Citations

e19090 Background: PET/CT remains crucial for end-of-treatment (EOT) evaluation in large B-cell lymphoma (LBCL), but low specificity results in unnecessary biopsies and patient discomfort. Circulating tumor DNA (ctDNA)-based minimum residual illness (MRD) may aid in the identification of actual residual sickness. Methods: We conducted a systematic review and meta-analysis of diagnostic accuracy using MEDLINE, Embase, CENTRAL, and Scopus. Eligible studies compared EOT ctDNA-MRD to PET/CT with verified recurrence or long-term remission. The outcomes were sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The study's quality was rated using the QUADAS-2 scale. A bivariate random-effects model combined sensitivity and specificity, yielding hierarchical summary receiver operating characteristic (HSROC) curves. Results: Nine studies with a total of 932 participants were included. ctDNA-MRD showed higher specificity (92%, 95% CI 88-95%) and PPV (81%, 95% CI 73-88%) than PET/CT (specificity 68%, 95% CI 60-75%; PPV 46%, 95% CI 38-55%), while maintaining similar sensitivity. The negative predictive value for ctDNA was higher (91%, 95% CI 86-95%) than for PET (79%, 95% CI 72-85%). Combined PET+ctDNA techniques had the highest diagnostic odds ratio and fewer false positives. The results were similar across Deauville criteria and testing systems. Conclusions: ctDNA-MRD has higher specificity and predictive value than PET/CT at EOT in LBCL and significantly improves risk categorization whether used alone or in conjunction with imaging. Clinical Takeaway: Incorporating ctDNA-MRD into EOT assessment can reduce unnecessary biopsies and enable more accurate, confidence-based post-treatment decision-making.

e14102 Background: High-quality glioma surgery requires multidisciplinary expertise, yet access to high-volume centers varies. National estimates of inpatient morbidity and resource utilization can identify actionable quality gaps and disparities. Methods: We analyzed the HCUP National Inpatient Sample (NIS) for adult admissions undergoing intracranial glioma resection from 2016–2022. Primary outcomes were in-hospital mortality and major complications (neurologic, infectious, thromboembolic, hemorrhagic). Secondary outcomes included length of stay (LOS), total charges, non-home discharge, and weekend admissions. Survey-weighted methods generated national estimates, and multivariable regression evaluated associations with hospital volume, teaching status, region, and patient-level socioeconomic variables, adjusting for age, comorbidities, and admission urgency. Results: Among 23,874 weighted admissions, in-hospital mortality was 2.1%, and major complications occurred in 14.7%. High-volume centers had lower odds of mortality (adjusted OR 0.62, 95% CI 0.51–0.75) and complications (OR 0.71, 95% CI 0.63–0.80) compared with low-volume hospitals. LOS was shorter at high-volume centers (median 5 vs 7 days, p < 0.001), with lower total charges. Patients from lower-income quartiles and rural areas had higher odds of complications and non-home discharge (OR 1.33, 95% CI 1.11–1.59). Weekend admissions were associated with modestly higher complication rates (OR 1.12, 95% CI 1.01–1.24). Conclusions: National inpatient outcomes for glioma resection vary by hospital volume and patient socioeconomic factors, highlighting disparities in access to high-quality surgical care. Clinical takeaway: Referral to high-volume centers and targeted support for vulnerable populations may reduce complications, optimize resource utilization, and improve equity in glioma surgical care.

e14101 Background: Pediatric and adolescent/young adult (AYA) malignant brain tumors remain a leading cause of cancer-related death. Population-level geographic and rural–urban disparities may reflect differences in access to specialized care and supportive services. Methods: Using CDC WONDER mortality data (1999–2023), we identified deaths from malignant brain tumors using ICD-10 codes. Pediatric (0–14 years) and AYA (15–39 years) populations were analyzed separately. Age-adjusted mortality rates (AAMR) per 100,000 were calculated by state, region, and urban–rural classification. Joinpoint regression assessed temporal trends, and interactions evaluated differential trends by rurality and geography. Results: A total of 14,532 deaths were analyzed. National AAMR declined modestly in pediatric patients (AAPC −1.1%, p < 0.01) but remained relatively stable in AYA patients (AAPC −0.3%, p = 0.12). Rural areas consistently showed higher mortality than urban areas in both age groups (p < 0.01). Regional disparities were evident, with highest pediatric and AYA mortality in the Southeast and Midwest. Inflection points indicated modest improvements following 2007 and 2015, likely reflecting advances in treatment and supportive care, but rural–urban gaps persisted. Rolling averages confirmed stability of these trends despite small-area data suppression. Conclusions: Geographic and rural–urban disparities in pediatric and AYA malignant brain tumor mortality persist despite modest national improvements, highlighting populations at greatest risk. Clinical takeaway: Targeted resource allocation and improved access to specialized neuro-oncology care in high-burden and rural regions are needed to reduce mortality and close disparities.

e14098 Background: For IDH-mutant WHO grade 2 gliomas, extent of resection (EOR) is thought to improve long-term outcomes, but optimal thresholds and survival benefit remain uncertain. Quantifying the impact of EOR can guide surgical planning and patient counseling. Methods: We performed a systematic review and meta-analysis of MEDLINE, Embase, CENTRAL, and Web of Science. Eligible studies reported EOR (continuous or categorical) and outcomes including overall survival (OS), progression-free survival (PFS), malignant transformation, seizure control, and treatment-related morbidity. Random-effects models pooled hazard ratios (HRs) for survival outcomes, and meta-regression assessed relationships between EOR, histologic subtype (astrocytoma vs oligodendroglioma), measurement method (MRI volumetrics vs surgeon estimate), and adjuvant therapy. Results: Twelve studies including 1,052 patients were analyzed. Higher EOR was associated with improved survival: pooled HR for OS per 10% incremental resection was 0.88 (95% CI 0.83–0.93), and for PFS 0.85 (95% CI 0.79–0.91). Patients achieving ≥90% resection had the greatest benefit, with 10-year OS of 88% versus 62% for <90% resection (p < 0.001). Higher EOR also reduced risk of malignant transformation (HR 0.67, 95% CI 0.53–0.85) and improved seizure control in 68% of evaluable patients. Results were consistent across histologic subtypes and measurement methods, with minimal heterogeneity (I² < 35%). Conclusions: Greater EOR in IDH-mutant grade 2 gliomas is strongly associated with improved survival, lower malignant transformation risk, and better seizure control, supporting maximal safe resection as the standard of care. Clinical takeaway: Surgical planning aiming for ≥90% resection can optimize long-term outcomes and quality of life in patients with IDH-mutant grade 2 gliomas.

Antibody–drug conjugates (ADCs) are reshaping the therapeutic approach to advanced gastrointestinal cancers by integrating tumor-specific monoclonal antibodies with potent cytotoxic payloads to improve targeted tumor cell destruction while minimizing systemic exposure. Compared to traditional chemotherapy, trastuzumab deruxtecan has significantly improved objective response rates and overall survival in HER2-positive gastric and gastroesophageal junction tumors after trastuzumab-based therapy. This supports its role as an important second-line or later treatment option. The ongoing advancement of ADCs targeting CLDN18.2, TROP2, and CEACAM5 indicates that this therapeutic category will continue to expand across gastrointestinal neoplasms. Nonetheless, these advancements are accompanied by a specific and clinically significant toxicity profile. Hematologic suppression, gastrointestinal side effects, hepatotoxicity, and notably interstitial lung disease (ILD) are essential consequences that may need inpatient assessment and care. Interstitial lung disease (ILD), although uncommon, may be severe or lethal if not identified immediately and treated swiftly with medication cessation and corticosteroids. In hospitalized patients, distinguishing ADC-related toxicity from infection or disease progression is often difficult owing to overlapping clinical manifestations, requiring meticulous evaluation and interdisciplinary cooperation. As ADCs are integrated into earlier treatment lines and across a broader patient population, hospital systems must evolve to ensure prompt identification, consistent management protocols, and efficient collaboration between oncology and inpatient teams. This study analyzes the mechanisms, clinical effectiveness, and safety profile of ADCs in gastrointestinal oncology, pointing out the importance of institutional preparedness to safely incorporate these medicines into standard clinical practice. These features also align ADC therapy with personalized medicine by emphasizing biomarker-guided patient selection and individualized toxicity monitoring.