Assessment of permanent brachytherapy combined with androgen deprivation therapy in an intermediate-risk prostate cancer group without a Gleason score of 4 + 3: a single Japanese institutional experience

Role of Brachytherapy Boost in Clinically Localized Intermediate and High-Risk Prostate Cancer: Lack of Benefit in Patients with Very High-Risk Factors T3b-4 and/or Gleason 9-10

Simple Summary

In general, brachytherapy (BT) improves biochemical control in intermediate-to high-risk prostate cancer. We previously reported that importance of very high-risk factors (VHR: T3b–4 or Gleason score 9–10) and patients with double VHR (VHR-2) showed the worst prognosis among high-risk groups. We explored the role of BT-boost in patients with VHR and compared it to intermediate- and other high-risk groups. We confirmed that BT-boost improved prostate-specific antigen (PSA) control but resulted in equivalent overall survival rates for the intermediate- and high-risk groups, except for the patients with VHR. In the VHR-1 group (single VHR), BT-boost showed superior PSA control to conventional-dose RT (EQD2 ≤ 72 Gy) but not to the dose-escalated radiotherapy group (EQD2 ≥ 74 Gy). In the VHR-2 group, BT-boost did not improve the biochemical control rate of either Conv RT or DeRT. BT-boost showed no benefit over modern DeRT in the patients with VHR.

Abstract

This study examined the role of brachytherapy boost (BT-boost) and external beam radiotherapy (EBRT) in intermediate- to high-risk prostate cancer, especially in patients with very high-risk factors (VHR: T3b–4 or Gleason score 9–10) as patients with double very high-risk factors (VHR-2: T3b–4 and Gleason score 9–10) previously showed worst prognosis in localized prostate cancer. We retrospectively reviewed multi-institutional data of 1961 patients that were administered radiotherapy (1091 BT-boost and 872 EBRT: 593 conventional-dose RT (Conv RT: equivalent to doses of 2 Gy per fraction = EQD2 ≤ 72 Gy) and 216 dose-escalating RT (DeRT = EQD2 ≥ 74 Gy). We found that BT-boost improved PSA control and provided an equivalent overall survival rate in the intermediate- and high-risk groups, except for patients within the VHR factor group. In the VHR-1 group (single VHR), BT-boost showed a superior biochemical control rate to the Conv RT group but not to the DeRT group. In the VHR-2 group, BT-boost did not improve outcomes of either Conv RT or DeRT groups. In conclusion, BT-boost showed no benefit to modern DeRT in the patients with VHR; therefore, they are not good candidates for BT-boost to improve outcome and may be amenable to clinical trials using multimodal intensified systemic treatments.

Novel Prognostic Index of High-Risk Prostate Cancer Using Simple Summation of Very High-Risk Factors

This study aimed to examine the role of very high-risk (VHR) factors (T3b-4 and Gleason score 9-10) for prognosis of clinically localized high-risk prostate cancer. We reviewed multi-institutional retrospective data of 1413 patients treated with radiotherapy (558 patients treated with external beam radiotherapy (EBRT) and 855 patients treated with brachytherapy (BT) ± EBRT. We introduced an index by simple summation of the number of VHR factors-VHR-0, VHR-1, and VHR-2. With median follow-up of 69.6 months, the 5-year biochemical disease free survival rate (bDFS), prostate cancer-specific mortality (PCSM), and distant metastasis-free survival (DMSF) rates were 59.4%, 7.65%, and 83.2% for the VHR-2 group, respectively; 86.7%, 1.50%, and 95.4% for the VHR-1 group, respectively; and 93.1%, 0.12%, and 98.2% for the VHR-0 group, respectively. The VHR-2 group had significantly worse bDFS, PCSM, and DMSF than the VHR-0 (hazard ratios: 4.55, 9.607, and 7.904, respectively) and VHR-1 (hazard ratios: 1.723, 2.391, and 1.491, respectively) groups. The VHR-2 group could be identified as a super high-risk group compared with other groups, and could be a good candidate for clinical trials using multimodal intensified treatments. Simple summation of the number of VHR factors is an easy and useful predictive index for bDFS, PCSM, and DMSF.

Radiotherapy for elder patients aged ≥80 with clinically localized prostate cancer - Brachytherapy enhanced late GU toxicity especially in elderly

Background and purpose

Elongation of life expectancy had led to marked increase in number of elderly patients with localized prostate cancer. However, the standard treatment for such patients is not well determined because of a high prevalence of comorbidities and slow growth of prostate cancer. The aim of this study is to examine the feasibility of radiotherapy for elderly patients aged ≥80 years.

Materials and methods

We compared 96 patients aged ≥80 years and 2333 younger patients (aged 60-79 years) using multi-institutional data included cT1-T4N0M0 prostate cancer treated with 902 external beam radiotherapy (EBRT) and 1527 brachytherapy (BT).

Results

The 5-year biochemical failure-free survival rate was similar between elderly ≥80 years and younger control (91.3% vs. 85.9%, p = 0.6171) (100%, 92.9%, 82.4% and 96.3%, 93.7%, 89% for low, intermediate and high risk group), and for the prostate cancer-specific survival rate (100% and 99.3%, p = 0.6171). The accumulated incidence of late gastrointestinal (GI) at 5 years was also similar between elderly and younger patients (3.5% vs. 2.5%, p = 0.6857). Brachytherapy improved biochemical control rate and reduced GI toxicity compared with EBRT, however, enhanced late genitourinary (GU) toxicity, especially in elderly patients. Elderly received brachytherapy showed highest rate of late GU toxicity grade ≥2 of 22.1% than the younger counterparts of 12.7% at 5 years, whereas younger patients treated with EBRT had 2.4% and elderly EBRT had 2.7% (p < 0.0001).

Conclusion

Elderly patients aged ≥80 years showed equivalent biochemical control, prostate cancer-related survival, and gastrointestinal toxicity profiles to younger patients. Meticulous care should be required for brachytherapy enhanced late GU toxicity, especially in elderly patients aged ≥80 years.

Effect of Androgen Deprivation Therapy on Other-Cause of Mortality in Elderly Patients with Clinically Localized Prostate Cancer Treated with Modern Radiotherapy: Is There a Negative Impact?

The influence of androgen deprivation therapy (ADT) on other-cause of mortality (OCM) was investigated in patients with localized prostate cancer treated with modern high-dose radiotherapy. A retrospective review was conducted on 1125 patients with localized prostate cancer treated with high-dose radiotherapy, including image-guided, intensity-modulated radiotherapy or brachytherapy with a median follow-up of 80.7 months. Overall survival rate was no different between ADT (+) and ADT (−) group in high-, intermediate-, and low-risk groups. OCM was found in 71 patients, consisting of 4% (10/258) in the ADT (−) group and 7% (61/858) in the ADT (+) group (p = 0.0422). The 10-year OCM-free survival rate (OCMFS), if divided by the duration of ADT (ADT naïve (ADT (−)), ADT <2-year, and ADT ≥2-year groups), showed statistical significance, and was 90.7%, 88.2%, and 78.6% (p = 0.0039) for the ADT (−), ADT <2-year, and ADT ≥2-year groups, respectively. In patients aged ≥75 years, 10-year OCMFS for ADT (−), ADT <2-, and ADT ≥2-year groups was 93.5% (at 115.6 months), 85.6%, and 60.7% (p = 0.0189), respectively, whereas it was 90.7%, 89.9%, and 89.0% (p = 0.4716), respectively, in their younger counterparts. In localized prostate cancer patients, treatment with longer ADT for ≥2 years potentially increases the risk of OCM, especially in patients aged ≥75 years.

Radiothrerapy for Elderly Patients Aged ≥75 Years with Clinically Localized Prostate Cancer-Is There a Role of Brachytherapy?

We compared radiotherapy outcomes between 241 elderly patients aged ≥75 years and 867 younger controls (age <75 years) with clinically localized prostate cancer. The elderly group showed an equivalent actuarial seven-year biochemical failure-free survival rate (7y-bNED) (94.9%) to the younger control group (96.4%, p = 0.593). The incidence of late genitourinary (GU) and gastrointestinal (GI) toxicities grade ≥2 was also similar between the elderly and younger cohorts, while no grade ≥4 adverse events occurred. We also examined the role of brachytherapy (BT) in the elderly group, in comparison with image-guided intensity-modulated radiotherapy (IG-IMRT). BT showed superior 7y-bNED (94.1%) than IG-IMRT (84.6%, p = 0.0183) in elderly patients, which was 100% (100% for BT and 100% for IG-IMRT, p > 0.999) for the low-risk group, 94.6% (92.8% and 100%, p = 0.203) for the intermediate-risk group, and 80.5% (91.2% and 73.6%, p = 0.0195) for the high-risk group. BT showed higher GU toxicity and equivalent GI toxicity to IG-IMRT. In conclusion, elderly patients showed bNED and toxicity that were equivalent to those observed in younger controls, and BT is a plausible option also for healthy elderly with potential to improve bNED, with higher but acceptable GU toxicity.

High-dose-rate brachytherapy monotherapy versus low-dose-rate brachytherapy with or without external beam radiotherapy for clinically localized prostate cancer

BACKGROUND

To compare the outcome of high-dose-rate interstitial brachytherapy (HDR-BT) monotherapy and low-dose-rate brachytherapy (LDR-BT) with or without external beam radiotherapy (EBRT) for localized prostate cancer.

METHODS AND MATERIALS

We compared 352 patients treated with HDR-BT as monotherapy (median follow-up time 84 months, NCCN risk classification; low: intermediate: high = 28:145:179) and 486 patients with LDR-BT with or without EBRT (90 months, 194:254:38). HDR-BT treated advanced disease with more hormonal therapy than LDR-BT. LDR-BT excluded patients with T3b-T4 tumor and initial PSA >50 ng/ml. Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias.

RESULTS

The actuarial 5-year biochemical failure-free survival rates (bNED) were 92.9% and 95.6% (p = 0.25) in the HDR-BT and LDR-BT groups, respectively, and it was 100% and 97.3% (p = 0.99) in the low-risk, 95.6% and 94.3% (p = 0.19) in the intermediate, 89.6% and 94.9% (p = 0.26) in the high-risk groups, and 93.1% and 94.9% (p = 0.98) in selected high-risk group excluding T3b-4 and initial PSA ≥50. IPTW correction also indicated no difference in bNED between LDR-BT and HDR-BT groups. LDR-BT showed a higher incidence of genitourinary (GU) toxicity grade ≥2 than that of HDR-BT in the acute phase and grade 1 toxicity in late phase. Acute GU toxicity grade ≥1 predicted late GU toxicity grade ≥2. External beam radiotherapy plus LDR-BT elevated GI toxicity than LDR-BT only group. Accumulated incidence of late grade ≥2 GU and GU toxicity was equivalent between HDR-BT and LDR-BT. No grade 4 or 5 toxicities were detected in either modality.

CONCLUSION

HDR-BT monotherapy showed an equivalent outcome to that of LDR-BT with or without EBRT for low-, intermediate- and selected high-risk patients. LDR-BT showed equivalent incidence of grade ≥2 late GI and GU toxicities and higher grade ≥2 acute GU toxicity as that of HDR-BT as a monotherapy.

Comparison of Image-Guided Intensity-Modulated Radiotherapy and Low-dose Rate Brachytherapy with or without External Beam Radiotherapy in Patients with Localized Prostate Cancer

To compare the outcome of low-dose rate brachytherapy (LDR-BT) and image-guided intensity-modulated radiotherapy (IG-IMRT) for localized prostate cancer, we examined 488 LDR-BT and 269 IG-IMRT patients. IG-IMRT treated older and advanced disease with more hormonal therapy than LDR-BT, which excluded T3b–T4 tumor and initial PSA > 50 ng/ml. The actuarial five-year biochemical failure-free survival rate was 88.7% and 96.7% (p = 0.0003) in IG-IMRT and LDR-BT, respectively; it was 88.2% (85.1% for IG-IMRT and 94.9% for LDR-BT, p = 0.0578) for the high-risk group, 95.2% (91.6% and 97.0%, p = 0.3361) for the intermediate IG-IMRT and 96.8% (95.7% and 97%, p = 0.8625) for the low-risk group. Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias. IPTW showed a statistically significant difference between LDR-BT and IG-IMRT in high risk (p = 0.0009) and high risk excluding T3-4/initial PSA > 50 ng/ml group (p = 0.0073). IG-IMRT showed more gastrointestinal toxicity (p = 0.0023) and less genitourinary toxicity (p < 0.0001) than LDR-BT. LDR-BT and IG-IMRT showed equivocal outcome in low- and intermediate-risk groups. For selected high-risk patients, LDR-BT showed more potential to improve PSA control rate than IG-IMRT.

Living Donor Kidney Transplantation After Brachytherapy for Prostate Cancer: Case Report

INTRODUCTION

There is no obvious criterion about kidney transplantation for patients with pretransplant malignancy. Minimum tumor-free waiting periods differ according to type of cancer, staging, site of occurrence, response to therapy, and risk of cancer recurrence. We report a case of living donor kidney transplantation (LDKT) in a patient after brachytherapy for prostate cancer.

CASE REPORT

The patient was a 65-year-old man with chronic kidney disease due to chronic glomerular nephritis. He received hemodialysis 3 times a week. His prostate-specific antigen level (PSA) was high (6.57 ng/mL), and he was diagnosed with prostate cancer (T1cN0M0, Gleason Score 3 + 4 = 7, 3/10) by needle biopsy in urology. He was treated with maximum androgen blockade (MAB) therapy and brachytherapy in May 2014. He underwent LDKT from a spousal donor at our department in December 2015, because urologists concluded that the prostate cancer was completely cured. Immunosuppression consisted of induction with basiliximab and maintenance with tacrolimus, mizoribine, and steroids. The postoperative course was uneventful. He discharged at postoperative day 29 with a serum creatinine level of 1.30 mg/dL. Three months after LDKT, his PSA level was 0.477 ng/mL, and there was no evidence of prostate cancer recurrence.

CONCLUSION

This is the first case of LDKT for patients with prostate cancer after brachytherapy in combination with MAB. There is no recurrence of prostate cancer so far; however, careful follow-up including PSA is necessary and important.

Permanent prostate brachytherapy and short-term androgen deprivation for intermediate-risk prostate cancer in Japanese men: outcome and toxicity

OBJECTIVES

To evaluate the interim outcomes of low-dose-rate permanent brachytherapy (PB) combined with short-term androgen deprivation therapy (ADT) in Japanese men with intermediate-risk prostate cancer excluding those with a Gleason score of 4+3.

METHODS

The Protocol-intermediate-risk group (Protocol-IRG) was defined as clinical stage T1c-T2c, Gleason score of 3+4, or lower and prostatic-specific antigen (PSA) level lower than 20 ng/mL. A total of 308 patients underwent brachytherapy in the protocol-IRG group (n=152) or in the low-risk group (n=156). Patients in Protocol-IRG had received at least 6 months of ADT before and after PB. Supplemental external beam radiotherapy was not used. Planned followup by PSA was carried out every 3 months for the first 2 years and every 6 months thereafter. The PSA failure was defined as nadir+2 ng/mL. Patients' Expanded Prostate Cancer Index Composite was recorded before and 3 years after treatment.

RESULTS

The median followup was 68 and 68 months for the protocol-IRG and the low-risk groups, respectively. The 5-year biological disease-free survival rates in the low-risk and protocol-IRG groups were 94.8 and 94.6%, respectively. As far as survival rates were concerned, there were no significant differences between the two groups. Overall satisfaction and sexual function at 3 years after PB had significantly improved compared with pretreatment (p=0.01 and p=0.01, respectively).

CONCLUSIONS

In intermediate-risk prostate patients, excluding those with a biopsy Gleason score of 4+3, brachytherapy with short-term ADT can be an effective treatment option for Japanese men.