Report of the third Asian Prostate Cancer study meeting

The Asian Prostate Cancer (A-CaP) study is an Asia-wide initiative that was launched in December 2015 in Tokyo, Japan, with the objective of surveying information about patients who have received a histopathological diagnosis of prostate cancer (PCa) and are undergoing treatment and clarifying distribution of staging, the actual status of treatment choices, and treatment outcomes. The study aims to clarify the clinical situation for PCa in Asia and use the outcomes for the purposes of international comparison. Following the first meeting in Tokyo in December 2015, the second A-CaP meeting was held in Seoul, Korea, in September 2016. This, the third A-CaP meeting, was held on October 14, 2017, in Chiang Mai, Thailand, with the participation of members and collaborators from 12 countries and regions. In the meeting, participating countries and regions presented the current status of data collection, and the A-CaP office presented a preliminary analysis of the registered cases received from each country and region. Participants discussed ongoing challenges relating to data input and collection, institutional, and legislative issues that may present barriers to data sharing, and the outlook for further patient registrations through to the end of the registration period in December 2018. In addition to A-CaP-specific discussions, a series of special lectures were also delivered on the situation for health insurance in the United States, the correlation between insurance coverage and PCa outcomes, and the outlook for robotic surgery in the Asia-Pacific region. Members also confirmed the principles of authorship in collaborative studies, with a view to publishing original articles based on A-CaP data in the future.

Gemigliptin, a novel dipeptidyl peptidase-IV inhibitor, exerts a synergistic cytotoxicity with the histone deacetylase inhibitor PXD101 in thyroid carcinoma cells

PURPOSE

The influence of the dipeptidyl peptidase-IV inhibitor gemigliptin alone or in combination with the histone deacetylase inhibitor PXD101 on survival of thyroid carcinoma cells was investigated.

METHODS

SW1736, TPC-1, 8505C and BCPAP human thyroid carcinoma cells were used. To assess cell survival, cell viability, the percentage of viable cells and dead cells, cytotoxic activity, ATP levels and FACS analysis were measured. To validate the impact of gemigliptin combined with PXD101, the interactions were estimated by obtaining combination index in cells treated with two agents.

RESULTS

In cells treated with gemigliptin or PXD101, cell viability, the percentage of viable cells and ATP levels were reduced, and the percentage of dead cells and cytotoxic activity were elevated. In cells treated with both gemigliptin and PXD101, compared with PXD101 alone, cell death was augmented, and all of the combination index values were lower than 1.0, suggesting the synergism between gemigliptin and PXD101. The percentage of apoptotic cells, and the protein levels of Bcl2 and cleaved poly (ADP-ribose) polymerase were elevated, and the protein levels of xIAP and survivin were reduced. The protein levels of phospho-Akt and phospho-AMPK were elevated, and cell migration was reduced.

CONCLUSIONS

Our results demonstrate that gemigliptin induces cytotoxicity in thyroid carcinoma cells. Moreover, gemigliptin has a synergistic activity with PXD101 in the induction of cell death through involvement of Bcl2 family proteins, xIAP and survivin as well as mediation of Akt and AMPK in thyroid carcinoma cells.

Declining incidence of benign lesions among small renal masses treated with surgery: Effect of diagnostic tests for characterization

PURPOSE

We evaluated the changes in the incidence of benign lesions in surgically removed small renal masses (SRMs) and the effect of diagnostic tests for characterizing SRMs.

METHODS

We included 2,707 patients receiving surgery for SRMs (<4cm). Trends in the incidence of benign histology were evaluated according to the surgery year (period 1: 2001-2005, 2: 2006-2010, and 3: 2011-2015). Multivariable logistic regression analysis was performed to identify factors associated with benign lesions. Additionally, the number of surgeries prevented due to benign histological findings on renal mass biopsies (RMB) done on 206 patients with SRM during study period was evaluated.

RESULTS

Benign histology was identified in 192 (7.1%) patients. Incidence of benign histology was 9.7%, 7.0%, and 6.3% for period 1, 2 and 3, respectively. The uses of multiphase computed tomography and magnetic resonance imaging were more common in periods 2 and 3 than in period 1 (P<0.001). The use of RMB in period 3 was higher than in periods 1 and 2 (0.8 vs. 0.9 vs. 9.0%, P<0.001). In multivariable analysis, older age, male sex, larger tumor size, and recent surgery year (period 3 vs. 1, odds ratio = 0.62, P = 0.028) were independently associated with decreased odds of benign lesions. The number of prevented surgeries by performing RMB was 0, 10, and 39 in periods 1, 2, and 3, respectively.

CONCLUSIONS

Incidence of benign histology after surgery for SRMs declined during recent years, which might be associated with the recent increased use of RMB.

Two-dimensional plasmonic grating for increased quantum efficiency in midwave infrared nBn detectors with thin absorbers

We demonstrate a strategy for increasing the operating temperatures of nBn midwave infrared (MWIR) focal plane arrays, based on the use of two-dimensional plasmonic gratings to enhance the quantum efficiency (QE) of structures with very thin absorbers. Reducing the absorber volume correspondingly reduces the dark current in a diffusion-limited photodiode, while light trapping mediated by the plasmonic grating increases the net absorbance to maintain high QE. The plasmonically enhanced nBn MWIR sensors with absorber thicknesses of only 0.5 μm exhibit peak internal QEs as high as 57%, which enables a 5-fold reduction in dark current. Numerical simulations indicate the potential for further improvement.

Induction of immunoglobulin transcription factor 2 and resistance to MEK inhibitor in melanoma cells

Primary or acquired resistance to MEK inhibitors has been a barrier to successful treatment with MEK inhibitors in many tumors. In this study, we analyzed genome-wide gene expression profiling data from 6 sensitive and 6 resistant cell lines to identify candidate genes whose expression changes are associated with responses to a MEK inhibitor, selumetinib (AZD6244). Of 62 identified differentially expressed genes, we selected Immunoglobulin Transcription Factor 2, also known as transcription factor 4 as a potential drug resistance marker for further analysis. This was because the ITF-2 expression increase in resistant cell lines was relatively high and a previous study has suggested that ITF-2 functions as an oncogene in human colon cancers. We also established an AZD6244 resistant cell line (M14/AZD-3) from an AZD6244 sensitive M14 cell line. The expression of the ITF-2 was elevated both in primary AZD6244 resistant cell line, LOX-IMVI and acquired resistant cell line, M14/AZD-3. Targeted silencing of ITF-2 by siRNA significantly enhanced susceptibility to AZD6244 in resistant cells. Wnt/β-catenin pathway was activated through direct interaction of p-ERK and GSK3β. Our results suggest that up-regulation of the ITF-2 gene expression is associated with cellular resistance to MEK inhibitors, and activation of Wnt signaling pathway through interaction of p-ERK and GSK3β seems to be a mechanism for increase of ITF-2.

Stereotactic body-radiotherapy boost dose of 18 Gy vs 21 Gy in combination with androgen-deprivation therapy and whole-pelvic radiotherapy for intermediate- or high-risk prostate cancer: a study protocol for a randomized controlled, pilot trial

Background

Combination therapy using external-beam radiotherapy (EBRT) with a brachytherapy boost has demonstrated superior biochemical control than dose-escalated EBRT alone. Whereas brachytherapy is disadvantageous because it is an invasive procedure, stereotactic body-radiotherapy (SBRT) using CyberKnife could emulate the dose distribution of brachytherapy and is a non-invasive and safe modality to control intra-fractional movement. We therefore adopted SBRT using CyberKnife as a boost therapy after whole-pelvic radiotherapy (WPRT).

Methods/design

In this prospective, randomized, single-center, pilot study for intermediate- and high-risk prostate cancer without nodal or distant metastasis, after androgen-deprivation therapy and WPRT, patients will be randomized to one of two SBRT boost regimens, i.e., 18 or 21 Gy administered in three fractions every other day.

Discussion

The aim of this trial is to evaluate acute toxicities using both physician- and patient-reported outcomes and short-term biochemical control with SBRT boost following WPRT. Additionally, chronic toxicities and long-term biochemical control will be evaluated as secondary endpoints in this trial. Based on the generated results, we will plan the full-scale phase II study for selecting the SBRT boost dose.

Trial registration

ClinicalTrials.gov, ID; NCT03322020. Retrospectively registered on 26 October 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2574-y) contains supplementary material, which is available to authorized users.

Perisomatic changes in h-channels regulate depressive behaviors following chronic unpredictable stress

Chronic stress can be a precipitating factor in the onset of depression. Lentiviral-mediated knockdown of HCN1 protein expression and reduction of functional I_h produce antidepressant behavior. However, whether h-channels are altered in an animal model of depression is not known. We found that perisomatic HCN1 protein expression and I_h-sensitive physiological measurements were significantly increased in dorsal but not in ventral CA1 region/neurons following chronic unpredictable stress (CUS), a widely accepted model for major depressive disorder. Cell-attached patch clamp recordings confirmed that perisomatic I_h was increased in dorsal CA1 neurons following CUS. Furthermore, when dorsal CA1 I_h was reduced by shRNA-HCN1, the CUS-induced behavioral deficits were prevented. Finally, rats infused in the dorsal CA1 region with thapsigargin, an irreversible inhibitor of the SERCA pump, exhibited anxiogenic-like behaviors and increased I_h, similar to that observed following CUS. Our results suggest that CUS, but not acute stress, leads to an increase in perisomatic I_h in dorsal CA1 neurons and that HCN channels represent a potential target for the treatment of major depressive disorder.

Evaluation of abundance of artificial radionuclides in food products in South Korea and sources

Food samples are collected nationwide from January 2016 to February 2017 and their contents of artificial radionuclides are measured to address the growing concerns regarding the radioactive contamination of food products in Korea. Specifically, 900 food samples are collected for this study and their contents of representative artificial radionuclides ¹³⁴Cs, ¹³⁷Cs, ^239,240Pu, and ⁹⁰Sr are analyzed. The analysis shows that the activity concentrations of ¹³⁷Cs in fish range from minimum detectable activity (MDA) to 340 mBq/kg of fresh weight. The concentration factor (CF) determined for ¹³⁷Cs as a measure of its bioavailability is calculated to be ca. 74 and found to be very similar to that (100) recommended by the International Atomic Energy Agency. With an MDA of <0.221 mBq/kg, the results reveal that ^239,240Pu values in fish are below the MDA. The activity concentrations of ¹³⁷Cs and ⁹⁰Sr are lower than the MDA in both shellfish and seaweed, while the activity concentrations of ^239,240Pu in shellfish range from 0.26 to 2.18 mBq/kg, and for seaweed samples range from 2.07 to 3.38 mBq/kg. The atom ratios of ²⁴⁰Pu/²³⁹Pu in shellfish caught at the Korean coast vary from 0.209 to 0.237, with a mean of 0.227. The higher ²⁴⁰Pu/²³⁹Pu atom ratio determined in shellfish is thought to be caused by the plutonium transported from the Pacific Proving Grounds rather than other sources such as the Fukushima nuclear power plant accident. The activity concentrations of ¹³⁷Cs in mushrooms are found to vary from 1.0 to 21.4 Bq/kg, with the highest concentrations observed in the Oak (shiitake) and Sarcodon asparatus. ¹³⁴Cs is detected in three mushroom specimens collected from Jeju Island and about 3-3.6% of ¹³⁷Cs present in the wild mushrooms native to the Jeju Island are introduced as a result of the Fukushima nuclear plant accident. The annual effective doses of ¹³⁷Cs received through consumption of mushrooms and fish are 2.0 × 10^-4 mSv yr^-1 and 3.9 × 10^-5 mSv yr^-1, and those values are negligible compared to the annual effective doses limit of 1 mSv yr^-1.

The Ability of Human Nasal Inferior Turbinate-Derived Mesenchymal Stem Cells to Repair Vocal Fold Injuries

Objective This study investigated the ability of implanted human nasal inferior turbinate-derived mesenchymal stem cells (hTMSCs) to repair injured vocal folds. To this end, we used quantitative real-time polymerase chain reaction (PCR) to analyze the early phase of wound healing and histopathological analysis to explore the late phase of wound healing in xenograft animal models. Study Design Prospective animal study. Setting Research laboratory. Subjects and Methods The right-side lamina propria of the vocal fold was injured in 20 rabbits and 30 rats. Next, hTMSCs were implanted into half of the injured vocal folds (hTMSC groups). As a control, phosphate-buffered saline (PBS) was injected into the other half of the injured vocal folds (PBS groups). Rat vocal folds were harvested for polymerase chain reaction (PCR) at 1 week after injury. Rabbit vocal folds were evaluated endoscopically and the larynges harvested for histological and immunohistochemical examination at 2 and 8 weeks after injury. Results In the hTMSC group, PCR showed that hyaluronan synthase ( HAS) 1, HAS 2, and transforming growth factor ( TGF)-β1 were significantly upregulated compared with the PBS group. Procollagen type III ( COL III) messenger RNA expression was significantly upregulated in the PBS group compared with the normal group. Histological analyses showed that hTMSC administration afforded more favorable collagen and hyaluronic acid deposition than was evident in the controls. Implanted hTMSCs were observed in injured vocal folds 2 weeks after implantation. Conclusions Our results show that hTMSCs implantation into injured vocal folds facilitated vocal fold regeneration, with presenting antifibrotic effects.

Androgen deprivation therapy during and after post-prostatectomy radiotherapy in patients with prostate cancer: a case control study

Background

Here we assessed the influence of androgen deprivation therapy (ADT) during and/or after post-prostatectomy radiotherapy (RT) on biochemical recurrence (BCR) and radiographic progression in patients with prostate cancer.

Methods

Patients with prostate cancer who underwent post-prostatectomy RT were analyzed. BCR and radiographic progression after RT were compared according to the concurrent or salvage ADT. Cox regression analyses were used to identify risk factors for BCR and radiographic progression.

Results

Of the 227 patients who underwent post-prostatectomy RT, 95 (41.9%) received concurrent ADT for a median of 17.0 months. Despite more aggressive disease characteristics in the concurrent ADT group than in the RT-only group, the former had a better 5-year BCR-free survival rate than the latter (66.1 vs. 53.9%; p = 0.016), whereas the radiographic progression rate was not significantly different between two groups. On the other hand, salvage ADT after post-RT BCR significantly delayed radiographic progression (5-year radiographic progression-free survival; 75.2 vs. 44.5%; p = 0.002).

Conclusions

Concurrent ADT improved BCR-free survival, and salvage ADT after post-RT BCR improved radiographic progression-free survival. To maximize the oncological benefit, ADT of sufficient duration should be implemented.

Preclinical efficacy of dendritic cells derived from bone marrow hematopoietic stem cells for the treatment of syngeneic prostate cancer immune cell therapy

361

Background: PCas are characterized by a primary androgen dependent stage, during which growth is promoted by androgen and suppressed by androgen deprivation or blockade, with even metastatic disease being promptly susceptible to hormonal manipulation; however, despite initial success, androgen deprivation therapy eventually fails because of the development of CRPC. Despite the approval of new clinical trials such as docetaxel, enzalutamide and sipuleucel-T, which is a cell therapy drug, the clinical efficacy is limited. Therefore, there is a desperate need for the limited effectiveness of treatment in an aging society and the development of successful treatments for patients who fail treatment. In this study, we investigated the anticancer effect of prostate cancer using anti-cancer immunity cell vaccine based on the next generation dendritic cell immunotherapy. Methods: FACS and ELISA were performed with stem-DC to analyze phenotype and cytokine expression. To quantify the effect on the tumor growth, we constructed a TRAMP-C1 model and observed for safety, efficacy and induction of antigen-specific immune responses. And we also analyzed proliferation and activation of allogeneic-T cells by therapeutic dendritic cells. Results: From the stem-DC, immune-stimulatory cytokine IL-12 and interferone-gamma was measured higher level than monocyte derived DC (Mo-DC). A DC marker CD11c+CD8a+ cell was higher expression in stem-DC than Mo-DC. After DC injection, tumor size was reduced in stem-DC compared to Mono-DC and vehicle group in TRAMP model. To confirm stem-DC/lysate induce more systemic anti-tumor immunity than Mo-DC/lysate, we checked effector T cells in splenic lymphocytes from prostate cancer bearing mice. The frequency of IFN-γ secreting CD8+ T cells in stem-DC treated group was significantly higher than that in Mo-DC treated group. It shows that the therapeutic responses were associated with induction of IFN-γ secreting CD8+ T cells. Conclusions: Stem-DC, which was developed from hematopoietic stem cells in an optimized manner, proved to be effective and stable as an excellent anti-cancer immunotherapeutic agent for prostate cancer.

Incidence and Dose-volume Analysis of Acute Bladder Toxicity following Pelvic Radiotherapy

Aims and Background

The authors performed this prospective study to evaluate the incidence of acute bladder toxicity following pelvic radiation therapy and to determine any dosimetric predictors for the toxicity.

Methods and Study Design

Acute bladder toxicity was evaluated weekly by physicians using the Common Terminology Criteria for Adverse Events (CTCAE version 4.0). At the same time, the International Prostate Symptom Score (IPSS) and Overactive Bladder Symptom Score (OABSS) were also assessed by each patient during radiation therapy. We contoured the bladder wall, solid bladder and trigone on the planning computed tomography and analyzed dose-volume histograms to determine which of these could be the most suitable dosimetric predictor.

Results

Of 92 eligible patients, 27 (29%) demonstrated CTCAE grade 2 acute bladder toxicity, with nocturia as the most frequently observed symptom. IPSS demonstrated better agreement with CTCAE than OABSS. In receiver-operating characteristic curve analysis, the largest area under the curve was observed for V20 of both the bladder wall and the bladder.

Conclusions

Acute bladder toxicity during pelvic radiation therapy is not a trivial complication and should be actively investigated. Dose-volume relationships demonstrate that both bladder wall V20 and bladder solid V20 are useful surrogates for identifying patients at high risk of toxicity. The roles of IPSS and OABSS need to be validated in a larger study.

Inhibition of EHMT2/G9a epigenetically increases the transcription of Beclin-1 via an increase in ROS and activation of NF-κB

We previously reported that BIX-01294 (BIX), a small molecular inhibitor of euchromatic histone-lysine N-methyltransferase 2 (EHMT2/G9a), induces reactive oxygen species (ROS)-dependent autophagy in MCF-7 cells. Herein, we analyzed the epigenetic mechanism that regulates the transcription of Beclin-1, a tumor suppressor and an autophagy-related gene (ATG). Inhibition of EHMT2 reduced dimethylation of lysine 9 on histone H3 (H3K9me2) and dissociated EHMT2 and H3K9me2 from the promoter of Beclin-1. To this promoter, RNA polymerase II and nuclear factor kappa B (NF-κB) were recruited in a ROS-dependent manner, resulting in transcriptional activation. Moreover, treatment with BIX reversed the suppression of Beclin-1 by the cooperative action of EHMT2 and DNA methyltransferase 1 (DNMT1). Accordingly, a combination treatment with BIX and 5-Aza-2′-deoxycytidine (5-Aza-Cd), a DNMT1 inhibitor, exerted a synergistic effect on Beclin-1 expression. Importantly, high levels of EHMT2 expression showed a significant association with low levels of Beclin-1 expression, which was related to a poor prognosis. These findings suggest that EHMT2 can directly repress Beclin-1 and that the inhibition of EHMT2 may be a useful therapeutic approach for cancer prevention by activating autophagy.

Image-guided, whole-pelvic, intensity-modulated radiotherapy for biochemical recurrence following radical prostatectomy in high-risk prostate cancer patients

Background

The optimal field size of salvage radiotherapy (SRT) for biochemical recurrence, particularly for patients with high-risk prostate cancer, remains undefined. This retrospective analysis was performed to investigate oncological outcomes as well as treatment-related toxicity following salvage intensity-modulated radiotherapy (IMRT) to the whole pelvis and to compare the results with other studies implementing a small field size of the prostate bed.

Methods

The medical records of 170 patients with high-risk prostate cancer who received SRT for biochemical recurrence following prostatectomy were reviewed. Whole-pelvic IMRT was administered with a median dose of 66 Gy in 30 fractions. To improve treatment accuracy, an endorectal balloon device and daily cone-beam computed tomography were utilized. Androgen-deprivation therapy combined with SRT was administered to 97 (57.1%) patients.

Results

Eventually, 68 (40.0%) patients showed biochemical progression (BCP) after SRT. With a median follow-up period of 56 months, the 5-year BCP-free survival was 38.6%. The overall and cause-specific survival rates were 90.9% and 96.7%, respectively. Regarding BCP-free survival analysis, pathological T stage, persistent prostate-specific antigen (PSA) elevation after prostatectomy, and preSRT PSA level were significant prognostic factors on univariate analysis. On multivariate analysis, pathological T stage and preSRT PSA value retained their significance. Acute and late grade-3 genitourinary toxicities were observed in one (0.6%) and five (2.9%) patients, respectively. One patient each developed acute and late grade-3 gastrointestinal toxicity.

Conclusion

SRT to whole pelvis using IMRT and image guidance is as safe as SRT to the prostate bed, but its efficacy should be confirmed in ongoing randomized trials. PreSRT PSA was the only controllable prognostic factor, suggesting the benefit of early SRT.

Factors associated with testosterone recovery after androgen deprivation therapy in patients with prostate cancer

Purpose

We investigated factors affecting testosterone recovery after androgen deprivation therapy (ADT) withdrawal in patients with prostate cancer.

Materials and Methods

The medical records of patients who underwent radical prostatectomy with ADT were retrospectively reviewed. In all, 221 patients were included in the analysis. Testosterone recovery was defined as supra-castration (SC) (testosterone levels in serum >50 ng/dL) or out of hypogonadism (OH) (>300 ng/dL) after ADT withdrawal. Kaplan-Meier analyses were used to estimate testosterone recovery after ADT cessation. Cox regression analyses were used to determine the factors affecting the recovery of testosterone.

Results

After ADT, 206 patients (93.2%) recovered to the SC level and 122 patients (55.2%) recovered to the OH level. Patients treated with ADT for ≤18 months recovered to OH in a mean of 6.8 months (74.6%), but patients treated with ADT for >18 months recovered in a mean of 9.7 months (27.5%). In multivariate analyses, age (hazard ratio [HR], 0.915; p<0.001), serum level of sex hormone-binding globulin (SHBG) (HR, 1.015; p=0.002), initial testosterone level (HR, 1.002; p=0.002), and ADT duration (HR, 0.915; p<0.001) were associated with recovery to the OH level after ADT withdrawal, and hypertension (HR, 0.697; p=0.029) and duration of ADT (HR, 0.979; p=0.012) were significantly associated with recovery to SC.

Conclusions

In patients treated with ADT for ≤18 months, testosterone recovers to the OH level more often and faster after ADT cessation. Age, SHBG level, initial testosterone level, and ADT duration are associated with testosterone recovery.

Pathological and oncological features of Korean prostate cancer patients eligible for active surveillance: analysis from the K-CaP registry

Background

A web-based multicenter Korean Prostate Cancer Database (K-CaP) was established to provide urologists with information on Korean prostate cancer (PCa) patients treated with radical prostatectomy (RP). We utilized the K-CaP registry to identify pathological features and oncological outcomes of Korean PCa patients eligible for active surveillance (AS).

Methods

The K-CaP registry consisted of 6415 patients who underwent RP from May 2001 to April 2013 at five institutions. Preoperative clinicopathological data were collected to identify patients who were eligible for at least one contemporary AS protocol. Patients who had received neoadjuvant androgen deprivation therapy or a 5α-reductase inhibitor, who had <10 total biopsy cores, or who had incomplete data were excluded. Biochemical recurrence (BCR) was defined as prostate-specific antigen (PSA) level ≥0.2 ng/ml following RP.

Results

A total of 560 patients were identified, and the median follow-up period was 52.0 (interquartile range, 39.0-67.3) months. Pathologically insignificant PCa, defined as organ-confined disease with Gleason score ≤6 was observed in 314 (56.1%) patients. Pathological upgrading (Gleason score ≥7) and upstaging (≥pT3) were observed in 237 (42.3%) and 75 (13.4%) patients, respectively. Unfavorable disease (extracapsular extension, seminal vesicle invasion, or Gleason score ≥8) was observed in 85 (15.2%) patients. PSA density ≤0.2 ng/ml/cc and maximal single core involvement ≤20% were revealed as independent preoperative predictors of pathologically insignificant PCa.

Conclusion

Contemporary Western AS protocols unreliably predict pathologically insignificant PCa in Korean men. Korean men may harbor more aggressive PCa features than Western men, and thus, a more stringent AS protocol is needed.

Combination of Androgen Deprivation Therapy and Salvage Radiotherapy versus Salvage Radiotherapy Alone for Recurrent Prostate Cancer after Radical Prostatectomy

INTRODUCTION

To assess the value of androgen deprivation therapy (ADT) on salvage radiotherapy (RT) in post-prostatectomy recurrent prostate cancer patients, we compared the oncologic outcomes between patients receiving RT + ADT and those receiving RT alone.

MATERIALS AND METHODS

We reviewed the records of patients diagnosed with prostate cancer between 1995 and 2011, including 93 patients who underwent salvage RT and 69 patients who underwent salvage RT + ADT. The ADT-free duration after withdrawal was calculated to verify testosterone recovery.

RESULTS

Presalvage prostate serum antigen (PSA) was the only significantly different characteristic between the 2 groups (p < 0.001). The ADT-free duration was greater than 6 months in >80% of patients. Presalvage PSA ≥0.6 ng/mL, pathologic stage ≥T3b, and RT + ADT were significantly associated with biochemical progression after salvage treatment. RT + ADT reduced biochemical progression in patients with seminal vesicle invasion or presalvage PSA ≥0.6 ng/mL (p = 0.001) compared to RT alone; biochemical progression-free probability was unchanged in seminal vesicle noninvasive prostate cancer patients with presalvage PSA <0.6 ng/mL (p = 0.541).

CONCLUSIONS

RT + ADT reduced the risk of biochemical progression after salvage treatment in patients with seminal vesicle invasion or presalvage PSA ≥0.6 ng/mL, but had no effect in patients with seminal vesicle noninvasive disease and presalvage PSA <0.6 ng/mL.