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.

Cancer-specific survival after radical prostatectomy versus external beam radiotherapy in high-risk and very high-risk African American prostate cancer patients

BACKGROUND

To test for differences in cancer-specific mortality (CSM) rates between radical prostatectomy (RP) vs external beam radiotherapy (EBRT) in National Comprehensive Cancer Network (NCCN) high-risk African American patients, as well as Johns Hopkins University (JHU) high-risk and very high-risk patients.

MATERIALS AND METHODS

Within the Surveillance, Epidemiology, and End Results database (2010-2016), we identified 4165 NCCN high-risk patients, of whom 1944 (46.7%) and 2221 (53.3%) patients qualified for JHU high-risk or very high-risk definitions. Of all 4165 patients, 1390 (33.5%) were treated with RP versus 2775 (66.6%) with EBRT. Cumulative incidence plots and competing risks regression models addressed CSM before and after 1:1 propensity score matching between RP and EBRT NCCN high-risk patients. Subsequently, analyses were repeated separately in JHU high-risk and very high-risk subgroups. Finally, all analyses were repeated after landmark analyses were applied.

RESULTS

In the NCCN high-risk cohort, 5-year CSM rates for RP versus EBRT were 2.4 versus 5.2%, yielding a multivariable hazard ratio of 0.50 (95% confidence interval [CI] 0.30-0.84, p = 0.009) favoring RP. In JHU very high-risk patients 5-year CSM rates for RP versus EBRT were 3.7 versus 8.4%, respectively, yielding a multivariable hazard ratio of 0.51 (95% CI: 0.28-0.95, p = 0.03) favoring RP. Conversely, in JHU high-risk patients, no significant CSM difference was recorded between RP vs EBRT (5-year CSM rates: 1.3 vs 1.3%; multivariable hazard ratio: 0.55, 95% CI: 0.16-1.90, p = 0.3). Observations were confirmed in propensity score-matched and landmark analyses adjusted cohorts.

CONCLUSIONS

In JHU very high-risk African American patients, RP may hold a CSM advantage over EBRT, but not in JHU high-risk African American patients.

Treatment Strategies for High-Risk Localized and Locally Advanced and Oligometastatic Prostate Cancer

Simple Summary

The definitions of locally advanced and oligometastatic prostate cancer are ambiguous, and there are no standard treatments for these. Although multidisciplinary treatment combining systemic and local treatment may be effective, there are many unresolved issues such as the choice of local treatment, use of new endocrine agents and chemotherapy, and selection of optimal patients. The present article discusses the definitions, diagnoses, and treatment of very high-risk prostate cancer and oligometastatic prostate cancer.

Abstract

Despite the significant advances in the treatment of high-risk prostate cancer, patients with very high-risk features such as being locally advanced (clinical stage T3–4 or minimal nodal involvement), having a high Gleason pattern, or with oligometastasis may still have a poor prognosis despite aggressive treatment. Multidisciplinary treatment with both local and systemic therapies is thought to be effective, however, unfortunately, there is still no standard treatment. However, in recent years, local definitive therapy using a combination of radiotherapy and androgen deprivation is being supported by several randomized clinical trials. This study reviews the current literature with a focus on the definition of very high-risk prostate cancer, the role of modern imaging, and its treatment options.

Patient characteristics and acute cardiovascular event rates among patients with very high-risk and non-very high-risk atherosclerotic cardiovascular disease

BACKGROUND

The risk for subsequent major cardiovascular (CV) events among patients with very high-risk (VHR) atherosclerotic CV disease (ASCVD) remains to be fully elucidated.

HYPOTHESIS

We assessed the characteristics and major CV event rates of patients with VHR versus non-VHR ASCVD in a real-world setting in the United States (US), hypothesizing that patients with VHR ASCVD would have higher CV event rates.

METHODS

This was a retrospective cohort study conducted from January 01, 2011, to June 30, 2018, in the US using the Prognos LDL-C database linked to the IQVIA PharMetrics Plus® database supplemented with the IQVIA prescription claims (Dx/LRx) databases. Patients were ≥18 years old and had  ≥2 non-ancillary medical claims in the linked databases at least 30 days apart. The study was conducted in 2 stages: (1) identification of patients with ASCVD who met the definition of VHR ASCVD and a matched cohort of non-VHR ASCVD patients using the incidence density sampling (IDS) approach; (2) estimation of the occurrence of major CV events.

RESULTS

Among patients with ≥1 major ASCVD event (N=147,679), most qualified as VHR ASCVD (79.5%). There were 115,460 patients each in IDS-matched VHR and non-VHR ASCVD cohorts. The composite myocardial infarction/ischemic stroke event rates in the VHR and non-VHR ASCVD cohorts were 8.04 (95% confidence interval [95% CI]: 7.87-8.22) and 0.82 (95% CI: 0.77-0.88) events per 100 patient-years, respectively, during the 1-year post-index period.

CONCLUSIONS

Most patients with ≥1 previous major ASCVD event treated in real-world US clinical practice qualified as VHR ASCVD. Patients with VHR ASCVD had much higher rates of major CV events versus non-VHR ASCVD patients.

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.

Very high-risk prostate cancer: stratification by outcomes of radiotherapy and long-term androgen deprivation therapy

AIM

The definition of very high-risk (VHR) prostate cancer is currently based on the study of radical prostatectomy. We aimed to identify a suitable definition for VHR group following external beam radiation therapy (EBRT) and long-term androgen-deprivation therapy (ADT).

METHODS

This retrospective study included 356 high-risk patients treated with EBRT and long-term ADT. A median follow-up time was 68 months. At first, associations of previously described prognostic factors with biochemical disease-free survival (bDFS), clinical relapse-free survival (cRFS) and prostate cancer-specific survival (CSS) were examined. Second, the combination of significant adverse factors in the first analysis served as VHR test definitions. For each factor, a Cox proportional hazards model was used to calculate their hazard ratios for bDFS and cRFS. The logrank test was used to evaluate the association between each factor and CSS.

RESULTS

Primary Gleason pattern 5, T4 and ≥ 5 or 4 cores with Gleason score 8-10 were risk factors associated with bDFS, cRFS and CSS. Eleven VHR test definitions composed of these adverse factors were associated significantly with bDFS, cRFS and CSS. The final definition was described by primary Gleason pattern 5 or T4 or ≥ 4 cores with Gleason score 8-10 because of the largest sample size of 38% among 11 test definitions. bDFS, cRFS and CSS of the VHR group were significantly lower compared with other high-risk patients (P < 0.001, P < 0.001 and P = 0.015, respectively).

CONCLUSION

These VHR criteria were best fitted following EBRT with long-term ADT.

High-dose-rate brachytherapy and hypofractionated external beam radiotherapy combined with long-term hormonal therapy for high-risk and very high-risk prostate cancer: outcomes after 5-year follow-up

The purpose of this study was to report the outcomes of high-dose-rate (HDR) brachytherapy and hypofractionated external beam radiotherapy (EBRT) combined with long-term androgen deprivation therapy (ADT) for National Comprehensive Cancer Network (NCCN) criteria-defined high-risk (HR) and very high-risk (VHR) prostate cancer. Data from 178 HR (n = 96, 54%) and VHR (n = 82, 46%) prostate cancer patients who underwent (192)Ir-HDR brachytherapy and hypofractionated EBRT with long-term ADT between 2003 and 2008 were retrospectively analyzed. The mean dose to 90% of the planning target volume was 6.3 Gy/fraction of HDR brachytherapy. After five fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administered. All patients initially underwent ≥ 6 months of neoadjuvant ADT, and adjuvant ADT was continued for 36 months after EBRT. The median follow-up was 61 months (range, 25-94 months) from the start of radiotherapy. The 5-year biochemical non-evidence of disease, freedom from clinical failure and overall survival rates were 90.6% (HR, 97.8%; VHR, 81.9%), 95.2% (HR, 97.7%; VHR, 92.1%), and 96.9% (HR, 100%; VHR, 93.3%), respectively. The highest Radiation Therapy Oncology Group-defined late genitourinary toxicities were Grade 2 in 7.3% of patients and Grade 3 in 9.6%. The highest late gastrointestinal toxicities were Grade 2 in 2.8% of patients and Grade 3 in 0%. Although the 5-year outcome of this tri-modality approach seems favorable, further follow-up is necessary to validate clinical and survival advantages of this intensive approach compared with the standard EBRT approach.