Predicting the outcome of salvage radiation therapy for recurrent prostate cancer after radical prostatectomy

Critical review of prostate cancer predictive tools

Prostate cancer is a very complex disease, and the decision-making process requires the clinician to balance clinical benefits, life expectancy, comorbidities and potential treatment-related side effects. Accurate prediction of clinical outcomes may help in the difficult process of making decisions related to prostate cancer. In this review, we discuss attributes of predictive tools and systematically review those available for prostate cancer. Types of tools include probability formulas, look-up and propensity scoring tables, risk-class stratification prediction tools, classification and regression tree analysis, nomograms and artificial neural networks. Criteria to evaluate tools include discrimination, calibration, generalizability, level of complexity, decision analysis and ability to account for competing risks and conditional probabilities. The available predictive tools and their features, with a focus on nomograms, are described. While some tools are well-calibrated, few have been externally validated or directly compared with other tools. In addition, the clinical consequences of applying predictive tools need thorough assessment. Nevertheless, predictive tools can facilitate medical decision-making by showing patients tailored predictions of their outcomes with various alternatives. Additionally, accurate tools may improve clinical trial design.

Dosimetric comparison of three-dimensional conformal radiotherapy in salvage radiotherapy for PSA relapse after radical prostatectomy

The purpose of this study is to compare three-dimensional conformal radiotherapy (3D-CRT) plans in a setting of salvage radiotherapy after radical prostatectomy (RP) and to simulate whether dose escalation is possible with the most adequate 3D-CRT technique. This study included consecutive 10 patients underwent salvage radiotherapy (RT) for biochemical relapse of prostate cancer after RP. Normal structures included the rectum, bladder, and femoral head. For each patient, four different treatment plans including four fields RT (4F-RT), dynamic conformal arc radiotherapy (DCAT), six fields RT (6F-RT), and DCAT with rectum hollow-out technique (DCAT-HO), were created to entire the prostate bed. The parameters of the maximum and mean doses received by organs at risk (OAR), target coverage, dose homogeneity for the planning target volume (PTV) were compared. All plans were considered to be clinically tolerable for PTV coverage and dose homogeneity. The rectum sparing at the high dose area for DCAT-HO was considered to be the most superior to those for other three techniques by comparison of the dose delivered to a 1%, 5%, and 10% volume of the rectum. In the simulation of dose escalation to 70 Gy with DCAT-HO, OAR met a requirement of the dose-volume constraints. However, in the simulation of dose escalation to 72 Gy, the rectum that receives 60 to 65 Gy and bladder that receives 65 Gy exceeded the optimal dose-volume constraints. DCAT-HO was considered to be one of the most appropriate techniques in 3D-CRT if dose escalation to 70 Gy might be needed in a setting of salvage RT after RP in the future.

Treatment failure and clinical progression after salvage therapy in men with biochemical recurrence after radical prostatectomy: radiotherapy vs androgen deprivation

OBJECTIVE

To compare the outcomes between salvage radiotherapy (RT) and androgen-deprivation therapy (ADT), to investigate factors determining clinical progression (CP) in men with prostate cancer.

PATIENTS AND METHODS

The study comprised 121 patients with biochemical recurrence while on follow-up by prostate-specific antigen (PSA) measurement, without adjuvant therapy after radical prostatectomy, received RT (45) or ADT (76). Failure after salvage therapy was defined as a PSA level of >0.2 ng/mL. Clinical, pathological and treatment factors were analysed.

RESULTS

The clinicopathological characteristics were similar between the RT and ADT groups except that men in the RT group were younger (61.4 vs 65.4 years). After ADT, salvage failed in 10 (13%) after a mean (sd) of 18.5 (4.5) months of treatment, and 6.7 months after salvage failed all patients progressed clinically. After RT, salvage failed in 22 (49%) after 30.7 (5.2) months of response. Upon RT failure, all patients received ADT, after which in three (14%) patients the treatment failed again after 20.1 months of treatment and progressed to CP after 6.5 months, while in the remaining 19 (86%) patients the PSA level remained undetectable for 37.6 (7.7) months. On multivariate analysis, pathological stage (> or =T3b) and Gleason grade 5 disease were independently prognostic of CP.

CONCLUSION

Salvage RT alone and combined with subsequent ADT provided PSA control in most patients, significantly increasing CP-free survival compared with initial ADT. Patients with a short PSA doubling time (<3 months) are at high risk of failed salvage treatment after RT, and initial ADT might be considered. Regardless of salvage method, advanced pathological stage and Gleason grade 5 were factors prognostic of CP.

Radiation therapy after radical prostatectomy: impact on metastasis and survival

PURPOSE

Although secondary radiation therapy decreases the risk of biochemical progression after radical prostatectomy, its impact on metastasis and survival is less well established. We evaluated the impact of adjuvant and salvage radiotherapy on clinical progression and mortality.

MATERIALS AND METHODS

A total of 361 patients who received adjuvant radiation were matched based on clinicopathological features to patients who did not receive adjuvant radiation in a 2:1 case-control ratio. Postoperative survival was estimated using the Kaplan-Meier method and compared using the log rank test. A second cohort of 2,657 men who experienced biochemical recurrence after prostatectomy was separately evaluated. Cox proportional hazard regression models were used to analyze the impact of salvage radiotherapy on disease progression and survival.

RESULTS

Adjuvant radiotherapy was associated with significantly improved 10-year biochemical recurrence-free survival (63% vs 45%, p <0.001), local recurrence-free survival (97% vs 82%, p <0.001) and a decreased need for late hormone therapy (17% vs 28%, p = 0.002) but did not impact systemic progression and overall survival (p = 0.94 and 0.27, respectively). Of the 2,657 patients who experienced biochemical recurrence after surgery 856 (32.3%) received salvage radiation. On multivariate analysis salvage radiotherapy decreased the risk of local recurrence (HR 0.13, 95% CI 0.06-0.28, p <0.0001) and delayed hormonal therapy (HR 0.81, 95% CI 0.71-0.93, p = 0.003) and systemic progression (HR 0.24, 95% CI 0.13-0.45, p <0.0001) but did not significantly impact mortality (p = 0.48).

CONCLUSIONS

Adjuvant and salvage radiation provide long-term local control and decrease the need for delayed hormonal therapy but neither improves survival. These results must be weighed against the potential morbidity of postoperative radiation when counseling patients.

Salvage high-intensity focused ultrasound for biopsy-confirmed local recurrence of prostate cancer after radical prostatectomy

OBJECTIVE

To present experience in high-intensity focused ultrasound (HIFU) used as a salvage therapy for biopsy-confirmed local recurrence at the vesico-urethral anastomosis after radical prostatectomy (RP).

PATIENTS AND METHODS

From July 2006, four patients diagnosed with prostate cancer recurrence after RP were treated with HIFU, with or without salvage radiotherapy, using the Sonablate 500 (Focus Surgery, IN, USA). Biochemical failure was defined as in increase in prostate-specific antigen (PSA) level of >0.2 ng/mL. No patients received any adjuvant therapy after HIFU therapy before reporting failure.

RESULTS

The mean age and initial PSA level before RP was 74 years and 10.0 ng/mL, respectively. After RP, one patient was stage T2aN0M0, two were stage T3N0M0 and the last had an unknown pathological stage. Three patients received external beam radiotherapy as salvage therapy after RP. The mean PSA level before HIFU, tumour volume at the vesico-urethral lesion and operative duration were 4.3 ng/mL, 4.6 mL and 27 min, respectively. Adenocarcinomas were confirmed by biopsy of the tumour at the vesico-urethral anastomotic lesion before HIFU. At 24 months of follow-up, patients 2 and 4 were classified a biochemically disease-free. Biopsies at the anastomotic site after HIFU in three patients showed no malignancy, with fibrosis. There were no complications.

CONCLUSION

Salvage HIFU for patients with recurrence after RP is feasible, even though they received salvage radiotherapy before HIFU. More patients and a longer follow-up are needed to evaluate the safety and oncological adequacy of this new approach.

Late toxicity after postprostatectomy salvage radiation therapy

PURPOSE

To evaluate late toxicity in patients who received salvage external beam radiotherapy (EBRT) for a detectable prostate-specific antigen (PSA) level after radical prostatectomy (RP).

METHODS

A cohort of 308 consecutive patients underwent salvage EBRT from July 1987 through June 2003 for a detectable PSA level after RP. All were treated with high-energy photons (6-20 MV) to a median dose of 64.8 Gy (range: 54.0-72.4 Gy) in 1.8- to 2.0-Gy fractions.

RESULTS

Median follow-up from the completion of EBRT was 60 months (range: 1 day-174 months). Late toxicity occurring more than 90 days after EBRT completion was identified in 41 patients (13%). Twelve patients (3.9%) had grade 2 urethral strictures and were treated with urethral dilation, 3 patients had grade 3 cystitis, and 1 had a grade 4 rectal complication. These numbers correspond to an estimated 0.7% (95% confidence interval, 0.0-1.6%) of patients experiencing a grade 3 or 4 complication by 5 years after the start of EBRT.

CONCLUSIONS

Salvage EBRT for a detectable PSA level after RP is the only curative treatment in this setting. This treatment can be administered in a manner that results in a low likelihood of late complications.

Counseling patients about sexual health when considering post-prostatectomy radiation treatment

Prostate cancer is the second most frequently diagnosed cancer in men in the United States. Many men with clinically localized prostate cancer survive for 15 years or more. Although early detection and successful definitive treatments are increasingly common, a debate regarding how aggressively to treat prostate cancer is ongoing because of the effect of aggressive treatment on the quality of life, including sexual functioning. We examined current research on the effect of post-prostatectomy radiation treatment on sexual functioning, and suggest a way in which patient desired outcomes might be taken into consideration while making decisions with regard to the timing of radiation therapy after prostatectomy.

Radiotherapy and concomitant temozolomide during the first and last weeks in high grade gliomas: long-term analysis of a phase II study

We tested the efficacy and safety of temozolomide (TMZ) when given concomitantly to radiotherapy only in the first and last weeks of treatment to patients affected by high grade gliomas. Conformal radiotherapy (CTV1: tumor bed + residual tumor if present + 1.5 cm, 5,940 cGy, 180 cGy/day; CTV2: oedema, 3,960 cGy, 180 cGy/day) was associated with TMZ, 75 mg/m(2) x 5 days, the first and last weeks of radiotherapy. Adjuvant chemotherapy with TMZ (150 mg/mq daily x 5 days, q28 on the first cycle, 200 mg/mq daily x 5 days, q28 for the following cycles) was given, after chemoradiation, until disease progression or up to 6 cycles. From October 2000 to December 2003, 29 patients (25 GBL, 86.2%; 4 AA, 13.8%) were enrolled in this study. Twenty-two patients (75.8%) received a median 6 cycles of adjuvant chemotherapy with TMZ (range 1-20). Hematological toxicity was absent during concomitant chemoradiation and mild in adjuvant therapy, while neurological toxicity (seizures) was observed only in one case. At a median follow-up of 66 months (range 3-96), median progression-free survival (PFS) was 8 months, with a 1- and 2-year PFS of 46.7 and 28.7%, respectively; median overall survival (OS) time was 21 months, with a 1- and 2-year OS of 69.2 and 42.3%, respectively. In our experience, TMZ proved to be effective even when given only during the first and the last week of radiotherapy, with lower hematological toxicity.

Location, extent and number of positive surgical margins do not improve accuracy of predicting prostate cancer recurrence after radical prostatectomy

PURPOSE

Positive surgical margins increase the risk of biochemical recurrence after radical prostatectomy by 2 to 4-fold. The risk of biochemical recurrence may be influenced by the anatomical location and extent of positive surgical margins. In a multicenter study we analyzed the predictive usefulness of several subclassifications of positive surgical margins.

MATERIALS AND METHODS

The clinical information and followup data of 7,160 patients treated with radical prostatectomy alone at 1 of 3 institutions between 1995 and 2006 were modeled using Cox proportional hazards regression analysis for biochemical recurrence. Positive surgical margins were analyzed as solitary vs multiple, focal vs extensive and apical location vs other. The usefulness of these subclassifications was assessed by the improvement in predictive accuracy of nomograms containing these parameters compared to one in which the surgical margin was modeled simply as positive vs negative.

RESULTS

The 7-year progression-free probability was 60% in patients with positive surgical margins. A positive surgical margin was significantly associated with biochemical recurrence (HR 2.3, p <0.001) after adjusting for age, prostate specific antigen, pathological Gleason score, pathological stage and year of surgery. An increased risk of biochemical recurrence was associated with multiple vs solitary positive surgical margins (adjusted HR 1.4, p = 0.002) and extensive vs focal positive surgical margins (adjusted HR 1.3, p = 0.004) on multivariable analysis. However, neither parameter improved the predictive accuracy of a nomogram compared to one in which surgical margin status was modeled as positive vs negative (concordance index 0.851 vs 0.850 vs 0.850).

CONCLUSIONS

The number and extent of positive surgical margin significantly influence the risk of biochemical recurrence after radical prostatectomy. However, the empirical prognostic usefulness of subclassifications of positive surgical margins is limited.

Early prostate-specific antigen changes and the diagnosis and prognosis of prostate cancer

PURPOSE OF REVIEW

To delineate how recent findings on prostate-specific antigen (PSA) can improve prediction of risk, detection, and prediction of clinical endpoints of prostate cancer (PCa).

RECENT FINDINGS

The widely used PSA cut-point of 4.0 ng/ml increasingly appears arbitrary, but no cut-point achieves both high sensitivity and high specificity. The accuracy of detecting PCa can be increased by additional predictive factors and a combinations of markers. Evidence implies that a panel of kallikrein markers improves the specificity and reduces costs by eliminating unnecessary biopsies. Large, population-based studies have provided evidence that PSA can be used to predict PCa risk many years in advance, improve treatment selection and patient care, and predict the risk of complications and disease recurrence. However, definitive evidence is currently lacking as to whether PSA screening lowers PCa -specific mortality.

SUMMARY

PSA is still the main tool for early detection, risk stratification, and monitoring of PCa. However, PSA values are affected by many technical and biological factors. Instead of using a fixed PSA cut-point, using statistical prediction models and considering the integration additional markers may be able to improve and individualize PCa diagnostics. A single PSA measurement at early middle age can predict risk of advanced PCa decades in advance and stratify patients for intensity of subsequent screening.

Early salvage radiotherapy for patients with PSA relapse after radical prostatectomy

PURPOSE

To assess the effectiveness of early salvage radiotherapy (RT) for patients with prostate-specific antigen (PSA) relapse after radical prostatectomy (RP) retrospectively.

METHODS

Fifty-one patients underwent salvage RT for biochemical relapse of prostate cancer initially treated with RP. All patients had persistent or rising PSA >0.20 ng/ml at some point after surgery, or three successive PSA elevations after a postoperative nadir if PSA was < or =0.20 ng/ml. Most (96%) of pre-RT PSA were less or equal to 0.50 ng/ml, and median value was 0.25 ng/ml (range, 0.05-0.90 ng/ml). Median RT dose was 60 Gy (range, 50-66 Gy). Multivariate Cox regression analysis was performed for PSA before RP and salvage RT, margin status, seminal vesicle involvement, extracapsular invasion, Gleason score, PSA doubling time (PSADT), and RT dose to identify significant predictors of biochemical outcome.

RESULTS

Median follow-up was 36 months. The 3-year biochemical no evidence of disease rate (bNED) was 55.1%. On multivariate analysis only the following factors were significantly associated with improved bNED: PSADT >3.0 months (P = 0.008), Gleason score < or =7 (P = 0.01), and RT dose > or =60 Gy (P = 0.028).

CONCLUSIONS

Although a total dose of 60 Gy was effective at a low pre-RT PSA levels with short follow-up, an RT dose > or =60 Gy resulted in superior biochemical outcomes even in patients with a pre-RT PSA < or =0.50 ng/ml.

Salvage radiotherapy for rising prostate-specific antigen levels after radical prostatectomy for prostate cancer: dose-response analysis

PURPOSE

To investigate the association between external beam radiotherapy (EBRT) dose and biochemical failure (BcF) of prostate cancer in patients who received salvage prostate bed EBRT for a rising prostate-specific antigen (PSA) level after radical prostatectomy.

METHODS AND MATERIALS

We evaluated patients with a rising PSA level after prostatectomy who received salvage EBRT between July 1987 and October 2007. Patients receiving pre-EBRT androgen suppression were excluded. Cox proportional hazards models were used to investigate the association between EBRT dose and BcF. Dose was considered as a numeric variable and as a categoric variable (low, <64.8 Gy; moderate, 64.8-66.6 Gy; high, >66.6 Gy).

RESULTS

A total of 364 men met study selection criteria and were followed up for a median of 6.0 years (range, 0.1-19.3 years). Median pre-EBRT PSA level was 0.6 ng/mL. The estimated cumulative rate of BcF at 5 years after EBRT was 50% overall and 57%, 46%, and 39% for the low-, moderate-, and high-dose groups, respectively. In multivariable analysis adjusting for potentially confounding variables, there was evidence of a linear trend between dose and BcF, with risk of BcF decreasing as dose increased (relative risk [RR], 0.77 [5.0-Gy increase]; p = 0.05). Compared with the low-dose group, there was evidence of a decreased risk of BcF for the high-dose group (RR, 0.60; p = 0.04), but no difference for the moderate-dose group (RR, 0.85; p = 0.41).

CONCLUSIONS

Our results suggest a dose response for salvage EBRT. Doses higher than 66.6 Gy result in decreased risk of BcF.

Validation of a nomogram to predict disease progression following salvage radiotherapy after radical prostatectomy: results from the SEARCH database

OBJECTIVE

To externally validate the nomogram published by Stephenson et al. (termed the 'Stephenson nomogram') to predict disease progression after salvage radiotherapy (SRT) among patients with prostate cancer from the Shared Equal Access Regional Cancer Hospital (SEARCH) database.

PATIENTS AND METHODS

We analysed data from 102 men treated with SRT for prostate-specific antigen (PSA) failure after prostatectomy, of whom 30 (29%) developed disease progression after SRT during a median follow-up of 50 months. The predicted 6-year progression-free survival (PFS) was compared to the actuarial PFS using calibration plots. The accuracy of the nomogram to risk-stratify men for progression was assessed by the concordance index.

RESULTS

The median PSA and PSA doubling time before SRT was 0.6 ng/mL and 10.3 months, respectively. The 6-year actuarial disease-free progression after SRT was 57% (95% confidence interval 42-69%). The overall concordance index of the Stephenson nomogram was 0.65. The nomogram predicted failure more accurately at the extremes of risk (lowest and highest) but in intermediate groups, the accuracy was less precise. Of the 11 variables used in the nomogram, only negative margins and high PSA level before SRT were significantly associated with increased disease progression.

CONCLUSION

The Stephenson nomogram is an important tool to predict disease progression after SRT following radical prostatectomy. It adequately predicted progression in SEARCH with reasonable accuracy. Also, in SEARCH, disease progression was predicted by similar disease characteristics. However, the overall modest performance of the model in our validation cohort indicates there is still room for improvement in predictive models for disease progression after SRT.

Phase III postoperative adjuvant radiotherapy after radical prostatectomy compared with radical prostatectomy alone in pT3 prostate cancer with postoperative undetectable prostate-specific antigen: ARO 96-02/AUO AP 09/95

PURPOSE

Local failure after radical prostatectomy (RP) is common in patients with cancer extending beyond the capsule. Two randomized trials demonstrated an advantage for adjuvant radiotherapy (RT) compared with a wait-and-see policy. We conducted a randomized, controlled clinical trial to compare RP followed by immediate RT with RP alone for patients with pT3 prostate cancer and an undetectable prostate-specific antigen (PSA) level after RP.

METHODS

After RP, 192 men were randomly assigned to a wait-and-see policy, and 193 men were assigned to immediate postoperative RT. Eligible patients had pT3 pN0 tumors. Patients who did not achieve an undetectable PSA after RP were excluded from treatment according to random assignment (n = 78; 20%). Of the remaining 307 patients, 34 patients on the RT arm did not receive RT and five patients on the wait-and-see arm received RT. Therefore, 114 patients underwent RT and 154 patients were treated with a wait-and-see policy. The primary end point was biochemical progression-free survival.

RESULTS

Biochemical progression-free survival after 5 years in patients with undetectable PSA after RP was significantly improved in the RT group (72%; 95% CI, 65% to 81%; v 54%, 95% CI, 45% to 63%; hazard ratio = 0.53; 95% CI, 0.37 to 0.79; P = .0015). On univariate analysis, Gleason score more than 6 and less than 7, PSA before RP, tumor stage, and positive surgical margins were predictors of outcome. The rate of grade 3 to 4 late adverse effects was 0.3%.

CONCLUSION

Adjuvant RT for pT3 prostate cancer with postoperatively undetectable PSA significantly reduces the risk of biochemical progression. Further follow-up is needed to assess the effect on metastases-free and overall survival.

[Which imaging methods should be used prior to salvage radiotherapy after prostatectomy for prostate cancer?]

Prostatectomy is one of the most widely used methods for treatment of adenocarcinoma of the prostate. According to anatomopathological criteria, between 10 and 40% of patients will display biochemical relapse in the absence of adjuvant radiotherapy. Anatomopathological and biochemical criteria are powerful tools for selecting patients for salvage radiotherapy. The aim of this article is to review literature on the latest progress in radiological and nuclear medicine techniques and their performance levels, in order to determine local, regional and metastatic relapses associated with the techniques and specify the radiotherapy target volume. Magnetic resonance imaging (MRI) displays the best sensitivity and specificity for examination of the prostate bed and enables simultaneous assessment of the pelvic region - thus diminishing the utility of computed tomography. The performance levels of MRI will probably continue to improve, with the use of dynamic MRI and MR spectroscopy. Despite the development of new markers like (11)C and (18)F choline and acetate, the sensitivity of positron emission tomography is still low. Prospective studies with an appropriate methodology are necessary for specifying the technique's value in this context.

Clinical significance and treatment of biochemical recurrence after definitive therapy for localized prostate cancer

PURPOSE

Radical prostatectomy and external beam radiation therapy are the established and definitive interventions for clinically localized prostate cancer. These treatment modalities are yet subject to failure observed first by biochemical recurrence, defined by increases in the serum PSA level. We investigated the significance of biochemical recurrence after definitive therapy and the available salvage therapy options for cancer recurrence.

METHODS

A literature search was performed in PubMed, and applicable studies addressing biochemical recurrence and salvage options after radical prostatectomy or external beam radiation therapy were reviewed.

RESULTS

After radical prostatectomy, a detectable serum PSA level indicates biochemical recurrence. Whether to administer salvage therapy locally or systemically depends largely on prognostic factors including PSA doubling time, Gleason's score, pathologic stage, and the time interval between radical prostatectomy and biochemical recurrence. Early initiation of salvage therapy has been shown to significantly impact on cancer outcomes. After external beam radiation therapy, no single PSA level can define biochemical recurrence. Instead, it has been defined by increases in the PSA level above the nadir. Following radiation therapy, PSA doubling time and Gleason score play important roles in determining the need for local versus systemic salvage therapy.

CONCLUSIONS

After the diagnosis of biochemical recurrence, it is critical to perform a timely clinical assessment using the prognostic factors mentioned above. Prompt initiation of salvage therapy may prevent subsequent clinical progression and prostate cancer-specific mortality.

Development of RTOG consensus guidelines for the definition of the clinical target volume for postoperative conformal radiation therapy for prostate cancer

PURPOSE

To define a prostate fossa clinical target volume (PF-CTV) for Radiation Therapy Oncology Group (RTOG) trials using postoperative radiotherapy for prostate cancer.

METHODS AND MATERIALS

An RTOG-sponsored meeting was held to define an appropriate PF-CTV after radical prostatectomy. Data were presented describing radiographic failure patterns after surgery. Target volumes used in previous trials were reviewed. Using contours independently submitted by 13 radiation oncologists, a statistical imputation method derived a preliminary "consensus" PF-CTV.

RESULTS

Starting from the model-derived CTV, consensus was reached for a CT image-based PF-CTV. The PF-CTV should extend superiorly from the level of the caudal vas deferens remnant to >8-12 mm inferior to vesicourethral anastomosis (VUA). Below the superior border of the pubic symphysis, the anterior border extends to the posterior aspect of the pubis and posteriorly to the rectum, where it may be concave at the level of the VUA. At this level, the lateral border extends to the levator ani. Above the pubic symphysis, the anterior border should encompass the posterior 1-2 cm of the bladder wall; posteriorly, it is bounded by the mesorectal fascia. At this level, the lateral border is the sacrorectogenitopubic fascia. Seminal vesicle remnants, if present, should be included in the CTV if there is pathologic evidence of their involvement.

CONCLUSIONS

Consensus on postoperative PF-CTV for RT after prostatectomy was reached and is available as a CT image atlas on the RTOG website. This will allow uniformity in defining PF-CTV for clinical trials that include postprostatectomy RT.

Adjuvant radiation therapy after radical prostatectomy: when is it indicated?

Radical prostatectomy is the most commonly used treatment option in the United States for men with clinically localized prostate cancer. Up to 30% of these patients, particularly those with adverse pathological risk factors, will develop a biochemical recurrence within 10 years. Patients with a biochemical recurrence have a higher rate of local recurrence and cancer-specific mortality. Current accepted treatment options include salvage radiation therapy, hormone therapy, or a combination of both, depending on whether the disease recurrence is biochemical, local, or systemic. The role of adjuvant radiation therapy (ART) after prostatectomy in patients with adverse pathological risk factors prior to biochemical or clinical recurrence is unclear. Recent randomized trials have demonstrated that ART significantly improves multiple patient outcomes, including overall and cancer-specific survival, without major untoward effects. The evidence in support of using ART is evolving with the long-term follow-up of several long-term prospective trials. The decision to use ART should be based on the patient's pathological characteristics, clinical status, side effects, and open communication between the patient and provider.

Can dutasteride delay or prevent the progression of prostate cancer in patients with biochemical failure after radical therapy? Rationale and design of the Avodart after Radical Therapy for Prostate Cancer Study

OBJECTIVE

To describe the Avodart after Radical Therapy for prostate cancer Study (ARTS), investigating the use of dutasteride (a dual 5alpha-reductase inhibitor that suppresses intraprostatic dihydrotestosterone, reduces tumour volume and improves other markers of tumour regression in prostate cancer) to prevent or delay disease progression in patients with biochemical recurrence after therapy with curative intent.

PATIENTS AND METHODS

An increasing serum prostate-specific antigen (PSA) level after radical prostatectomy (RP) or radiotherapy (RT) is indicative of recurrent prostate cancer and typically pre-dates clinically detectable metastatic disease by several years. ARTS is an ongoing European multicentre trial in which patients are stratified by previous therapy (RP with or without salvage RT vs primary RT) and randomized to double-blind treatment with dutasteride 0.5 mg or placebo once daily for 2 years. Eligible patients will have a PSA doubling time (DT) of 3-24 months. Biochemical recurrence is defined as three increases in PSA level from the nadir, with each increase > or =4 weeks apart and each PSA level > or =0.2 ng/mL, and a final PSA level of > or =0.4 ng/mL (after RP) or > or =2 ng/mL (after primary RT). Study endpoints include time to PSA doubling, time to disease progression, treatment response (PSA decrease or an increase of < or =15% from baseline), changes in PSA and PSADT, and changes in anxiety (Memorial Anxiety Scale for Prostate Cancer). CONCLUSIONS ARTS: will be the first study to evaluate the effects of dutasteride on PSADT, disease progression and treatment response in patients with biochemical failure after RP or RT, and should help to elucidate the potential role of dual 5alpha-reductase inhibition in prostate cancer.

Bone imaging in prostate cancer

Bone metastases of solid tumors are common, and about 80% of them occur in patients with breast, lung or prostate cancer. Bone metastases can be suspected clinically and by laboratory tests; however, a final diagnosis relies on radiographic evidence. Bone metastases of prostate cancer usually have osteoblastic characteristics, manifested by pathological bone resorption and formation. Conventional bone scans (e.g. with (99m)Tc-labeled methylene diphosphonate) are preferred to plain-film radiography for surveillance of the entire skeleton. Radiologic diagnosis of bone metastases, particularly in patients with low burden of disease, is difficult because noncancerous bone lesions that mimic cancer are common. Conventional bone scans are limited by their low sensitivity and high false-negative rate (up to 40%) compared with advanced bone-imaging modalities such as PET, PET-CT and MRI, which might assist or replace conventional scanning methods. The correct diagnosis of bone involvement in prostate cancer is crucial to assess the effects of therapy on the primary tumor, the patient's prognosis, and the efficacy of bone-specific treatments that can reduce future bone-associated morbidity. In addition, predictive tools such as nomograms enable the identification of patients at risk of bone involvement during the course of their disease. Such tools may limit treatment costs by avoidance of unnecessary tests and might reduce both short-term and long-term complication rates.

Conventional treatments of localized prostate cancer

Established therapeutic approaches for clinically localized prostate cancer include watchful waiting (active surveillance), radical prostatectomy, and radiotherapy. The risk of progression during surveillance is related to the initial cancer stage and grade; reasonable evidence has supported the safety and feasibility, during a period of 5-10 years, of an active surveillance regimen for men with low-risk prostate cancer. The progression rates at >10 years have not yet been studied in modern trials. Patients with low-risk tumor characteristics can be actively monitored without sacrificing the possibility of cure and without being exposed to an undue risk of disease progression, although some patients will not accept the emotional burden of living with an untreated cancer. Focal ablation might be an attractive alternative to active surveillance for some patients with low-risk cancer, if it proves to have minimal adverse effects on their quality of life. Radical prostatectomy is an effective form of therapy for patients with clinically significant prostate cancer; however, outcomes are highly sensitive to variations in surgical technique. Because of the risks of perioperative complications and urinary and sexual dysfunction, which appear to be as great with robotic-assisted prostatectomy as with any other technique, patients with low-risk cancer, especially those >60 years, might be attracted to more conservative alternatives, including active surveillance, radiotherapy, and focal ablation. External beam radiotherapy is an effective, noninvasive form of therapy, but it carries the long-term risks of troublesome bowel and sexual and urinary dysfunction. It might be too aggressive for many low-risk cancers detected in screened populations. For more aggressive cancers, local recurrence after radiotherapy carries substantial morbidity and low rates of long-term cancer control. Brachytherapy, a convenient, effective form of radiotherapy, is targeted at selected patients with clinically confined cancer and a prostate size of <60 g without evidence of extraprostatic extension on imaging. However, excellent outcomes require meticulous technique; acute urinary symptoms are frequent; and the long-term risks of proctitis and erectile dysfunction are comparable to the risks associated with external beam radiotherapy. Androgen-deprivation therapy is not recommended for men with localized prostate cancer who would otherwise be candidates for surgery or radiotherapy, because, even with short-term use, the risk of side effects, including osteopenic fracture and major cardiovascular events, serious. For locally extensive cancer, androgen-deprivation therapy should be used alone only for the relief of local symptoms in men with a life expectancy of <5 years who are not eligible for more aggressive treatment.

Adjuvant radiotherapy for pathological T3N0M0 prostate cancer significantly reduces risk of metastases and improves survival: long-term followup of a randomized clinical trial

PURPOSE

Extraprostatic disease will be manifest in a third of men after radical prostatectomy. We present the long-term followup of a randomized clinical trial of radiotherapy to reduce the risk of subsequent metastatic disease and death.

MATERIALS AND METHODS

A total of 431 men with pT3N0M0 prostate cancer were randomized to 60 to 64 Gy adjuvant radiotherapy or observation. The primary study end point was metastasis-free survival.

RESULTS

Of 425 eligible men 211 were randomized to observation and 214 to adjuvant radiation. Of those men under observation 70 ultimately received radiotherapy. Metastasis-free survival was significantly greater with radiotherapy (93 of 214 events on the radiotherapy arm vs 114 of 211 events on observation; HR 0.71; 95% CI 0.54, 0.94; p = 0.016). Survival improved significantly with adjuvant radiation (88 deaths of 214 on the radiotherapy arm vs 110 deaths of 211 on observation; HR 0.72; 95% CI 0.55, 0.96; p = 0.023).

CONCLUSIONS

Adjuvant radiotherapy after radical prostatectomy for a man with pT3N0M0 prostate cancer significantly reduces the risk of metastasis and increases survival.

Predictive models for newly diagnosed prostate cancer patients

Accurate risk assessment is of paramount importance to newly diagnosed prostate cancer patients and their physicians. Risk prediction models help identify those at high (or low) risk of disease progression and guide discussions about prognosis and treatment. Widely used, well-validated prediction tools are based on standard, readily available clinical and pathologic parameters, but do not include biomarkers, some of which may have an important role in predicting prognosis or determining therapeutic options. A new approach, known as systems pathology, may improve the accuracy of traditional prediction methods and provide patients with a more personalized risk assessment of clinically relevant outcomes. The ultimate goal of prediction models is to improve medical decision making.

Systematic review of pretreatment prostate-specific antigen velocity and doubling time as predictors for prostate cancer

PURPOSE

Pretreatment prostate-specific antigen (PSA) dynamics (PSA velocity and PSA doubling time) are widely advocated as useful prognostic markers in prostate cancer. We aimed to assess the published evidence for the clinical utility of PSA dynamics in this population.

METHODS

We conducted a systematic review of studies published before March 2007 in which a PSA dynamic (velocity or doubling time) was calculated in patients before definitive treatment, a subsequent event (such as biopsy or recurrence) was ascertained, and the association between the two was analyzed. Our principal end point was the type of analysis reported, particularly whether the predictive accuracy of a statistical model that included both absolute PSA level and a PSA dynamic was compared with that of a model that included only PSA.

RESULTS

Eighty-seven articles were eligible for analysis. The most common end points were biopsy (42 articles), and either recurrence (14 articles) or metastases or death (14 articles) after definitive therapy. Although PSA dynamics were generally found to be associated with outcome, only one article compared predictive accuracy of models with and without a PSA dynamic: this reported that PSA velocity improved prediction slightly (from 0.81 to 0.83), but was subject to verification bias. No article used decision analytic methods to examine the clinical impact of PSA dynamics.

CONCLUSION

There is little evidence that calculation of PSA velocity or doubling time in untreated patients provides predictive information beyond that provided by absolute PSA level alone. We see no justification for the use of PSA dynamics in clinical decision making before treatment in early-stage prostate cancer.

A multi-institutional matched-control analysis of adjuvant and salvage postoperative radiation therapy for pT3-4N0 prostate cancer

OBJECTIVES

It is unclear whether postoperative salvage radiation therapy (SRT) and early adjuvant radiotherapy (ART) after radical prostatectomy lead to equivalent long-term tumor control. We studied a group of patients undergoing ART by comparing them with a matched control group undergoing SRT after biochemical failure.

METHODS

Using a multi-institutional database of 2299 patients, 449 patients with pT3-4N0 disease were eligible for inclusion, including 211 patients receiving ART and 238 patients receiving SRT. Patients were matched in a 1:1 ratio according to preoperative prostate-specific antigen Gleason score, seminal vesicle invasion, surgical margin status, and follow-up from date of surgery.

RESULTS

A total of 192 patients were matched (96:96). The median follow-up was 94 months from surgery and 73 months from RT completion. There was a significant reduction in biochemical failure with ART compared with SRT. The 5-year freedom from biochemical failure (FFBF) from surgery was 75% after ART, compared with 66% for SRT (hazard ratio [HR] = 1.6, P = .049). The 5-year FFBF from the end of RT was 73% after ART, compared with 50% after SRT (HR = 2.3, log rank [LR] P = .0007). From the end of RT, SRT and Gleason score >or=8 were independent predictors of diminished FFBF. From the date of surgery, Gleason score >or=8 was a significant predictor of FFBF.

CONCLUSIONS

Early ART for pT3-4N0 prostate cancer significantly reduces the risk of long-term biochemical progression after radical prostatectomy compared with SRT. Gleason score >or=8 was the only factor on multivariate analysis associated with metastasic progression.

Adjuvant and salvage radiotherapy after prostatectomy for prostate cancer: a literature review

PURPOSE

Given that postprostatectomy recurrence of prostate cancer occurs in 10-40% of patients, the best use of immediate postoperative radiotherapy (RT) in high-risk patients and salvage RT for biochemical recurrence remains a topic of debate. We assessed the levels of evidence (in terms of efficacy, prognostic factors, and toxicity) for the following treatment strategies: immediate postoperative RT alone, salvage RT alone, and the addition of androgen deprivation therapy to the two RT strategies.

METHODS AND MATERIALS

A systematic literature search for controlled randomized trials, noncontrolled trials, and retrospective studies between 1990 and 2008 was performed on PubMed, CancerLit, and MEDLINE. Only relevant articles that had appeared in peer-reviewed journals were selected. We report on the levels of evidence (according to the National Cancer Institute guidelines) supporting the various treatment strategies.

RESULTS

Immediate postoperative RT improves biochemical and clinical progression-free survival (Level of evidence, 1.ii) but has no significant effect on metastasis-free survival or overall survival. A pathologic review is of particular importance for correctly analyzing the treatment strategies. Low-grade morbidity has been significantly greater in the postoperative groups, but no severe toxicity has been observed. The influence of immediate postoperative RT on postprostatectomy continence appears to be slight; therefore, immediate postoperative RT should be considered in patients with major risk factors for local relapse (Level of evidence, 1.ii). On the basis of extensive retrospective data, salvage RT is effective in biochemical relapse after prostatectomy; some patients with few adverse prognostic factors might also benefit from salvage RT (Level of evidence, 3.ii). The addition of androgen deprivation therapy to immediate postoperative or salvage RT has only been supported by weak, retrospective data (Level of evidence, 3.ii).

CONCLUSION

Prospective randomized trials are needed to compare immediate postoperative RT with salvage RT and to assess the value of androgen deprivation therapy in this setting.