Genomic signature for oligometastatic disease in non-small cell lung cancer patients with brain metastases.

Purpose/objectives: Biomarkers for extracranial oligometastatic disease remain elusive and few studies have attempted to correlate genomic data to the presence of true oligometastatic disease. Methods: Patients with non-small cell lung cancer (NSCLC) and brain metastases were identified in our departmental database. Electronic medical records were used to identify patients for whom liquid biopsy-based comprehensive genomic profiling (Guardant Health) was available. Extracranial oligometastatic disease was defined as patients having ≤5 non-brain metastases without diffuse involvement of a single organ. Widespread disease was any spread beyond oligometastatic. Fisher's exact tests were used to screen for mutations statistically associated (p<0.1) with either oligometastatic or widespread extracranial disease. A risk score for the likelihood of oligometastatic disease was generated and correlated to the likelihood of having oligometastatic disease vs widespread disease. For oligometastatic patients, a competing risk analysis was done to assess for cumulative incidence of oligometastatic progression. Cox regression was used to determine association between oligometastatic risk score and oligoprogression. Results: 130 patients met study criteria and were included in the analysis. 51 patients (39%) had extracranial oligometastatic disease. Genetic mutations included in the Guardant panel that were associated (p<0.1) with the presence of oligometastatic disease included ATM, JAK2, MAP2K2, and NTRK1, while ARID1A and CCNE1 were associated with widespread disease. Patients with a positive, neutral and negative risk score for oligometastatic disease had a 78%, 41% and 11.5% likelihood of having oligometastatic disease, respectively (p<0.0001). Overall survival for patients with positive, neutral and negative risk scores for oligometastatic disease was 86% vs 82% vs 64% at 6 months (p=0.2). Oligometastatic risk score was significantly associated with the likelihood of oligoprogression based on the Wald chi-square test. Patients with positive, neutral and negative risk scores for oligometastatic disease had a cumulative incidence of oligometastatic progression of 77% vs 35% vs 33% at 6 months (p=0.03). Conclusions: Elucidation of a genomic signature for extracranial oligometastatic disease derived from non-invasive liquid biopsy appears feasible for NSCLC patients. Patients with this signature exhibited higher rates of early oligoprogression. External validation could lead to a biomarker that has the potential to direct local therapies in oligometastatic patients.

Predictors of brain metastases in patients with oligometastatic solid tumours treated with stereotactic body radiation therapy.

PURPOSE: In patients with oligometastatic disease (OMD) treated with stereotactic body radiation therapy (SBRT), those who develop brain metastases (BrM) may have poor outcomes. We aimed to investigate variables associated with BrM development in this population. METHODS: Patients with ≤ 5 extracranial metastases from solid tumors treated with SBRT from 2008 to 2016 at Sunnybrook Odette Cancer Centre were included. We investigated the association between covariates and CIBrM (cumulative incidence of BrM) using Fine-Gray analysis, and progression-free survival (PFS) and overall survival (OS) using Cox regression. We investigated the association between extracranial progression and CIBrM using time-based conditional analysis. RESULTS: Among 404 patients, the most common primary sites were lung, colorectal, prostate, breast and kidney. Median follow-up was 49 months. Median PFS was 25 months. Median OS was 70 months. 58 patients developed BrM, and 5-year CIBrM was 16%. On multivariable analysis, number of extracranial metastases, location of metastases, total planning target volume (PTV), and time from primary diagnosis to OMD were not associated with CIBrM, although several of these variables were associated with extracranial PFS and OS. Primary site was associated with CIBrM, with colorectal and prostate cancer associated with lower CIBrM compared to lung cancer. Widespread extracranial progression (≥ 5 sites) within 24, 36, 48 and 60 months of OMD diagnosis was independently associated with higher CIBrM. CONCLUSION: In patients with OMD treated with SBRT, baseline variables related to extracranial disease burden and distribution were not associated with BrM development, while primary site and widespread extracranial progression were associated with BrM development.

Brain Metastatic Prostate Adenocarcinoma: Avoiding Mistaken Identities.

Brain metastatic carcinoma is a rare occurrence among prostate cancer metastases. 68Gallium prostate-specific membrane antigen PET-CT ([68Ga]PSMA PET/CT) is commonly used for prostate cancer staging and detection of biochemical recurrences. However, various CNS tumors exhibit activity on [68Ga]PSMA PET/CT and may often be included in the differential diagnosis. Herein, we present a case of brain metastatic prostate cancer successfully treated with surgical resection and adjuvant stereotactic Gamma Knife radiosurgery (GKRS) followed by androgen deprivation therapy (ADT) to emphasize the need for histologic confirmation. A 70-year-old male with a history of very high-risk prostatic adenocarcinoma presented with biochemical recurrence following radical prostatectomy and irradiation of the prostatic fossa. [68Ga]PSMA PET/CT and MRI identified a solitary lesion in the left occipital lobe; differential diagnosis included prostate metastasis, meningioma, or a new metastatic primary lesion. The patient underwent surgical resection, and immunohistochemical staining confirmed the lesion as brain metastatic prostate adenocarcinoma. One month after resection, the patient underwent GKRS to the tumor bed and two additional metastases, followed by ADT. Repeated imaging 15 months after GKRS revealed stable posttreatment changes with no evidence of new metastases, thus demonstrating durable, effective local and systemic control. Brain metastatic prostate adenocarcinoma without nodal or osseous metastases is a rare phenomenon. The affinity of [68Ga]PSMA PET/CT for non-prostate histologies such as meningioma introduces uncertainty into the diagnostic process. This case demonstrates the durable local control conferred by GKRS toward these lesions and emphasizes the need for clinical, radiographic, and histopathologic data to identify disease presentations and facilitate appropriate treatment regimens.

Emerging Indications for Interventional Oncology: A Comprehensive Systematic Review of Image-Guided Thermal Ablation for Metastatic Non-cervical Lymph Node Disease.

INTRODUCTION: Lymphatic node metastatic disease encompasses a distinct oncological entity which has been associated with poor prognosis. Image-guided thermal ablation has recently been proposed as a safe and alternative treatment for these lesions. The aim of this systematic review is to evaluate the pooled safety and efficacy of thermal ablation techniques for the treatment of oligometastatic non-cervical lymph nodal disease. RECENT FINDINGS: A systematic search of the three major databases (MEDLINE, EMBASE, and CENTRAL) from inception to 30 December 2023 was conducted according to the PRISMA Guidelines. Observational studies reporting technical success, complications and oncologic outcomes were included. Meta- analysis was performed by estimating the pooled incidence rates and risk ratios by fitting random-effect models. Overall, 8 studies were included, comprising of 225 patients and 305 ablated LNMs and a median follow-up of 12 months. The combined data analysis showed that technical success after thermal ablation was 98% (CI: 95%-99%), major complication rate was 1% (CI: 95%-99%), pooled overall response rate was 72% (CI: 54%-87%), local tumor progression rate was 18% (CI: 8%-33%) and disease-free survival rate was 68% (CI: 51%-81%). No difference between radiofrequency ablation and cryoablation was found for every outcome during subgroup analysis. Image-guided percutaneous thermal ablation (with either radiofrequency ablation or cryoablation) is safe and effective for the treatment of oligometastatic LMN disease, however further studies to confirm these findings are still needed.

Feasibility, safety and outcomes of stereotactic radiotherapy for ultra-central thoracic oligometastatic disease guided by linear endobronchial ultrasound-inserted fiducials.

BACKGROUND & PURPOSE: Local treatment of oligometastases has been found to improve survival and prognosis. Stereotactic body radiotherapy (SBRT) has emerged as a treatment option for oligometastases but its use in ultra-central (UC) areas can cause significant toxicity and mortality. Fiducial markers (FM) can be used to improve SBRT accuracy, and can be inserted in the central thorax using linear endobronchial ultrasound (EBUS) bronchoscopy. Outcomes of FM-guided SBRT for UC thoracic oligometastases is unknown. METHODS: A single-centre retrospective study investigating the feasibility, safety and outcomes of both linear EBUS-inserted FMs and subsequent FM-guided SBRT for UC-oligometastatic disease. Motion analyses of FMs were also performed. RESULTS: Thirty outpatients underwent 32 EBUS-FM insertion procedures with 100 % success, and no major procedural mortality or morbidity. Minor complications were 4.8 % incidence of delayed FM-displacement. UC FM-guided SBRT was completed in 20 patients with 99.9 % fractions delivered. Median SBRT dose delivered was 40 Gy over a median of 8 fractions. Majority of adverse events were Grade 1 and there was no SBRT-related mortality. Local control with SBRT was 95 %, with overall survival at 1-year and 3-years of 90 % and 56.3 % respectively. Median overall survival after SBRT was 43.6 months. FM movements in UC areas were recorded being greatest in the superior-inferior axis. CONCLUSION: Combined linear EBUS sampling and FM-insertion in UC thoracic oligometastatic disease is feasible and safe. UC-SBRT to oligometastases using FM guidance was found to have minimal complications and associated with moderate survival up to 3 years post-treatment.

Brain Metastases as Inaugural Sign of Non-Small Cell Lung Carcinoma: Case Series and Review of Literature.

In the era of immune checkpoint inhibitors (ICI), managing non-oncogene driven non-small cell lung cancer (NSCLC) with brain metastases (BM) is challenging, especially when brain involvement is the initial sign. Patients with newly diagnosed brain metastatic NSCLC without epidermal growth factor receptor (EFGR) nor anaplastic lymphoma kinase (ALK) alterations were retrospectively included. Twenty-five patients were analyzed; 15 (60%) had symptomatic BM as the first sign (group 1), while 10 (40%) had BM discovered during complementary examinations (group 2). Fourteen patients (56%) had concomitant extracerebral metastases, primarily in group 2. Eight (32%) had oligometastatic disease, with seven in group 1. Over half received chemotherapy and pembrolizumab as first-line treatment. BM surgical resection occurred in twelve (80%) patients in group 1 and one in group 2. Median cerebral progression-free survival was 10 months: 12 in group 1 and 5 in group 2. Median overall survival was 25 months: not reached in group 1 and 6 months in group 2. This case series highlights survival outcomes for patients with inaugural BM, a demographic underrepresented in pivotal trials. Oligometastatic disease and symptomatic BM as initial signs seem associated with better prognosis due to increased use of multimodal local approaches. Combining local approaches with first-line ICI+/- chemotherapy appears to improve survival in brain metastatic NSCLC. A literature review was conducted to explore key questions regarding upfront ICI alone or in combination with systemic drugs or local approaches in brain metastatic NSCLC.

13-year survival oligometastatic Merkel cell carcinoma: a case report.

BACKGROUND: Merkel cell carcinomas are rare, aggressive skin tumors with high metastatic potential and poor prognosis. Their treatment is classically based on surgery with adjuvant external radiotherapy for localized tumors or on immunotherapy or chemotherapy, sometimes associated with radiotherapy, for metastatic stages. Those tumors are highly radiosensitive due to their neuroendocrine and undifferentiated nature, but they usually fail to rapidly respond to treatment. CASE PRESENTATION: We report the case of a 65-year-old retired female patient of Caucasian (German) origin with locally advanced Merkel cell carcinoma of the buttock, with pancreatic metastases synchronous at diagnosis, treated with local radiotherapy of the right buttock without regional lymph node irradiation followed by a sequential chemotherapy; 1 year later, the patient developed an isolated pancreatic recurrence treated with exclusive radiotherapy. The patient was still alive at 13 years with complete remission. CONCLUSION: External radiotherapy can be an effective alternative to surgery for locally advanced or even oligometastatic Merkel cell carcinomas.

Focal therapy for oligometastatic and oligoprogressive renal cell carcinoma: a narrative review.

Metastatic renal cell carcinoma (RCC) can present with oligometastatic disease and/or develop oligoprogression following systemic therapy. Cytoreductive and focal metastasis-directed therapy options include resection, stereotactic ablative radiation and thermal ablation. Aggressive focal therapy may allow delay in initiation of or modification to systemic therapy and improve clinical outcomes. In this narrative review we synthesize current practice guidelines and prospective data on focal therapy management options and highlight future research. Patient selection and the choice of focal treatment techniques are controversial due to limited and heterogeneous data and patients may benefit from multidisciplinary evaluation. Prospective comparative trials with clearly defined inclusion criteria and relevant end points are needed to clarify the risks and benefits of different approaches.

[Box: see text].

The Role of Surgery in Metastatic Renal Cell Carcinoma in 2024.

Renal cell carcinoma (RCC) is the most common solid tumour of the kidney and accounts for 3% of all cancers. While immune checkpoint inhibitor (ICI)-based combination therapies have emerged as the first-line treatment for metastatic renal cell carcinoma (mRCC), the role of surgery has become more controversial. This review summarizes the evidence, current role and future directions for surgery in mRCC management. The survival benefits of cytoreductive nephrectomy (CN) shown in the interferon era have encountered increasing disputes in the tyrosine-kinase inhibitor (TKI) and ICI eras. Undoubtedly, several systematic reviews based on retrospective data have supported the survival benefits of CN. Nevertheless, 2 prospective trials, CARMENA and SURTIME, proved that sunitinib as the upfront therapy resulted in noninferior survival outcomes compared with immediate CN. The safety of CN does have solid ground in the current literature. Several studies suggested that preoperative systemic therapy did not seem to aggravate perioperative complications or mortality rates, in experienced centres. Meticulous patient selection is the rule of thumb in the modern management of mRCC patients. The limitations of the existing prognostication models, however, must be acknowledged. Clinicians should adopt a multidisciplinary and holistic approach and contemplate all patient, disease, surgeon and socio-economical factors, before deciding who should go for surgery. The advent of metastasis-directed therapy (MDT) and survival benefits of adjuvant pembrolizumab shown in the oligometastatic subgroup, where complete metastasectomy could be achieved (M1 NED), calls for more comparative studies against upfront ICI combinations. In summary, CN brings survival benefits to well-selected good-to-intermediate-risk mRCC patients. Individualized and multidisciplinary care is pivotal.

Case report of a patient with an intraosseous meningioma presenting as possible metastasis from prostate cancer: Diagnostic dilemma and review of literature.

Intraosseous meningiomas are a rare subtype of meningiomas representing approximately 2% of all cases. They can confound a diagnosis of other bone lesions including metastatic tumors. We present a case of a patient with prostate cancer who on staging workup was suspected to have a skull metastasis. Both bone scan and CT Head demonstrated a lesion in the right frontal calvarium. Surgical resection and pathology revealed an intraosseous meningioma. The patient was restaged as having localized prostate cancer and the was offered curative treatment for his malignancy. The case highlights the importance of obtaining tissue diagnosis in cases of radiographic isolated oligometastatic disease in patients with a known primary malignancy.

The Role of Surgery in "Oligometastatic" Pancreas Cancer.

The majority of patients diagnosed with pancreatic cancer already have metastatic disease at the time of presentation, which results in a 5-year survival rate of only 13%. However, multiagent chemotherapy regimens can stabilize the disease in select patients with limited metastatic disease. For such patients, a combination of curative-intent therapy and systemic therapy may potentially enhance outcomes compared to using systemic therapy alone. Of note, the evidence supporting this approach is primarily derived from retrospective studies and may carry a significant selection bias. Looking ahead, ongoing prospective trials are exploring the efficacy of curative-intent therapy in managing oligometastatic pancreatic cancer and the implementation of treatment strategies based on specific biomarkers. The emergence of these trials, coupled with the development of less invasive therapeutic modalities, provides hope for patients with oligometastatic pancreatic cancer.

Prognostic value of circulating tumor cells in oligorecurrent hormone-sensitive prostate cancer patients undergoing stereotactic body radiation therapy.

BACKGROUND: Stereotactic body radiation therapy (SBRT) is an effective metastasis-directed therapy for managing oligometastatic prostate cancer patients. However, it lacks reliable biomarkers for risk stratification. Circulating Tumor Cells (CTC) show promise as minimally invasive prognostic indicators. This study evaluates the prognostic value of CTC in oligorecurrent hormone-sensitive prostate cancer (orHSPC). METHODS: orHSPC patients with 1-3 nodal and/or bone metastases undergoing SBRT were enrolled (N = 35), with a median follow-up time of 42.1 months. CTC levels were measured at baseline (T0), 1 month (T1), and 3 months (T2) post-SBRT using a novel metabolism-based assay. These levels were correlated with clinical outcomes through Cox-regression and Kaplan-Meier analyses. RESULTS: Median CTC counts were 5 at T0, 8 at T1, and 5 at T2 with no significant variation over time. Multivariate analysis identified high (≥5/7.5 mL) T0 CTC counts (HR 2.9, 95% CI 1.3-6.5, p = 0.01, median DPFS 29.7 vs. 14.0 months) and having more than one metastasis (HR 3.9, 95% CI 1.8-8.6, p < 0.005, median DPFS 34.1 vs. 10.7 months) as independent predictors of distant progression-free survival (DPFS). CTC assessment successfully stratified patients with a single metastasis (HR 3.4, 95% CI 1.1-10.2, p = 0.03, median DPFS 42.1 vs. 16.7 months), but not those with more than one metastasis. Additionally, a combined score based on CTC levels and the number of metastases effectively stratified patients. CONCLUSION: The study demonstrates that hypermetabolic CTC could enhance risk stratification in orHSPC patients undergoing SBRT, particularly in patients with limited metastatic burden, potentially identifying patients with indolent disease who are suitable for tailored SBRT interventions.

OligoM-Cancer: A multidimensional information platform for deep phenotyping of heterogenous oligometastatic cancer.

Patients with oligometastatic cancer (OMC) exhibit better response to local therapeutic interventions and a more treatable tendency than those with polymetastatic cancers. However, studies on OMC are limited and lack effective integration for systematic comparison and personalized application, and the diagnosis and precise treatment of OMC remain controversial. The application of large language models in medicine remains challenging because of the requirement of high-quality medical data. Moreover, these models must be enhanced using precise domain-specific knowledge. Therefore, we developed the OligoM-Cancer platform (http://oligo.sysbio.org.cn), pioneering knowledge curation that depicts various aspects of oligometastases spectrum, including markers, diagnosis, prognosis, and therapy choices. A user-friendly website was developed using HTML, FLASK, MySQL, Bootstrap, Echarts, and JavaScript. This platform encompasses comprehensive knowledge and evidence of phenotypes and their associated factors. With 4059 items of literature retrieved, OligoM-Cancer includes 1345 valid publications and 393 OMC-associated factors. Additionally, the included clinical assistance tools enhance the interpretability and credibility of clinical translational practice. OligoM-Cancer facilitates knowledge-guided modeling for deep phenotyping of OMC and potentially assists large language models in supporting specialised oligometastasis applications, thereby enhancing their generalization and reliability.

The Role of Metastasectomy in Patients with Liver-Only Metastases from Gastric Adenocarcinoma.

BACKGROUND: The role of metastasectomy in patients with liver-only metastases from gastric adenocarcinoma remains under investigation. Therefore, we performed a national registry analysis comparing surgical treatment options for patients with gastric adenocarcinoma and liver-only metastases. PATIENTS AND METHODS: In this retrospective National Cancer Database (2010-2019) study, adults (≥ 18 years) with gastric adenocarcinoma and liver-only metastases (no brain, bone, or lung metastases) were included. Patients were stratified into four groups: no surgical treatment, primary tumor resection (PTR), liver metastasectomy, and PTR with liver metastasectomy. Survival was evaluated using the Kaplan-Meier method, log-rank test, and Cox regression. RESULTS: Of 10,977 included patients, 93.6% underwent no surgical treatment, 4.6% PTR alone, 0.8% liver metastasectomy alone, and 1.0% both PTR and liver metastasectomy. The median OS after no surgical treatment was 6.5 months, after PTR alone 10.9 months, after liver metastasectomy alone 9.9 months, and after PTR and liver metastasectomy 18.6 months. In multivariable analysis, when adjusting for age, sex, race/ethnicity, insurance status, Charlson-Deyo score, chemotherapy, and radiation, PTR and liver metastasectomy was associated with superior OS compared with no surgical treatment (HR 2.17, 95% CI 1.76-2.69, p < 0.001), PTR alone (HR 1.42, 95% CI 1.12-1.79, p = 0.003), and liver metastasectomy alone (HR 1.96, 95% CI 1.45-2.64, p < 0.001). CONCLUSIONS: These data suggest that, in highly selected patients with gastric adenocarcinoma and synchronous liver-only metastases and favorable biology, surgical resection might grant a survival advantage.

Oligometastatic non-small cell lung cancer: Impact of local and contemporary systemic treatment approaches on clinical outcome.

Oligometastatic (OMD) non-small cell lung cancer (NSCLC) is a distinct but heterogeneous entity. Current guidelines recommend systemic therapy and consolidation with local ablative therapy (LAT). However, evidence regarding the optimal choice of multimodal treatment approaches is lacking, in particular with respect to the integration of immunotherapy. This real-world study identified 218 patients with OMD NSCLC (2004-2023, prespecified criteria: ≤5 metastases in ≤2 organ systems) from three major German comprehensive cancer centers. Most patients had one (72.5%) or two (17.4%) metastatic lesions in a single (89.9%) organ system. Overall survival (OS) was significantly longer with a single metastatic lesion (HR 0.54, p = .003), and female gender (HR 0.4, p < .001). Median OS of the full cohort was 27.8 months, with 29% survival at 5 years. Patients who had completed LAT to all NSCLC sites, typically excluding patients with early progression, had a median OS of 34.4 months (37.7% 5-year OS rate) with a median recurrence-free survival (RFS) of 10.9 months (13.3% at 5 years). In those patients, systemic treatment as part of first-line therapy was associated with doubling of RFS (12.3 vs. 6.4 months, p < .001). Despite limited follow-up of patients receiving chemo-immunotherapy (EU approval 2018/2019), RFS was greatly improved by adding checkpoint inhibitors to chemotherapy (HR 0.44, p = .008, 2-year RFS 51.4% vs. 15.1%). In conclusion, patients with OMD NSCLC benefitted from multimodality approaches integrating systemic therapy and local ablation of all cancer sites. A substantial proportion of patients achieved extended OS, suggesting a potential for cure that can be further augmented with the addition of immunotherapy.

Use of Personalized Ultra-Fractionated Stereotactic Adaptive Radiotherapy for Oligometastatic Lung Adenocarcinoma: Leveraging CT-Guided Online Adaptive Radiotherapy.

Management of oligometastatic non-small cell lung cancer (OM-NSCLC) has changed considerably in recent years, as these patients were found to have better survival with systemic therapy followed by consolidative radiation. Stereotactic body radiotherapy (SBRT), characterized by high doses of radiation delivered in a limited number of fractions, has been shown to have improved local control compared to conventionally fractionated radiation in early-stage lung cancer, but its use in large tumors, ultra-central tumors, or mediastinal nodal regions is limited due to concerns of toxicity to nearby serial mediastinal structures. Recent improvements in image guidance and fast replanning allow adaptive radiotherapy to be used to personalize treatment to the patient's daily anatomy and ensure accurate dose delivery to the tumor while minimizing dose and toxicity to normal. Adaptive SBRT can expand its use into ultra-central tumors that otherwise may not be amenable to SBRT or enable alternative fractionation schedules such as personalized ultra-fractionated stereotactic adaptive radiotherapy (PULSAR) with one-month intervals between fractions. In this case, we report a patient initially presenting with bulky OM-NSCLC of the left lung and mediastinum with an isolated left femur metastasis who was referred for consolidative radiotherapy after systemic therapy. We demonstrate how CT-guided online adaptive radiotherapy to the lung and mediastinum can be used despite the long time interval between treatments. In addition, adaptive plans lead to a substantial decrease in the heart dose, with moderate decreases in other organs compared to non-adaptive plans. This case demonstrates the feasibility of using adaptive radiotherapy for PULSAR of ultra-central OM-NSCLC.

Evidence and emerging trends in local therapy for metastatic hormone-sensitive prostate cancer: a narrative review.

Introduction: Metastatic hormone-sensitive prostate cancer (mHSPC) displays both simultaneous and sequential patterns of metastasis, emphasizing a comprehensive treatment approach that integrates both local therapy and systemic treatment strategies. The increasing use of molecular imaging has led to a rise in mHSPC diagnoses, underscoring the importance of identifying the right patient population and effective treatment concepts for this disease state. Results: Two prospective trials, HORRAD and STAMP EDE, investigated prostate radiotherapy (RT) for mHSPC; however, they did not show an overall survival (OS) benefit in the unselected cohort. Nonetheless, RT showed favorable outcomes in patients with fewer than five bone metastases, resulting in a 7% 3-year survival improvement and supporting the integration of RT in multimodal treatment for men with oligometastatic mHSPC. Regarding cytoreductive prostatectomy (cRP), the TRoMbone Trial confirmed its feasibility and safety. In addition, findings from the FUSCC-OMPCa Trial demonstrated improved 3-year radiographic progression-free survival and OS rates with acceptable rates of complications and incontinence. Recent data from the LoMP registry have further supported superior OS and cancer-specific survival (CSS) in patients undergoing cRP compared to systemic therapy alone. Notably, no significant differences in OS and CSS were observed between the cRP and RT groups. However, cRP-treated patients exhibited superior 2-year local event-free survival when compared to those treated with RT. Conclusion: RT in combination with systemic therapy remains the established first-line treatment for low-burden mHSPC, though the exact definition of low metastatic burden remains contentious. Precise assessment of metastatic burden is vital to identify patients who would derive the greatest benefit from RT. As treatment paradigms evolve, embracing multimodal approaches holds potential for optimizing outcomes in patients with mHSPC. Further research is needed to solidify the role of cRP as a standard therapeutic approach and to refine treatment strategies for improved patient outcomes.

Influence of Tumor Characteristics and Time to Metastatic Disease on Oncological Outcomes in Metachronous Metastatic Prostate Cancer Patients.

INTRODUCTION: Metachronous metastatic prostate cancer (mmPCa) patients harbor different characteristics and outcomes, relative to DeNovo metastatic PCa patients. Onset of metastatic disease might be influenced by primary PCa characteristics such as Gleason score (GS) or cancer stage, as well as overall survival (OS) by timing of metastatic onset. PATIENTS AND METHODS: We relied on an institutional tertiary-care database to identify mmPCa patients. Kaplan Meier and Cox Regression models tested for onset of metastases and OS, stratified according to GS, pathological stage and time to mmPCa. RESULTS: Of 341 mmPCa patients, 8% harbored GS6 versus 41% versus 51% GS7 and GS8-10. Median time to onset of metastatic disease was 79 versus 54 versus 41 months for GS6 versus GS7 versus GS8-10 (P = .01). Moreover, median time to onset of metastases was 64 versus 44 months for pT1-2 versus pT3-4 mmPCa patients undergoing radical prostatectomy (P = .027). In multivariable Cox regression models, higher GS and pT-stage was associated with earlier onset of metastases. Additionally, significant OS differences could be observed for time interval of < 24 versus 24-60 versus 60-120 versus ≥ 120 months between primary PCa diagnosis and onset of mmPCa. Specifically, median OS was 56 versus 69 versus 97 months versus not reached (P < .01) for these categories. In multivariable Cox regression, shorter time to metastatic onset was associated with shorter OS. CONCLUSION: Timing of mmPCa is strongly influenced by grading and pT-stage in real-life setting. OS benefits can be observed with longer time interval between primary PCa diagnosis and onset of mmPCa.