Salvage radiation therapy for prostate specific antigen progression following radical prostatectomy: 10-year outcome estimates

PSA decay during salvage radiotherapy for prostate cancer as a predictor of disease outcome - 5 year follow-up of a prospective observational study

•

Biochemical recurrence after prostatectomy is treated with salvage radiotherapy.

•

Several established pre-treatment factors predict outcome.

•

PSA decay rate measured early during salvage radiotherapy is a better predictor than any of these.

•

It can be used to personalize future therapies.

Background and purpose

Biochemical recurrence after prostatectomy is commonly treated with salvage radiotherapy (SRT). In this prospective observational study we investigated the PSA decay rate, determined by predefined serial PSA measurements during SRT, as a predictor for treatment outcome.

Materials and methods

Between 2013 and 2016, 214 patients were included in the study. The prescribed dose to the prostate bed was 70 Gy in 35 fractions (7 weeks) without hormonal treatment. PSA was measured weekly during SRT. Assuming first order kinetics, a PSA decay-rate constant (k) was calculated for 196 eligible patients. The ability of k to predict disease progression was compared with known clinical prediction parameters using Cox regression, logistic regression and ROC analyses. Disease progression was defined as continuously rising PSA after SRT, PSA increase by ≥0.2 ng/ml above nadir after SRT, hormonal treatment or clinical progression.

Results

After a median follow up of 4.7 years the estimated failure-free survival at 5 years was 56%. The PSA decay-rate constant (k) was found to be the strongest predictor of disease progression in both uni-and multivariable analyses.

Conclusion

The addition of k to established clinical variables significantly improves the possibility to predict treatment outcome after SRT and could be used to personalize future therapies.

Long-term Outcome of Prostate Cancer Patients Who Exhibit Biochemical Failure Despite Salvage Radiation Therapy After Radical Prostatectomy

OBJECTIVES

Salvage radiation therapy (SRT) is an effective treatment for recurrent prostate cancer (PCa) after radical prostatectomy. We report the long-term outcome of men who developed biochemical recurrence (BCR) after SRT and were treated >14 years ago.

METHODS

In total, 61 patients treated with SRT from 1992 to 2000 at our institution were identified. Survival was calculated by Kaplan-Meier method. Log-rank test and Cox regression were used to determine significance of clinical parameters.

RESULTS

The median follow-up was 126 months (interquartile range, 66-167 mo). Thirty-four (56%) had prostate-specific antigen (PSA) failure after SRT. At 10 years, overall survival (OS) was 67%, freedom from PSA failure (FFPF) was 33%, prostate cancer-specific survival (PCSS) was 84%, and distant metastases-free survival (DMFS) was 84%. Pathologic T-stage, Gleason score, seminal vesicle involvement, and pre-SRT PSA were associated with FFPF. For patients who failed SRT, the median time to BCR after SRT was 30 mo. A total of 19 (68%) received androgen deprivation therapy. The median OS was 13.6 years. At 10 years from time of BCR, OS was 59%, PCSS was 73%, DMFS was 75%, and castration-resistant-free survival was 70%. Early SRT failure correlated with significantly decreased DMFS and PCSS. Ten-year DMFS from SRT was 43% (BCR≤1 y) versus 91% (BCR>1 y).

CONCLUSIONS

Extended follow-up demonstrates that despite SRT failure, PCSS remains high in select patients. Early failure (≤1 y after SRT) predicted for significantly worse outcome and may represent a subgroup with more aggressive disease that may be considered for further prospective clinical studies.

Post-prostatectomy radiotherapy adversely affects urinary continence irrespective of radiotherapy regime

PURPOSE

To investigate the influence of different postoperative radiotherapy (RT) regimes on post-prostatectomy continence and QoL.

METHODS

Men after prostatectomy (RP) and RT were assigned in adjuvant (ART), early salvage (ESRT) and salvage radiotherapy (SRT) groups depending on time of initiation, indication and pre-RT-PSA (≤/>0.5 ng/ml). Continence and QoL outcomes were evaluated by validated questionnaire. Statistical analysis included students t test, Chi square, Fisher's test, ROC- and McNemar-Bowker-Analyses.

RESULTS

The mean follow-up was 5.1 years. 33.5, 38.2 and 28.3% received ART, ESRT and SRT, respectively. Mean time to RT was 0.3 (±0.4), 1.8 (±2.5) and 3.3 (±3.6) years respectively. Differences in age at RP (p = 0.54) and RT (p = 0.47) between groups were not significant. Mean-RT-dose was similar (p = 0.70). Differences in continence distribution between groups before (p = 0.56) and after RT (p = 0.38) were not significant. No significant differences were observed for frequency (p = 0.58) or amount (p = 0.88) of urine loss, impact on QoL (p = 0.13) and ICIQ-SF scores (p = 0.69) between groups. Even though no significant difference in post-RT-continence (p = 0.89) was observed in the direct comparison between groups, a significant worsening of long-term continence was observed in all groups (p < 0.001). We found no cutoff and no time-point after RP at which this negative effect of RT on continence became insignificant (AUC = 0.474). A subgroup with apparent local recurrence showed no differences for ICIQ-SF-score (p = 0.155), QoL (0.077), incontinence grade (p = 0.387), frequency (p = 0.182) and amount (p = 0.415) of urine loss. Proportionally more men in this subgroup remembered deterioration of continence after RT (p = 0.029).

CONCLUSION

Postoperative RT adversely affects long-term continence; this negative effect is irrespective of time of initiation or indication for RT. These results suggest a need for innovative strategies of prostate cancer therapy with lasting oncological, functional and QoL outcomes.

Influential factors in the response to salvage radiotherapy after radical prostatectomy

OBJECTIVE

To analyze the influential factors in the response in prostatectomized patients with subsequent biochemical relapse (BCR) and treated with salvage radiotherapy (RTP).

MATERIAL AND METHODS

We analyzed 313 patients with pT2/pT3 prostate cancer who were receiving salvage therapy due to biochemical relapse (from a series of 1,310 radical prostatectomies between 1989-2012). Of the 313 patients; 159 (50.8%) only received androgen deprivation (AD), 63 (20.1%) Radiotherapy (RTP) plus concomitant AD and 91 (29.1%) only RTP. Of these, 57 (62.6%) have maintained complete response and 34 (37.4%) had failure response with post-RTP BCR.

RESULTS

Study of the group treated exclusively with salvage RTP. Ninety-one patients were treated with salvage RTP. Median follow-up was 6.4 years and median to recurrence 11 months. Post-RTP biochemical relapse-free survival (PRBRFS) was 68 ± 7% and 30 ± 10% in 5 to 10 years. Median PRBRFS was 7.3 years (6.3-8.3). Initial PSA (HR: 1.08; 95% CI: 1.01-1.1 P=.02) with best PSA cut-off point PSA>20 ng/ml (HR: 13.6; 95% CI: 2.1-86 P=.005) and PSA pre-RTP (HR: 1.9; 95% CI: 1.2-3.3; P=.009), best PSA cut-off point PSA preRTP 0.92 ng/ml (HR: 4.5; 95% CI: 1.3-15.6; P=.01) showed independent influence in the response in the multivariate study. PRBRFS at 5 years, 81 ± 9% versus 58 ± 9% with initial PSA <20 or >20 ng/ml (P=.03). PRBRFS at 5 years, 93 ± 5% versus 53 ± 10% according to PSA pre-RTP <0.9 or >0.9 ng/ml (P=.02).

CONCLUSIONS

In patients treated with salvage RTP after radical prostatectomy, the preoperative PSA>20 ng/ml and PSA preRTP>0.92 ng/ml shows an independent influence on the response.

Suggestion for the prostatic fossa clinical target volume in adjuvant or salvage radiotherapy after a radical prostatectomy

BACKGROUND AND PURPOSE

To assess the location of recurrent tumors and suggest the optimal target volume in adjuvant or salvage radiotherapy (RT) after a radical prostatectomy (RP).

MATERIAL AND METHODS

From January 2000 to December 2012, 113 patients had been diagnosed with suspected recurrent prostate cancer by MRI scan and received salvage RT in the Samsung Medical Center. This study assessed the location of the suspected tumor recurrences and used the inferior border of the pubic symphysis as a point of reference.

RESULTS

There were 118 suspect tumor recurrences. The most common site of recurrence was the anastomotic site (78.8%), followed by the bladder neck (15.3%) and retrovesical area (5.9%). In the cranial direction, 106 (87.3%) lesions were located within 30 mm of the reference point. In the caudal direction, 12 lesions (10.2%) were located below the reference point. In the transverse plane, 112 lesions (94.9%) were located within 10mm of the midline.

CONCLUSIONS

A MRI scan acquired before salvage RT is useful for the localization of recurrent tumors and the delineation of the target volume. We suggest the optimal target volume in adjuvant or salvage RT after RP, which includes 97% of suspected tumor recurrences.

Salvage Low-Dose-Rate Brachytherapy for Prostate Cancer Local Recurrence after Radical Prostatectomy: Our First three Patients

Purpose of the Study

To present our initial experience with brachytherapy (BT) as a primary salvage procedure for the treatment of prostate cancer (PCa) local recurrence following radical retropubic prostatectomy (RRP).

Methods

From December 2009 to May 2010, three patients underwent salvage BT due to local recurrences of high risk PCa after extrafascial RRP without additional adjuvant therapies. Local recurrence was confirmed by prostate biopsy and the relapse was well defined by endorectal ultrasonography and magnetic resonance imaging. Metastatic screening was negative. The patients were followed-up according to the American Brachytherapy Society guidelines.

Results

The median dose delivered to 90% of the local relapse (D90) was 115 Gy. The three patients reached a prostate specific antigen (PSA) nadir value within the first year that remained stable at a mean follow-up of 32 months. As regards morbidity, moderate de novo urgency was reported by only one patient.

Conclusions

We think that our data confirms the feasibility and safety of salvage BT as a possible alternative option to external beam radiotherapy (EBRT) for the treatment of locally recurrent PCa in selected patients when performed by experienced centers. However, larger series of patients with longer follow-ups are needed to define the oncologic role of this procedure.

Radiotherapy in the management of prostate cancer after radical prostatectomy

The choice of treatment options for prostate cancer patients who have undergone radical prostatectomy depends on their risk profile, which is determined by the tumor node metastasis (TNM) status, histopathologic findings, and the pre- and post-radical prostatectomy PSA characteristics. The results of large clinical studies with a 10-year follow-up or more are the backbone of predictive models for risk estimates that incorporate these criteria and also for guideline recommendations. For low-to-intermediate-risk prostate cancer patients and older patients, observation with--in case of biochemical recurrence--early salvage radiotherapy can be advised after R0 resection, thus, avoiding overtreatment. After R1 resection, adjuvant radiotherapy should be considered. Patients with two or more positive lymph nodes and/or with distant metastasis may benefit from adjuvant hormone deprivation therapy. Beyond this rough outline, detailed analysis of subgroups is still required (and ongoing) to enable individually optimized treatment.

Risk factors predicting the outcome of salvage radiotherapy in patients with biochemical recurrence after radical prostatectomy

OBJECTIVES

Salvage radiotherapy is the only curative treatment for patients with prostate cancer showing biochemical progression after radical prostatectomy. In this study, we evaluated the clinicopathological parameters that influence the outcome of salvage radiotherapy.

METHODS

Medical records of 49 patients who underwent salvage radiotherapy after radical prostatectomy from 1997 to 2008 at the Graduate School of Medicine, Kyoto University, were retrospectively reviewed. Radiotherapy was carried out with 66 Gy on the prostatic bed.

RESULTS

Biochemical progression-free survival after salvage radiotherapy at 2, 5 and 7 years was 51.0%, 42.2% and 42.2%, respectively. Significant parameters predicting biochemical progression after salvage radiotherapy by Cox regression analysis were prostatectomy Gleason score sum ≥ 8 (hazard ratio 0.08; 95% confidence interval 0.03-0.22; P=0.001), prostate-specific antigen nadir after radical prostatectomy ≥ 0.04 ng/mL (hazard ratio 0.30; 95% confidence interval 0.13-0.69; P=0.005) and negative surgical margin (hazard ratio 0.28; 95% confidence interval 0.12-0.70; P=0.006). When the patients were subgrouped by these risk factors, the 5-year progression-free survival rates after salvage radiotherapy were 77.8%, 50.0% and 6.7% in patients with 0, 1 and ≥ 2 predictors, respectively.

CONCLUSION

In order to discriminate favorable candidates for salvage radiotherapy, Gleason score of prostatectomy, prostate-specific antigen nadir after prostatectomy and positive surgical margin represent independent predictors. Thus, progression-free survival might be more precisely predicted according to the presence/absence of these risk factors. The significance of this risk classification should be confirmed by large prospective studies.

Postoperative radiotherapy after radical prostatectomy: indications and open questions

Biochemical relapse after radical prostatectomy occurs in approximately 15–40% of patients within 5 years. Postoperative radiotherapy is the only curative treatment for these patients. After radical prostatectomy, two different strategies can be offered, adjuvant or salvage radiotherapy. Adjuvant radiotherapy is defined as treatment given directly after surgery in the presence of risk factors (R1 resection, pT3) before biochemical relapse occurs. It consists of 60–64 Gy and was shown to increase biochemical relapse-free survival in three randomized controlled trials and to increase overall survival after a median followup of 12.7 years in one of these trials. Salvage radiotherapy, on the other hand, is given upon biochemical relapse and is the preferred option, by many centers as it does not include patients who might be cured by surgery alone. As described in only retrospective studies the dose for salvage radiotherapy ranges from 64 to 72 Gy and is usually dependent on the absence or presence of macroscopic recurrence. Randomized trials are currently investigating the role of adjuvant and salvage radiotherapy. Patients with biochemical relapse after prostatectomy should at the earliest sign of relapse be referred to salvage radiotherapy and should preferably be treated within a clinical trial.

Adjuvant radiotherapy following radical prostatectomy for prostate cancer

BACKGROUND

Men who have a radical prostatectomy (RP) for prostate cancer that does not involve lymph nodes, but extends beyond the prostate capsule into the seminal vesicles or to surgical margins, are at increased risk of relapse. In men with these high risk factors, radiotherapy (RT) directed at the prostate bed after surgery may reduce this risk, and be curative.

OBJECTIVES

To evaluate the effect of adjuvant RT following RP for prostate cancer in men with high risk features compared with RP.

SEARCH METHODS

We searched the Cochrane Prostatic Diseases and Urological Cancers Specialised Register (23 February 2011), the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE (January 1966 to February 2011), PDQ® (Physician Data Query) trial registry databases for ongoing studies (2 November 2010), reference lists from selected studies and reviews, and handsearched relevant conference proceedings.

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing RP followed by RT with RP alone.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the studies for inclusion and bias and extracted data for analysis. Authors were contacted to clarify data and obtain missing information.

MAIN RESULTS

We found three RCTs involving 1815 men. Adjuvant RT following prostatectomy did not affect overall survival at 5 years (RD (risk difference) 0.00; 95% CI -0.03 to 0.03), but improved survival at 10 years (RD -0.11; 95% CI -0.20 to -0.02). Adjuvant RT did not improve prostate cancer-specific mortality at 5 years (RD -0.01; 95% CI -0.03 to 0.00). Adjuvant RT did not reduce metastatic disease at 5 years (RD -0.00; 95% CI -0.04 to 0.03), but reduced it at 10 years (RD -0.11; 95% CI -0.20 to -0.01). It improved local control at 5 and 10 years (RD -0.10; 95% CI -0.13 to -0.06 and RD -0.14; 95% CI -0.21 to -0.07, respectively), and biochemical progression-free survival at 5 years and 10 years (RD -0.16; 95% CI -0.21 to -0.11 and RD -0.29; 95% CI -0.39 to -0.19, respectively). There were no data for clinical disease-free survival. Adjuvant RT increased acute and late gastrointestinal toxicity [do you have the rd for this?], urinary stricture (RD 0.05; 95% CI 0.01 to 0.09) and incontinence (RD 0.04; 95% CI 0.01 to 0.08). It did not increase erectile dysfunction or degrade quality of life (RD 0.01; 95% CI -0.06 to -0.26), but with limited data.

AUTHORS' CONCLUSIONS

Adjuvant RT after RP improves overall survival and reduces the rate of distant metastases, but these effects are only evident with longer follow up. At 5 and 10 years it improves local control and reduces the risk of biochemical failure, although the latter is not a clinical endpoint. Moderate or severe acute and late toxicity is minimal. There is an increased risk of urinary stricture and incontinence, but no detriment to quality of life, based on limited data. Given that the majority of men who have undergone a RP have a longer life expectancy, radiotherapy should be considered for those with high-risk features following radical prostatectomy. The optimal timing is unclear.

Salvage radiotherapy after prostatectomy - what is the best time to treat?

PURPOSE

Salvage radiotherapy (SRT) is applied routinely in patients with biochemical relapse after radical prostatectomy (RP). However, only ∼30% of these patients achieve a durable response after 10 years. As a standard, 66 Gy are given, ideally with a PSA below 0.5 ng/ml. We tried to determine more precisely the optimal PSA for starting SRT.

MATERIAL AND METHODS

In 301 prostate cancer patients without hormonal treatment, we analysed the impact on the biochemical response (bNED) to SRT of two pre-SRT PSA levels, namely below or above the median of 0.28 ng/ml.

RESULTS

The median follow-up time for the entire group was 30 months. In 151 patients, SRT commenced at a PSA ≤ 0.28 ng/ml, in 150 at > 0.28 ng/ml. Eighty-two patients (27%) developed biochemical progression during follow up. The calculated two-year bNED was 74% for the entire group, 78% versus 61% for a PSA ≤ or > 0.28 ng/ml, respectively. In multivariate analysis, pT(3b), resection status, pre-SRT PSA dichotomized at median, PSA post-SRT undetectable, and PSA doubling time were statistically significant independent predictors of progression after SRT.

CONCLUSIONS

Our findings suggest that a PSA of ≤ 0.28 ng/ml improves bNED compared with a PSA before SRT of > 0.28 ng/ml.

Impact of pathological tumor stage for salvage radiotherapy after radical prostatectomy in patients with prostate-specific antigen < 1.0 ng/ml

BACKGROUND

To evaluate prognostic factors in salvage radiotherapy (RT) for patients with pre-RT prostate-specific antigen (PSA) < 1.0 ng/ml.

METHODS

Between January 2000 and December 2009, 102 patients underwent salvage RT for biochemical failure after radical prostatectomy (RP). Re-failure of PSA after salvage RT was defined as a serum PSA value of 0.2 ng/ml or more above the postradiotherapy nadir followed by another higher value, a continued rise in serum PSA despite salvage RT, or initiation of systemic therapy after completion of salvage RT. Biochemical relapse-free survival (bRFS) was estimated using the Kaplan-Meier method. Multivariate analysis was performed using the Cox proportional hazards regression model.

RESULTS

The median follow-up period was 44 months (range, 11-103 months). Forty-three patients experienced PSA re-failure after salvage RT. The 4-year bRFS was 50.9% (95% confidence interval [95% CI]: 39.4-62.5%). In the log-rank test, pT3-4 (p < 0.001) and preoperative PSA (p = 0.037) were selected as significant factors. In multivariate analysis, only pT3-4 was a prognostic factor (hazard ratio: 3.512 [95% CI: 1.535-8.037], p = 0.001). The 4-year bRFS rates for pT1-2 and pT3-4 were 79.2% (95% CI: 66.0-92.3%) and 31.7% (95% CI: 17.0-46.4%), respectively.

CONCLUSIONS

In patients who have received salvage RT after RP with PSA < 1.0 ng/ml, pT stage and preoperative PSA were prognostic factors of bRFS. In particular, pT3-4 had a high risk for biochemical recurrence after salvage RT.

Can early implementation of salvage radiotherapy for prostate cancer improve the therapeutic ratio? A systematic review and regression meta-analysis with radiobiological modelling

PURPOSE

For prostate cancer that is thought to be locally recurrent after prostatectomy, the optimal timing, dose and techniques for salvage radiotherapy (SRT) have not been established. Here we perform a systematic review of published reports including regression meta-analysis and radiobiologic modelling to identify predictors of biochemical disease control and late toxicity.

METHODS

We performed a review of published series reporting treatment outcomes following SRT. Studies with at least 30 patients, median PSA before SRT of less than 2.0 ng/mL, and median follow-up of greater than 36 months were identified. Univariate and multivariate analyses were performed to test Gleason Score, SRT dose, SRT timing, pre-SRT PSA, whole pelvic irradiation and androgen deprivation therapy as predictors of 5-year biochemical progression-free survival (bPFS) and severe (grade≥3) late GI and GU toxicity. bPFS and toxicity data were fit to tumour control probability and normal tissue complication probability models, respectively.

RESULTS

Twenty-five articles met the inclusion criteria for this analysis. Five-year bPFS ranged from 25% to 70%. Severe late GI toxicity rates were 0% to 9%, and severe late GU toxicity rates were 1-11%. On multivariate analysis, bPFS increased with SRT dose by 2.5% per Gy and decreased with pre-SRT PSA by 18.3% per ng/mL (p<0.001). Late GI and GU toxicity increased with SRT dose by 1.2% per Gy (p=0.012) and 0.7% per Gy (p=0.010), respectively. Radiobiological models demonstrate the interaction between pre-SRT PSA, SRT dose and bPFS. For example, an increase in pre-SRT PSA from 0.4 to 1.0 ng/mL increases the SRT dose required to achieve a 50% bPFS rate from 60 to 70Gy. This could increase the rate of severe late toxicity by approximately 10%.

CONCLUSION

Biochemical control rates following SRT increase with SRT dose and decrease with pre-SRT PSA. Severe late GI and GU toxicity rates also increase with SRT dose. Radiobiological models suggest that the therapeutic ratio of SRT may be improved by initiating treatment at low PSA levels.

Image-guided radiotherapy using surgical clips as fiducial markers after prostatectomy: a report of total setup error, required PTV expansion, and dosimetric implications

PURPOSE

To determine the total setup error and the required planning target volume (PTV) margin for prostate bed without image guided radiotherapy (IGRT), and to demonstrate the feasibility and dosimetric benefit of IGRT post prostatectomy using surgical clips.

MATERIALS AND METHODS

Seventeen patients were treated with intensity modulated radiotherapy (IMRT) to the prostate bed with a 1cm PTV margin. Three-dimensional shifts of the surgical clips inside the prostate bed were measured with respect to the isocenter from 364 orthogonal kV image pairs, and the total setup error was calculated to determine the required PTV margin. Alternative IMRT plans using 5mm or 1cm PTV expansion were generated and compared for rectal and bladder sparing.

RESULTS

Surgical clips were reproducibly and reliably identified. The mean (standard deviation) shifts in the left-right (LR), superior-inferior (SI), and anterior-posterior (AP), axes were: -0.1 mm (1.7 mm), 0.6 mm (2.4 mm), and -2.1 mm (2.6 mm), respectively. The required PTV margins were calculated to be 6, 8, and 9 mm in the LR, AP, and SI axis, respectively. A PTV expansion of 5mm, compared to 1cm, significantly reduced V65 Gy to the rectum by 10%.

CONCLUSIONS

In the absence of IGRT, a non-uniform PTV margin of 6mm LR, 8mm AP, and 9 mm SI should be considered. Use of clips as fiducial markers can decrease the total setup error, enable a smaller PTV margin, and improve rectal sparing.

Dose escalation for patients with decreasing PSA during radiotherapy for elevated PSA after radical prostatectomy improves biochemical progression-free survival: results of a retrospective study

PURPOSE

The optimal dose for salvage radiotherapy (SRT) after radical prostatectomy (RP) is still not defined. It should be at least 66 Gy. In the present study, the suitability of PSA regression as a selection criterion for an SRT dose escalation to 70.2 Gy was examined.

PATIENTS AND METHODS

Between 1997 and 2007, 301 prostate cancer patients received SRT after RP at the Charité - University Medicine Berlin, Campus Benjamin Franklin. None of the patients had antihormone therapy prior to SRT. A total of 234 patients received 66.6 Gy. From 2002 on, 67 patients with a PSA decrease during SRT were irradiated with 70.2 Gy. The influence of this selection and dose escalation on freedom from biochemical progression (bNED) was analyzed.

RESULTS

The median follow-up of the whole group was 30 months, the median pre-SRT PSA was 0.28 ng/ml. Of the patients, 27% (82/301) developed biochemical progression, 31% from the 66.6 Gy cohort (73/292) and 13% from the 70.2 Gy cohort (9/67) (p = 0.01). The calculated 2-years bNED was 74% for the whole group, 88% vs. 71% after 70.2 Gy and 66.6 Gy, respectively (p = 0.01). In a multivariate analysis, the total dose (p = 0.017), the re-achievement of an undetectable PSA after SRT (p = 0.005), and the infiltration of the seminal vesicles (p = 0.049) were independent parameters of bNED.

CONCLUSION

Our analysis suggests that patient selection during SRT for a dose escalation to 70.2 Gy can improve the freedom from biochemical progression in patients with SRT after RP.

Prostate-specific membrane antigen-based therapeutics

Prostate cancer (PC) is the most common noncutaneous malignancy affecting men in the US, leading to significant morbidity and mortality. While significant therapeutic advances have been made, available systemic therapeutic options are lacking. Prostate-specific membrane antigen (PSMA) is a highly-restricted prostate cell-surface antigen that may be targeted. While initial anti-PSMA monoclonal antibodies were suboptimal, the development of monoclonal antibodies such as J591 which are highly specific for the external domain of PSMA has allowed targeting of viable, intact prostate cancer cells. Radiolabeled J591 has demonstrated accurate and selective tumor targeting, safety, and efficacy. Ongoing studies using anti-PSMA radioimmunotherapy with ¹⁷⁷Lu-J591 seek to improve the therapeutic profile, select optimal candidates with biomarkers, combine with chemotherapy, and prevent or delay the onset of metastatic disease for men with biochemical relapse. Anti-PSMA monoclonal antibody-drug conjugates have also been developed with completed and ongoing early-phase clinical trials. As PSMA is a selective antigen that is highly overexpressed in prostate cancer, anti-PSMA-based immunotherapy has also been studied and utilized in clinical trials.

Salvage radiotherapy following biochemical relapse after radical prostatectomy: proceedings of the Genito-Urinary Radiation Oncologists of Canada consensus meeting

For patients with recurrent prostate cancer after radical prostatectomy, salvage radiotherapy is the only potentially curative treatment option. However, until recently there has been a paucity of data on the effectiveness of this approach. In light of recently published studies, the Genito-Urinary Radiation Oncologists of Canada (GUROC) met and crafted a consensus statement regarding the current place of salvage radiotherapy. GUROC also identified gaps in current knowledge and identified ongoing study protocols that will advance our knowledge in this area.This report summarizes the main conclusions of the meeting and the commentary provided during the consensus-building process, and outlines the consensus statement that was subsequently adopted.

Salvage radiotherapy for prostate-specific antigen relapse after radical prostatectomy for prostate cancer: a single-center experience

OBJECTIVE

The aim of this study was to investigate the efficacy and prognostic factors of salvage radiotherapy for prostate-specific antigen relapse after radical prostatectomy for prostate cancer at a single center in Japan.

METHODS

A retrospective review of the medical records of 51 patients who underwent salvage radiotherapy for prostate-specific antigen relapse after radical prostatectomy was carried out. Salvage radiotherapy was undergone for the single indication of at least two consecutive prostate-specific antigen elevations >0.1 ng/ml. Salvage radiotherapy was delivered to the prostatic bed at a total dose of 60 or 64 Gy. Late toxicity was scored according to the Common Terminology Criteria for Adverse Events 3.0.

RESULTS

A total dose of 60 and 64 Gy were administered to 26 and 25 patients, respectively. The median prostate-specific antigen level at the initiation of radiotherapy was 0.29 ng/ml (range, 0.11-1.10 ng/ml). With a median follow-up of 57.3 months (range, 9.9-134.0 months), the prostate-specific antigen relapse-free rate at 5 years was 50.7%. Multivariate analysis using Cox's proportional hazards regression model revealed that the Gleason score at radical prostatectomy ≥8 significantly predicted prostate-specific antigen relapse after salvage radiotherapy (hazard ratio 4.531; 95% confidence interval 1.413-14.535; P=0.011). The prostate-specific antigen relapse-free rate at 5 years in the Gleason score at radical prostatectomy ≤7 and at radical prostatectomy ≥8 was 62.7 and 15.4%, respectively.

CONCLUSIONS

Salvage radiotherapy was effective for prostate-specific antigen relapse after radical prostatectomy with tolerable toxicities in Japanese patients. A high Gleason score seemed to be a poor prognostic factor.

Treatment of men with rising prostate-specific antigen levels following radical prostatectomy

Approximately one-third of patients who undergo radical prostatectomy for prostate cancer will develop a detectable prostate-specific antigen (PSA) level within 10 years. Biochemical recurrence of disease is defined as a rising PSA level in the absence of clinical or radiographic evidence of disease. Management of PSA recurrence is controversial, as prostate cancer may take an indolent course, or it may aggressively develop into metastatic disease. The only potentially curative treatment for biochemical failure after prostatectomy is salvage radiotherapy. Noncurative treatment options include hormone therapy or clinical trials of a novel systemic agent. This article will address management options for a rising PSA level after prostatectomy, as well as ongoing studies exploring molecular biomarkers as prognostic tumor markers and potential targets for prostate cancer therapy.

Efficacy and tolerance of salvage radiotherapy after radical prostatectomy, with emphasis on high-risk patients suited for adjuvant radiotherapy

BACKGROUND AND PURPOSE

Goals of this study are to report the outcomes and tolerance of salvage radiotherapy (SRT) after prostatectomy, to identify risk factors for failure after SRT and to evaluate how these results compare with published results of immediate post-operative adjuvant radiotherapy (ART).

MATERIAL AND METHODS

Men receiving SRT for elevated PSA levels after radical prostatectomy (RP) were included. Biochemical progression-free survival (bPFS), overall survival (OS) and disease-specific survival (DSS) were estimated. Risk factors for biochemical failure and death were evaluated. Late toxicity and quality of life were evaluated. Secondary bPFS (defined as bPFS from prostatectomy until progression after radiotherapy) was calculated for high-risk patients (pT3 and/or positive surgical margins) in order to compare SRT outcomes with ART.

RESULTS

197 Men were included. Five-year bPFS after SRT was 59% (95% CI 49-69%). Five-year OS and DSS were 90% (85-96%) and 97% (93-100%), respectively. Capsular perforation (pT≥T3), negative surgical margins and serum PSA>1 ng/ml at the start of RT were significant predictors of lower bPFS. Patients without any negative factors had a 5-year bPFS of 89%. No severe late toxicity was reported. Five-year secondary bPFS for SRT in high-risk patients was 78% and comparable with published results for ART.

CONCLUSIONS

Salvage radiotherapy for patients with organ-confined prostate cancer was effective and well tolerated. SRT outcomes were comparable with published ART results for high-risk patients. Initially monitoring serum PSA and considering early SRT for these patients are not harmful and might be a valuable alternative for immediate ART.

PET/CT Imaging and Radioimmunotherapy of Prostate Cancer

Prostate cancer is a common cancer in men and continues to be a major health problem. Imaging plays an important role in the clinical management of patients with prostate cancer. An important goal for prostate cancer imaging is more accurate disease characterization through the synthesis of anatomic, functional, and molecular imaging information. Positron emission tomography (PET)/computed tomography (CT) in oncology is emerging as an important imaging tool. The most common radiotracer for PET/CT in oncology, (18)F-fluorodeoxyglucose (FDG), is not very useful in the imaging of prostate cancer. However, in recent years other PET tracers have improved the accuracy of PET/CT imaging of prostate cancer. Among these, choline labeled with (18)F or (11)C, (11)C-acetate, and (18)F-fluoride has demonstrated promising results, and other new radiopharmaceuticals are under development and evaluation in preclinical and clinical studies. Large prospective clinical PET/CT trials are needed to establish the role of PET/CT in prostate cancer patients. Because there are only limited available therapeutic options for patients with advanced metastatic prostate cancer, there is an urgent need for the development of more effective treatment modalities that could improve outcome. Prostate cancer represents an attractive target for radioimmunotherapy (RIT) for several reasons, including pattern of metastatic spread (lymph nodes and bone marrow, sites with good access to circulating antibodies) and small volume disease (ideal for antigen access and antibody delivery). Furthermore, prostate cancer is also radiation sensitive. Prostate-specific membrane antigen is expressed by virtually all prostate cancers, and represents an attractive target for RIT. Antiprostate-specific membrane antigen RIT demonstrates antitumor activity and is well tolerated. Clinical trials are underway to further improve upon treatment efficacy and patient selection. This review focuses on the recent advances of clinical PET/CT imaging and RIT of prostate cancer.

A matched control analysis of adjuvant and salvage high-dose postoperative intensity-modulated radiotherapy for prostate cancer

PURPOSE

It is unclear whether immediate adjuvant radiotherapy for high-risk disease at prostatectomy (capsule perforation, seminal vesicle invasion, and/or positive surgical margins) is equivalent to delayed salvage radiotherapy at biochemical recurrence. We performed a matched case analysis comparing high-dose adjuvant intensity modulated radiotherapy (A-IMRT) with salvage IMRT (S-IMRT).

METHODS AND MATERIALS

One hundred forty-four patients with high-risk disease at prostatectomy were referred for A-IMRT, and 134 patients with high-risk disease were referred at biochemical recurrence (rising prostate-specific antigen [PSA], following prostatectomy, above 0.2 ng/ml) for S-IMRT. Patients were matched in a 1:1 ratio according to preoperative PSA level, Gleason score, and pT stage. Median doses of 74 Gy and 76 Gy were prescribed for A-IMRT and S-IMRT, respectively. We report biochemical relapse free survival (bRFS) rates using the Kaplan-Meier method. Univariate and multivariate analyses were used to examine tumour- and treatment-related factors.

RESULTS

A total of 178 patients were matched (89:89). From the end of radiotherapy, the median follow-up was 36 months for both groups. The 3-year bRFS rate for the A-IMRT group was 90% compared to 65% for the S-IMRT group (p < 0.05). On multivariate analysis, S-IMRT, Gleason grades of ≥ 4+3, perineural invasion, preoperative PSA level of ≥ 10 ng/ml, and omission of androgen deprivation (AD) were independent predictors for a reduced bRFS (p < 0.05). From the date of surgery, the median follow-up was 43 and 60 months for A-IMRT and S-IMRT, respectively. The 3-year bRFS rate for A-IMRT was 91% compared to 79% for S-IMRT (p < 0.05). On multivariate analysis, Gleason grades of ≥ 4+3, perineural invasion, and omission of AD were independent predictors for a reduced bRFS (p < 0.05). S-IMRT was no longer an independent prognostic factor (p = 0.08).

CONCLUSIONS

High-dose A-IMRT significantly improves 3-year bRFS compared to S-IMRT. Gleason grades of ≥ 4+3, perineural invasion, and omission of AD were independent prognostic factors for a decreased bRFS, both from the dates of surgery and from radiotherapy.

Long-term follow-up and risk of cancer death after radiation for post-prostatectomy rising prostate-specific antigen

PURPOSE

The results of salvage radiation therapy for rising prostate-specific antigen (PSA) levels after radical prostatectomy appear favorable, but the ultimate outcome is uncertain, given the relatively short follow-up in most studies. We report on a group of patients at a median follow-up of 13.9 years after salvage radiation therapy.

METHODS AND MATERIALS

From 1990 to 1995, 92 patients were referred postoperatively for radiation for a rising PSA level. PSA level at the time of referral ranged from 0.1 to 30.5 ng/ml (median, 1.5 ng/ml). The median time from surgery to radiation was 2.1 years (range,, 0.3-7.4 years). Radiation was directed to the prostatic fossa only with a median dose of 6,500 cGy (range, 6,000-7,000 cGy).

RESULTS

Eighty-five patients experienced a PSA drop after radiation, as predicted by Gleason score and PSA level at the start of radiation. Five- and 10-year biochemical failure free survival (BFFS) was 35% and 26%, respectively, and overall survival was 86% and 67%, respectively. Median survival was 12.0 years, and median BFF was 2.3 years. The presurgery PSA level was not predictive, but the PSA level at the start of radiation predicted a response. Patients with Gleason 8 to 9 cancers had a significantly higher progression rate than those with lower Gleason scores. There were no significant differences in outcomes based on pathology findings (none vs. positive margins vs. positive seminal vesicles). Overall, 22 (24%) patients died directly from prostate cancer, resulting in a 10-year cancer-specific survival rate of 82%. Multivariate analysis risk factors for dying of cancer were Gleason's score (8 to 9) and PSA at the start of radiation therapy (>1.0 ng/ml).

CONCLUSIONS

Patients have a good response to salvage radiation therapy. A small but durable subgroup appears to have permanent control. In those for whom therapy fails, radiation delays the need for other salvage therapy, indicating at least a transient benefit to most patients.

Anti-prostate-specific membrane antigen-based radioimmunotherapy for prostate cancer

Despite recent advances, advanced prostate cancer is suboptimally responsive to current chemotherapeutic agents. Radiolabeled monoclonal antibody therapy that targets prostate-specific membrane antigen (PSMA) shows promise and is an area of active investigation. J591 is a deimmunized IgG monoclonal antibody developed to target the extracellular domain of PSMA. Preclinical and early phase clinical studies using radiolabeled J591 have demonstrated efficacy in targeting tumor cells and decreasing levels of prostate-specific antigen. Radiolabeled J591 is well-tolerated, nonimmunogenic, and can be administered in multiple doses. The dose-limiting toxicity is reversible myelosuppression with little nonhematologic toxicity. Future studies will include approaches to optimize patient selection and incorporate novel strategies to improve the success of anti-PSMA radioimmunotherapy.

Salvage radiotherapy for patients with PSA relapse following radical prostatectomy: issues and challenges

A progressively rising level of serum prostate specific antigen (PSA) after radical prostatectomy (RP) invariably indicates the recurrence of prostate cancer. The optimal management of patients with post-RP PSA relapse has remained uncertain due to a wide variability in the natural course of post-RP PSA relapse and the inability to separate a recurrent disease confined to the prostate bed from that with occult distant metastasis. Management uncertainty is further compounded by the lack of phase III clinical studies demonstrating which therapeutic approach, if any, would prolong life with no significant morbidity. Radiotherapy has been the main therapeutic modality with a curative potential for patients with post-RP PSA relapse. This review article depicts issues and challenges in the management of patients with post-RP PSA relapse, presents the literature data for the efficacy of salvage radiotherapy, either alone or in combination of androgen ablation therapy, and discusses future directions that can optimize treatment strategies.

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.

Achieving an undetectable PSA after radiotherapy for biochemical progression after radical prostatectomy is an independent predictor of biochemical outcome--results of a retrospective study

PURPOSE

Salvage radiotherapy (SRT) is commonly used to treat patients with biochemical failure after radical prostatectomy (RP). Retrospective series have demonstrated biochemical response in approximately 60-75% of patients, but only a significantly lower rate of patients achieves a response with a decrease of the prostate-specific antigen (PSA) to a value below the limits of detectability. Therefore, long-term response at 10 years is only about 20-25% in all of these patients. The purpose of this study was to determine prognostic factors with impact on achieving the undetectable PSA range after SRT and to define the role of this end point.

METHODS AND MATERIALS

Between 1997 and 2004, 162 patients received SRT at the Charité Universitätsmedizin, Berlin. No patient had hormonal treatment before SRT and 90% of the patients (143) had a SRT dose of 66 Gy. We analyzed the impact of nine potential risk factors on achieving an undetectable PSA after RT and on biochemical relapse-free survival (bNED) after SRT.

RESULTS

Median follow-up time was 41.5 months and median PSA pre-RT was 0.33 ng/mL. Calculated bNED for 3.5 years was 54%. A total of 60% of the patients achieved an undetectable PSA after SRT. Univariate analysis demonstrated statistically significant predictors of biochemical progression after SRT: Gleason score (p = 0.01), PSA pre-SRT (p = 0.031), tumor stage (p = 0.047), and persistent detectable PSA after RT (p < 0.00005). In multivariate analysis, margin status (p = 0.017) and PSA pre-SRT (p = 0.002) were significant predictors of an undetectable PSA after SRT. The most significant independent predictor of bNED was "PSA undetectable after RT" (p < 0.0005) with a hazard ratio of 8.4, thus leading to a calculated bNED at 3.5 years of 75% compared with only 18% for those patients, who did not achieve an undetectable PSA after SRT. The rate of severe Grade 3-4 side effects was below 2.5%.

CONCLUSIONS

The study represents one of the largest retrospective single-institution series of SRT for increasing PSA after RP in patients without any hormonal treatment before the initiation of SRT. Our findings suggest that achieving an undetectable PSA after RT is an important prognosticator for a high chance of cure and patients with a low PSA pre-SRT, positive surgical margins, and low tumor stage at the time of RP are best candidates for SRT.

[pT3R1 prostate cancer : Immediate or delayed radiotherapy after radical prostatectomy?]

Approximately 50-60% of patients with tumor stage pT3R1 after radical prostatectomy (RP) who do not receive adjuvant therapy develop biochemical progression. At present it is unclear whether these patients should undergo immediate adjuvant irradiation or whether a wait and see approach should be adopted while monitoring PSA until the PSA level rises from zero and then initiate salvage radiotherapy (SRT).Three randomized trials showed that an absolute improvement of 20% in the 5-year biochemical no evidence of disease (bNED) could be achieved by administering adjuvant radiotherapy with 60 Gy in patients with tumor stage pT3R1, even with a PSA level around zero after RP. The rate of serious late effects is low. On the other hand, there are numerous, albeit retrospective studies, which provide evidence that SRT after an increase in PSA above zero is an effective treatment, but with higher total doses of 66-70 Gy and a higher rate of late effects. Prognostic factors such as the PSA level before radiotherapy is started, PSA doubling time, R1 resection, PSA velocity, and the Gleason score have a significant impact on both the return of the PSA level to zero and the bNED. Depending on the risk factor, between 20 and 70% of patients again achieve PSA levels around zero after SRT. Retrospective comparative studies suggest a benefit of adjuvant radiotherapy; prospective randomized trials do not exist.Adjuvant radiotherapy after RP in stage pT3R1 tumor and SRT in cases of PSA rising above zero or persistent PSA levels are valid options for the management of high-risk patients after RP. SRT requires higher total doses and thus carries a higher risk of late complications. A benefit has been demonstrated for bNED, but not for survival. The approach should be discussed with the individual patient.

Prostate-specific antigen doubling time is a reliable predictor of imageable metastases in men with biochemical recurrence after radical retropubic prostatectomy

OBJECTIVES

To examine the incidence of imageable metastases at the time of biochemical recurrence after radical prostatectomy and to determine whether prostate-specific antigen doubling time (PSADT) reliably predicts these imageable metastases.

METHODS

Between October 2000 and October 2005, 1112 men underwent open radical retropubic prostatectomy by a single surgeon. All men were advised to undergo bone scintigraphy and an abdominal/pelvic imaging study at the time of biochemical recurrence. We ascertained the sensitivity, specificity, and positive and negative predictive values of a PSADT cut-point of 3 months to predict the presence of imageable metastases.

RESULTS

Seventy-four (6.7%) men developed a biochemical recurrence and imageable metastases were demonstrable in 7 cases. Imageable metastases were identified in 11.3% and 7.5% of men undergoing bone scans and abdominal/pelvic imaging, respectively. Extracapsular extension, and older age positive surgical margins, and PSADT were associated with a significantly greater risk of exhibiting imageable metastases. The sensitivity, specificity, and positive and negative predictive values of a PSADT cut-point of 3 months for predicting imageable metastasis were 100%, 98.0%, 87.5%, and 100%, respectively.

CONCLUSIONS

A relatively small proportion of men at the time of developing biochemical recurrence after radical prostatectomy exhibit imageable metastasis. The 100% sensitivity and negative predictive value of a PSADT cut-point of 3 months strongly suggests that PSADT can be used as an excellent proxy for imageable metastasis. Omitting routine bone scintigraphy and body imaging at the time of biochemical recurrence minimizes the costs, inconvenience, and anxiety associated with these studies.

[PSA and follow-up after treatment of prostate cancer]

A first serum total PSA assay is recommended during the first three months after treatment. When PSA is detectable, PSA assay should be repeated three months later to confirm this elevation and to estimate the PSA doubling time (PSADT). In the absence of residual cancer, PSA becomes undetectable by the first month after total prostatectomy: less than 0.1 ng/ml (or less than 0.07 ng/ml) for the ultrasensitive assay method and less than 0.2 ng/ml for the other methods. In the presence of residual cancer, PSA either does not become undetectable or increases after an initial undetectable period. A consensus has been reached to define recurrence as PSA greater than 0.2 ng/ml confirmed on two successive assays. After external beam radiotherapy, PSA can decrease after a mean interval of one to two years to a value less than 1 ng/ml (predictive of recurrence-free survival). Biochemical recurrence after radiotherapy is defined by an increase of PSA by 2 ng or more above the PSA nadir, whether or not it is associated with endocrine therapy. After endocrine therapy, the PSA nadir is correlated with recurrence-free survival. PSA is decreased for a mean of 18 to 24 months followed by a rise in PSA, corresponding to hormone-independence. The time to recurrence or the time to reach the nadir and the PSA doubling time after local therapy with surgery or radiotherapy have a diagnostic value in terms of the site of recurrence, local or metastatic and a prognostic value for survival and response to complementary radiotherapy or endocrine therapy. A PSADT less than eight to 12 months is correlated with a high risk of metastatic recurrence and 10-year mortality. The histological and biochemical characteristics in favour of local recurrence are Gleason score less or equal to seven (3+4), elevation of PSA after a period greater than 12 months and PSADT greater than 10 months. In other cases, recurrence is predominantly metastatic. The risk of demonstrating metastasis in the case of biochemical recurrence after total prostatectomy and before endocrine therapy depends on the PSA level and the PSADT. No consensus has been reached concerning the indication for complementary investigations by bone scan and abdominopelvic CT in patients with biochemical recurrence after treatment of localized cancer without endocrine therapy. However, when PSADT greater than six months, the risk of metastasis is less than 3% even for PSA greater than 30 ng/ml. When PSADT less than six months and PSA greater than 10 ng/ml, the risk of metastasis is close to 50%.

Prostate specific antigen nadir determined using ultra-sensitive prostate specific antigen as a predictor of biochemical progression after radical prostatectomy in Japanese males

OBJECTIVES

We examined whether the prostate specific antigen (PSA) nadir is a good predictor of biochemical failure after radical prostatectomy.

METHODS

We retrospectively reviewed clinico-pathological data in 257 patients who underwent radical prostatectomy. Twenty-nine patients of whom PSA nadir did not reach 0.1 ng/mL and three patients in whom second line therapy was started before biochemical failure were excluded, and 225 patients were subject to this study. We evaluated the changes in PSA value at very low (from less than 0.01-0.10 ng/mL) levels using an ultra-sensitive PSA assay after radical prostatectomy. Biochemical failure was defined as three consecutive elevations of PSA to above 0.1 ng/mL.

RESULTS

Biochemical failure-free survival was attained by 89.9% of patients at 1 year, 83.0% at 2 years, and 81.0% at 5 years. PSA nadir more than 0.01 ng/mL was strongly associated with biochemical failure after radical prostatectomy (P < 0.0001). Mean time to reach PSA nadir was 3.1 months. Preoperative PSA > 20 ng/mL (P = 0.0013), clinical T stage = T2 (P = 0.0462), Gleason score 8-10 (P = 0.0243) were also independent predictors of biochemical progression.

CONCLUSIONS

Prostate specific antigen nadir determined by ultra-sensitive PSA assay is an important parameter that is objective, reliable, and easily measured, and useful for predicting the subgroups of patients both most likely and unlikely to exhibit biochemical progression.

Prostate specific antigen recurrence after definitive therapy

PURPOSE

We estimate that approximately 70,000 men yearly have prostate specific antigen-only recurrence after failed definitive therapy. The ideal salvage therapy for these men is not clear. Treatment must be individualized based on the patient risk of progression, the likelihood of success and the risks involved with the therapy. However, to do so the risks and benefits of the various options must be known. Therefore, we provide a comprehensive overview of the natural history and treatment options for men with prostate specific antigen-only recurrence.

MATERIALS AND METHODS

A literature review and overview of prostate specific antigen-only recurrence after failed definitive therapy was done.

RESULTS

The natural history after prostate specific antigen-only recurrence is long but variable. Median time from prostate specific antigen-only recurrence after radical prostatectomy to prostate cancer death exceeds 16 years, although some men die within 1 year after PSA recurrence. Rapid prostate specific antigen doubling time is the best prognostic factor for poor outcome. Salvage radiation therapy after radical prostatectomy results in a 45% 4-year prostate specific antigen response rate, although long-term outcomes appear poor. To our knowledge the effect on survival is not known. Salvage radical prostatectomy is rarely performed but in the highly selected patient it may provide some benefit. There are no randomized studies of early vs late hormonal therapy for men with prostate specific antigen-only recurrence. A retrospective study suggested delayed metastasis when therapy was begun early but only in men at high risk. This mirrors other data suggesting that men at high risk may derive significant benefits from early hormonal therapy, whereas men at low risk are unlikely to benefit and may be harmed by hormonal therapy.

CONCLUSIONS

Prostate specific antigen-only recurrence is the most common form of advanced prostate cancer. Optimal salvage treatments and timing of these treatments remain controversial.

[Prevention of local recurrence using adjuvant radiotherapy after radical prostatectomy. Indications, results, and side effects]

Depending on the tumor stage, 15-60% of patients develop a rise in PSA from levels around zero following radical prostatectomy. It is unclear whether this involves a local, systemic, or a mixed form of local/systemic progression. In addition to a multitude of retrospective studies, the results of three randomized trials are available that have already been published in full or in abstract form. For pT3 prostate cancer with extraprostatic extension, data are available from three randomized trials that consistently evidence an absolute decrease in biochemical progression rate of 20% after 4-5 years. These findings confirm the results of numerous retrospective studies. The large majority of authors employ total radiation doses of 60 Gy with single doses of 2 Gy. One randomized trial has shown that an increased local control rate is the basis for prolonged biochemical progression-free survival. The rate of acute and late radiation sequelae after three-dimensionally planned prostatic fossa radiotherapy (RT) with 60 Gy is very low; the rate of more severe late sequelae is <2%. Data on the status of pT2 prostate cancer with positive surgical margins are worse. The current findings are controversial and require further investigations. Basically, however, adjuvant RT is also possible for pT2 cancers with positive surgical margins. The efficacy of adjuvant RT for patients with positive surgical margins of pT3 carcinomas, whether or not they achieve PSA levels around zero, has been substantiated. A prolongation of survival time has, however, not yet been established because the follow-up period is too short. Randomized trials are still needed for cases of organ-confined prostate cancer (pT2 R1). It is unclear whether adjuvant RT is superior to RT when PSA levels increase beyond zero after radical prostatectomy. Randomized trials addressing this issue are still lacking.

Adjuvant Radiotherapy after Radical Prostatectomy: Indications, Results and Side Effects

BACKGROUND

Within 5 years following radical prostatectomy, between 15 and 60% of patients with pT3 prostate carcinomas show an increasing prostate-specific antigen (PSA) level as a sign of local and/or systemic tumor progression. Apart from a large number of retrospective investigations, available results are present only from three randomized studies which have either been completely published or are only in abstract form.

RESULTS

For pT3 prostate carcinomas the data from the three randomized studies agree, showing an around 20% reduced biochemical progression rate after 4-5 years. With these data the results of numerous retrospective studies have been confirmed. The majority of the authors use total doses of 60 Gy with single doses of 2 Gy. From one randomized study an increased local control rate is proposed as the basis for the extended freedom from biochemical progression. The rate of acute and late side effects after three-dimensional radiotherapy with 60 Gy is very small and the rate of severe side effects is below 2%. The data for pT2 prostate carcinomas with positive margins are worse. Here controversy exists, and further investigations are required. In principle, however, adjuvant radiotherapy seems reasonable also for pT2 carcinomas with positive margins (determined by bNED - no biochemical evidence of disease).

CONCLUSIONS

The effectiveness of adjuvant radiotherapy for patients with pT3 tumors and positive margins with and without detectable PSA levels is discussed. A survival advantage has not been demonstrated to date. For patients with positive margins in organ-limited prostate carcinomas (pT2 R1) randomized studies are recommended. It is unclear whether adjuvant radiotherapy is superior to radiotherapy for PSA levels increasing from the undetectable range after radical prostatectomy. To answer this question randomized studies are needed.