Oncological control in high-risk prostate cancer after radical prostatectomy and salvage radiotherapy compared to radiotherapy plus primary hormone therapy

Characterizing Surgical and Radiotherapy Outcomes in Non-metastatic High-Risk Prostate Cancer: A Systematic Review and Meta-Analysis

Background Identifying the optimal management of high-risk non-metastatic prostate cancer (PCa) is an important public health concern, given the large burden of this disease. We performed a meta-analysis of studies comparing PCa-specific mortality (CSM) among men diagnosed with high-risk non-metastatic PCa who were treated with primary radiotherapy (RT) and radical prostatectomy (RP). Methods Medline and Embase were searched for articles between January 1, 2005, and February 11, 2020. After title and abstract screening, two authors independently reviewed full-text articles for inclusion. Data were abstracted, and a modified version of the Newcastle-Ottawa Scale, involving a comprehensive list of confounding variables, was used to assess the risk of bias. Results Fifteen studies involving 131,392 patients were included. No difference in adjusted CSM in RT relative to RP was shown (hazard ratio, 1.02 [95% confidence interval: 0.84, 1.25]). Increased CSM was found in a subgroup analysis comparing external beam radiation therapy (EBRT) with RP (1.35 [1.10, 1.68]), whereas EBRT combined with brachytherapy (BT) versus RP showed lower CSM (0.68 [0.48, 0.95]). All studies demonstrated a high risk of bias as none fully adjusted for all confounding variables. Conclusion We found no difference in CSM between men diagnosed with non-metastatic high-risk PCa and treated with RP or RT; however, this is likely explained by increased CSM in men treated with EBRT and decreased CSM in men treated with EBRT + BT studies relative to RP. High risk of bias in all studies identifies the need for better data collection and confounding control in the PCa research.

Benefits and Risks of Primary Treatments for High-risk Localized and Locally Advanced Prostate Cancer: An International Multidisciplinary Systematic Review

CONTEXT

The optimal treatment for men with high-risk localized or locally advanced prostate cancer (PCa) remains unknown.

OBJECTIVE

To perform a systematic review of the existing literature on the effectiveness of the different primary treatment modalities for high-risk localized and locally advanced PCa. The primary oncological outcome is the development of distant metastases at ≥5 yr of follow-up. Secondary oncological outcomes are PCa-specific mortality, overall mortality, biochemical recurrence, and need for salvage treatment with ≥5 yr of follow-up. Nononcological outcomes are quality of life (QoL), functional outcomes, and treatment-related side effects reported.

EVIDENCE ACQUISITION

Medline, Medline In-Process, Embase, and the Cochrane Central Register of Randomized Controlled Trials were searched. All comparative (randomized and nonrandomized) studies published between January 2000 and May 2019 with at least 50 participants in each arm were included. Studies reporting on high-risk localized PCa (International Society of Urologic Pathologists [ISUP] grade 4-5 [Gleason score {GS} 8-10] or prostate-specific antigen [PSA] >20 ng/ml or ≥ cT2c) and/or locally advanced PCa (any PSA, cT3-4 or cN+, any ISUP grade/GS) or where subanalyses were performed on either group were included. The following primary local treatments were mandated: radical prostatectomy (RP), external beam radiotherapy (EBRT) (≥64 Gy), brachytherapy (BT), or multimodality treatment combining any of the local treatments above (±any systemic treatment). Risk of bias (RoB) and confounding factors were assessed for each study. A narrative synthesis was performed.

EVIDENCE SYNTHESIS

Overall, 90 studies met the inclusion criteria. RoB and confounding factors revealed high RoB for selection, performance, and detection bias, and low RoB for correction of initial PSA and biopsy GS. When comparing RP with EBRT, retrospective series suggested an advantage for RP, although with a low level of evidence. Both RT and RP should be seen as part of a multimodal treatment plan with possible addition of (postoperative) RT and/or androgen deprivation therapy (ADT), respectively. High levels of evidence exist for EBRT treatment, with several randomized clinical trials showing superior outcome for adding long-term ADT or BT to EBRT. No clear cutoff can be proposed for RT dose, but higher RT doses by means of dose escalation schemes result in an improved biochemical control. Twenty studies reported data on QoL, with RP resulting mainly in genitourinary toxicity and sexual dysfunction, and EBRT in bowel problems.

CONCLUSIONS

Based on the results of this systematic review, both RP as part of multimodal treatment and EBRT + long-term ADT can be recommended as primary treatment in high-risk and locally advanced PCa. For high-risk PCa, EBRT + BT can also be offered despite more grade 3 toxicity. Interestingly, for selected patients, for example, those with higher comorbidity, a shorter duration of ADT might be an option. For locally advanced PCa, EBRT + BT shows promising result but still needs further validation. In this setting, it is important that patients are aware that the offered therapy will most likely be in the context a multimodality treatment plan. In particular, if radiation is used, the combination of local with systemic treatment provides the best outcome, provided the patient is fit enough to receive both. Until the results of the SPCG15 trial are known, the optimal local treatment remains a matter of debate. Patients should at all times be fully informed about all available options, and the likelihood of a multimodal approach including the potential side effects of both local and systemic treatment.

PATIENT SUMMARY

We reviewed the literature to see whether the evidence from clinical studies would tell us the best way of curing men with aggressive prostate cancer that had not spread to other parts of the body such as lymph glands or bones. Based on the results of this systematic review, there is good evidence that both surgery and radiation therapy are good treatment options, in terms of prolonging life and preserving quality of life, provided they are combined with other treatments. In the case of surgery this means including radiotherapy (RT), and in the case of RT this means either hormonal therapy or combined RT and brachytherapy.