High-risk prostate cancer: combination of high-dose, high-precision radiotherapy and androgen deprivation therapy

Suboptimal use of hormonal therapy among German men with localized high-risk prostate Cancer during 2005 to 2015: analysis of registry data

Background

This study assesses the use of hormonal therapy to treat high-risk localized prostate cancer (HRLPCa) cases diagnosed between 2005 and 2015.

Methods

All N_0-XM₀ with ≥T_3a, or PCa cases with poorly differentiated feature (equivalent to Gleason score ≥ 8), diagnosed between 2005 and 2015 were extracted from German population-based cancer registries. Cases treated by surgery or chemotherapy were excluded. Description of hormonal therapy use by HRLPCa cases’ profile was presented. Relative risk (RR) was computed with a log-link function to identify factors associated with hormonal therapy use among radiotherapy-treated HRLPCa cases.

Results

A total of 5361 HRLPCa cases were analyzed. Only 27.6% (95% confidence interval [CI]: 26.4–28.8%) of the HRLPCa cases received hormonal therapy in combination with radiotherapy. The use of combined hormonal therapy and radiotherapy varied from 19.8% in Saxony to 47.8% in Schleswig-Holstein.

Application of hormonal therapy was higher for the locally advanced cases compared to the poorly differentiated cases (relative risk [RR] = 1.28; 95%CI: 1.19, 1.37). Older patients showed a slightly increased use of hormonal therapy (RR for a 10-year age increase = 1.09; 95%CI: 1.02, 1.16). Compared to PCa cases from the most affluent residential areas, cases from the least affluent (RR = 0.71; 95%CI: 0.55, 0.92) and medium (RR = 0.75; 95%CI: 0.58, 0.96) areas had decreased use of hormonal therapy. The introduction of the German S3-guideline did not make a marked difference in the uptake of both hormonal therapy and radiotherapy (RR = 1.02; 95%CI: 0.95, 1.09).

Conclusion

This study found a low use of hormonal therapy among HRLPCa patients treated without surgery. The introduction of the German S3-guideline for prostate cancer treatment does not seem to have impacted hormonal therapy use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09677-z.

Combined hyperthermia and radiotherapy for prostate cancer: a systematic review

Optimization of treatment strategies for prostate cancer patients treated with curative radiation therapy (RT) represents one of the major challenges for the radiation oncologist. Dose escalation or combination of RT with systemic therapies is used to improve tumor control in patients with unfavorable prostate cancer, at the risk of increasing rates and severity of treatment-related toxicities. Elevation of temperature to a supra-physiological level has been shown to both increase tumor oxygenation and reduce DNA repair capabilities. Thus, hyperthermia (HT) combined with RT represents a compelling treatment strategy to improve the therapeutic ratio in prostate cancer patients. The aim of the present systematic review is to report on preclinical and clinical evidence supporting the combination of HT and RT for prostate cancer, discussing future applications and developments of this combined treatment.

Membrane translocation and activation of GnRH receptor sensitize prostate cancer cells to radiation

BACKGROUND

GnRH analogs are widely used as neoadjuvant agents for radiotherapy in prostate cancer (PCa) patients, with well-documented effects in reducing tumor bulk and increasing progression-free survival. GnRH analogs act locally in the prostate by triggering apoptosis of PCa cells via activation of the GnRH receptor (GnRHR). During PCa progression, the distribution of GnRHR within the cell is altered, with reduced expression in the cell membrane and remaining sequestered in the endoplasmic reticulum. Pharmacoperone IN3 is able to relocalize GnRHR to the cell membrane. The aim of this study was to evaluate the effect of radiation on PCa cells pretreated with leuprolide, alone or in combination with IN3, as radiosensitizers.

MATERIAL AND METHODS

PC3 and human PCa primary cell cultures were treated with IN3 for 24 h, followed by different doses of leuprolide for 48 h and, finally, single doses of radiation (3, 6, and 9 Gy). After radiation, cell survival, apoptosis, cell cycle distribution, and colony growth were evaluated.

RESULTS

Radiation reduced cell survival and increased apoptosis in a dose-dependent manner. This effect was also directly related to leuprolide concentration. Pretreatment with IN3 enhanced apoptosis and decreased cell survival, also observing a higher proportion of cells arrested in G2.

CONCLUSION

Neoadjuvant leuprolide increases radiation-mediated apoptosis of PCa cells. This effect was enhanced by pretreatment with pharmacoperone IN3. Clinical use of IN3 as a radiosensitizer combined with androgen deprivation therapy to improve survival of patients with PCa remains to be evaluated.

68Ga-PSMA-PET/CT-directed IGRT/SBRT for oligometastases of recurrent prostate cancer after initial surgery

Background: We evaluated efficacy and toxicity of ⁶⁸Ga-PSMA-Positron Emission Tomography/Computed Tomography (PET/CT)-directed stereotactic body radiotherapy and image-guided radiotherapy (SBRT/IGRT) for oligometastases of prostate cancer recurrences after previous surgery.Methods: Nineteen patients were analyzed within a prospective PET-registry study (064/2013BO1) and retrospectively analyzed (807/2017BO2) fulfilling the following inclusion criteria: biochemical recurrence after radical prostatectomy, ≤five ⁶⁸Ga-PSMA-PET/CT positive lesions. Biochemical control was evaluated with EORTC (European Organization for Research and Treatment of Cancer)- and Phenix-definitions. Toxicity was scored according to CTCAE-criteria v. 4.03.Results: A total of 38 oligometastases (19 patients, 2 with re-treatment) were treated with SBRT/IGRT from October 2014 to July 2017. ⁶⁸Ga-PSMA-PET/CT-positive lesions were detected on average 39 months (5-139) after prostatectomy (pT2b-3b pN0-1 cM0). Mean PSA (Prostate-specific antigen)-level at time of imaging reached 2.2 ng/mL (range 0.2-10.1). PET/CT-positive lesions were treated with different fractionation schedules reaching biological equivalent doses (BED) of 116.7-230.0 Gy. Concomitant androgen deprivation therapy (ADT) was given in seven patients. After a median follow-up of 17 months (4-42) all patients were alive. Estimated 1-year PSA- control (n = 19) reached 80.8% (Phenix) and 67.5% (EORTC). A PSA-decline (≥50%) was detected in 16/19 patients after radiotherapy. Higher graded G3+-acute toxicity did not occur. Temporary late G3-proctitis was detected in one patient.Conclusions: Reaching of nadir ≤0.1 or 0.2 ng/mL was associated by improved DMFS (distant metastases free survival) and could serve as a surrogate endpoint for RT of oligometastases after initial prostatectomy. Short term effects of ⁶⁸Ga-PSMA-PET/CT-based ablative radiotherapy for oligometastases demonstrated an acceptable toxicity profile and favorable biochemical response.

Consensus statements on the management of clinically localized prostate cancer from the Hong Kong Urological Association and the Hong Kong Society of Uro-Oncology

OBJECTIVE

To formulate consensus statements to facilitate physician management strategies for patients with clinically localized prostate cancer (PCa) in Hong Kong by jointly convening a panel of 12 experts from the two local professional organizations representing PCa specialists, who had previously established consensus statements on the management of metastatic PCa for the locality.

METHODS

Through a series of meetings, the panellists discussed their clinical experience and the published evidence regarding various areas of the management of localized PCa, then drafted consensus statements. At the final meeting, each drafted statement was voted on by every panellist based on its practicability of recommendation in the locality.

RESULTS

A total of 76 consensus statements were ultimately accepted and established by panel voting.

CONCLUSION

Derived from the recent evidence and major overseas guidelines, along with local clinical experience and practicability, the consensus statements were aimed to serve as a practical reference for physicians in Hong Kong for the management of localized PCa.

DNA Damage Response in Prostate Cancer

Prostatic adenocarcinoma (PCa) remains a significant health concern. Although localized PCa can be effectively treated, disseminated disease remains uniformly fatal. PCa is reliant on androgen receptor (AR); as such, first-line therapy for metastatic PCa entails suppression of AR signaling. Although initially effective, recurrent tumors reactivate AR function, leading to a lethal stage of disease termed castration-resistant PCa (CRPC). Recent findings implicate AR signaling in control of DNA repair and show that alterations in DNA damage repair pathways are strongly associated with disease progression and poor outcome. This review will address the DNA repair alterations observed in the clinical setting, explore the anticipated molecular and cellular consequence of DNA repair dysfunction, and consider clinical strategies for targeting tumors with altered DNA repair.

Androgen Deprivation Therapy Potentiates the Efficacy of Vascular Targeted Photodynamic Therapy of Prostate Cancer Xenografts

Purpose: WST11 vascular targeted photodynamic therapy (VTP) is a local ablation approach relying upon rapid, free radical-mediated destruction of tumor vasculature. A phase III trial showed that VTP significantly reduced disease progression when compared with active surveillance in patients with low-risk prostate cancer. The aim of this study was to identify a druggable pathway that could be combined with VTP to improve its efficacy and applicability to higher risk prostate cancer tumors.Experimental Design: Transcriptome analysis of VTP-treated tumors (LNCaP-AR xenografts) was used to identify a candidate pathway for combination therapy. The efficacy of the combination therapy was assessed in mice bearing LNCaP-AR or VCaP tumors.Results: Gene set enrichment analysis identifies the enrichment of androgen-responsive gene sets within hours after VTP treatment, suggesting that the androgen receptor (AR) may be a viable target in combination with VTP. We tested this hypothesis in mice bearing LNCaP-AR xenograft tumors by using androgen deprivation therapy (ADT), degarelix, in combination with VTP. Compared with either ADT or VTP alone, a single dose of degarelix in concert with VTP significantly inhibited tumor growth. A sharp decline in serum prostate-specific antigen (PSA) confirmed AR inhibition in this group. Tumors treated by VTP and degarelix displayed intense terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining 7 days after treatment, supporting an increased apoptotic frequency underlying the effect on tumor inhibition.Conclusions: Improvement of local tumor control following androgen deprivation combined with VTP provides the rationale and preliminary protocol parameters for clinical trials in patients presented with locally advanced prostate cancer. Clin Cancer Res; 24(10); 2408-16. ©2018 AACR.

Radiotherapy before and after radical prostatectomy for high-risk and locally advanced prostate cancer

OBJECTIVES

Men with localized high-risk prostate cancer carry significant risk of prostate cancer-specific mortality. The best treatment approach to minimize this risk is unclear. In this review, we evaluate the role of radiation before and after radical prostatectomy.

METHODS AND MATERIALS

A critical review of the literature was performed regarding the application of external radiation therapy (RT) in combination with prostatectomy for high-risk localized prostate cancer.

RESULTS

Up to 70% of men with high-risk localized disease may require adjuvant therapy because of adverse pathologic features or biochemical recurrence in the absence of systemic disease. The utility of adjuvant RT among men with adverse pathologic features are well established at least regarding minimizing biochemical recurrence risk. The optimal timing of salvage radiation is the subject of ongoing studies. Neoadjuvant RT requires further study but is a potentially attractive method because of decreased radiation field sizes and potential radiobiologic benefits of delivering RT before surgery. Salvage prostatectomy is effective at treating local recurrence after radiation but is associated with significant surgical morbidity.

CONCLUSIONS

Combining local therapies including radical prostatectomy and RT can be a reasonable approach. Care should be taken at the initial presentation of high-risk localized prostate cancer to consider and plan for the likelihood of multimodality care.

Androgen withdrawal fails to induce detectable tissue hypoxia in the rat prostate

BACKGROUND

It has been reported that significant hypoxia may occur in the rat prostate following androgen deprivation (AD). It is well known that hypoxia substantially reduces radiation sensitivity of cells both in vitro and in vivo. Given that contemporary management of men with intermediate and high-risk prostate cancer includes the use of neoadjuvant androgen suppression and radiation, AD-induced hypoxia in the prostate could result in suboptimal therapeutic results. Given this concern, we fully investigate possible AD-induced hypoxia in the ventral prostate (VP) of adult rats by two independent methods.

METHODS

Tissue pO2 levels in the VP of adult Spraque-Dawley rats were evaluated prior to and at various time points following castration by two independent techniques. First, an Oxylab tissue oxygen monitor with a 240 μm probe was used for quantitative monitoring of global VP oxygenation. Second, fluorescence immunohistochemistry using the hypoxia marker EF5, known to be metabolically activated by hypoxic cells, was used to evaluate cell-to-cell variation in hypoxia at various days post-castration.

RESULTS

Neither the oxygen probe nor EF5 method demonstrate any substantive change in pO2 levels in the rat VP at any time point post-castration.

CONCLUSIONS

We find no evidence that the rat VP becomes hypoxic at any point following castration using an animal model that closely mimics the human prostate. These data are in contrast to previous reports suggesting prostatic hypoxia occurs following AD and provide assurance that our present therapeutic strategy of neoadjuvant AD followed by radiation is not compromised by AD-induced tissue hypoxia.

Inflammation enhanced X-irradiation-induced colonic tumorigenesis in the Min mouse

Inflammation is potential risk factor of various human malignancies. Inflammatory bowel syndromes such as ulcerative colitis are well known as risk factors for colon cancer. Here, we examined enhancing effects of dextran sulfate sodium (DSS)-associated inflammation on X-irradiation induced colonic tumorigenesis in Min and wild-type (WT) mice. Animals were X-irradiated at 1.5 Gy at 5 weeks of age (at 0 experimental week) and 2% DSS in drinking water was administered at 5 or 11 experimental weeks. Mice were sacrificed at 16 weeks and incidence and multiplicity of colonic tumors were assessed. Incidence of colonic tumors in Min mouse was increased from 33.3% to 100% (p<0.05) with X-irradiation alone, whereas no tumors were developed in WT mice. In DSS-treated Min mice, X-irradiation increased the number of colonic tumors. Total number of colonic tumors was increased 1.57 times to 30.7±3.83 tumors/mouse with X-irradiation+DSS at 5 weeks comapared to 19.6±2.9 in corresponding DSS alone group (p<0.05). When the duration of inflammation was compared, longer period of DSS effect promoted more colonic tumorigenesis. Collectively, we conclude that X-irradiation and DSS-induced inflammation act synergistically for colonic tumorigenesis.

La Radioterapia Nel Trattamento Del Carcinoma Della Prostata: Indicazioni, Evoluzione Tecnologica e Approcci Integrati

Prostate cancer is a heterogeneous, indolent or sometimes aggressive tumor. Treatment options are various and without proved superiority. Radiotherapy (RT) plays a key role in the disease history. Technological evolution with Intensity Modulate Radiation Therapy (IMRT) and Image Guided Radiation Therapy (IGRT) allowed improvement, with significant results on local control and survival. Hypofractionation, Stereotactic Body RT (SBRT) and new brachytherapy approachs are still under investigation, with promising opportunities. Adjuvant vs salvage postoperative RT, hormone association, prophylactic pelvic irradiation are still under debate, but guidelines express overlapping indications.

Multidisciplinary managements will be the future for care optimization, providing the best tool for holistic and informed patients' choice.

Intraprostatic distribution and long-term follow-up after AdV-tk immunotherapy as neoadjuvant to surgery in patients with prostate cancer

A phase I-II study to evaluate gene mediated cytotoxic immunotherapy in newly diagnosed prostate cancer before radical prostatectomy was conducted in Monterrey, Mexico.