5-year Progression-free Survival Research Articles

Benefit of consolidative radiation in patients with extranodal limited-stage diffuse large B-cell lymphoma: a multicenter retrospective study in China.

Approximately 40% of limited-stage (stage I and II) diffuse large B-cell lymphoma (LS-DLBCL) presents with extranodal disease. Extranodal LS-DLBCL may have significant biological differences and associated with worse outcomes than nodal disease. Although rituximab based chemoimmunotherapy is standard of first-line treatment, the role of consolidative radiotherapy (RT) in this particular subgroup is controversial. In this multicenter retrospective study, we evaluated the survival benefit of consolidative RT in patients diagnosed with extranodal LS-DLBCL and received rituximab-based chemoimmunotherapy with or without consolidative RT. A total of 328 patients were included, 129 patients (39.3%) received chemoimmunotherapy and consolidative RT, and 199 patients (60.7%) received chemoimmunotherapy alone. With a median follow-up of 5.1 years (range, 0.3-14.8 years), 5-year progression-free survival (PFS) and overall survival (OS) for all patients were 75.4% and 83.9%, respectively. In multivariate analyses, the addition of consolidative RT was associated with superior OS (P = 0.004) and PFS (P = 0.005). High stage-modified International Prognosis Index (SM-IPI) risk predicted worse OS (P = 0.001) and PFS (P = 0.005). Also, propensity score-matched analyses showed RT improved both OS (hazard ratio [HR] 0.228, 95% confidence index [CI] 0.111-0.467, P < 0.001) and PFS (HR 0.308, 95% CI 0.167-0.566, P < 0.001). Among patients who achieved CR, 49 patients (16.6%) developed disease relapse, of which 30.6% relapsed at local sites. Consolidative RT significantly reduced relapse risk (P = 0.002). Our results demonstrated that consolidative RT significantly improved outcomes in patients with extranodal LS-DLBCL in the rituximab era.

Short-term versus long-term metronomic adjuvant chemotherapy in locally advanced nasopharyngeal carcinoma: A propensity score-matched real-world study

BackgroundThis retrospective study aimed to determine the optimal metronomic chemotherapy duration (MTCD) as adjuvant therapy for patients with locally advanced nasopharyngeal carcinoma (LANPC). MethodsThis study involved LANPC patients treated with metronomic chemotherapy (MTC) using a 5-FU prodrug (S1, capecitabine, or tegafur) from May 2013 to September 2020. The optimal MTCD threshold was established using X-tile Bioinformatics software. The overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS) were compared between short-term and long-term groups using propensity score matching (PSM). ResultsA total of 546 patients were analyzed. MTCD was an independent prognostic factor for OS, PFS, and DMFS (all P < 0.05). Patients were categorized into long-term (>3 months) and short-term (≤3 months) MTCD groups. After a median follow-up of 48 months, significant differences were observed in 4-year OS (97.0 % vs. 87.1 %; P < 0.01), PFS (84.6 % vs. 70.9 %; P < 0.01), DMFS (87.3 % vs. 78.8 %; P < 0.01), and LRRFS (95.3 % vs. 87.4 %; P < 0.01) between the long-term and short-term groups. In the PSM-matched cohort of 196 patients per group, the long-term group demonstrated superior 4-year OS and LRRFS (97.3 % vs. 87.1 %, P < 0.01; 95.2 % vs. 90.0 %, P < 0.05). No significant differences in acute toxicities were observed between the groups (P > 0.05). ConclusionExtended MTC with a 5-FU prodrug (>3 months) may benefit NPC patients. Further prospective studies are needed to validate these findings.

Omics-imaging signature-based nomogram to predict the progression-free survival of patients with hepatocellular carcinoma after transcatheter arterial chemoembolization

BACKGROUND Enhanced magnetic resonance imaging (MRI) is widely used in the diagnosis, treatment and prognosis of hepatocellular carcinoma (HCC), but it can not effectively reflect the heterogeneity within the tumor and evaluate the effect after treatment. Preoperative imaging analysis of voxel changes can effectively reflect the internal heterogeneity of the tumor and evaluate the progression-free survival (PFS). AIM To predict the PFS of patients with HCC before operation by building a model with enhanced MRI images. METHODS Delineate the regions of interest (ROI) in arterial phase, portal venous phase and delayed phase of enhanced MRI. After extracting the combinatorial features of ROI, the features are fused to obtain deep learning radiomics (DLR)_Sig. DeLong's test was used to evaluate the diagnostic performance of different typological features. K-M analysis was applied to assess PFS in different risk groups, and the discriminative ability of the model was evaluated using the C-index. RESULTS Tumor diameter and diolame were independent factors influencing the prognosis of PFS. Delong's test revealed multi-phase combined radiomic features had significantly greater area under the curve values than did those of the individual phases (P &lt; 0.05).In deep transfer learning (DTL) and DLR, significant differences were observed between the multi-phase and individual phases feature sets (P &lt; 0.05). K-M survival analysis revealed a median survival time of high risk group and low risk group was 12.8 and 14.2 months, respectively, and the predicted probabilities of 6 months, 1 year and 2 years were 92%, 60%, 40% and 98%, 90%,73%, respectively. The C-index was 0.764, indicating relatively good consistency between the predicted and observed results. DTL and DLR have higher predictive value for 2-year PFS in nomogram. CONCLUSION Based on the multi-temporal characteristics of enhanced MRI and the constructed Nomograph, it provides a new strategy for predicting the PFS of transarterial chemoembolization treatment of HCC.

PA-MSHA improves prognosis of patients undergoing radical cystectomy: a retrospective cohort study using inverse probability of treatment weighting.

To observe the effect of Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) on the prognosis and the incidence of lymphatic leakage in patients undergoing radical cystectomy (RC). A total of 129 patients who underwent RC in Lanzhou University Second Hospital from 2013 to 2022 were enrolled in this study. They were divided into 43 patients treated with PA-MSHA and 86 patients in the control group. Inverse probability of treatment weighting (IPTW) was applied to reduce potential selection bias. Kaplan-Meier method and Cox regression analysis were used to analyze the effect of PA-MSHA on the survival of patients and the incidence of postoperative lymphatic leakage. The PA-MSHA group exhibited improved overall survival (OS) and cancer-specific survival (CSS) rates compared to the control group. The 3-year and 5-year overall survival (OS) rates for the PA-MSHA group were 69.1% and 53.2%, respectively, compared to 55.6% and 45.3% for the control group (Log-rank=3.218, P=0.072). The 3-year and 5-year cancer-specific survival (CSS) rates for the PA-MSHA group were 73.3% and 56.5%, respectively, compared to 58.0% and 47.3% for the control group (Log-rank=3.218, P=0.072). Additionally, the 3-year and 5-year progression-free survival (PFS) rates for the PA-MSHA group were 74.4% and 56.8%, respectively, compared to 57.1% and 52.2% for the control group (Log-rank=2.016, P=0.156). Multivariate Cox regression analysis indicates that lymph node metastasis and distant metastasis are poor prognostic factors for patients, while the use of PA-MSHA can improve patients' OS (HR: 0.547, 95%CI: 0.304-0.983, P=0.044), PFS (HR: 0.469, 95%CI: 0.229-0.959, P=0.038) and CSS (HR: 0.484, 95%CI: 0.257-0.908, P=0.024). The same trend was observed in the cohort After IPTW adjustment. Although there was no significant difference in the incidence of postoperative lymphatic leakage [18.6% (8/35) vs. 15.1% (84.9%), P=0.613] and pelvic drainage volume [470 (440) ml vs. 462.5 (430) ml, P=0.814] between PA-MSHA group and control group, PA-MSHA could shorten the median retention time of drainage tube (7.0 d vs 9.0 d) (P=0.021). PA-MSHA may improve radical cystectomy in patients with OS, PFS, and CSS, shorten the pelvic drainage tube retention time.

The safety and efficacy of volumetric modulated Arc therapy combined with computer tomography-guided adaptive brachytherapy for locally advanced cervical cancer: a single institution experience

BackgroundVolumetric modulated arc therapy (VMAT) is a novel form of IMRT, which can deliver more accurate dose distribution and shorten treatment time. Compared to MRI-guided adaptive brachytherapy, which is recommended as gold standard imaging for cervical cancer contours, CT-guided adaptive brachytherapy (CTGAB) is more available, more widespread, and more affordable in many centers. This study aims to retrospectively analyze the efficacy and the safety of VMAT combined with CTGAB for patients with locally advanced cervical cancer.Methods and materialsThis study retrospectively analyzed 102 patients with locally advanced cervical cancer who underwent VMAT and CTGAB. Clinical outcomes including local control (LC), overall survival (OS) and progression-free survival (PFS), tumor response to treatment evaluated by the Response Evaluation Criteria in Solid Tumors (RECIST) (version 1.1), and toxicities including gastrointestinal toxicity, urinary toxicity and hematologic toxicity evaluated by the Common Terminology Criteria for Adverse Events (CTCAE) (version 5.0) were analyzed. The Kaplan-Meier method was used to calculate LC, OS, and PFS.ResultsMedian follow-up time was 19 months. Complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) occurred in 68 (66.7%), 24 (23.5%), 4 (3.92%), and 6 (5.88%), respectively. The 2-year and 3-year OS were 89.6% and 83%, respectively. The 2-year and 3-year PFS were 84.2% and 74.3%, respectively. The 2-year and 3-year LC were 90.1% and 79.3%, respectively. The average cumulative D2cm3 in the rectum, the bladder, the colon, and the small intestine were 78.07 (SD: 0.46) Gy, 93.20 (SD: 0.63) Gy, 63.55 (SD: 1.03) Gy and 61.07 (SD: 0.75) Gy, respectively. The average cumulative D90% of the high-risk clinical target volume (HR-CTV) was 92.26 (SD: 0.35) Gy. Grade ≥ 3 gastrointestinal and urinary toxicities occurred in 4.9% and 0.98%, respectively. 1.96% of patients were observed grade ≥ 4 gastrointestinal toxicities and none of the patients observed grade ≥ 4 urinary toxicities.ConclusionVMAT combined with CTGAB for locally advanced cervical cancer was an effective and safe treatment method, which showed satisfactory LC, OS, PFS, and acceptable toxicities.

A study of microRNAs as new prognostic biomarkers in anal cancer patients.

MicroRNA (MiR) influences the growth of cancer by regulation of mRNA for 50-60% of all genes. We present as per our knowledge the first global analysis of microRNA expression in anal cancer patients and their prognostic impact. Twenty-nine patients with T1-4 N0-3 M0 anal cancer treated with curative intent from September 2003 to April 2011 were included in the study. RNA was extracted from fresh frozen tissue and sequenced using NGS. Differentially expressed microRNAs were identified using the R-package DEseq2 and the endpoints were time to progression (TTP) and cancer specific survival (CSS). Five microRNAs were significantly associated with 5-year progression free survival (PFS): Low expression of two microRNAs was associated with higher PFS, miR-1246 (100% vs. 55.6%, p = 0.008), and miR-135b-5p (92.9% vs. 59.3%, p = 0.041). On the other hand, high expressions of three microRNAs were associated with higher PFS, miR-148a-3p (93.3% vs. 53.6%, p = 0.025), miR-99a-5p (92.9% vs. 57.1%, p = 0.016), and let-7c-3p (92.9% vs. 57.1%, p = 0.016). Corresponding findings were documented for CSS. Our study identified five microRNAs as prognostic markers in anal cancer. MiR-1246 and microRNA-135b-5p were oncoMiRs (miRs with oncogene effects), while miR-148a-3p, miR- 99a-5p, and let-7c-3p acted as tumour suppressors in anal cancer patients.

Combination Targeted Therapy in Relapsed Diffuse Large B-Cell Lymphoma

BackgroundThe identification of oncogenic mutations in diffuse large B-cell lymphoma (DLBCL) has led to the development of drugs that target essential survival pathways, but whether targeting multiple survival pathways may be curative in DLBCL is unknown.MethodsWe performed a single-center, phase 1b–2 study of a regimen of venetoclax, ibrutinib, prednisone, obinutuzumab, and lenalidomide (ViPOR) in relapsed or refractory DLBCL. In phase 1b, which included patients with DLBCL and indolent lymphomas, four dose levels of venetoclax were evaluated to identify the recommended phase 2 dose, with fixed doses of the other four drugs. A phase 2 expansion in patients with germinal-center B-cell (GCB) and non-GCB DLBCL was performed. ViPOR was administered every 21 days for six cycles.ResultsIn phase 1b of the study, involving 20 patients (10 with DLBCL), a single dose-limiting toxic effect of grade 3 intracranial hemorrhage occurred, a result that established venetoclax at a dose of 800 mg as the recommended phase 2 dose. Phase 2 included 40 patients with DLBCL. Toxic effects that were observed among all the patients included grade 3 or 4 neutropenia (in 24% of the cycles), thrombocytopenia (in 23%), anemia (in 7%), and febrile neutropenia (in 1%). Objective responses occurred in 54% of 48 evaluable patients with DLBCL, and complete responses occurred in 38%; complete responses were exclusively in patients with non-GCB DLBCL and high-grade B-cell lymphoma with rearrangements of MYC and BCL2 or BCL6 (or both). Circulating tumor DNA was undetectable in 33% of the patients at the end of ViPOR therapy. With a median follow-up of 40 months, 2-year progression-free survival and overall survival were 34% (95% confidence interval [CI], 21 to 47) and 36% (95% CI, 23 to 49), respectively.ConclusionsTreatment with ViPOR was associated with durable remissions in patients with specific molecular DLBCL subtypes and was associated with mainly reversible adverse events. (Funded by the Intramural Research Program of the National Cancer Institute and the National Center for Advancing Translational Sciences of the National Institutes of Health and others; ClinicalTrials.gov number, NCT03223610.)

Ibrutinib in Combination with R-GemOx in Patients with Relapsed or Refractory Diffuse Large B-cell Lymphoma of Nongerminal Center B-cell-like Type: Phase II Clinical Trial of the Spanish GELTAMO Group.

This phase II clinical trial evaluated the combination of ibrutinib with rituximab, gemcitabine, and oxaliplatin (R-GemOx) in patients with nongerminal center B-cell-like (non-GCB) diffuse large B-cell lymphoma (DLBCL). The IBDCL trial (NCT02692248) included patients with histologic diagnosis of non-GCB DLBCL with relapsed or refractory disease and non-candidates for stem-cell transplantation. Patients received an induction treatment consisting of six or eight cycles of R-GemOx at standard doses every 2 weeks, in combination with ibrutinib (560 mg daily), followed by a maintenance treatment with ibrutinib for a maximum of 2 years. The primary objective was to evaluate the overall response rate after four cycles. Sixty-four patients were included, 72% of them refractory to the last regimen. The overall response rate and complete remission rate after the fourth cycle were 53% [95% confidence interval (CI), 41-65] and 34% (95% CI, 24-46), respectively. Twenty-four (37%) patients started maintenance, and 7 (11%) completed the planned 2 years. After a median follow-up of 29.7 months (range: 0.4-48.6), the estimated 2-year progression-free survival and overall survival were 18% (95% CI, 8-28) and 26% (95% CI, 14-37), respectively. The most common grade ≥3 treatment-related adverse events were thrombocytopenia (44%), neutropenia (30%), and anemia (14%). Grade ≥3 infectious and cardiovascular treatment-related adverse events were reported in 6 (9%) and 1 (2%) patient, respectively. Ibrutinib in combination with R-GemOx, followed by ibrutinib maintenance, demonstrated encouraging antitumor activity with durable responses and a manageable toxicity in patients with non-GCB DLBCL.

What is the best salvage therapy for Hodgkin lymphoma?

Historically, salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplant (HDT/ASCT) was the mainstay approach for relapsed or refractory classic HL. The emergence of novel agents for HL, such as brentuximab vedotin and programmed death-1 (PD-1) blockade has revolutionized therapeutic strategies, yielding excellent results. This review aims to provide a comprehensive overview of new salvage therapies and offer insights into forthcoming therapeutic options. The incorporation of brentuximab vedotin and PD-1 blockade into salvage therapy before HDT/ASCT has led to markedly improved outcomes. Notably, PD-1 based salvage studies yield posttransplant 2-year progression-free survival rates approaching 90%, marking a significant advancement in the treatment of Hodgkin lymphoma (HL). Studies are beginning to explore nontransplant treatment approaches following front-line treatment failure and may identify certain risk groups eligible for these strategies. The landscape of HL treatment is rapidly evolving, leading to significant changes in the standard of care. Novel agents are now administered earlier in the disease course, resulting in higher cure rates. The focus of treatment is shifting towards achieving cure with minimal toxicity, reducing exposure to various agents, and advancing research in optimizing treatment sequencing and patient selection for less intensive therapies.

Efficacy and safety of MIL62, a novel glycoengineered type Ⅱ anti-CD20 monoclonal antibody, combined with lenalidomide in patients with relapsed/refractory follicular lymphoma or marginal zone lymphoma: a multicentre, single-arm, phase 1b/2 trial

MIL62, a novel glycoengineered type Ⅱ anti-CD20 monoclonal antibody, with a nearly completely afucosylated N-glycans in Fc region, has demonstrated superior activity compared with rituximab and obinutuzumab invitro and invivo, respectively. This multicentre, single-arm, phase 1b/2 trial aimed to explore the efficacy, pharmacokinetics, and safety of MIL62 combined with lenalidomide in patients with relapsed/refractory (R/R) follicular lymphoma (FL) or marginal zone lymphoma (MZL). Eligible patients included those who had histopathologically confirmed CD20 positive FL (grade 1-3a) or MZL and failed to be treated with rituximab. Patients received intravenously infused MIL62 1000mg (cycle 1: day 1, 15; cycles 2-8: day 1, cycles 10 and 12: day 1) combined with oral lenalidomide (once a day, days 2-22, the initial dose was 10mg, and the maximum dose was 20mg) for 12 cycles, 28 days as a cycle. The primary endpoint was objective response rate (ORR) assessed by investigator per Lugano 2014 criteria every 3 cycles. This study was registered in ClinicalTrials.gov (NCT04110301). Between November 22, 2019 and December 22, 2020, 54 patients were enrolled from 11 hospitals in China and received study treatment. Fifty patients were included in the efficacy analysis set, and 43 patients (86%, 95% CI: 73, 94) achieved objective response, meeting the pre-specified primary endpoint. Disease control rate was 96% (48/50, 95% CI: 86, 100), proportion of patients with duration of response (DoR) > 6 months was 77% (33/43). The median follow-up for survival was 12.3 months (IQR 12.0-12.6). The 1-year progression-free survival rate was 72% (95% CI: 57, 83), 9-month DoR rate was 74% (95% CI: 58, 85), and 1-year overall survival rate was 98% (95% CI: 85, 100). Most common TRAEs were neutropenia (93%, 50/54), leukopenia (85% 46/54), thrombocytopenia (61% 33/54), lymphopenia (32% 17/54), and alanine aminotransferase increased (20% 11/54). MIL62 combined with lenalidomide showed promising efficacy in patients with R/R FL and MZL. A multicentre, randomized, open-label, phase Ⅲ trial of MIL62 combined with lenalidomide versus lenalidomide in anti-CD20 monoclonal antibody refractory FL patients is ongoing (NCT04834024). Beijing Mabworks Biotech Co. Ltd, Beijing China and the National Science and Technology Major Project for Key New Drug Development (2017ZX09304015).

The Role of CyberKnife Stereotactic Radiosurgery in Recurrent Cranial Medulloblastomas across Pediatric and Adult Populations.

Background/Objectives: Medulloblastoma is the most common malignant brain tumor in children. In recent decades, the therapeutic landscape has undergone significant changes, with stereotactic radiosurgery (SRS) emerging as a promising treatment for recurrent cases. Our study provides a comprehensive analysis of the long-term efficacy and safety of SRS in recurrent medulloblastomas across both pediatric and adult patients at a single institution. Methods: We retrospectively reviewed the clinical and radiological records of patients who underwent CyberKnife SRS for recurrent cranial medulloblastomas at our institution between 1998 and 2023. Follow-up data were available for 15 medulloblastomas in 10 patients. The cohort comprised eight pediatric patients (ages 3-18) and two adult patients (ages 19-75). The median age at the time of SRS was 13 years, the median tumor volume accounted for 1.9 cc, the median biologically equivalent dose (BED) was 126 Gy, and the single-fraction equivalent dose (SFED) was 18 Gy. The SRS was administered at 75% of the median isodose line. Results: Following a median follow-up of 39 months (range: 6-78), 53.3% of the medulloblastomas progressed, 13.3% regressed, and 33.3% remained stable. The 3-year local tumor control (LTC) rate for all medulloblastomas was 65%, with lower rates observed in the adult cohort (50%) and higher rates in pediatric patients (67%). The 3-year overall survival (OS) rate was 70%, with significantly higher rates in pediatric patients (75%) compared to adult patients (50%). The 3-year progression-free survival (PFS) rate was 58.3%, with higher rates in pediatric patients (60%) compared to adult patients (50%). Two pediatric patients developed radiation-induced edema, while two adult patients experienced radiation necrosis at the latest follow-up, with both adult patients passing away. Conclusions: Our study provides a complex perspective on the efficacy and safety of CyberKnife SRS in treating recurrent cranial medulloblastomas across pediatric and adult populations. The rarity of adverse radiation events (AREs) underscores the safety profile of SRS, reinforcing its role in enhancing treatment outcomes. The intricacies of symptomatic outcomes, intertwined with factors such as age, tumor location, and prior surgeries, emphasize the need for personalized treatment approaches. Our findings underscore the imperative for ongoing research and the development of more refined treatment strategies for recurrent medulloblastomas. Given the observed disparities in treatment outcomes, a more meticulous tailoring of treatment approaches becomes crucial.

CP-06. PEDIATRIC CRANIOPHARYNGIOMA: SINGLE CENTER RETROSPECTIVE STUDY OF SURVIVAL, ENDOCRINOLOGIC, AND VISION OUTCOMES IN 90 PATIENTS

Abstract BACKGROUND Craniopharyngioma is histologically benign. However, due to its location, morbidity is high and may be impacted by therapeutic approach. METHODS A retrospective study of patients treated for craniopharyngioma at Seattle Children’s Hospital from 1996-2023 was performed. Surgical approach, extent of resection, subsequent surgery, radiation and medical therapies, and serial surveillance magnetic resonance imaging for progression were reviewed. Five-year overall survival (OS) and progression free survival (PFS) were calculated and morbidity including endocrine and vision dysfunction was described. RESULTS 90 patients were included of which 53(58.9%) were male. Median age at diagnosis was 8.70 (range 1.39-25.17) years. Surgical approach included endoscopic (N=24), craniotomy (N=64), and combined (N=2). Extent of resection was biopsy N=2, subtotal resection N=7, near total resection N=38, gross total resection N=30. Pathology was adamantinomatous subtype in all cases and 68 had a documented CTNNB1 alteration and 3 had a BRAF alteration in those with molecular analysis. 5-year OS was 96.1% (SE 0.13) and 5-year PFS was 51.9% (SE0.21), with median follow-up of 97 months. Transcranial compared to endoscopic endonasal approach was associated with increased risk of progression (62% vs 30%, OR 1.23). 34 patients were treated with radiation upfront (N=19) or at progression (N=15). 55% of patients at diagnosis and an additional 30% in follow up had pituitary hormone dysfunction. Hypothalamic obesity was documented in 31% of patients and varied by surgical approach. At presentation, ophthalmologic abnormalities included optic nerve edema (18%) and optic nerve pallor (24%) and 30% had abnormal visual acuity. Following initial surgery, 50% had improvement in visual acuity, 35% stable and 15% had worsened visual acuity. CONCLUSIONS Upfront surgical strategy may impact risk of disease recurrence; however, its relationship to long term morbidity is not clear. Further work to delineate therapeutic strategies and their relationship to morbidity in this patient population is needed.

Comparative efficacy of Bacillus Calmette-Guérin instillation and radical cystectomy treatments for high-risk non-muscle-invasive urothelial cancer classified as high-grade T1 in initial and repeat transurethral resection of bladder tumor.

To compare the differential therapeutic effects of Bacillus Calmette-Guérin (BCG) instillation and radical cystectomy (RC) for high-risk non-muscle-invasive urothelial cancer (NMIBC) classified as high-grade T1 in initial and repeat transurethral resection of bladder tumors (TURBT) and to construct a prediction model. We retrospectively analyzed the clinical data of patients with malignant bladder tumors treated at the First Affiliated Hospital of Soochow University from January 2016 to December 2017 and compared the differences in 1-year, 2-year, 3-year, 5-year, and comprehensive overall survival (OS) and progression-free survival (PFS) between BCG instillation treatment and RC treatment. Survival curves were drawn to show differences in OS and PFS between the two groups. Concurrently, univariate and multivariate COX analyses were performed to identify risk factors affecting OS and PFS, and a nomogram was created. In total, 146 patients were included in the study, of whom 97 and 49 were in the BCG and RC groups, respectively. No statistical differences were observed in the 1- and 2-year OS and PFS between the two groups, whereas significant statistical differences were found in the 3-year, 5-year, and comprehensive OS and PFS. Survival curves also confirmed the statistical differences in OS and PFS between the BCG and RC groups. Multivariate COX analysis revealed that the treatment method, concomitant satellite lesions, and albumin-to-alkaline phosphatase ratio (AAPR) were independent risk factors affecting OS and PFS. The nomogram that was further plotted showed good predictive ability for OS and PFS. For patients who exhibit high-level T1 pathology after both initial and repeat TURBT, especially those with low AAPR, and concomitant satellite lesions, choosing RC as a treatment method offers a better prognosis.

LGG-37. A PHASE III STUDY COMPARING TWO CARBOPLATIN CONTAINING REGIMENS FOR CHILDREN AND YOUNG ADULTS WITH PREVIOUSLY UNTREATED LOW-GRADE GLIOMA

Abstract BACKGROUND Low-grade glioma (LGG) is the most common childhood central nervous system tumor. Carboplatin/vincristine (CV) is a standard of care regimen used for incompletely resected tumors. Monthly carboplatin is an alternative regimen that has not been prospectively compared to CV previously in untreated patients. METHODS Patients ≤ 21 years with LGG and no treatment besides surgery were eligible. Patients were stratified according to NF1 status and randomized to Arm A (carboplatin/vincristine) or Arm B (carboplatin monthly). The primary endpoint was 3-year progression-free survival (PFS). Secondary endpoint analysis is underway and includes quality of life, tumor response rates, toxicity and association of molecular alterations on outcomes. Analyses included log-rank test and descriptive statistics. RESULTS There were 95 evaluable patients with a median age of 5 (range 0-18) years; 67 non-NF1 subjects (32 Arm A, 35 Arm B) and 28 NF1 subjects (14 Arm A, 14 Arm B). Three-year PFS was superior for patients without NF1 treated on Arm A (58%; 95% CI: 38%, 74%) versus Arm B (33%; 95% CI: 18%, 49%) (p=0.04). In patients with NF1, there was no statistical difference in PFS between those treated on Arm A (71%; 95% CI: 41%, 88%) and Arm B (93%; 95% CI: 59%, 99%) (p=0.08). Grade 3/4 toxicity neutropenia was more commonly seen in Arm A patients compared to Arm B for both NF and non-NF1 patients. Peripheral neuropathy was also more commonly seen in non-NF1 patients (Grade 1-4; 32%) compared to NF1 patients (7%) for patients treated on Arm A. There were 15 carboplatin reactions (Grade 1-4); 7 non-NF1 on Arm A, 3 non-NF1 on Arm B, and 5 NF1 on Arm A. CONCLUSIONS Non-NF1 patients treated with carboplatin and vincristine show statistically significant improved PFS compared to monthly carboplatin. Patients with NF1 are statistically underpowered due to low accrual.

BIOM-02. DISSECTING CDK4/6 INHIBITOR RESISTANCE MECHANISMS IN RECURRENT PEDIATRIC BRAIN TUMORS WITH LONGITUDINAL CSF LIQUID BIOPSIES FROM THE SJDAWN CLINICAL TRIAL

Abstract BACKGROUND SJDAWN (NCT03434262) is a St. Jude Children’s Research Hospital phase 1 trial that assessed the safety and benefit of CDK4/6 inhibitor-based therapy in patients with relapsed CNS tumors. To capture tumor evolution dynamics and arising resistance mechanisms in response to treatment, 143 longitudinal CSF samples were collected from 34/68 (50%) patients for cell-free DNA (cfDNA) analysis. METHODS cfDNA was extracted from CSF liquid biopsies and analyzed using a novel methylation-based platform that integrates copy number, tumor classification, and deconvolution of methylation signatures into normal vs. disease fractions. Samples with measurable residual disease (MRD) were further characterized by deep whole-genome sequencing to discover mutation-driven resistance mechanisms. When available, pre- and post-SJDAWN tumor tissues were processed for single-nucleus multi-omics to track tumor evolution at single-cell resolution. RESULTS In the context of CDK4/6 inhibitor-based therapy, longitudinal cfDNA assessment revealed treatment-induced selection for subclones with focal amplification of positive cell cycle regulators CDK6, CCND2, and MYCN. Emergence of these resistance mechanisms notably preceded disease progression on MRI and CSF cytology by up to 6 months. Of the 68 patients enrolled on SJDAWN, 4 patients (3 Group 3/4, subtype III medulloblastomas and 1 anaplastic ependymoma) achieved &amp;gt;2-year progression-free survival. Interestingly, serial cfDNA profiling of 1 long-term survivor (Group 3/4, subtype III medulloblastoma) exhibited undetectable MRD status for &amp;gt;1.5 years prior to reemergence, suggesting tumor senescence by CDK4/6 inhibition may impede circulating tumor DNA (ctDNA) release kinetics. CSF liquid biopsies were further evaluated in comparison to matched tumor tissues, and changes in CSF-specific subclones were observed in response to treatment. CONCLUSIONS In addition to early MRD detection, liquid biopsies capture tumor evolution dynamics and can inform developing resistance mechanisms. Focal amplification of CDK6, CCND2, and MYCN facilitates CDK4/6 inhibitor resistance. In responders, treatment-induced senescence may inhibit ctDNA release kinetics.

EPEN-19. IMPACT OF MOLECULAR SUBTYPING ON PROGNOSIS IN CHILDREN AND ADOLESCENTS WITH SPINAL EPENDYMOMA

Abstract PURPOSE Ependymomas of the spinal cord are rare among children and adolescents, and the individual risk of disease progression is difficult to predict. Recent advances in subtyping the main molecular groups, myxopapillary ependymoma (MPE) and spinal ependymoma (SP-EPN), have successfully identified distinct risk groups among adult patients. This study aims at evaluating the prognostic impact of MPE subtypes A and B in a pediatric cohort. METHODS Eighty-three patients with spinal ependymoma ≤22 years registered in the HIT-MED database between 1992 and 2022 were included. Forty-seven tumors were analyzed regarding global DNA methylation. In six cases, antibodies against HOXB13 and MYCN were used as surrogate markers for the methylation group. Twenty-eight MPE were further classified into subtypes by t-distributed stochastic neighbor embedding (t-SNE) analysis. RESULTS MPE (n=32, 63%) was the most common molecular type followed by SP-EPN (n=17, 33%) and MYCN-amplified ependymoma (n=2, 4%). One case remained molecularly unclear, and one was excluded due to reclassification as anaplastic pilocytic astrocytoma. MPE subtyping identified 18 MPE-A and 9 MPE-B (inconclusive: n=1). 5-year progression-free survival (5y-PFS) did not significantly differ between MPE and SP-EPN (65% vs. 78%, p=0.64). MYCN-amplification was associated with early relapses and with death in one patient. Patients with MPE-B may have a tendency towards superior 5y-PFS compared to MPE-A (86% vs. 56%, p=0.15), irrespective of the use of adjuvant treatment. MPE-A was more frequently disseminated at time of diagnosis (n=6/18) than MPE-B (n=1/8, not evaluable: n=1; p=0.28). CONCLUSION Molecular subtyping of spinal ependymoma in children does not allow to separate patients into distinct risk groups, yet. However, the potentially favorable PFS among patients with MPE-B prompts the consideration of treatment de-intensification for this group. Larger cohorts and further insights into the molecular heterogeneity of these tumors are needed to complete the basis for future clinical decision-making.

LMIC-19. A RETROSPECTIVE ANALYSIS OF PEDIATRIC RECURRENT PINEOBLASTOMA IN BEIJING

Abstract OBJECTIVE To explore the clinical characteristics of pediatric recurrent pineoblastoma in Beijing. METHODS Eighteen patients with newly diagnosed pineoblastoma were admitted to Beijing Shijitan Hospital between January 2014 and December 2022. The clinical data were retrospectively analyzed. RESULTS Among the 18 patients (M/F=8:1), all were treated with surgery, and both radiotherapy and chemotherapy were administered. Nine patients experienced recurrence, and 2 patients died at last follow-up. The Median follow-up time were 56 months. The 5-year progression-free survival (PFS) and 5-year overall survival (OS) were (42.0±13.1) %, and (88.1±7.9) %, respectively. Among the 9 recurrent patients, one was &amp;lt; 3 years, and 8 cases ≥ 3 years. One girl and 8 boys relapsed; 7 cases were M0 and 2 with metastases at diagnosis; 7 cases were GTR; Two cases experienced recurrence within one year (10 months each), and one died. The other 7 patients relapsed after one year, the median time to first relapse were 24.0 (range: 10.0~49.0)months. The sex, age group, metastases at diagnosis, GTR or not, recurrent sites were not significantly affects PFS. Although the 9 recurrent patients received both cerebral and spinal irradiation and chemotherapy followed by surgery, the different order of chemotherapy or radiotherapy first were significantly affected the duration of remission. The median time before the first relapse after surgery was longer in those who treated under the order of craniospinal irradiation followed by chemotherapy than those of the inverse order (29m vs 13m, χ2=6.528, P=0.011). In addition, one case with germline mutation of Dicer1, experienced recurrences more than 3 times although received second surgery and second radiotherapy, and multiple cycles of chemotherapy in our center, which indicates poorer outcome. CONCLUSION Pineoblastoma is rare and prone to relapse, the order of chemotherapy first may have shorter remission time before the first recurrence after surgery (P&amp;lt; 0.05).

MDB-92. EFFECT OF REDUCED-DOSE CRANIOSPINAL IRRADIATION AND REDUCED-DOSE ADJUVANT CHEMOTHERAPY ON CHILDREN AND ADOLESCENTS WITH WNT MEDULLOBLASTOMA WITHOUT RESIDUAL OR METASTATIC DISEASE: RESULTS FROM THE SJMB12 CLINICAL TRIAL

Abstract BACKGROUND In response to studies showing medulloblastoma (MB) survival is not only contingent on clinical factors (e.g. metastases, residual disease) but also on molecular factors (e.g. molecular group, gene aberrations), we launched the SJMB12 (NCT01878617) trial to stratify treatment using both clinical and molecular risk factors. Specifically, we sought to evaluate if patients with WNT-group MB, without metastatic (M0) or residual disease (R0), treated with reduced-dose craniospinal irradiation (CSI) and reduced-dose cyclophosphamide-based chemotherapy could maintain a high survival with fewer treatment-related side effects. METHODS Tumors were molecularly stratified via immunohistochemistry and fluorescence in-situ hybridization. Patients with WNT tumors were grouped into 3 strata: W1 (M0, R0, classic histology, monosomy of chromosome 6); W2 (M0, R0, without monosomy 6 or classic histology); W3 [metastatic (M+), residual disease (R+), or MYC/MYCN amplification]. Treatment of W1 consisted of 15-Gy CSI/51-Gy primary site (0.5cm CTV margin) followed by 4 cycles of chemotherapy resulting in cumulative doses of 8 mg/m2 vincristine, 300 mg/m2 cisplatin, 12 gm/m2 cyclophosphamide. Serial audiology, neurocognitive, and endocrine evaluations were conducted over a six-year follow-up period. RESULTS From 2013-2022, 72 patients enrolled onto the W1 stratum: median age was 10.3 years (4.9-22.0); 62.5% female; median time of follow-up was 4.5 years (1.1-10.1). 5-year progression-free survival (PFS) and overall survival were 90.4 ± 5.1% and 98.6 ± 2.1%, respectively. Five patients had PFS events: 4 relapses and 1 accidental death. Relapsed disease was local in 2, distant in 1, and mixed in 1. Time to relapse was &amp;gt; 2 years from enrollment for 3 patients. Severe ototoxicity (SIOP grade ≥ 3) at the end of therapy occurred in 14.4 ± 4.5%. Neurocognitive, endocrine, and detailed molecular data are forthcoming. CONCLUSIONS Patients with low-risk WNT-MB maintained a high PFS (&amp;gt;90%) when treated with reduced-dose CSI and reduced-dose cyclophosphamide-based chemotherapy. Preliminary data suggests fewer treatment-related side effects.

LGG-01. PROGNOSTIC UTILITY AND CHARACTERISTICS OF MIB-1 LABELING INDEX AS A PROLIFERATIVE ACTIVITY MARKER IN CHILDHOOD LOW-GRADE GLIOMA: A RETROSPECTIVE OBSERVATIONAL STUDY

Abstract BACKGROUND The prognostic utility of MIB-1 labeling index (LI) in pediatric low-grade glioma (PLGG) has not yet conclusively been described. We assess the correlation of MIB-1 LI and tumor growth velocity, aiming to contribute to the understanding of clinical implications and the predictive value of MIB-1 LI as an indicator of proliferative activity and progression-free survival (PFS) in pediatric low-grade glioma. METHODS MIB-1 LI of a cohort of 172 pediatric low-grade gliomas were comprehensively characterized. Correlation to tumor growth velocity, assessed by sequential MRI-based three-dimensional volumetric analyses, and PFS was analyzed. RESULTS Mean MIB-1 LI accounted for 2.7 % (range: &amp;lt;1 – 10) and showed a significant decrease to 1.5 % at secondary surgery (p =.0013). A significant difference of MIB-1 LI in different histopathological types and a correlation to tumor volume at diagnosis could be shown. Linear regression analysis showed a correlation between MIB-1 LI and preoperative TGV (R² =.55, p &amp;lt;.0001), while correlation to tumor growth velocity remarkably decreased after incomplete resection (R² =.08, p =.013). Log-rank test showed no impact of MIB-1 LI on 5-year PFS after incomplete (MIB-1 LI &amp;gt; 1 vs ≤ 1%: 48 vs 46 %, p =.73) and gross-total resection (MIB-1 LI &amp;gt; 1 vs ≤ 1%: 89 vs 95 %, p =.75). CONCLUSIONS This data confirms a correlation of MIB-1 LI and radiologically detectable tumor growth velocity in PLGG for the first time. Compared to preoperative tumor growth rates, a crucially decreasing correlation of MIB-1 LI and tumor growth velocity after surgery may result in limited prognostic capability of MIB-1 LI in pediatric low-grade glioma.

LGG-42. TWENTY YEARS OF PROGRESS IN MANAGING LOW GRADE GLIOMA: THE EXPERIENCE OF THE UNIVERSITY OF CAPE TOWN’S COMBINED PAEDIATRIC NEURO-ONCOLOGY SERVICE FROM 2001 TO 2022

Abstract BACKGROUND This study aimed to review the management of childhood low grade gliomas (WHO I and II) by the University of Cape Town’s combined neuro-oncology service at Red Cross War Memorial Children’s and Groote Schuur Hospitals. METHODS All patients diagnosed with low grade glioma between 2001 and 2022 were included in this retrospective study. Real time decision-making during the study period was achieved via a weekly neuroimaging meeting, and surveillance by a combined monthly clinic attended by paediatric endocrinology and educational psychology. Despite state of the art surgical and radiotherapy facilities, molecular diagnostics, monoclonal antibodies and small molecules were only available to selected patients. RESULTS Among 129 children, aged 0.38 to 14.58 years [median 5.36], six had Tuberous Sclerosis and 11 had Neurofibromatosis-1. The commonest sites were cerebellum (26%), hypothalamus (17%) and optic pathway (16%), and 12 patients (9%) had metastatic disease, mostly grade I supratentorial tumours. Twenty-three patients were diagnosed on imaging without histology, six of whom were biopsied subsequently, yielding a total of 96 grade I and 16 grade II tumours. Initial management was expectant in 16% (including 8 of the 11 Nf-1 tumours), surgery in the form of debulking or total resection in 53%, chemotherapy in 24% and radiotherapy in 8%. Ultimately 36% received chemotherapy and 29% radiotherapy (almost all of them focal RT), and only 16% of those treated with radiotherapy progressed. Estimated 5-year Overall Survival (OS) and Progression Free Survival (PFS) was 90.5% and 52.6% for the whole group. Patients treated with chemotherapy had an OS of 87.2% and a PFS of 39.2%. PFS and OS were inferior for metastatic disease but not for grade II tumours. CONCLUSIONS Low grade glioma can be managed effectively in a middle-income country setting. Multidisciplinary team management is crucial to achieving positive outcomes regardless of context.