BACKGROUND: Emerging randomized data, mostly from phase II trials, have suggested that patients with oligometastatic cancers may benefit from ablative treatments such as stereotactic ablative radiotherapy (SABR). However, phase III data testing this paradigm are lacking, and many studies have examined SABR in the setting of metachronous oligometastatic disease. The goal of the SABR-SYNC trial is to assess the effect of SABR in patients with oligometastatic cancers and a synchronous primary tumor.
METHODS: One hundred and eighty patients will be randomized in a 1:2 ratio between standard of care (SOC) palliative-intent treatments vs. SOC + ablative therapy (SABR preferred) to all sites of known disease. Randomization will be stratified based on histology and number of metastases at enrollment. SABR may be delivered in 1-, 3- and 5-fraction regimens, with recommended doses of 20 Gy, 30 Gy, and 35 Gy, respectively. Non-SABR local modalities (e.g. surgery, thermal ablation, conventional radiation) may be used for treatment of the primary or metastases at the discretion of the treating physicians, if those modalities are clinically preferred. The primary endpoint is overall survival, and secondary endpoints include progression-free survival, time to development of new metastatic lesions, time to initiation of next systemic therapy, quality of life, and toxicity. Translational endpoints include assessment of circulating tumor DNA and immunological predictors of outcomes.
CONCLUSIONS: SABR-SYNC will provide phase III data to assess the impact of SABR on overall survival in a population of patients with synchronous oligometastases. The translational component will attempt to identify novel prognostic and predictive biomarkers to aid in clinical decision making.
BACKGROUND: Clinicaltrials.gov NCT05717166 (registration date: Feb. 8, 2023).

UNASSIGNED: Data on metastasis-directed radiotherapy (MDRT) are limited, particularly regarding its association with the prostate-specific antigen (PSA) doubling time (PSADT). The present study evaluated the oncological outcomes of MDRT on the basis of the PSADT in oligo-recurrent prostate cancer patients.
UNASSIGNED: We retrospectively reviewed clinical data of 35 MDRTs for 29 patients at the Kitasato University Hospital, targeting oligometastatic prostate cancer developed after radical treatment for non-metastatic prostate cancer. Thirty-five MDRTs were classified into the PSADT >3 months (n=25) or PSADT ≤3 months group (n=10). Statistical analyses were performed to compare associations between the two PSADT groups and oncological outcomes such as progression-free survival (PFS) and PSA response after MDRT.
UNASSIGNED: There were no significant differences between the two groups in terms of the clinicopathological features. Kaplan-Meier analysis showed that PFS was significantly better in the PSADT >3 months group than in the PSADT ≤3 months group [median: 13.3 versus (vs.) 2.6 months, p=0.046]. Regarding castration sensitivity, the predictive role of PSADT >3 months was maintained in 21 patients who received MDRT without prior salvage hormone therapy (median PFS: 12.7 vs. 2.6 months, p=0.024). In the castration-resistant setting (n=14), the frequency of a decrease in serum PSA levels after MDRT by 90% was 54.5% (median PFS: 23.1 months).
UNASSIGNED: MDRT can provide benefit especially for patients with PSADT ≥3 months who had oligo-recurrence after the radical treatment for non-metastatic prostate cancer.

BACKGROUND: Local therapies may benefit patients with oligometastatic cancer. However, there were limited data about pancreatic cancer. Here, we compared the efficacy and safety of stereotactic body radiation therapy (SBRT) to the primary tumor and all oligometastases with SBRT to the primary tumor alone in patients with metastatic pancreatic cancer.
METHODS: A retrospective review of patients with synchronous oligometastatic pancreatic cancer (up to 5 lesions) receiving SBRT to all lesions (including all oligometastases and the primary tumor) were performed. Another comparable group of patients with similar baseline characteristics, including metastatic burden, SBRT doses, and chemotherapy regimens, receiving SBRT to the primary tumor alone were identified. The primary endpoint was overall survival (OS). The secondary endpoints were progression frees survival (PFS), polyprogression free survival (PPFS) and adverse events.
RESULTS: There were 59 and 158 patients receiving SBRT to all lesions and to the primary tumor alone. The median OS of patients with SBRT to all lesions and the primary tumor alone was 10.9 months (95% CI 10.2-11.6 months) and 9.3 months (95% CI 8.8-9.8 months) (P < 0.001). The median PFS of two groups was 6.5 months (95% CI 5.6-7.4 months) and 4.1 months (95% CI 3.8-4.4 months) (P < 0.001). The median PPFS of two groups was 9.8 months (95% CI 8.9-10.7 months) and 7.8 months (95% CI 7.2-8.4 months) (P < 0.001). Additionally, 14 (23.7%) and 32 (20.2%) patients in two groups had grade 3 or 4 treatment-related toxicity.
CONCLUSIONS: SBRT to all oligometastases and the primary tumor in patients with pancreatic cancer may improve survival, which needs prospective verification.

Renal cell cancer (RCC) has traditionally been considered radioresistant. Because of this, conventional radiotherapy (RT) has been predominantly relegated to the palliation of symptomatic metastatic disease. The implementation of stereotactic ablative radiotherapy (SABR) has made it possible to deliver higher ablative doses safely, shifting the renal radioresistance paradigm. SABR has increasingly been adopted into the multidisciplinary framework for the treatment of locally recurrent, oligoprogressive, and oligometastatic disease. Furthermore, there is growing evidence of SABR as a non-invasive definitive therapy in patients with primary RCC who are medically inoperable or who decline surgery, unsuited to invasive ablation (surgery or percutaneous techniques), or at high-risk of requiring post-operative dialysis. Encouraging outcomes have even been reported in cases of solitary kidney or pre-existing chronic disease (poor eGFR), with a high likelihood of preserving renal function. A review of clinical evidence supporting the use of ablative radiotherapy (SABR) in primary, recurrent, and metastatic RCC has been conducted. Given the potential immunogenic effect of the high RT doses, we also explore emerging opportunities to combine SABR with systemic treatments. In addition, we explore future directions and ongoing clinical trials in the evolving landscape of this disease.

OBJECTIVE: The efficacy of local therapy for oligometastatic disease (OMD) remains unclear. This study aimed to evaluate the prognostic utility of the classification system for OMD and explore which groups may benefit from stereotactic body radiation therapy (SBRT).
METHODS: This single-center retrospective study included 45 patients (52 sites) with solid tumors and 1-3 extracranial oligometastases who underwent SBRT for all metastases at our institution between January 2018 and December 2021. OMD states were classified based on the European Society for Radiotherapy and Oncology (ESTRO) and the European Organisation for Research and Treatment of Cancer (EORTC) classification system. Local control (LC), overall survival (OS), and progression-free survival (PFS) for each group were analyzed using the Kaplan-Meier method. Acute and late adverse events (AEs) were evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.
RESULTS: The median follow-up period was 14 months (range: 0-48 months). The numbers of patients in the de novo (first diagnosis of OMD), repeat (previous history of OMD), and induced (previous history of polymetastatic disease) OMD groups were 15, 17, and 13, respectively. The LC rates at one year for the entire, de novo, repeat, and induced cohorts were 87.2%, 87.5%, 90.2%, and 83.9%, respectively (p=0.80). The one-year PFS rates for each group were 35.0%, 56.7%, and 29.9%, respectively (p=0.58). The one-year OS rates for each group were 80.0%, 86.2%, and 80.8%, respectively (p=0.50). Grade 2 or 3 AEs occurred in five patients (10.4%). No grade 4 or 5 AEs were observed.
CONCLUSIONS: SBRT is safe and highly effective for local control. Patients with repeat OMD demonstrated a trend of longer PFS, suggesting that this subgroup may benefit from local therapy at metastatic sites.

Background: Lymph-nodal prostate cancer oligometastases are differently treated according to their site: pelvic are locoregional lymph nodes; instead, para-aortic lymph nodes are considered as distant metastases. The aim of the study was a comparison between para-aortic and pelvic oligometastases treated with stereotactic body radiation therapy (SBRT). Methods: This is a retrospective analysis. De novo metastatic or extra-nodal disease were excluded. Univariate and multivariate analyses were performed; the pattern of recurrence was also evaluated. A propensity score matching (PSM) was applied to create comparable cohorts. The primary end-point was the progression-free survival (PFS). The secondary end-points were biochemical relapse-free survival (BRFS), ADT-free survival (ADTFS), polymetastases-free survival (PMFS), local progression-free survival (LPFS), and pattern of relapse. Results: In total, 240 lymph-nodal oligometastases in 164 patients (127 pelvic and 37 para-aortic) were treated. The median PFS was 20 and 11 months in pelvic and para-aortic patients, respectively (p = 0.042). The difference was not confirmed in the multivariate analysis (p = 0.06). The median BRFS was 16 and 9 months, respectively, in the pelvic and para-aortic group (p = 0.07). No statistically significant differences for ADTFS or PMFS were detected. The cumulative 5-year LPFS was 90.5%. In PSM, no statistically significant differences for all the study end-points were detected. Conclusions: Patients affected by para-aortic disease might have a PFS comparable to pelvic disease; local control is high in both cohorts. Our results also support the use of SBRT for para-aortic metastases.

The rationale behind the \"International Consensus Conference for Advanced Breast Cancer\" (ABC) is to standardize the treatment of patients with advanced or metastatic breast cancer worldwide using an evidence-based approach. The aim is also to ensure that patients in all countries receive adequate treatment based on current treatment recommendations and standards. The 7th International Consensus Conference on Advanced Breast Cancer (ABC7) took place from November 9 to 12, 2023 in Lisbon/Portugal. ABC7 focused on metastatic disease as well as on locally advanced and inflammatory breast cancer. Special topics included the treatment of oligometastatic patients, leptomeningeal disease, treatment of brain metastases, and pregnant women with ABC. As in previous years, patient advocates from all over the world participated in the consensus conference and were involved in decision making.

UNASSIGNED: In the multidisciplinary management of oligometastatic, persistent, or recurrent (MPR) ovarian cancer, radiotherapy (RT) is becoming a more and more worthwhile treatment to potentially improve the chronicity of the disease. Particle beam RT has proved to be effective in several gynecological malignancies, but so far no data are available for ovarian cancer.
UNASSIGNED: This is a real-world, retrospective, bi-institutional, single-arm study aimed to assess the effectiveness and the safety of carbon ion RT (CIRT) in this setting. The co-first endpoints are 1-year and 2-year actuarial local control (LC) rates and the objective response rate (ORR) defined on a \"per lesion\" basis. The secondary endpoint was toxicity. Actuarial outcomes were evaluated using the Kaplan-Meier method while potential predictors were explored using the Log-rank test. Bi-variable logistic regression was employed in the analysis of factors predicting the complete response on a per-lesion basis.
UNASSIGNED: 26 patients accounting for a total of 36 lesions underwent CIRT with a total median dose of 52.8 Gy[RBE] (range: 39-64 Gy[RBE]). Five patients received CIRT for re-irradiation. No concomitant systemic therapies were administered during CIRT. Within 12 months after the treatment, 17 lesions (47 %) achieved complete response while 18 (50 %) obtained a partial response with an ORR of 97 %. The achievement of a complete response is related to the dose per fraction (>4.2 Gy[RBE], p = 0.04) and total dose (>52,8 Gy[RBE], p = 0.05). The 1-year LC was 92 % and the 2-year LC was 83 %, according to the achievement of a CR (p = 0.007) and GTV ≤ 14 cm3 (p = 0.024). No grade > 3 toxicities were recorded both in naïve and re-irradiated patients. PARP-i and anti-VEGF seemed not to exacerbate the risk of severe toxicities.
UNASSIGNED: CIRT was effective and safe in MPR ovarian cancers, even in the case of re-irradiation. Largest cohort studies and longer follow-up are needed to confirm these data.

Oligometastases are defined as a number of detectable metastases less or equal to 5. In castrate-resistant oligo metastatic prostate Cancer (CR oligoM PC), Metastases-Directed Ablative radiotherapy (MDRT) is poorly investigated. Our study retrospectively reviewed the cases of CR oligoM PC treated with MDRT in 8 French high-volume radiotherapy centers. OS and PFS are defined as the delay between the first day of MDRT and death (OS) or progression according to PCWG criteria (PFS). OS and PFS are evaluated according to Kaplan Meyer, curves are compared with log rank test. Logistic regression was used to identify predictive factors for outcome: bone versus node metastasis, ISUP grade, PSA doubling Time (PSADT) at the time of MDRT, time to castration resistance. 107 patients were included in the study, among those 197 metastases received MDRT. For the overall population, the median follow-up was 25.2 months (1,4-145). OS was 93 % at 2 years and 81,4% at 3 years. At 2 years, 100 % of patients with node-only metastasis were alive versus 88,7% among those who have bone metastases (p = 0,72). The median PFS was 12,6 months (IC 95 % [9,6; 17]), with no difference among patients with node only disease versus the rest of the cohort. The PFS was 18,2 months (10,0; 32,4) in patients with PSADT >6 months versus 10,7 months (8,9; 14,3) when PSADT was inferior to 6 months. However, this difference did not reach significant. We did not find a correlation neither between ISUP grade (1-2 versus 3-4-5) and PFS, nor between hormone-sensitivity duration and PFS. Patients receiving MDRT for CR oligoM PC have a good prognosis with 81,6% OS at 3 years. PSA DT longer than 6 months could be related to better PFS. MDRT strategy could postpone the onset of new systemic treatment with median PFS >1 year.

BACKGROUND: Stereotactic body radiotherapy (SBRT) is increasingly used to treat disease in the oligometastatic (OM) setting due to mounting evidence demonstrating its efficacy and safety. Given the low population representation in prospective studies, we performed a systematic review and meta-analysis of outcomes of HNC patients with extracranial OM disease treated with SBRT.
METHODS: A systematic review was conducted with Cochrane, Medline, and Embase databases queried from inception to August 2022 for studies with extracranial OM HNC treated with stereotactic radiotherapy. Polymetastatic patients (>five lesions), mixed-primary cohorts failing to report HNC separately, lack of treatment to all lesions, nonquantitative endpoints, and other definitive treatments (surgery, conventional radiotherapy, and radioablation) were excluded. The meta-analysis examined the pooled effects of 12- and 24-month local control (LC) per lesion, progression-free survival (PFS), and overall survival (OS). Weighted random-effects were assessed using the DerSimonian and Laird method, with heterogeneity evaluated using the I2 statistic and Cochran Qtest. Forest plots were generated for each endpoint.
RESULTS: Fifteen studies met the inclusion criteria (639 patients, 831 lesions), with twelve eligible for quantitative synthesis with common endpoints and sufficient reporting. Fourteen studies were retrospective, with a single prospective trial. Studies were small, with a median of 32 patients (range: 6-81) and 63 lesions (range: 6-126). The OM definition varied, with a maximum of two to five metastases, mixed synchronous and metachronous lesions, and a few studies including oligoprogressive lesions. The most common site of metastasis was the lung. Radiation was delivered in 1-10 fractions (20-70 Gy). The one-year LC (LC1), reported in 12 studies, was 86.9% (95% confidence interval [CI]: 79.3-91.9%). LC2 was 77.9% (95% CI: 66.4-86.3%), with heterogeneity across studies. PFS was reported in five studies, with a PFS1 of 43.0% (95% CI: 35.0-51.4%) and PFS2 of 23.9% (95% CI: 17.8-31.2%), with homogeneity across studies. OS was analyzed in nine studies, demonstrating an OS1 of 80.1% (95% CI: 74.2-85.0%) and OS2 of 60.7% (95% CI: 51.3-69.4%). Treatment was well tolerated with no reported grade 4 or 5 toxicities. Grade 3 toxicity rates were uniformly below 5% when reported.
CONCLUSIONS: SBRT offers excellent LC and promising OS, with acceptable toxicities in OM HNC. Durable PFS remains rare, highlighting the need for effective local or systemic therapies in this population. Further investigations on concurrent and adjuvant therapies are warranted.