Multimodal therapy for oligometastatic prostate cancer: results from a single-centre study

Introduction. In recent years, interest in the use of radical prostatectomy (RPE) as one of the components of a multimodal approach in patients with lymphogenous disseminated and metastatic prostate cancer (PCa) has grown significantly. At the same time, the dearth of large randomized trials does not make it possible to use this technique in wide clinical practice outside of clinical trials.Purpose of the study. To evaluate the effectiveness of multimodal therapy using combined chemo-hormonal, surgical and radiation therapy in patients with primary oligometastatic hormone-sensitive PCa.Material and methods. The study included 48 patients with primary oligometastatic prostate cancer who received combination treatment within the internal one-research-center protocol. At the first stage, all patients underwent combined drug therapy with docetaxel (75 mg/m2 intravenously every 3 weeks for 6 courses) and degarelix. Patients who had a decrease in PSA level ≤ 2 ng/ml and registered stabilization of the disease according to radiological examination were treated surgically through RPE with extended pelvic and retroperitoneal lymph node dissection. Radiation therapy was performed only in patients with the presence of bone lesions at a dose of 50-70 Gy to the location of bone metastases in the stage 3 plan of combined multimodal therapy.Results. PCa biochemical relapse was verified in 27 (56.3%) patients during the median follow-up of 10 months. The average time to PSA increase was 9.0 ± 5.7 months (from 1 to 24 months), median — 7 months, Six-month PSA relapse-free survival (PSA-RFS) was 61.2 ± 7.5%; 1-year PSA-RFS — 38.0 ± 8.6%. The average duration before the initiation of hormonal therapy was 12 ± 6.1 months (from 3 to 27 months), median: 10 months. Six-month survival before the drug administration was 72.6 ± 6.8%; twelve-month survival: 40.9 ± 8.7%. About 40% of patients with oligometastatic PCa had no signs of progression and did not receive any other drug therapy for 12 months after completion of protocol treatment.Conclusions. Analysis of the study results demonstrates satisfactory oncological outcomes of the studied treatment option in patients with newly diagnosed oligometastatic hormone-sensitive PCa, as well as a low likelihood of side effects and complications. Nevertheless, it is necessary to continue conducting larger and more structured randomized trials to determine the possibility of applying this therapeutic approach in clinical practice.

[18F]FMCH PET/CT biomarkers and similarity analysis to refine the definition of oligometastatic prostate cancer

Background The role of image-derived biomarkers in recurrent oligometastatic Prostate Cancer (PCa) is unexplored. This paper aimed to evaluate [18F]FMCH PET/CT radiomic analysis in patients with recurrent PCa after primary radical therapy. Specifically, we tested intra-patient lesions similarity in oligometastatic and plurimetastatic PCa, comparing the two most used definitions of oligometastatic disease. Methods PCa patients eligible for [18F]FMCH PET/CT presenting biochemical failure after first-line curative treatments were invited to participate in this prospective observational trial. PET/CT images of 92 patients were visually and quantitatively analyzed. Each patient was classified as oligometastatic or plurimetastatic according to the total number of detected lesions (up to 3 and up to 5 or > 3 and > 5, respectively). Univariate and intra-patient lesions' similarity analysis were performed. Results [18F]FMCH PET/CT identified 370 lesions, anatomically classified as regional lymph nodes and distant metastases. Thirty-eight and 54 patients were designed oligometastatic and plurimetastatic, respectively, using a 3-lesion threshold. The number of oligometastic scaled up to 60 patients (thus 32 plurimetastatic patients) with a 5-lesion threshold. Similarity analysis showed high lesions' heterogeneity. Grouping patients according to the number of metastases, patients with oligometastatic PCa defined with a 5-lesion threshold presented lesions heterogeneity comparable to plurimetastic patients. Lesions within patients having a limited tumor burden as defined by three lesions were characterized by less heterogeneity. Conclusions We found a comparable heterogeneity between patients with up to five lesions and plurimetastic patients, while patients with up to three lesions were less heterogeneous than plurimetastatic patients, featuring different cells phenotypes in the two groups. Our results supported the use of a 3-lesion threshold to define oligometastatic PCa.

Prostate-Specific Membrane Antigen (PSMA) Theranostics for Treatment of Oligometastatic Prostate Cancer

Theranostics, a combination of therapy and diagnostics, is a field of personalized medicine involving the use of the same or similar radiopharmaceutical agents for the diagnosis and treatment of patients. Prostate-specific membrane antigen (PSMA) is a promising theranostic target for the treatment of prostate cancers. Diagnostic PSMA radiopharmaceuticals are currently used for staging and diagnosis of prostate cancers, and imaging can predict response to therapeutic PSMA radiopharmaceuticals. While mainly used in the setting of metastatic, castrate-resistant disease, clinical trials are investigating the use of PSMA-based therapy at earlier stages, including in hormone-sensitive or hormone-naïve prostate cancers, and in oligometastatic prostate cancers. This review explores the use of PSMA as a theranostic target and investigates the potential use of PSMA in earlier stage disease, including hormone-sensitive metastatic prostate cancer, and oligometastatic prostate cancer.