6.8) days. Survival was also improved from a mean of 19.7 (+/-1.1) to 32.3 (+/-4.8) and 26.1 (+/-5.0) to 34.1 (+/-6.1) days in the mammary and prostate models, respectively. Evidence of systemic benefits from the use of adjuvant Ad-tk therapy was demonstrated by a significant reduction in lung nodules from a mean of 17 to 3.5. These results suggest that Ad-tk gene therapy may be a useful adjuvant for patients undergoing surgery for treatment of cancer.

Chemical disease-free survival in localized carcinoma of prostate treated with external beam irradiation: comparison of American Society of Therapeutic Radiology and Oncology Consensus or 1 ng/mL as endpoint

PURPOSE

To compare postirradiation biochemical disease-free survival using the American Society of Therapeutic Radiology and Oncology (ASTRO) Consensus or elevation of postirradiation prostate-specific antigen (PSA) level beyond 1 ng/mL as an endpoint and correlate chemical failure with subsequent appearance of clinically detected local recurrence or distant metastasis.

METHODS AND MATERIALS

Records of 466 patients with histologically confirmed adenocarcinoma of the prostate treated with irradiation alone between January 1987 and December 1995 were analyzed; 339 patients were treated with bilateral 120 degrees arc rotation and, starting in 1992, 117 with three-dimensional conformal irradiation. Doses were 68--77 Gy in 1.8 to 2 Gy daily fractions. Minimum follow-up is 4 years (mean, 5.5 years; maximum, 9.6 years). A chemical failure was recorded using the ASTRO Consensus or when postirradiation PSA level exceeded 1 ng/mL at any time. Clinical failures were determined by rectal examination, radiographic studies, and, when clinically indicated, biopsy.

RESULTS

Six-year chemical disease-free survival rates using the ASTRO Consensus according to pretreatment PSA level for T1 tumors were: < or = 4 ng/mL, 100%; 4.1--20 ng/mL, 80%; and > 20 ng/mL, 50%. For T2 tumors the rates were: < or = 4 ng/mL, 91%; 4.1--10 ng/mL, 81%; 10.1--20 ng/mL, 55%; 20.1--40 ng/mL, 63%; and > 40 ng/mL, 46%. When postirradiation PSA levels higher than 1 ng/mL were used, the corresponding 6-year chemical disease-free survival rates for T1 tumors were 92% for pretreatment PSA levels of < or = 4 ng/mL, 58--60% for levels of 4.1--20 ng/mL, and 30% for levels > 20 ng/mL. For T2 tumors, the 6-year chemical disease-free survival rates were 78% in patients with pretreatment PSA levels of 4--10 ng/mL, 45% for 10.1--40 ng/mL, and 25% for > 40 ng/mL. Of 167 patients with T1 tumors, 30 (18%) developed a chemical failure, 97% within 5 years from completion of radiation therapy; no patient has developed a local recurrence or distant metastasis. In patients with T2 tumors, overall 45 of 236 (19%) had chemical failure, 94% within 5 years of completion of radiation therapy; 4% have developed a local recurrence, and 10%, distant metastasis. In patients with T3 tumors, overall, 24 of 65 (37%) developed a chemical failure, 100% within 3.5 years from completion of radiation therapy; 4% of these patients developed a local recurrence within 2 years, and 12% developed distant metastasis within 4 years of completion of irradiation. The average time to clinical appearance of local recurrence or distant metastasis after a chemical failure was detected was 5 years and 3 years, respectively.

CONCLUSION

There was a close correlation between the postirradiation nadir PSA and subsequent development of a chemical failure. Except for patients with T1 tumors and pretreatment PSA of 4.1--20 ng/mL, there is good agreement in 6-year chemical disease-free survival using the ASTRO Consensus or PSA elevations above 1 ng/mL as an endpoint. Although the ASTRO Consensus tends to give a higher percentage of chemical disease-free survival in most groups, the differences with longer follow-up are not statistically significant (p > 0.05). It is important to follow these patients for at least 10 years to better assess the significance of and the relationship between chemical and clinical failures.

Enhanced therapeutic effect of HSV-tk+GCV gene therapy and ionizing radiation for prostate cancer

Standard therapies for prostate cancer including radiation, prostatectomy, and hormone ablation have significant toxicities and recurrence risk. HSV-tk gene therapy may be effective in combination with radiation therapy due to complementary mechanisms and distinct toxicity profiles. Mouse prostate tumors transplanted subcutaneously were treated by either gene therapy involving intratumoral injection of AdV-tk followed by systemic ganciclovir or local radiation therapy or the combination of gene and radiation therapy. Both single-therapy modalities showed a 38% decrease in tumor growth compared to controls. The combined treatment resulted in a decrease of 61%. In addition the combined-therapy group had a mean survival of 22 days versus 16.6 days for single therapy and 13.8 days for nontreated controls. To analyze systemic anti-tumor activity, lung metastases were generated by tail vein injection of RM-1 prostate cancer cells on the same day that they were injected subcutaneously. The primary tumors were treated as before with AdV-tk followed by ganciclovir, radiation, or the combination. The number of lung nodules was reduced by 37% following treatment with AdV-tk, whereas radiotherapy alone had no effect on metastatic growth. The combination led to an additional 50% reduction in lung colonization. Primary tumors that received the combination therapy had a marked increase in CD4 T cell infiltrate. This is the first report showing a dramatic systemic effect following the local combination treatment of radiation and AdV-tk. A clinical study using this strategy has been initiated and patient accrual is ongoing.

The clinical utility of the percent of positive prostate biopsies in predicting biochemical outcome following external-beam radiation therapy for patients with clinically localized prostate cancer

PURPOSE

An investigation was performed of the clinical utility of the percent of positive prostate biopsies in predicting prostate-specific antigen (PSA) outcome following external-beam radiation therapy (RT) for men with PSA-detected or clinically palpable prostate cancer.

METHODS AND MATERIALS

A Cox regression multivariable analysis was used to determine whether the percent of positive prostate biopsies provided clinically relevant information about PSA outcome following external beam RT in 473 men while accounting for the previously established risk groups based on the pretreatment PSA level, biopsy Gleason score, and the 1992 American Joint Commission on Cancer (AJCC) clinical T stage.

RESULTS

Controlling for the known prognostic factors, the percent of positive prostate biopsies added clinically significant information (p = 0.02) regarding time to PSA failure following RT. Specifically, 76% of the patients in the intermediate risk group (1992 AJCC T(2b) or biopsy Gleason 7 or PSA > 10 ng/mL and < or = 20 ng/mL) could be classified into either an 30% or 85% 5-year PSA control cohort using the preoperative prostate biopsy data.

CONCLUSION

The previously validated stratification of PSA outcome following radical prostatectomy (RP) using the percent of positive prostate biopsies in intermediate-risk patients is also clinically significant for men treated with external beam RT. The percent positive prostate biopsies should be considered in conjunction with the PSA level, biopsy Gleason score, and 1992 AJCC clinical T stage when counseling patients with newly diagnosed and clinically localized prostate cancer about PSA outcome following RP or external beam RT.

Five-year retrospective, multi-institutional pooled analysis of cancer-related outcomes after cryosurgical ablation of the prostate

OBJECTIVES

To define the potential role of cryosurgical ablation of the prostate (CSAP) as a treatment option for patients with localized prostate carcinoma (PCA), we performed a retrospective outcomes analysis of a large database of patients undergoing CSAP constructed from five institutions and compared this with matching outcomes from contemporary reports of patient outcomes after radiotherapy.

METHODS

A total of 975 patients who underwent CSAP as primary therapy from January 1993 to January 1998 with sufficient outcomes data available were identified. Patients were stratified into three groups on the basis of their clinical features. Biochemical-free survival (BFS), post-CSAP biopsy results, and post-CSAP morbidities were calculated and recorded.

RESULTS

The median follow-up for all patients was 24 months. The percentages of patients in the low, medium, and high-risk groups were 25%, 34%, and 41%, respectively. For prostate-specific antigen thresholds of less than 0.5 and less than 1.0 ng/mL, the 5-year actuarial BFS ranged from 36% to 61% and 45% to 76%, respectively, depending on the risk category. Overall, the positive biopsy rate was 18%. Morbidities included impotence in 93%, incontinence in 7.5%, rectourethral fistula in 0.5%, and transurethral resection of the prostate in 13% of patients (10% approved warming catheters versus 40% nonapproved).

CONCLUSIONS

For each risk group, the 5-year BFS and positive biopsy rate after CSAP was comparable to matching outcomes reported after radiotherapy. Morbidities also seemed comparable, with impotence rates higher and rectal injury rates lower after CSAP than after radiotherapy. These data indicate that CSAP can be performed with low morbidity and can produce cancer-related results comparable to those reported for patients undergoing radiotherapy.

Failure free survival following brachytherapy alone for prostate cancer: comparison with external beam radiotherapy

BACKGROUND AND PURPOSE

To compare failure free survival (FFS) for brachytherapy (BT) alone and external beam radiotherapy (EBXRT) alone.

MATERIALS AND METHODS

Between 12/88 and 12/95, 1527 and 695 T(1) or T(2) Nx-No Mo prostate cancer patients (from the Arizona Oncology Services database) were treated with either EBXRT or BT, respectively. The median age was 74 years. Median follow-up for EBXRT and BT patients was 41.3 and 51.3 months, respectively.

RESULTS

Overall FFS at 5 years for EBXRT and BT were 69 and 71%, respectively (P=0.91). No significant difference in FFS at 5 years was observed between EBXRT and BT for either T(1) (78 vs. 83%, P=0.47) or T(2) (67 vs. 67%, P=0.89) tumours. Superior outcomes for Gleason 8-10 lesions treated with EBXRT vs. BT (5 years FFS 52 vs. 28%, P=0.04) were observed; outcomes for lower grade lesions when analysed by Gleason score alone did not significantly differ according to treatment received. Patients with initial PSA values 10-20 ng/dl had an improved FFS with EBXRT vs. BT (70 vs. 53%, P=0.001); outcomes for patients with initial PSA ranges 0-4 ng/dl, >4-10 ng/dl and >20 ng/dl did not differ significantly with treatment received.

CONCLUSIONS

EBXRT and BT appear to be equally efficacious for low-risk patients having T(1)/T(2) disease with Gleason scores <6 and PSA <10 ng/dl. Patients with Gleason scores 8-10 or PSA >10 ng/dl-<20 ng/dl) appear to fare worse with BT alone compared with EBXRT. Neither EBXRT nor BT were particularly effective for patients with a presenting PSA >20 ng/dl.

The role of active treatment in early prostate cancer

The dramatic increase in the number of patients diagnosed with localized prostate cancer in the last decade presents a difficult challenge for physicians. Because the window of opportunity for cure is short it is vital to begin treatment before the cancer cells invade neighbouring tissues and organs or metastasise to other sites. This pressure of increased patient numbers provided clinicians with the opportunity to investigate other treatment options. New surgical techniques including laparoscopic radical prostatectomy, improving therapeutic radiation by the introduction of conformal radiotherapy, neutron radiation, cryosurgery, high intensity focussed ultrasound (HIF) and the revival of brachytherapy with or without external beam radiation are currently being investigated. The goal of these techniques is to treat localized prostate cancer based on the endpoints of disease specific mortality, no evidence of disease, absent or low levels of prostate-specific antigen (PSA), reduced side-effects, improved quality of life and importantly increased cost-efficacy. It is important to remember however, that watchful waiting and endocrine therapy are still valid therapy options in certain patient groups. The lack of randomized, prospective trials on local treatment of prostate cancer, makes it difficult to compare the efficacy of the different treatments, especially in terms of disease-specific survival. Trials are now in progress but it will be several years before results are available. In the meantime, we need to focus on surrogate endpoints, side effects, quality of life and the cost-efficacy of each treatment. It is also important to ensure that patients are kept informed and up-to-date with any new therapeutic developments.

Pathologic findings and prostate specific antigen outcome after radical prostatectomy for patients diagnosed on the basis of a single microscopic focus of prostate carcinoma with a gleason score </= 7

BACKGROUND

Whether patients who are diagnosed on the basis of a single microscopic focus of prostate carcinoma with a Gleason score </= 7 (micro PC) have potentially life-threatening disease if they are not treated is unknown.

METHODS

Pathologic findings and prostate specific antigen (PSA) outcome after radical prostatectomy (RP) for men who were diagnosed with micro PC were determined. Of 917 patients who were managed with RP during 1989-1999 at the Brigham and Women's Hospital, 66 patients (7%) were diagnosed on the basis of micro PC. Pathologic stage, tumor grade, tumor volume, margin status, and PSA outcome were investigated and are reported. Estimates of PSA outcome were calculated using the actuarial method of Kaplan and Meier. Pairwise comparisons were made using the log rank test.

RESULTS

The finding of micro PC at biopsy was associated with macroscopic disease (involving at least half of a single lobe) in 92% of the patients in this series. Although these men had favorable pathologic findings (94% had organ confined disease, 89% had negative tumor margins, and 79% had a prostatectomy Gleason score </= 6), approximately 10% of the patients failed biochemically within 5 years after RP.

CONCLUSIONS

The finding of micro PC at biopsy should not be used as a surrogate for clinically insignificant disease.

Additional treatments and reimbursement rates associated with prostate cancer treatment for patients undergoing radical prostatectomy, interstitial brachytherapy, and external beam radiotherapy

OBJECTIVES

To define patterns of treatment among contemporary patients undergoing radical prostatectomy, interstitial radiation, and external beam radiation for prostate cancer.

METHODS

We analyzed 291 consecutive patients (Stage T1-T3NXM0) who underwent definitive local treatment for prostate cancer with radical prostatectomy, interstitial seed implantation, or external beam radiation. Patients were stratified into three risk groups based on clinical T stage, serum prostate-specific antigen level at diagnosis, and biopsy Gleason score. The frequency of additional treatments, including androgen deprivation and external beam radiation, given within 3 months of initial local therapy was assessed. Patterns of care were compared and adjusted for risk.

RESULTS

Of the 291 patients, 107 (36. 8%) underwent radical prostatectomy, 94 (32.3%) underwent interstitial seed implantation, and 90 (30.9%) underwent external beam radiation. Use of combination therapy differed significantly according to the type of initial local treatment and risk category. No patient in the low-risk group received combination therapy. For patients in the intermediate and high-risk groups, the frequency of combination therapy was significantly lower in the radical prostatectomy group when compared with either the interstitial seed implantation (P <0.001 and P <0.02, respectively) or external beam radiation group (P <0.001 and P <0.001, respectively).

CONCLUSIONS

There are significant differences in resource utilization for contemporary patients undergoing definitive local therapy for prostate cancer. These differences may have a significant effect on treatment cost and morbidity, and they will likely make short-term comparisons between different treatment modalities difficult because of the high use of androgen deprivation in men treated with radiation therapy.