Metastasis-directed Therapy Research Articles

Radiation Oncologists' Perspectives on Oligometastatic Prostate Cancer: A Survey from Korean Oligometastasis Working Group.

Interest in the oligometastatic prostate cancer (OMPC) is increasing, and various clinical studies have reported the benefits of metastasis-directed radiation therapy (MDRT) in OMPC. However, the recognition regarding the adopted definitions, methodologies of assessment, and therapeutic approaches is diverse among radiation oncologists. This study aims to evaluate the level of agreement for issues in OMPC among radiation oncologists. We generated 15 key questions (KQs) for OMPC relevant to definition, diagnosis, local therapies, and endpoints. Additionally, three clinical scenarios representing synchronous metastatic prostate cancer (mPC) (case 1), metachronous mPC with visceral metastasis (case 2), and metachronous mPC with castration-resistance and history of polymetastasis (case 3) were developed. The 15 KQs were adapted according to each scenario and transformed into 23 questions with 6-9 per scenario. The survey was distributed to 80 radiation oncologists throughout the Republic of Korea. Answer options with 0.0-29.9%, 30-49.9%, 50-69.9%, 70-79.9%, 80-89.9%, and 90-100% agreements were considered as no, minimal, weak, moderate, strong, and near perfect agreement, respectively. Forty-five candidates voluntarily participated in this study. Among 23 questions, near perfect (n = 4), strong (n = 3), or moderate (n = 2) agreements were shown in nine. For the case recognized as OMPC with agreements of 93% (case 1), near perfect agreements on the application of definitive radiation therapy (RT) for whole metastatic lesions were achieved. While ≥70% agreements regarding optimal dose-fractionation for metastasis-directed RT (MDRT) has not been achieved, stereotactic body RT (SBRT) is favored by clinicians with higher clinical volume. For the case recognized as OMPC, near perfect agreement for the application of definitive RT for whole metastatic lesions was reached. SBRT was more favored as a MDRT by clinicians with a higher clinical volume.

Veterans Affairs seamless phase II/III randomized trial of standard systemic therapy with or without PET-directed local therapy for oligometastatic prostate cancer (VA STARPORT).

TPS5120 Background: The concept of metastasis-directed therapy (MDT) using radiation or surgery for oligometastatic (OM) prostate cancer (pCa) has evolved from an anecdotal hypothesis to a promising approach that may optimally balance toxicity and oncologic efficacy. Recently, there have been multiple smaller phase II randomized trials that have shown a signal of efficacy for MDT in OM pCa. Most studies have compared MDT to observation alone as the control arm, included only recurrent OM patients, and included up to 3-5 sites of metastasis. It is in this context, that the VA STARPORT trial was initiated in 2021 to definitively determine the role of MDT in Veterans with oligorecurrent pCa in 1-5 sites. Yet, the diagnosis and management of metastatic pCa have since evolved. The SABR-COMET-10 trial recently completed enrollment and compares systemic therapy alone or with MDT in patients with 1-10 metastases from various histologies. While pCa PET/CT imaging was only available for Veterans with biochemical recurrence in 2021, PSMA PET/CT now allows for the improved diagnosis of OM in Veterans with de novo pCa—a growing cohort of patients without a clear standard of care. Therefore, to maximize the impact and generalizability of the trial, VA STARPORT has been amended to allow for de novoOM and 1-10 metastases. The primary goal of VA STARPORT is to determine if adding PET-directed local therapy (PDLT) to standard systemic therapy (SST) improves disease control compared to SST alone in Veterans with recurrent and de novooligometastatic pCa. Methods: VA STARPORT is a phase II/III randomized trial open at 18 VA medical centers comparing SST alone (Arm 1) or with PDLT (Arm 2) in Veterans with OM pCa. Key eligibility criteria include recurrent or de novohormone-sensitive metastatic pCa and 1-10 metastatic lesions on any FDA-approved pCa PET/CT. The primary endpoint is castration-resistant prostate cancer-free survival (CRPC-free survival). Secondary endpoints include radiographic PFS, clinical PFS, freedom from index lesion progression, toxicity, quality of life, and prostate cancer-specific and overall survival. SST is delivered using any NCCN guideline-concordant regimen in both arms. PDLT can be either radiation or surgery to all sites of cancer. Regarding local therapy, de novo patients in Arm 1 receive prostate-directed RT, and in Arm 2 receive PDLT to all metastases and the prostate. For recurrent patients in Arm 1 there is no local therapy, while in Arm 2 patients receive PDLT. All participants undergo somatic tumor sequencing using the VA National Precision Oncology Program. Assuming a hazard ratio of 0.60 for SST + PDLT vs SST, two-sided alpha = 0.05 and 90% power, a total of 464 participants will be randomized to generate 166 CRPC-free survival events by the end of the active study phase. Recruitment is ongoing and 150 patients have been enrolled. Clinical trial information: NCT04787744 .

Multidisciplinary real-world management of metastatic castration-sensitive prostate cancer: A French national study (PROFILE study)

While androgen deprivation therapy (ADT) has been the standard of care for patients with metastatic castration-sensitive prostate cancer (mCSPC), recent strategies like intensification of systemic treatment (Rozet et al., 2020) (i.e. adding another treatment to ADT) and radiotherapy have improved overall survival. PROFILE, a national retrospective multicentric real-world study, involved patients with mCSPC recruited by medical oncologists, urologists, and radiation oncologists, and who started treatment between November 2020 and May 2021. Patients by sites were included consecutively. Data were collected from medical records. Primary objectives were to: (1) describe retrospectively the characteristics of whole population of patients with mCSPC as well as subgroups defined by prognostic factors in France at diagnosis; (2) identify current practices for managing mCSPC in a real-life clinical setting. Among the 416 patients with mCSPC included in the PROFILE study, 315 (76%) were synchronous (metastasis at the initial diagnosis) and 101 (24%) were metachronous patients (metastasis diagnosed post-progression). A majority (83% of synchronous and 73% of metachronous patients) received an intensified systemic treatment (ADT plus ARSI [androgen-receptor signaling inhibitors]±chemotherapy±primary tumour radiotherapy±metastasis-directed therapy [MDT]), while only 40% of low-volume patients received prostate radiotherapy. This study depicts the standardization of new therapeutic strategies for patients with mCSPC in France with most of them receiving an intensified treatment, mainly with ADT+ARSI (64% of synchronous intensified patients and 76% of metachronous intensified patients). Most of patients were assessed using conventional imaging (CT scan and/or bone scan). Overall, PROFILE results are in line with French and European guidelines for diagnosis, management, and follow-up of such patients (Rozet et al., 2020; Cornford et al., 2021).

Prostate Cancer Lung Metastasis: Clinical Insights and Therapeutic Strategies.

Prostate cancer lung metastasis represents a clinical conundrum due to its implications for advanced disease progression and the complexities it introduces in treatment planning. As the disease progresses to distant sites such as the lung, the clinical management becomes increasingly intricate, requiring tailored therapeutic strategies to address the unique characteristics of metastatic lesions. This review seeks to synthesize the current state of knowledge surrounding prostate cancer metastasis to the lung, shedding light on the diverse array of clinical presentations encountered, ranging from subtle radiological findings to overt symptomatic manifestations. By examining the diagnostic modalities utilized in identifying this metastasis, including advanced imaging techniques and histopathological analyses, this review aims to provide insights into the diagnostic landscape and the challenges associated with accurately characterizing lung metastatic lesions in prostate cancer patients. Moreover, this review delves into the nuances of therapeutic interventions employed in managing prostate cancer lung metastasis, encompassing systemic treatments such as hormonal therapies and chemotherapy, as well as metastasis-directed therapies including surgery and radiotherapy.

Protocol for CHAMPION study: a prospective study of maximal-cytoreductive therapies for patients with de novo metastatic hormone-sensitive prostate cancer who achieve oligopersistent metastases during systemic treatment with apalutamide plus androgen deprivation therapy

BackgroundThe proposed trial is to examine the feasibility of prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT)-guided cytoreduction plus apalutamide and androgen deprivation therapy (ADT) for newly diagnosed metastatic hormone-sensitive prostate cancer (mHSPC) at oligometastatic state.MethodsCHAMPION (NCT05717582) is an open-label, single-arm, phase II trial, planning to enroll newly diagnosed mHSPC cases with oligometastases (≤ 10 distant metastatic sites in conventional imaging). Patients will receive 6 cycles of apalutamide plus ADT. Patients with oligometastatic disease at PSMA PET/CT after 3 treatment cycles will receive cytoreductive radical prostatectomy. PSMA PET/CT-guided metastasis-directed external radiation therapy will be determined by the investigators. Apalutamide plus ADT will be continued for 2 weeks postoperatively. The primary endpoint is the proportion of patients with undetectable prostate-specific antigen (PSA), no disease progression, and no symptom deterioration after 6 cycles of apalutamide plus ADT. Secondary endpoints include the percentage of patients with PSA ≤ 0.2 ng/mL and oligometastases by the end of 3 treatment cycles, PSA response rate, and safety. Fleming’s two-stage group sequential design will be adopted in the study, where the null hypothesis is that the rate of patients with an undetectable PSA is ≤ 40% after 6 cycles of treatment, while the alternate hypothesis is an undetectable PSA of > 60%; with one-sided α = 0.05, power = 0.80, and an assumed dropout rate of 10%, the required number of patients for an effective analysis is 47. Enrolment in the study commenced in May 2023.DiscussionThe multi-modal therapy based on treatment response may improve the prognosis of newly diagnosed mHSPC patients with oligometastases.Trial registrationThe study is registered with Clinical Trials.Gov (NCT05717582). Registered on 8th February 2023.

Oligometastatic prostate cancer: local treatment and metastasis-directed therapy

Oligometastatic prostate cancer: local treatment and metastasis-directed therapy

Assessing the effect of metastasis-directed therapy in oligometastatic disease using the restricted mean survival time

BackgroundMetastasis-directed therapy (MDT) with stereotactic body radiotherapy (SBRT) is emerging as an effective therapeutic option for oligometastatic disease (OMD). However, a lack of phase III data, consensus guidelines, and toxicity concerns limit its widespread use. Randomized controlled trials (RCTs) routinely report hazard ratios (HRs) and medians that lack clear clinical and robust interpretation. Restricted-mean survival time (RMST) is the duration of time a patient is expected to survive over the follow-up period, providing a robust and interpretable alternative. We analyzed the efficacy of SBRT using RMST.MethodsAll registered RCTs of ablative radiotherapy in OMD in ClinicalTrials.gov through 2022 were identified. Data were reconstructed from Kaplan–Meier curves, and the HRs and RMST differences were estimated for surrogate endpoints (SEs) and overall survival (OS).ResultsSix studies comprising 426 patients met the inclusion criteria. The RMST differences for SEs ranged from 4.6 months in a study by Iyengar et al. to 11.1 months in SABR-COMET. The RMST differences for OS in SABR-COMET, Gomez et al., and SINDAS studies were 12.6, 15 and 7.9 months, respectively.ConclusionRMST demonstrates the efficacy of local treatment in OMD. Representing the expected survival time, this method effectively communicates outcomes to patients and clinicians.

Abstract PO3-19-01: A Randomized Controlled Trial of Metastasis-directed Therapy for Oligometastases in Breast Cancer (OLIGAMI trial; JCOG2110)

Abstract Background: Oligometastases were initially described as a concept bridging localized disease with widespread distant metastases, but a consensus on its definition has yet to be reached. Recently, the term "metastasis-directed therapy" (MDT) was coined to encompass local therapy for distant metastases, including surgery and radiation therapy (RT), especially stereotactic body radiation therapy (SBRT). Though OLIGO-BC1 and SABR-COMET have indicated the potential benefits of MDT for oligometastases, NRG-BR002 revealed no significant difference in progression-free survival (PFS). As a definitive conclusion to this clinical question has not been reached, there is an increasing demand for phase III trials focusing on breast cancer (BC). We planned the JCOG2110, also called as OLIGAMI trial . Design: OLIGAMI trial is a multi-institutional, two-arm, open-label, randomized controlled phase III trial being conducted with the participation of 50 hospitals belonging to Japan Clinical Oncology Group. After the first registration, all patients will be performed in a 12-week, subtype-specific, systemic therapy consisting of CDK4/6 inhibitors with hormonal therapy for luminal BC, docetaxel with trastuzumab and pertuzumab for HER2-positive BC, chemotherapy with immune checkpoint inhibitors for triple-negative BC expressing PD-L1, and olaparib for cases harboring BRCA mutations. For other triple-negative BC, chemotherapy will be administered. If this 12-week systemic therapy dose not cause any progression or complete response, patients proceed to second registration for randomization; arm A continues same systemic therapy alone, and arm B performs MDT followed by same systemic therapy. The MDT will involve either RT or surgery, and RT will involve mainly SBRT and partly conventional RT. Eligibility criteria: OLIGAMI trial will encompass all subtypes of advanced BC. The key criteria of the first registration are as follows: 1) Histologically diagnosed as invasive BC. Biopsy from oligometastases is desirable but not required. 2) Diagnosed with advanced BC with oligometastases by neck to pelvis enhanced CT, FDG-PET, and brain enhanced MRI. 3) Oligometastases defined as: (i) Maximum diameter of each tumor is 3 cm or less. (ii) Total number of 3 or less. (iii) In case of brain metastasis, maximum diameter is 2 cm or less and asymptomatic. 4) The patient with local recurrence is included. 5) De novo stage IV BC is included. The criteria of secondary registration are as follows: 1) The planned number of courses of systemic therapy has been performed. 2) No progression or new distant metastasis by response evaluation. 3) At least one oligometastaseis remains. Specific Aims: OLIGAMI trial aims to confirm the superiority of MDT to systemic therapy for oligometastases of BC. The primary endpoint is overall survival (OS) after randomization, while the secondary endpoints include OS after first registration, PFS, progression site (oligometastases vs. non-oligometastases), PFS specifically related to MDT (restricted arm B), proportion of adverse events and serious adverse events, and the non-progression proportion of health-related quality of life. Statistical methods: The sample size was calculated as 268 to detect 12% of 5-year OS difference with one-sided alpha of 0.05, power of 70%, 3 years of accrual, and 5 years of follow up. Therefore, we assumed the planned sample size for second registration for randomization as 270. We set the number of first registration as 340, assuming that there may be some patients with progression or complete response after the systemic therapy for 12 weeks. Present accrual and target accrual: The patient accrual will start in August 2023. Enrolment of 340 patients for first registration is planned over a 3-year accrual period. Contact information: Principal investigator, Toshiyuki Ishiba, MD. Ph.D. ishiba0313@gmail.com Citation Format: Toshiyuki Ishiba, Ikuno Nishibuchi, Fumitaka Hara, Keita Sasaki, Ryo Sadate, Yuta Sekino, Ryunosuke Machida, Haruhiko Fukuda, Takahiro Kogawa, Tomomi Fujisawa, Yasuaki Sagara, Yoichi Naito, Kaori Terata, Yukinori Ozaki, Akihiko Shimomura, Takehiko Sakai, Chizuko Kanbayashi, Tsuguo Iwatani, Hideo Shigematsu, Kenji Tamura, Takashi Mizowaki, Michio Yoshimura, Naoto Shikama, Tadahiko Shien, Hiroji Iwata. A Randomized Controlled Trial of Metastasis-directed Therapy for Oligometastases in Breast Cancer (OLIGAMI trial; JCOG2110) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-19-01.

Treatment escalation and de-escalation of de-novo metastatic castration-sensitive prostate cancer.

Androgen receptor signaling inhibitors combined with androgen deprivation therapy have become the standard of care for metastatic castration-sensitive prostate cancer (mCSPC), regardless of tumor volume or risk. However, survival of approximately one-third of these patients has not improved, necessitating further treatment escalation. On the other hand, for patients with oligometastatic mCSPC, there is an emerging role for local radiation therapy. Although data remain scarce, it is expected that treatment of both primary tumor as well as metastasis-directed therapy may improve survival outcomes. In these patients, systemic therapy may be de-escalated to intermittent therapy. However, precise risk stratification is necessary for risk-based treatment escalation or de-escalation. In addition to risk stratification based on clinical parameters, research has been conducted to incorporate genomic and/or transcriptomic data into risk stratification. In future, an integrated risk model is expected to precisely stratify patients and guide treatment strategies. Here, we first review the transition of the standard treatment for mCSPC over the last decade and further discuss the newest concept of escalating or de-escalating treatment using a multi-modal approach based on the currently available literature.

1057: Clinical efficacy of SBRT as adrenal gland metastasis-directed therapy in oligometastatic patients

1057: Clinical efficacy of SBRT as adrenal gland metastasis-directed therapy in oligometastatic patients

From biology to the clinic - exploring liver metastasis in prostate cancer.

Liver metastases from prostate cancer are associated with an aggressive disease course and poor prognosis. Results from autopsy studies indicate a liver metastasis prevalence of up to 25% in patients with advanced prostate cancer. Population data estimate that ~3-10% of patients with metastatic castration-resistant prostate cancer harbour liver metastases at the baseline, rising to 20-30% in post-treatment cohorts, suggesting that selective pressure imposed by novel therapies might promote metastatic spread to the liver. Liver metastases are associated with more aggressive tumour biology than lung metastases. Molecular profiling of liver lesions showed an enrichment of low androgen receptor, neuroendocrine phenotypes and high genomic instability. Despite advancements in molecular imaging modalities such as prostate-specific membrane antigen PET-CT, and liquid biopsy markers such as circulating tumour DNA, early detection of liver metastases from prostate cancer remains challenging, as both approaches are hampered by false positive and false negativeresults, impeding the accurate identification of early liver lesions. Current therapeutic strategies showed limited efficacy in this patient population. Emerging targeted radionuclide therapies, metastasis-directed therapy, and novel systemic agents have shown preliminary activity against liver metastases, but require further validation. Treatment with various novel prostate cancer therapies might lead to an increase in the prevalence of liver metastasis, underscoring the urgent need for coordinated efforts across preclinical and clinical researchers to improve characterization, monitoring, and management of liver metastases from prostate cancer. Elucidating molecular drivers of liver tropism and interactions with the liver microenvironment might ultimately help to identify actionable targets to enhance survival in this high-risk patient group.

Detecting Metastatic Patterns of Oligometastatic Breast Cancer: A Comparative Analysis of 18F-FDG PET/CT and Conventional CT Imaging.

Metastasis-directed therapy has the potential to improve progression-free and overall survival in oligometastatic disease (OMD). For breast cancer, however, randomized trials have failed so far to confirm this finding. Because the concept of metastasis-directed therapy in OMD is highly dependent on the accuracy of the imaging modality, we aimed to assess the impact of 18F-FDG PET/CT on the definition of OMD in breast cancer patients. Methods: Eighty patients with a total of 150 18F-FDG PET/CT images (between October 2006 and January 2022) were enrolled in this retrospective study at the Technical University of Munich. The inclusion criteria were OMD, defined as 1-5 distant metastases, at the time of 18F-FDG PET/CT. For the current study, we systemically compared the metastatic pattern on 18F-FDG PET/CT with conventional CT. Results: At the time of 18F-FDG PET/CT, 21.3% of patients (n = 32) had a first-time diagnosis of metastatic disease, 40.7% (n = 61) had a previous history of OMD, and 38% (n = 57) had a previous history of polymetastatic disease. In 45.3% of cases, the imaging modality (18F-FDG PET/CT vs. conventional CT) had an impact on the assessment of whether OMD was present. An identical metastatic pattern was observed in only 32% of cases.18F-FDG PET/CT detected additional metastases in 33.3% of cases, mostly in the nonregional lymph node system. Conclusion: The use of 18F-FDG PET/CT had a substantial impact on the definition of OMD and detection of metastatic pattern in breast cancer. Our results emphasize the importance of establishing a standardized definition for imaging modalities in future trials and clinical practices related to metastasis-directed therapy in breast cancer patients.

Prostate-Specific Membrane Antigen PET Response Associates with Metastasis-Free Survival After Stereotactic Ablative Radiation in Oligometastatic Prostate Cancer

PurposeEmerging data suggest metastasis-directed therapy (MDT) improves outcomes in patients with oligometastatic castration-sensitive prostate cancer (omCSPC). Prostate-specific membrane antigen positron emission tomography (PSMA-PET) can detect occult metastatic disease and has been proposed as a biomarker for treatment response. Herein we identify and validate a PSMA-PET biomarker for metastasis-free survival (MFS) following MDT in omCSPC. Methods and materialsWe performed an international multi-institutional retrospective study of patients with omCSPC, defined as ≤3 lesions, treated with metastasis-directed stereotactic ablative radiation therapy who underwent PSMA-PET/CT prior to and after (median 6.2 months, range 2.4-10.9 months) treatment. Pre- and post-MDT PSMA-PET/CT SUVmax was measured for all lesions and PSMA response was defined as percent change in SUVmax of the least responsive lesion. PSMA response was evaluated as both a continuous variable and dichotomized as PSMA responders with a complete/partial response (at least 30% reduction in SUVmax) and PSMA non-responders with stable/progressive disease (less than a 30% reduction in SUVmax). PSMA response was correlated conventional imaging defined metastasis-free survival (MFS) with Kaplan-Meier and cox regression. ResultsA total of 131 patients with 261 treated metastases were included in the analysis, with median follow-up of 29 months (IQR 18.5-41.3). Following SABR, 70.2% of patients were classified as PSMA responders. Multivariable analysis demonstrated PSMA response as a continuous variable was associated with significantly worse MFS (HR=1.003, 95%CI 1.001-1.006; p=0.016). Patients classified as PSMA responders were found to have significantly improved median MFS of 39.9 vs 12 months (p=0.001) compared to PSMA non-responders. Our study is limited as it is a retrospective review of a heterogenous population. ConclusionsFollowing SABR, PSMA-PET response appears to be a radiographic biomarker that correlates with MFS in omCSPC. This approach holds promise for guiding clinical management of omCSPC and should be validated in a prospective setting.

Role of Metastasis-Directed Therapy in Genitourinary Cancers.

The treatment of oligometastatic genitourinary cancers is a rapidly advancing field with ablative radiotherapy as one of the critical treatment components. The oligometastatic disease state, which can be defined as 1-5 metastatic sites with a controlled primary, represents a distinct clinical state where comprehensive ablative local therapies may provide improved outcomes. Enhanced imaging has increased the number of patients identified with oligometastatic disease. Evidence for improved outcomes with metastasis-directed therapy (MDT) in oligometastatic genitourinary cancers is increasing, and previously published outcome data continues to mature with an increasing body of prospective data to inform the role of MDT in histology-specific settings or in the context of systemic therapy. In select patients, MDT can offer benefits beyond improved local control and allow for time off of systemic therapy, prolonged time until next therapy, or even the hope of cure. However, treatment decisions for locally ablative therapy must be balanced with consideration towards safety. There are exciting advances in technologies to target and adapt treatment in real-time which have expanded options for safer delivery and dose escalation to metastatic targets near critical organs at risk. The role of systemic therapies in conjunction with MDT and incorporation of tumor genetic information to further refine prognostication and treatment decision-making in the oligometastatic setting is actively being investigated. These developments highlight the evolving field of treatment of oligometastatic disease. Future prospective studies combining MDT with enhanced imaging and integrating MDT with evolving systemic therapies will enable the optimal selection of patients most likely to benefit from this "all-or-none" approach and reveal settings in which a combination of therapies could result in synergistic outcomes.

Metastasis-directed therapy in testicular cancer.

This review highlights the importance of addressing testicular cancer metastasizing beyond the retroperitoneum, focusing on multidisciplinary approaches and advances in treatment. Recent literature emphasizes on the evolving landscape of metastasis-directed therapy, including surgical interventions, chemotherapy regimens, and radiation therapy. The effectiveness of these treatments varies depending on the site of metastasis, with various approaches improving survival rates and quality of life for patients. We divide our review in an organ-specific manner and focus on chemotherapeutic, surgical, and radiation therapy approaches pertaining to each site of metastasis. Our review suggests the pressing need for continued research to refine and personalize treatment strategies. These efforts are important for enhancing clinical practice, ultimately leading to better outcomes for patients with metastatic testicular cancer.

Expert Perspectives on Controversies in Castration-Sensitive Prostate Cancer Management: Narrative Review and Report of the First US Prostate Cancer Conference Part 1.

Castration-sensitive prostate cancer (CSPC) is a complex and heterogeneous condition encompassing a range of clinical presentations. As new approaches have expanded management options, clinicians are left with myriad questions and controversies regarding the optimal individualized management of CSPC. The US Prostate Cancer Conference (USPCC) multidisciplinary panel was assembled to address the challenges of prostate cancer management. The first annual USPCC meeting included experts in urology, medical oncology, radiation oncology, and nuclear medicine. USPCC co-chairs and session moderators identified key areas of controversy and uncertainty in prostate cancer management and organized the sessions with multidisciplinary presentations and discussion. Throughout the meeting, experts responded to questions prepared by chairs and moderators to identify areas of agreement and controversy. The USPCC panel discussion and question responses for CSPC-related topics are presented. Key advances in CSPC management endorsed by USPCC experts included the development and clinical utilization of gene expression classifiers and artificial intelligence (AI) models for risk stratification and treatment selection in specific patient populations, the use of advanced imaging modalities in patients with clinically localized unfavorable intermediate or high-risk disease and those with biochemical recurrence, recommendations of doublet or triplet therapy for metastatic CSPC (mCSPC), and consideration of prostate and/or metastasis-directed radiation therapy in select patients with mCSPC. CSPC is a diverse disease with many therapeutic options and the potential for adverse outcomes associated with either undertreatment or overtreatment. Future studies are needed to validate and clinically integrate novel technologies, including genomics, AI, and advanced imaging, to optimize outcomes among patients with CSPC.

Long-Term Survival in Patients with Oligometastatic Non-Small Cell Lung Cancer by a Multimodality Treatment-Comparison with Stage III Disease.

Background: In patients with oligometastatic NSCLC, a cT3-cT4 primary tumor or an cN2/cN3 lymph node status was reported to be associated with unfavorable outcome. The aim of this study was to assess the importance of definitive or neoadjuvant thoracic radiochemotherapy for long-term outcome of these patients in order to find more appropriate treatment schedules. Methods: Analysis of the West Cancer Centre (WTZ) institutional database from 08/2016 to 08/2020 was performed. Patients with primary synchronous OMD, all without actionable driver mutations, who received definitive thoracic radiochemotherapy (RCT) or neoadjuvant RCT followed by surgery (trimodality treatment) were included. Survival outcome is compared with stage III NSCLC. Results: Altogether, 272 patients received concurrent radiochemotherapy. Of those, 220 presented with stage III (158 with definitive RCT, 62 with trimodality approach). A total of 52 patients had OMD patients with cT3/cT4 or cN2/cN3 tumors. Overall survival (OS) at five years for OMD patients was 28.3% (95%-CI: 16.4-41.5%), which was not significantly different from OS of patients with stage III NSCLC treated with definitive or neoadjuvant RCT (34.9% (95%-CI: 27.4-42.8%)). However, the PFS of OMD patients at five years or last follow-up was significantly worse than that of stage III patients (13.0% vs. 24.3%, p = 0.0048). The latter was due to a higher cumulative incidence of distant metastases in OMD patients (50.2% vs. 20.4% at 48 months, p < 0.0001) in comparison to stage III patients. A cross-validated classifier that included severe comorbidity, ECOG performance status, gender and pre-treatment serum CRP level as the most important factors in the univariable analysis, was able to divide the OMD patient group into two equally sized groups with a four-year survival rate of 49.4% in the good prognosis group and 9.9% in the poor prognosis group (p = 0.0021). Laboratory chemistry and clinical parameters, in addition to imaging and high-precision therapies, can help to predict and improve prognosis. Conclusions: A multimodality treatment approach and local metastases-directed therapy in addition to chemoimmunotherapy can lead to good long-term survival in patients with cT3/cT4 or cN2/cN3 OMD NSCLC without severe comorbidities and in good performance status and is therefore recommended.

Survival Outcomes following Pulmonary Metastasis-Directed Local Therapy (PM-LT) Relative to No Metastasis-Directed Intervention in Adenoid Cystic Carcinoma (ACC)

Survival Outcomes following Pulmonary Metastasis-Directed Local Therapy (PM-LT) Relative to No Metastasis-Directed Intervention in Adenoid Cystic Carcinoma (ACC)

Strong Correlation Between SUVmax on PSMA PET/CT and Numeric Drop-In γ-Probe Signal for Intraoperative Identification of Prostate Cancer Lesions.

Prostate-specific membrane antigen (PSMA) PET is used to select patients with recurrent prostate cancer for metastasis-directed therapy. A surgical approach can be achieved through radioguided surgery (RGS), using a Drop-In γ-probe that traces lesions that accumulate the radioactive signal. With the aim of guiding patient selection for salvage surgery, we studied the correlation between the SUVmax of lesions on preoperative PSMA PET/CT and their intraoperative counts/s measured using the Drop-In γ-probe. Methods: A secondary analysis based on the prospective, single-arm, and single-center feasibility study was conducted (NCT03857113). Patients (n = 29) with biochemical recurrence after previous curative-intent therapy and a maximum of 3 suggestive lesions within the pelvis on preoperative PSMA PET/CT were included. Patients treated with androgen deprivation therapy within 6 mo before surgery were excluded. All patients received an intravenous injection of 99mTc-PSMA-I&S 1 d before surgery. Radioguidance was achieved using a Drop-In γ-probe. Correlation was determined using the Spearman rank correlation coefficient (ρs). Subgroup analysis was based on the median SUVmax Results: In total, 33 lesions were visible on the PSMA PET/CT images, with a median overall SUVmax of 6.2 (interquartile range [IQR], 4.2-9.7). RGS facilitated removal of 31 lesions. The median Drop-In counts/s were 134 (IQR, 81-220) invivo and 109 (IQR, 72-219) ex vivo. The intensity of the values correlated with SUVmax (ρs = 0.728 and 0.763, respectively; P < 0.001). Subgroup analysis based on median SUVmax in the group with an SUVmax of less than 6 showed no statistically significant correlation with the numeric signal invivo (ρs = 0.382; P = 0.221) or the signal-to-background-ratio (ρs = 0.245; P = 0.442), whereas the group with an SUVmax of 6 or more showed respective statistically significant positive correlations (ρs = 0.774 [P < 0.001] and ρs = 0.647 [P = 0.007]). Conclusion: Our findings indicate that there is a direct relation between SUVmax on PSMA PET/CT and the readout recorded by the surgical Drop-In probe, thereby indicating that SUVmax can be used to select patients for PSMA RGS. For more definitive subgroup definitions for treatment recommendations, further studies are necessary to validate the present findings.

Stereotactic body radiotherapy for oligoprogression with or without switch of systemic therapy

BackgroundOligoprogression is defined as cancer progression of a limited number of metastases under active systemic therapy. The role of metastasis-directed therapy, using stereotactic body radiotherapy (SBRT), is controversial as is the continuation versus switch of systemic therapy. We report outcomes of oligoprogressive patients after SBRT, and compare those patients that continued or switched their current line of systemic therapy. Material/Methods.We included patients who developed up to 5 progressive extracranial metastases under systemic therapy for any solid organ malignancy and were treated with SBRT to all lesions at our institution between 01/2014 and 12/2019. Overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier method, and the interval to the next systemic therapy line determined using cumulative incidence functions. Multivariable Cox regression models were used to analyze the influence of baseline and post-progression variables on OS, PFS and survival with the next systemic therapy after SBRT. ResultsAmong 135 patients with oligoprogressive disease of which the most common primary tumor was lung cancer (n = 46, 34.1 %), 96 continued their current line of systemic therapy after oligoprogression. Among 39 who switched systemic therapy, 28 (71.8 %) paused or discontinued, while 11 (28.2 %) immediately started another systemic treatment. After a median follow-up of 27.2 months, patients that switched and those who continued systemic therapy after oligoprogression had comparable median OS (32.1 vs. 38.2 months, p = 0.47) and PFS (4.3 vs. 3.4 months, p = 0.6). The intervals to the next systemic therapy line were comparable between both cohorts (p = 0.6). An ECOG performance status of 2 and immediately starting a new systemic therapy after oligoprogression were associated with a poorer survival without next systemic therapy, while the de-novo OMD state was associated with better survival without next systemic therapy compared to the induced state. ConclusionOncological outcomes of patients that continued or switched systemic therapy after SBRT for oligoprogression were comparable, potentially indicating that further lines of treatment may be safely delayed in selected cases.