Radiation therapy for prostate cancer: What's the best in 2021

Magnetic resonance guided SBRT reirradiation in locally recurrent prostate cancer: a multicentric retrospective analysis

AIMS

Reirradiation of prostate cancer (PC) local recurrences represents an emerging challenge for current radiotherapy. In this context, stereotactic body radiation therapy (SBRT) allows the delivery of high doses, with curative intent. Magnetic Resonance guided Radiation Therapy (MRgRT) has shown promising results in terms of safety, feasibility and efficacy of delivering SBRT thanks to the enhanced soft tissue contrast and the online adaptive workflow. This multicentric retrospective analysis evaluates the feasibility and efficacy of PC reirradiation, using a 0.35 T hybrid MR delivery unit.

METHODS

Patients affected by local recurrences of PC and treated in five institutions between 2019 and 2022 were retrospectively collected. All patients had undergone previous Radiation Therapy (RT) in definitive or adjuvant setting. Re-treatment MRgSBRT was delivered with a total dose ranging from 25 to 40 Gy in 5 fractions. Toxicity according to CTCAE v 5.0 and treatment response were assessed at the end of the treatment and at follow-up.

RESULTS

Eighteen patients were included in this analysis. All patients had previously undergone external beam radiation therapy (EBRT) up to a total dose of 59.36 to 80 Gy. Median cumulative biologically effective dose (BED) of SBRT re-treatment was 213,3 Gy (103,1-560), considering an α/β of 1.5. Complete response was achieved in 4 patients (22.2%). No grade ≥ 2 acute genitourinary (GU) toxicity events were recorded, while gastrointestinal (GI) acute toxicity events occurred in 4 patients (22.2%).

CONCLUSION

The low rates of acute toxicity of this experience encourages considering MRgSBRT a feasibile therapeutic approach for the treatment of clinically relapsed PC. Accurate gating of target volumes, the online adaptive planning workflow and the high definition of MRI treatment images allow delivering high doses to the PTV while efficiently sparing organs at risk (OARs).

A Novel L-Phenylalanine Dipeptide Inhibits the Growth and Metastasis of Prostate Cancer Cells via Targeting DUSP1 and TNFSF9

Prostate cancer (PCa) is a common malignant cancer of the urinary system. Drug therapy, chemotherapy, and radical prostatectomy are the primary treatment methods, but drug resistance and postoperative recurrence often occur. Therefore, seeking novel anti-tumor compounds with high efficiency and low toxicity from natural products can produce a new tumor treatment method. Matijin-Su [N-(N-benzoyl-L-phenylalanyl)-O-acetyl-L-phenylalanol, MTS] is a phenylalanine dipeptide monomer compound that is isolated from the Chinese ethnic medicine Matijin (Dichondra repens Forst.). Its derivatives exhibit various pharmacological activities, especially anti-tumor. Among them, the novel MTS derivative HXL131 has a significant inhibitory effect against prostate tumor growth and metastasis. This study is designed to investigate the effects of HXL131 on the growth and metastasis of human PCa cell lines PC3 and its molecular mechanism through in vitro experiments combined with proteomics, molecular docking, and gene silencing. The in vitro results showed that HXL131 concentration dependently inhibited PC3 cell proliferation, induced apoptosis, arrested cell cycle at the G2/M phase, and inhibited cell migration capacity. A proteomic analysis and a Western blot showed that HXL131 up-regulated the expression of proliferation, apoptosis, cell cycle, and migration-related proteins CYR61, TIMP1, SOD2, IL6, SERPINE2, DUSP1, TNFSF9, OSMR, TNFRSF10D, and TNFRSF12A. Molecular docking, a cellular thermal shift assay (CETSA), and gene silencing showed that HXL131 had a strong binding affinity with DUSP1 and TNFSF9, which are important target genes for inhibiting the growth and metastasis of PC3 cells. This study demonstrates that HXL131 exhibited excellent anti-prostate cancer activity and inhibited the growth and metastasis of prostate cancer cells by regulating the expression of DUSP1 and TNFSF9.

Late Adverse Health Outcomes and Quality of Life after Curative Radiotherapy+ long-term ADT in Prostate Cancer Survivors:Comparison with men from the General Population

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More than 5 years after radiotherapy for prostate cancer ) 54 % elderly patients report at least one moderate or big problem within the urinary, bowel or sexual domain. (Controls : 30%)

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Such problems reduce Quality of Life., which, however ,is similar in the two cohorts , the least difference observed within the sexual domain.

Background

Few studies have described the impact of urinary, bowel and sexual Adverse Health Outcomes (AHOs) on Quality of Life (QoL) in Prostate Cancer Survivors living for more than 5 years after curative radiotherapy (“long-term PCaSs”), and compared the findings with those in men from general population. Here we assess self-reported AHOs in such PCaSs focusing on the association between problem experience and QoL. The findings are compared to corresponding symptoms in age-similar men from the general population without a PCa diagnosis (Norms).

Methods

Nine years (mean) after curative radiotherapy 1231 PCaSs and 3156 Norms completed the EPIC-26 questionnaire and the EORTC QLQ-C30 instrument. Domain Summary Scores (DSSs) for the urinary, bowel and sexual domains, the percentages of moderate/big dysfunctions and the proportions of overall problems were determined. Inter-cohort differences were interpreted based on cut-off values for published Minimal Clinically Important Differences (MCIDs). Multivariable linear regression models analyzed the associations between QoL and domain-related overall problems.

Results

Only the inter-cohort differences regarding bowel and sexual DSSs exceeded the respective MCIDs. Among PCaSs 54% had at least one moderate/big problem (Norms: 30%). In PCaSs and Norms, QoL increased with decreasing urinary and bowel problems, For sexuality this association was weaker in Norms and was almost lacking in PCaSs. Multivariable-adjusted QoL was similar in PCaSs and Norms, with general health being the strongest covariate.

Conclusions

During follow-up of long-term PCaSs health professionals should be aware of the survivors’ persisting moderate/big urinary, bowel or sexual problems associated with reduced QoL. In particular , alleviation of urinary and bowel problems can increase the men’s QoL.