Prostate-specific antigen nadir after high-dose-rate brachytherapy predicts long-term survival outcomes in high-risk prostate cancer

Patients with PSA below 0.2 ng/mL at 8 years post high-dose-rate brachytherapy have an extremely low risk of subsequent recurrence

OBJECTIVES

We have analyzed the long-term follow-up data of patients with prostate cancer (PCa) who underwent high-dose-rate brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) combined with long-term androgen deprivation therapy (ADT). The objective was to determine the optimal time for cessation of PSA monitoring after HDR-BT.

METHODS

We included 309 patients with clinical stage T1c-T4 N0-1 M0 PCa who received HDR-BT and EBRT combined with long-term ADT between 2005 and 2018. We stratified the patients based on their prostate-specific antigen (PSA) levels and identified the factors associated with biochemical recurrence (BCR) and clinical progression (CP).

RESULTS

The median follow-up duration was 98 months (range: 31-207 months). Among the 306 patients, 76 developed BCR and 47 developed CP subsequently. We found that the PSA levels at 3, 5, and 8 years significantly correlated with the oncological outcomes of brachytherapy. No patient with a PSA level ≤ 0.2 ng/mL at 8 years later developed BCR or CP.

CONCLUSION

Our long-term data suggest that in the presence of a PSA level ≤ 0.2 ng/mL at 8 years later, PSA monitoring may be safely discontinued due to the extremely low risk of subsequent oncological events. The data presented in this study will assist clinicians in determining the optimal management strategy for patients with PCa following HDR-BT and EBRT combined with long-term ADT.

Prognostic Value of Long Noncoding RNA SNHG11 in Patients with Prostate Cancer

The present study was aimed to explore the prognostic value of long noncoding RNA SNHG11 in prostate cancer, study its expression, and assess its effect on tumor progression. One hundred and twenty prostate cancer patients and 45 cases of benign prostate hyperplasia (BPH) patients were collected. RT-qPCR was used to test the expression of SNHG11 in prostate cancer and BPH tissues, as well as in cell lines. Kaplan-Meier survival analysis and Cox regression assays were introduced to evaluate the prognostic meaning of SNHG11 in prostate cancer. The CCK-8 assays were performed to explore the effect of SNHG11 on prostate cancer cell proliferation, and a Transwell assay was conducted to access the influence of SNHG11 on prostate cancer cell migration and invasion. SNHG11 expression level was upregulated both in prostate cancer tissues and cell lines. Overexpression of SNHG11 was significantly associated with Gleason score, clinical T stage, surgical margin status, and lymph node metastasis. Patients with high SNHG11 expression levels led to a shorter overall survival time and biochemical recurrence-free survival when compared with those of low expression levels. Multivariate Cox regression results suggested that SNHG11 has the potential to act as a prognostic marker for prostate cancer patients. Knockdown of SNHG11 suppressed 22RV1 cell proliferation, migration, and invasion. In conclusion, SNHG11 is upregulated in prostate cancer patients and predicts an unfavorable prognosis for prostate cancer patients. Its knockdown can weaken prostate cancer cell metastasis and growth in vitro.

PSA nadir predicts biochemical recurrence after external beam radiation therapy combined to high dose rate brachytherapy in the treatment of prostate cancer

INTRODUCTION

Prostate cancer (PCa) is the second most prevalent neoplasm among men in the world. Its treatment has a wide spectrum of alternatives and variables, ranging from active surveillance through radio and/or brachytherapy, to surgery.

OBJECTIVE

The present work aimed to identify the predictive factors for biochemical recurrence and to evaluate the toxicity of the treatment using the association of external beam radiation therapy (EBRT) with high dose rate brachytherapy (HDR-BT) applied in the treatment of patients with prostate cancer.

METHODS

Longitudinal retrospective study, using a prospectively collected database between 2005 and 2014 of 186 consecutive patients records with a diagnosis of low, intermediate, or high-risk prostate cancer treated with EBRT combined with HDR-BT, in a single medical institution located in the city of Campinas, SP, Brazil (Radium Institute). PSA increase over 2 ng/ml above the nadir PSA was considered as biochemical recurrence, following the definition of the Phoenix Consensus. Continuous and clinically relevant categorical variables (age, initial PSA, delivered dose in EBRT, number of implants, number of positive cores in transrectal biopsy, use of hormone blockade, Gleason score, TNM staging, post treatment PSA and PSA Nadir) were evaluated with absolute (n) and percentage (%) values using multiple logistic regression and validated our previously described optimal PSA nadir as predictor of biochemical recurrence.

RESULTS

Post treatment PSA was the only independent predictor of biochemical recurrence, P<0.0001. The lower the PSA nadir the lower the biochemical recurrence risk (P=0.0009). PSA nadir >1 was the best cutoff (P=0.018) determinant of biochemical recurrence. The incidence of grade 3 late toxicity to the genitourinary tract was 0.6%, and there were no cases of severe complications to the gastrointestinal tract.

CONCLUSION

External Beam Radiation Therapy conjugated to Brachytherapy in the treatment of Prostate Cancer has demonstrated low biochemical recurrence rates, mainly when PSA nadir <1, with low toxicity into both GU and GI tracts.

Trimodal therapy with high-dose-rate brachytherapy and hypofractionated external beam radiation combined with long-term androgen deprivation for unfavorable-risk prostate cancer

Purpose

To assess the outcomes of high-dose-rate (HDR) brachytherapy and hypofractionated external beam radiation therapy (EBRT) combined with long-term androgen deprivation therapy (ADT) in very-high-risk (VHR) versus high-risk (HR) prostate cancer (PCa), as defined in the National Comprehensive Cancer Network (NCCN) criteria.

Methods

Data from 338 consecutive HR or VHR PCa patients who had undergone this tri-modal therapy between 2005 and 2018 were retrospectively analyzed. Biochemical recurrence (BCR)-free, progression-free, overall, and cancer-specific survival (BCRFS/PFS/OS/CSS) rates were analyzed using the Kaplan–Meier method and Wilcoxon test. Cox regression models were used to evaluate candidate prognostic factors for survival. C‑indexes were used to assess model discrimination.

Results

Within a median follow-up of 84 months, 68 patients experienced BCR, 58 had disease progression including only 3 with local progression, 27 died of any cause, and 2 died from PCa. The 5‑year BCRFS, PFS, OS, and CSS rates were 82.2% (HR 86.5%; VHR 70.0%), 90.0% (HR 94.3%; VHR 77.6%), 95.7% (HR, 97.1%; VHR, 91.8%), and 99.6% (HR, 100%; VHR, 98.0%), respectively. In multivariable analyses that adjusted for standard clinicopathologic features, the risk subclassification was associated both PFS and OS (p = 0.0003 and 0.001, respectively). Adding the risk subclassification improved the accuracy of models in predicting BCRFS, PFS, and OS.

Conclusion

While the outcome of this trimodal approach appears favorable, VHR PCa patients had significantly worse oncological outcomes than those with HR PCa. The NCCN risk subclassification should be integrated into prognostic tools to guide risk stratification, treatment, and follow-up for unfavorable PCa patients receiving this trimodal therapy.

Supplementary Information

The online version of this article (10.1007/s00066-021-01784-3) contains supplementary material, which is available to authorized users.

Oncological Outcome of Combining Cytoreductive Prostatectomy and Metastasis-Directed Radiotherapy in Patients with Prostate Cancer and Bone Oligometastases: A Retrospective Cohort Study

Background

The current standard of care for metastatic prostate cancer (mPCa) is androgen deprivation therapy (ADT) with or without anti-androgen and chemotherapy. The aim of this study was to evaluate the efficacy and safety of a multimodal approach including local primary tumor therapy, metastasis-directed therapy (MDT), and hormonal therapy in patients with oligometastatic prostate cancer (PCa).

Methods

We reviewed data of patients with PCa and bone oligometastases at diagnosis treated in three institutions with ADT followed by cytoreductive surgery with or without metastases-directed radiotherapy. Oligometastases were defined as the presence of five or fewer metastatic lesions with the absence of visceral metastases. In this retrospective cohort study, 58 patients underwent cytoreductive radical prostatectomy and ADT. Of these, 26 patients (45%) received stereotactic body radiation therapy (SBRT) to all metastatic sites as a MDT. Oncological outcomes were analyzed using the Kaplan–Meier method.

Results

The median follow-up period was 46.2 months. Of the 58 patients, the 3-year castration-resistant prostate cancer (CRPC)-free survival and cancer-specific survival was 75.9% and 91.4%, respectively. Pre- or post-treatment predictive factors for progression to CRPC, including prostate-specific antigen (PSA) level at diagnosis ≥20 ng/mL, Gleason grade groups 5, clinical T stage cT3b-4, PSA nadir level of ≥0.05 ng/mL, and no MDT with SBRT, were significantly associated with progression to CRPC. Subgroup analysis showed that the MDT group had significantly better CRPC-free survival than the non-MDT group with Gleason grade groups 1–4 (HR=0.228; 95% CI= 0.056–0.926). A total of 3.4% of the patients had grade 2 acute genitourinary toxicities and 5.2% had grade 2 acute gastrointestinal toxicities. No late grade >2 adverse events were observed.

Conclusion

This multi-center, retrospective cohort study revealed the feasibility of combining cytoreductive prostatectomy and metastasis-directed radiotherapy for newly-diagnosed oligometastatic PCa. This treatment strategy has the potential to delay the progression to CRPC.

Results of 15 Gy HDR-BT boost plus EBRT in intermediate-risk prostate cancer: Analysis of over 500 patients

PURPOSE/OBJECTIVE

To report biochemical control associated with single fraction 15 Gy high-dose-rate brachytherapy (HDR-BT) boost followed by external beam radiation (EBRT) in patients with intermediate-risk prostate cancer.

MATERIALS AND METHODS

A retrospective chart review of all patients with intermediate-risk disease treated with a real-time ultrasound-based 15 Gy HDR-BT boost followed by EBRT between 2009 and 2016 at a single quaternary cancer center was performed. Freedom from biochemical failure (FFBF), cumulative incidence of androgen deprivation therapy use for biochemical or clinical failure post-treatment (CI of ADT) and metastasis-free survival (MFS) outcomes were measured.

RESULTS

518 patients met the inclusion criteria for this study. Median age at HDR-BT was 67 years (IQR 61-72). 506 (98%) had complete pathologic information available. Of these, 146 (28%) had favorable (FIR) and 360 (69%) had unfavorable (UIR) intermediate-risk disease. 83 (16%) received short course hormones with EBRT + HDR. Median overall follow-up was 5.2 years. FFBF was 91 (88-94)% at 5 years. Five-year FFBF was 94 (89-99)% and 89 (85-94)% in FIR and UIR patients, respectively (p = 0.045). CI of ADT was 4 (2-6)% at 5 years. Five-year CI of ADT was 1 (0-3)% and 5 (2-8)% in FIR and UIR patients, respectively (p = 0.085). MFS was 97 (95-98)% at 5 years. Five-year MFS was 100 (N/A-100)% and 95 (92-98)% in FIR and UIR patients, respectively (p = 0.020).

CONCLUSION

In this large cohort of intermediate-risk prostate cancer patients, 15 Gy HDR-BT boost plus EBRT results in durable biochemical control and low rates of ADT use for biochemical failure.

Long-term outcomes of combining prostate brachytherapy and metastasis-directed radiotherapy in newly diagnosed oligometastatic prostate cancer: A retrospective cohort study

BACKGROUND

Systemic Therapy in Advancing or Metastatic Prostate Cancer: Evaluation of Drug Efficacy (STAMPEDE) trial showed the survival benefit for prostate radiotherapy in newly diagnosed prostate cancer patients with a low metastatic burden. The result raises the next question whether additional radiotherapy to metastatic sites could improve the survival in those with a low metastatic burden.

METHODS

We evaluated the efficacy and safety of prostate-directed radiotherapy (PDRT) with or without metastasis-directed radiotherapy (MDRT) in newly diagnosed oligometastatic patients who underwent combination of high-dose-rate prostate brachytherapy, external beam radiotherapy, and androgen deprivation therapy. Forty patients with bone metastasis and node positive prostate cancer were retrospectively analyzed. Of these, 22 (55%), 3 (7%), and 15 (38%) patients had N1M0, M1a, and M1b, respectively. Eighteen patients (45%) received MDRT to all metastatic sites. All patients initially underwent ≧6 months of androgen deprivation therapy. Oligometastatic disease was defined as presence of five or fewer metastatic lesions. Median follow-up period was 62.5 months.

RESULTS

Of the 40 patients, the 5-year castration-resistant prostate cancer (CRPC)-free survival rate and cancer-specific survival was 64.4% and 87.9%, respectively. Pre- or post-treatment predictive value including prostate-specific antigen (PSA) at diagnosis ≥20 ng/mL, Gleason grade group 5, positive biopsy core rate ≥51%, PSA nadir level of ≥0.02 ng/mL after the radiotherapy, and no MDRT were significantly associated with progression to CRPC. Patients with MDRT had significantly higher probability of achieving a PSA level of <0.02 ng/mL than those without the therapy (88.8% vs 54.5%, P = 0.0354) and consequently had a better CRPC-free survival than those without the therapy (HR 0.319, 95%CI: 0.116-0.877). Comparing PDRT alone, PDRT with MDRT did not significantly increase the incidences of genitourinary and gastrointestinal toxicities.

CONCLUSIONS

This single-institutional study revealed the feasibility of combining prostate brachytherapy and MDRT for newly diagnosed oligometastatic prostate cancer. This combined approach has potential to prolong CRPC-free survival.

Long-term oncologic outcomes of radiotherapy combined with maximal androgen blockade for localized, high-risk prostate cancer

Background

To assess the oncologic outcomes of radiation therapy (RT) combined with maximal androgen blockade (MAB) and prostate-specific antigen (PSA) kinetics in patients with localized, high-risk prostate carcinoma (PCa).

Methods

Three-hundred twenty individuals with localized PCa who underwent RT + MAB in 2001–2015 were evaluated retrospectively. All patients had received 36 months of MAB therapy and 45 Gy of pelvic irradiation, plus a dose-escalated external beam radiation therapy (DE-EBRT) boost to 76~81 Gy (MAB + EBRT group), or a low-dose-rate prostate permanent brachytherapy (LDR-PPB) boost to 110 Gy with I-125 (MAB + EBRT + PPB group).

Results

Follow-up median is 90 months, ranging from 12 to 186 months; 117 (36.6%) and 203 (63.4%) cases underwent MAB + EBRT and MAB + EBRT + PPB, respectively. Multivariate Cox regression showed that the PPB regimen and PSA kinetics were positive indicators of oncologic outcomes. Compared with MAB + EBRT, MAB + EBRT + PPB remarkably improved PSA kinetics more pronouncedly: PSA nadir (1.3 ± 0.7 vs 0.11 ± 0.06 ng/mL); time of PSA decrease to nadir (7.5 ± 1.8 vs 3.2 ± 2.1 months); PSA doubling time (PSADT; 15.6 ± 4.2 vs 22.6 ± 6.1 months); decrease in PSA (84.6 ± 6.2% vs 95.8 ± 3.4%). Additionally, median times of several important oncologic events were prolonged in the MAB + EBRT + PPB group compared with the MAB + EBRT group: overall survival (OS; 12.3 vs 9.1 years, P < 0.001), biochemical recurrence-free survival (BRFS; 9.8 vs 6.5 years, P < 0.001), skeletal-related event (SRE; 10.4 vs 8.2 years, P < 0.001), and cytotoxic chemotherapy (CCT; 11.6 vs 8.8 years, P = 0.007).

Conclusion

MAB + EBRT + PPB is extremely effective in patients with localized, high-risk PCa, indicating that PPB may play a synergistic role in improving PSA kinetics and independently predicts oncologic outcomes.

Impact of five-tiered Gleason grade groups on prognostic prediction in clinical stage T3 prostate cancer undergoing high-dose-rate brachytherapy

BACKGROUND

We evaluated a five-tiered Gleason grade groups arising from the 2014 International Society of Urological Pathology consensus conference on prognostic prediction in clinical stage T3a (extracapsular invasion) and T3b (seminal vesicle involvement) prostate cancer undergoing high-dose-rate brachytherapy (HDR-BT).

METHODS

From November 2003 to December 2012, 283 patients with stage T3 prostate cancer received HDR-BT and external beam radiation therapy (EBRT) with long-term androgen deprivation therapy (ADT). Of these, 203 (72%) and 80 (28%) patients had stage T3a and T3b disease, respectively. The mean dose to 90% of the planning target volume was 7.5 Gy/fraction of HDR-BT. After five fractions, EBRT with 10 fractions of 3 Gy was administered. All patients first underwent ≥6 months of neoadjuvant ADT, and adjuvant ADT continued for 36 months. Median follow-up was 74 months from the start of radiotherapy.

RESULTS

The 10-year biochemical recurrence (BCR) -free rate for stage T3a and T3b disease was 79% and 64%, respectively (P = 0.0083). The 10-year cancer-specific survival (CSS) rate for stage T3a and T3b was 96% and 91%, respectively (P = 0.0305). Although grade groups ≥4 were independent predictors for BCR in cT3a patients (P = 0.0270), they failed to significantly predict prostate cancer-specific mortality (PCSM) among cT3a patients. Among cT3b patients, grade group 5 was a significant predictor of both BCR (P = 0.0017) and PCSM (P = 0.0233). Among stage T3a patients, no significant difference existed in 10-year CSS between grade groups 5 and 4 (94% vs 97%, P = 0.3960). In contrast, grade group 5 had a significantly worse outcome in 10-year CSS than grade group 4 among stage T3b patients (74% vs 100%, P = 0.0350).

CONCLUSIONS

Stage T3a patients with grade groups 4/5 and stage T3b with grade group 4 had fairly low PCSM risk. Approximately one of four patients among stage T3b patients with grade group 5 showed PCSM after combined HDR-BT and EBRT with long-term ADT. Stage T3b patients with grade group 5 may have a greater risk for PCSM.

Perioperative Search for Circulating Tumor Cells in Patients Undergoing Prostate Brachytherapy for Clinically Nonmetastatic Prostate Cancer

Despite the absence of local prostate cancer recurrence, some patients develop distant metastases after prostate brachytherapy. We evaluate whether prostate brachytherapy procedures have a potential risk for hematogenous spillage of prostate cancer cells. Fifty-nine patients who were undergoing high-dose-rate (HDR) or low-dose-rate (LDR) brachytherapy participated in this prospective study. Thirty patients with high-risk or locally advanced cancer were treated with HDR brachytherapy after neoadjuvant androgen deprivation therapy (ADT). Twenty-nine patients with clinically localized cancer were treated with LDR brachytherapy without neoadjuvant ADT. Samples of peripheral blood were drawn in the operating room before insertion of needles (preoperative) and again immediately after the surgical manipulation (intraoperative). Blood samples of 7.5 mL were analyzed for circulating tumor cells (CTCs) using the CellSearch System. While no preoperative samples showed CTCs (0%), they were detected in intraoperative samples in 7 of the 59 patients (11.8%; preoperative vs. intraoperative, p = 0.012). Positive CTC status did not correlate with perioperative variables, including prostate-specific antigen (PSA) at diagnosis, use of neoadjuvant ADT, type of brachytherapy, Gleason score, and biopsy positive core rate. We detected CTCs from samples immediately after the surgical manipulation. Further study is needed to evaluate whether those CTCs actually can survive and proliferate at distant sites.