Citations

Abstract We evaluated whether spike ripples, the combination of epileptiform spikes and ripples, provide a reliable and improved biomarker for the epileptogenic zone compared with other leading interictal biomarkers in a multicentre, international study. We first validated an automated spike ripple detector on intracranial EEG recordings. We then applied this detector to subjects from four centres who subsequently underwent surgical resection with known 1-year outcomes. We evaluated the spike ripple rate in subjects cured after resection [International League Against Epilepsy Class 1 outcome (ILAE 1)] and those with persistent seizures (ILAE 2–6) across sites and recording types. We also evaluated available interictal biomarkers: spike, spike-gamma, wideband high frequency oscillation (HFO, 80–500 Hz), ripple (80–250 Hz) and fast ripple (250–500 Hz) rates using previously validated automated detectors. The proportion of resected events was computed and compared across subject outcomes and biomarkers. Overall, 109 subjects were included. Most spike ripples were removed in subjects with ILAE 1 outcome (P < 0.001), and this was qualitatively observed across all sites and for depth and subdural electrodes (P < 0.001 and P < 0.001, respectively). Among ILAE 1 subjects, the mean spike ripple rate was higher in the resected volume (0.66/min) than in the non-removed tissue (0.08/min, P < 0.001). A higher proportion of spike ripples were removed in subjects with ILAE 1 outcomes compared with ILAE 2–6 outcomes (P = 0.06). Among ILAE 1 subjects, the proportion of spike ripples removed was higher than the proportion of spikes (P < 0.001), spike-gamma (P < 0.001), wideband HFOs (P < 0.001), ripples (P = 0.009) and fast ripples (P = 0.009) removed. At the individual level, more subjects with ILAE 1 outcomes had the majority of spike ripples removed (79%, 38/48) than spikes (69%, P = 0.12), spike-gamma (69%, P = 0.12), wideband HFOs (63%, P = 0.03), ripples (45%, P = 0.01) or fast ripples (36%, P < 0.001) removed. Thus, in this large, multicentre cohort, when surgical resection was successful, the majority of spike ripples were removed. Furthermore, automatically detected spike ripples localize the epileptogenic tissue better than spikes, spike-gamma, wideband HFOs, ripples and fast ripples.

34 Background: Prostate specific membrane antigen positron emission tomography (PSMA-PET) imaging improves prostate cancer visualization and has been proposed as a tool to guide treatment decisions. As PSMA-PET imaging agents were not approved in the United States (US) until December 2020, little is known about national patterns of PET imaging utilization. Methods: We conducted a dynamic cohort study to evaluate use of PET imaging among insurance beneficiaries aged 40-89 years with a diagnosis of prostate cancer using deidentified administrative claims from Blue Cross Blue Shield Axis. We calculated the proportions of patients undergoing PET imaging in semiannual periods from January 1, 2016, through December 31, 2022, examining tracers specific to prostate cancer, including PSMA-targeted agents as well as fluciclovine, sodium fluoride, and choline tracers. Cochran-Armitage tests were used to evaluate trends in the proportion of individuals receiving PET imaging over time. We also assessed the association between regional [hospital referral region (HRR)] level contextual sociodemographic and healthcare characteristics and regional use of PSMA-PET imaging in 2022 using chi-square tests. Results: There were 410,505 beneficiaries with prostate cancer identified in the study period. The semiannual proportion of patients undergoing PET imaging increased from 4.5 [(95% confidence interval (CI) 4.1-5.0] per 1,000 in the first half of 2016 to 41.7 (95% CI 40.6-42.9) per 1,000 in the second half of 2022, p<0.001. Increases in PET imaging were driven by uptake of PSMA-PET imaging, which increased from 0.7 (95% CI 0.6-0.9) per 1000 in the second half of 2021 to 37.5 (95% CI 36.4-38.6) per 1,000 in the second half of 2022, p<0.001. Following approvals of PSMA-PET agents, other forms of PET imaging rapidly decreased – from 18.2 (95% CI 17.4-18.9) per 1000 in the second half of 2021 to 4.6 (95% CI 4.3-5.0) per 1,000 in the same period of 2022, p<0.001. Compared to HRRs in quartile 1 (Q1), HRRs in Q4 of PSMA-PET use in 2022 had higher levels of education (25.0% with college education or higher in Q1 versus 29.4% in Q4, p=0.005) and median household income ($50,200 in Q1 versus $60,900 in Q4, p<0.001). Conclusions: In this study from a large commercial US health insurer, PSMA-PET was rapidly incorporated into clinical practice and is now the dominant prostate cancer radiotracer. However, the initial uptake of PSMA-PET may be accompanied by disparity, as our data suggests less use in areas with lower income and education measures.

Background Nephritis is a common manifestation of IgA vasculitis and is morphologically indistinguishable from IgA nephropathy. While MEST-C scores are predictive of kidney outcomes in IgA nephropathy, their value in IgA vasculitis nephritis has not been investigated in large multiethnic cohorts. Methods Biopsies from 262 children and 99 adults with IgA vasculitis nephritis ( N =361) from 23 centers in North America, Europe, and Asia were independently scored by three pathologists. MEST-C scores were assessed for correlation with eGFR/proteinuria at biopsy. Because most patients ( N =309, 86%) received immunosuppression, risk factors for outcomes were evaluated in this group using latent class mixed models to identify classes of eGFR trajectories over a median follow-up of 2.7 years (interquartile range, 1.2–5.1). Clinical and histologic parameters associated with each class were determined using logistic regression. Results M, E, T, and C scores were correlated with either eGFR or proteinuria at biopsy. Two classes were identified by latent class mixed model, one with initial improvement in eGFR followed by a late decline (class 1, N =91) and another with stable eGFR (class 2, N =218). Class 1 was associated with a higher risk of an established kidney outcome (time to ≥30% decline in eGFR or kidney failure; hazard ratio, 5.84; 95% confidence interval, 2.37 to 14.4). Among MEST-C scores, only E1 was associated with class 1 by multivariable analysis. Other factors associated with class 1 were age 18 years and younger, male sex, lower eGFR at biopsy, and extrarenal noncutaneous disease. Fibrous crescents without active changes were associated with class 2. Conclusions Kidney outcome in patients with biopsied IgA vasculitis nephritis treated with immunosuppression was determined by clinical risk factors and endocapillary hypercellularity (E1) and fibrous crescents, which are features that are not part of the International Study of Diseases of Children classification.

TPS236 Background: For patients with oligometastatic colorectal cancer (CRC), aggressive local therapy of isolated metastases, particularly in the liver, has been associated with long-term progression-free survival and overall survival (OS) primarily based on retrospective evidence. However, in patients with limited metastatic CRC that is deemed inoperable or those with additional disease outside of the liver or lungs, the role of local ablative therapies, including microwave ablation (MWA) and stereotactic body radiation therapy (SBRT), to render patients disease free is less clear. Further, despite the long history of treating oligometastatic CRC with local therapy, which is provider biased and not evidence based, questions remain regarding the benefit of extending the paradigm of metastatic directed therapy to patients with more extensive disease. This trial seeks to use a pragmatic multimodality approach that mirrors the current clinical dilemma. This study is designed to evaluate the safety and efficacy of adding total ablative therapy (TAT) of all sites of disease to standard of care systemic treatment in those with limited metastatic CRC. Methods: A022101 is a National Clinical Trials Network randomized phase III study planned to enroll 364 patients with newly diagnosed metastatic CRC (BRAF wild-type, microsatellite stable) with ≤4 sites of metastatic disease on baseline imaging. Liver-only metastatic disease is not permitted, and lesions must be amenable to any combination of surgical resection, MWA, and/or SBRT with SBRT required for at least one lesion. Patients receive first-line systemic therapy for 4-6 months and are then randomized 1:1, stratified by number of metastatic organ sites (1-2 vs. 3-4), timing of metastatic disease diagnosis (de novo vs. secondary), and presence of metastatic disease outside the liver and lungs in at least one site. Patients in Arm 1 will receive TAT which consists of treatment of all metastatic sites with SBRT ± MWA ± surgical resection followed by standard of care systemic therapy. Patients in Arm 2 will continue with standard of care systemic therapy alone. The primary endpoint is OS. Secondary endpoints include event-free survival, treatment-related toxicities, and local recurrence with exploratory biomarker analyses. The study needs 346 evaluable patients combined in the 2 arms to demonstrate an improvement in OS with a hazard ratio of 0.7 to provide 80% power with a one-sided alpha of 5%. The trial utilizes a group sequential design with two interim analyses (25% and 50% of events) for futility. The trial activated in January 2023 and recruitment is ongoing. Support: U10CA180821, U10CA180882; https://acknowledgments.alliancefound.org. U10CA180820 (ECOG-ACRIN); U10CA180868 (NRG); U10CA180888 (SWOG). Clinical trial information: NCT05673148 .

664 Background: Postoperative complications in patients with borderline resectable pancreatic cancer treated with neoadjuvant therapy and pancreatectomy in the national cooperative group setting have not been previously characterized. Further, the impact of preoperative hypofractionated radiotherapy on postoperative outcomes is largely unknown. We sought to quantify perioperative morbidity among patients with pancreatic cancer who received neoadjuvant modified FOLFIRINOX chemotherapy with or without hypofractionated radiotherapy on a multicenter clinical trial. Methods: The A021501 phase 2 trial randomized patients with borderline resectable pancreatic ductal adenocarcinoma to 8 doses of mFOLFIRINOX (Arm 1) or 7 doses of mFOLFIRINOX then hypofractionated radiotherapy (Arm 2), followed by pancreatectomy (Dec 31, 2016-Jan 1, 2019). Patients underwent resection according to defined operative standards at enrolling centers without specific requirements for either surgeon or hospital volume. Surgical complications and adverse events were assessed and captured at a single time point of 90 days after surgery and compared between treatment arms. Results: Of 126 enrolled patients, 51 (40%) underwent pancreatectomy (n=32, Arm 1; n=19, Arm 2) at 28 institutions. Vascular resection was performed in 19 patients (37%). One patient in Arm 2 died within 90 days after surgery. Rates of any surgical complication were 19% (n=6) in Arm 1 and 42% (n=8) in Arm 2 (p=0.07). Median length of stay was 7 days (range 5-38 days). Five (10%) patients required reoperation within 90 days. Readmission rates were higher in Arm 2 than Arm 1 (16% vs. 42%, p=0.04) but there were no differences in rates of reoperation, pancreatic fistula or abscess requiring drainage, or wound infection between study arms. 54% of patients (n=26/48) experienced a grade 3 or higher adverse event, with no difference between treatment arms (47% versus 67%, p=0.7). Rates of initiation of adjuvant therapy did not differ between treatment arms (66% vs. 68%, p=0.4). Pancreatic fistula and abscess were associated with adjuvant therapy (p<0.01). No difference in overall survival was observed based on occurrence of surgical complications (HR 1.1; 95% CI 0.5-2.6). Conclusions: In this national cooperative group study of patients with borderline resectable pancreatic cancer,postoperative complications following neoadjuvant chemotherapy, radiation, and surgical resection were consistent with rates previously reported by high-volume institutions and using large datasets. Multimodality trials of preoperative therapy for locoregionally advanced pancreatic cancer may be safely performed in the cooperative group setting. Clinical trial information: NCT02839343 .

55 Background: Nearly one-half of deficient mismatch repair (d-MMR) metastatic colorectal cancers (mCRC) demonstrate durable responses to immune checkpoint inhibitors (ICIs). Given preclinical data indicating that liver metastases sequester activated CD8+ T cells from systemic circulation, we examined clinical outcome by metastatic site. Methods: In a retrospective cohort of patients with d-MMR mCRCs treated at multiple centers in France (n=66), we sought to validate data from a U.S. cohort, and then performed pooled analysis (n=104). All patients received first-line ICI monotherapy. Metastatic site was analyzed in relationship to tumor response (RECIST version 1.1), and progression-free survival (PFS) by multivariable stratified Cox regression after adjustment for covariates. Results: Objective responses were achieved in 38/66 (58%) patients in the validation cohort. Best tumor response included 13 (20%) complete responses (CR), 25 (38%) partial responses (PR), 16 (25%) stable disease, and 11 (17%) progressive disease (PD). One-year and 5-year PFS rates were 73% and 67%, respectively; 18 (27%) patients progressed during immunotherapy. Best tumor response was attenuated in patients with liver metastasis ( P=0.03). Presence of liver metastasis, but not other sites, was associated with significantly poorer PFS after adjustment for covariates (HRadj 2.82; 95%CI, 1.08-7.39; Padj=0.03). In a pooled analysis, liver metastasis remained significantly and independently associated with poorer PFS (HRadj 3.18; 95%CI, 1.52-6.67; Padj=0.002) and with attenuated tumor best response (P=0.01). Conclusions: Metastasis to the liver, but not other sites, was validated as an independent factor associated with poorer response and survival after ICI treatment in d-MMR mCRCs. These data underscore the need for novel therapeutic strategies in these patients. [Table: see text]

31 Background: Incidence of early-onset colorectal cancer (eoCRC, <50 years of age at diagnosis) is increasing globally. However, little is known regarding symptom burden in this sub-population. We compared symptoms in patients with eoCRC to those of patients with average-onset CRC (aoCRC, diagnosed at age ≥ 50). Methods: E2C2 is a stepped-wedge, cluster-randomized pragmatic trial evaluating a collaborative care model for the assessment and management of six symptoms [Sleep disturbance, Pain, Physical function impairment, Anxiety, emotional Distress, and Energy deficit (SPPADE)]. Patients were asked to complete assessments rating each of these symptoms on an 11-point numerical rating scale. Symptom severity was classified as mild (0-3), moderate (4-6), or severe (7-10). We conducted a subgroup analysis of patients with CRC, comparing SPPADE symptoms on an initial survey, regardless of timing in treatment course, between patients with eoCRC and aoCRC. Results: Patients with CRC (n=4281) completed a survey between March 2019 and December 2022. Patient demographics and SPPADE symptoms are reported in the table. Patients with eoCRC were more likely to report severe sleep disturbance ( p<0.0001), pain ( p=0.03485), anxiety ( p<0.0001), emotional distress ( p<0.0001), and fatigue ( p=0.01083). In patients with eoCRC, women were more likely to report severe pain (12.6% vs 6.9%, p=0.0069), anxiety (16.1% vs 10.0%, p=0.012), emotional distress (12.1% vs 5.4%, p=0.00066), fatigue (18.9% vs 13.4%, p=0.038), and physical function impairment (10.1% vs 5.8%, p=0.026) compared to men. Conclusions: Patients with eoCRC reported higher symptom severity than patients with aoCRC. This suggests unique needs for symptom management in patients with eoCRC. Additional research is needed to evaluate how time since diagnosis, disease characteristics, cancer-directed treatment patterns, and co-occurring symptoms are associated with specific symptoms in this population. [Table: see text]

163 Background: Testing for BRAF and KRAS/NRAS mutations, HER2 amplifications, and MSI/MMR status is a standard of care for all patients with mCRC. There are limited real-world (RW) data regarding biomarker testing patterns among robust patients who are candidates for multiple LOT. We evaluated biomarker testing patterns among patients treated in community oncology practices who initiated regorafenib (REGO) and/or trifluridine/tipiracil (FTD/TPI), predominantly in 3rd or later lines of therapy. Methods: A retrospective analysis utilizing electronic medical record data from The US Oncology Network examined adult patients with mCRC who initiated REGO and/or FTD/TPI between 09/01/2015 and 11/30/2022 with follow-up until 05/31/2023. The proportion of patients tested for various biomarkers was assessed. Results: A total of 2684 mCRC patients initiated REGO and/or FTD/TPI (including 895 pts receiving both) in any LOT during the study period. The mean age of patients at baseline was 62.9 years, of whom 54.9% were male, 1599 (59.6%) patients were White and 436 (16.2%) were underrepresented minorities (Black or Hispanic/Latino). Patients were most commonly tested for KRAS mutations (75.2%) and least commonly for HER2 amplifications (22.6%). Age, gender, and race/ethnicity characteristics were similar between treatment subgroups, with 29.6% of minority and 23.1% of white patients not undergoing KRAS testing. Types of biomarkers tested and proportion of patients tested are reported in the table below. Conclusions: About one quarter of patients who were sufficiently robust to receive aggressive therapy did not undergo testing for KRAS, the oldest standard of care biomarker in CRC. We observed disparities by race/ethnicity. We also observed a correlation between rates of testing and treatment intensity, with patients who received both REGO and FTD/TPI having a higher rate of testing than those who received only one of the treatments. Understanding the pitfalls in biomarker testing will help pave the way for appropriate and equitable access to cancer care. [Table: see text]

115 Background: Randomized clinical trials provide the best evidence for the effects of a new treatment. However, the use of a placebo control arm may present practical and ethical concerns for enrolled patients and treating providers. The CRC ARCAD global database includes a total of 1,673 individual patient data (IPD) treated with placebo plus best supportive care in a salvage-line setting for refractory mCRC. By using placebo IPD, we have proposed to construct a synthetic control arm for clinical trials (Yoshino T. et al., Nature Medicine 2023). Methods: From 40,889 IPD from 59 studies in ARCAD mCRC database, 723 placebo pts were selected from 4 placebo-controlled randomized studies in a salvage-line setting (CORRECT, RECOURSE, CONCUR and TERRA). We analyzed the impact of baseline patient characteristics and various prognostic factors on outcome in the placebo control. Results: The adjusted hazard ratios (HRs) (95% confidence interval [CI]) were 0.52 (0.40-0.67) for the number of metastatic sites (1 vs 2+), 0.71 (0.59-0.84) for ECOG performance status (PS) (0 vs 1), 0.54 (0.45-0.66) for liver metastases (No vs Yes), 0.54 (0.40-0.71) for peritoneal metastases (No vs Yes), and 0.51 (0.38-0.70) for Royal Marsden Hospital (RMH) Score (consisting of albumin level, number of metastatic sites, and LDH level) (0-1 vs 2-3). Conclusions: Number of metastatic sites, ECOG PS, liver metastasis, peritoneal metastasis and RMH Score were significant prognostic factors in patients with mCRC receiving placebo in a salvage-line setting. Further prognostic factors should be investigated to increase the accuracy of the proposed synthetic control arm. [Table: see text]

107 Background: The "No Placebo Initiative" demonstrated that the survivals of patients (pts) receiving placebo in a salvage-line setting, exhibited no significant difference across trials (CORRECT, RECOURSE, CONCUR and TERRA). Therefore, we believe that a nomogram can be generated using the ARCAD database to predict survival of pts who completed standard therapy. Methods: Of 40,889 Individual patient data (IPD) from 59 studies, 723 pts received placebo from 4 randomized studies were pooled. The potential prognostic factors considered include BMI and Age. Imputed datasets were constructed by a multiple imputation method since the original dataset contains some missing values. Overall survival (OS) was defined as the time from randomization to death from any cause. Multivariate Cox proportional hazards models for OS were estimated based on the variables showing clinically and statistically significant by univariate analysis. Prediction performance of the final model was evaluated using the concordance index for survival data and calibration plots. Results: From univariate and multivariate analysis, ECOG performance status, Royal Marsden Hospital score (calculated by albumin level, LDH level, and number of metastatic site), primary site location, liver meta, peritoneal meta were selected as variables. We successfully developed a highly accurate nomogram to predict post-standard treatment prognosis for pts with mCRC. Concordance index for OS was 0.66. Conclusions: Although further validation in other cohorts is needed, this nomogram could be very useful to estimate the survival for clinical practice and enrolling in clinical trials. [Table: see text]