Alsulaiman, Abdullah

Purpose Neutropenic diet (ND) has historically been recommended to reduce infectious complications in patients with cancer. Although its use has declined over the past decade, recent studies, particularly in patients undergoing hematopoietic stem-cell transplantation (HSCT), have renewed concern regarding the safety of a liberalized diet (LD). We performed a meta-analysis of studies comparing ND with LD in patients with cancer. Methods We searched MEDLINE, Embase, and Cochrane databases from inception through January 2026. Comparative studies evaluating ND versus LD in adults or children with cancer were included. Primary outcomes were major infections and bacteremia/fungemia; secondary outcomes were pneumonia, diarrhea, and mortality. Random-effects meta-analyses were performed to calculate pooled relative risks (RRs) with 95% CIs. Results Fifteen studies including 4,320 patients met criteria for analysis. ND was not associated with significant differences in major infections (RR, 1.02 [95% CI, 0.88 to 1.18]; P = .795), bacteremia/fungemia (RR, 0.97 [95% CI, 0.78 to 1.22]; P = .805), pneumonia (RR, 0.98 [95% CI, 0.59 to 1.63]; P = .933), diarrhea (RR, 1.12 [95% CI, 0.96 to 1.31]; P = .159), or mortality (RR, 0.94 [95% CI, 0.77 to 1.15]; P = .632). Sensitivity analyses restricted to randomized controlled trials (RCTs) were consistent. In hematologic malignancy/HSCT studies (9 studies; 1,769 patients), no differences were observed across outcomes. In RCTs limited to these patients (6 studies; 855 patients), ND was associated with lower bacteremia/fungemia risk (RR, 0.67 [95% CI, 0.47 to 0.95]; P = .023), with no differences in other outcomes. Conclusion ND was not associated with reductions in major infections, pneumonia, diarrhea, or mortality compared with LD. These findings do not support routine implementation of ND for patients with short-term neutropenia or lower-risk cancer populations although selected high-risk patients, particularly those undergoing HSCT or experiencing prolonged neutropenia related to hematologic malignancies, may still warrant cautious dietary practices.

Purpose: Neuroendocrine neoplasms (NENs) are increasingly recognized to have a hereditary predilection, yet the prevalence and clinical relevance of pathogenic germline variants (PGVs) in unselected patients with NEN remain poorly defined. This prospective, multicenter study aimed to evaluate the prevalence and clinical utility of PGVs through universal multigene panel testing in a diverse cohort of patients with NENs. Patients and Methods: Between 2018 and 2024, we enrolled unselected patients with NENs from 3 Mayo Clinic Cancer Centers. Germline genetic testing was performed using a next-generation sequencing panel of up to 84 cancer predisposition genes. Patients were not selected based on age, disease stage, ethnicity, or family history. Variants were classified as PGVs, variants of uncertain significance (VUS), or negative. Clinical and demographic data were analyzed descriptively. Results: Among 88 patients, PGVs were identified in 15.9% (n=14), most frequently in high- or moderate-penetrance genes including MEN1 , CHEK2 , MITF , and MUTYH . PGVs were most commonly found in pancreatic NENs [n=12/55 (21.8%)], followed by small bowel NENs [n=2/20 (10%)], with no PGVs detected in lung NENs. Mismatch repair (MMR) gene alterations were identified in 5.7% of patients, including 1 MLH1 PGV and 4 MSH2/MSH6 VUS, 2 of which demonstrated MMR deficiency by protein testing. VUS were reported in 34.1% of patients. Notably, 35.7% of PGV-positive patients did not meet current NCCN or ACMG testing criteria, and 53.9% had PGVs in genes outside of cancer-specific guideline recommendations. Conclusions: Universal germline testing in unselected patients with NEN identified clinically relevant PGVs in over 15% of cases. These findings support broader genetic testing approaches to guide treatment, enhance familial risk assessment, and inform cascade testing—regardless of traditional clinical selection criteria.

e18574 Background: ND has historically been recommended to reduce infectious complications in cancer patients (pts). While the adoption of ND has declined over the last decade, recent studies - particularly in pts undergoing hematopoietic stem cell transplantation (HSCT) - have raised uncertainty regarding the safety of LD. Herein, we performed a meta-analysis of studies directly comparing ND with LD in pts with cancer. Methods: We conducted a systematic search of MEDLINE, Embase, and Cochrane databases from inception through January 2026. Comparative retrospective and prospective studies were included if they were comparing ND with LD in adults or children with cancer. Primary outcomes were major infections and bacteremia/fungemia. Secondary outcomes were pneumonia, diarrhea, and all-cause mortality. Random-effects meta-analyses were performed to calculate pooled risk ratios (RR) with 95% confidence intervals (CI). The review followed PRISMA 2020 guidelines. Results: Fifteen studies enrolling 4,320 patients were included in the primary analysis. Six studies enrolled only adult patients, three were restricted to pediatric populations, and six included mixed adult and pediatric cohorts. Across these studies, ND was not associated with a significant reduction in major infections (RR 1.02, 95% CI 0.88–1.18; p=0.795), bacteremia/fungemia (RR 0.97, 95% CI 0.78–1.22; p=0.805), pneumonia (RR 0.98, 95% CI 0.59–1.63; p=0.933), diarrhea (RR 1.12, 95% CI 0.96–1.31; p=0.159), or all-cause mortality (RR 0.94, 95% CI 0.77–1.15; p=0.632). Sensitivity analyses restricted to RCTs showed consistent results. Subgroup analysis of hematological/HSCT studies (9 studies; 1,769 pts) also showed no differences across outcome. Analysis restricted to RCTs in hematologic/HSCT pts (6 studies; 855 pts) showed no differences in major infections, pneumonia, diarrhea, or mortality; however, ND was associated with a lower risk of bacteremia/fungemia (RR 0.67, 95% CI 0.47–0.95; p=0.023). Heterogeneity across studies was low to moderate. Conclusions: ND was not associated with reductions in major infections, pneumonia, diarrhea, or mortality compared with LD. A reduction in bacteremia/fungemia was observed in RCTs of hematologic malignancy and HSCT pts. Overall, these findings suggest that routine ND implementation is unnecessary for most cancer pts, although cautious dietary practices may remain reasonable in selected high-risk hematologic malignancy/HSCT populations.

e16323 Background: Advanced EP-NEC are typically treated with the combination of platinum plus etoposide. Despite therapy, outcomes remain poor, with reported median overall survival (OS) of 12-13 months. Early initiation of systemic therapy is commonly practiced given the aggressiveness; however, recent data from small cell lung carcinoma (SCLC) suggest that shorter TTI does not necessarily improve OS. The impact of TTI on outcomes in EP-NEC has not been well studied. Methods: We conducted a multicenter retrospective cohort study across three Mayo Clinic sites including adults with biopsy-confirmed stage IV EP-NEC diagnosed between 2005 and 2025. TTI was defined as days from pathologic diagnosis to initiation of first-line systemic therapy. A binary cutoff (≤14 vs > 14 days) was determined using receiver operating characteristic (ROC) analysis, and TTI was also analyzed as a continuous variable. OS and progression-free survival (PFS) were estimated using the Kaplan–Meier method and evaluated using Cox proportional hazards models. Multivariable analyses adjusted for age, sex, ECOG performance status, presence of liver metastases, and first-line treatment strategy (chemotherapy alone vs chemotherapy plus immunotherapy). Results: Among 248 pts, median age was 61 years. Median OS for the cohort was 13.9 months (95% CI, 11.7–16.7), and median PFS was 5.7 months (95% CI, 5.3–6.3). Pts with TTI > 14 days had longer median OS compared with those treated within ≤14 days (16.4 vs 10.1 months), with improved OS on unadjusted analysis (HR 0.69, 95% CI 0.50–0.96; p = 0.028), though this association was not statistically significant after multivariable adjustment (HR 0.74, 95% CI 0.53–1.05; p = 0.097). Pts with TTI > 14 days also had longer median PFS compared with ≤14 days (6.5 vs 4.8 months), with improved PFS on unadjusted analysis (HR 0.67, 95% CI 0.51–0.88; p = 0.0038). On multivariable analysis, TTI > 14 days remained independently associated with improved PFS (HR 0.75, 95% CI 0.56–1.00; p = 0.047). However, when analyzed as a continuous variable, TTI was not independently associated with OS (HR 0.99, 95% CI 0.98–1.00; p = 0.173) or PFS (HR 0.99, 95% CI 0.98–1.00; p = 0.089). Conclusions: In this multicenter cohort of pts with metastatic EP-NEC, earlier initiation of systemic therapy (≤14 days) was not associated with improved overall survival, and longer time-to-treatment was independently associated with improved PFS. However, when TTI was analyzed as a continuous variable, no statistically significant associations were observed, suggesting that the observed benefit with delayed treatment may reflect pt selection or clinical context rather than a direct biological effect. These findings may provide reassurance in scenarios where short delays are necessary—for biomarker testing or clinical trial enrollment—and highlight the need for further investigation in the era of precision oncology.

e13635 Background: Melanoma is an aggressive skin malignancy with rising global incidence, for which checkpoint inhibitors (CPI) and BRAF-targeted therapies are standard of care in advanced disease. However, access to molecular diagnostics and CPI remains limited in conflict-affected regions such as Syria. Real-world data describing melanoma management in this setting are scarce. Methods: We conducted a retrospective study of all patients diagnosed with melanoma between 2022 and 2024 at Al-Bairouni University Hospital (ABUH), Syria’s primary oncology referral center. Demographic and clinical characteristics were analyzed for the entire cohort, and patients with advanced disease were evaluated for molecular testing and treatment patterns. Semi-structured interviews were conducted in a mixed advanced cancer subset (N = 35) to explore barriers to immunotherapy access. Results: Among 115 patients with melanoma, the median age at diagnosis was 57 years (IQR 44.5–67), and 54.7% were male. At presentation, 18.3% had stage I disease, 1.7% stage II, 2.6% stage III, and 40.9% stage IV disease; staging was unavailable in 36.5%. Among patients with advanced melanoma (n = 47), BRAF testing was performed in 17 (36.2%), with targeted therapy administered to 5/16 BRAF-positive patients. Only 7/47 patients (14.9%) received CPI, primarily as monotherapy. In the qualitative subset (predominantly lung cancer), five major barriers to immunotherapy access emerged: financial toxicity (n = 22), limited drug availability (n = 9), limited patient awareness (n = 8), geographic/logistical challenges (n = 5), and system delays (n = 4). Conclusions: Despite a substantial burden of advanced melanoma, access to molecular testing, targeted therapy and CPI in Syria remains limited. Qualitative findings highlight financial and structural barriers as primary drivers of limited access, underscoring the need for improved drug availability, diagnostic infrastructure, and patient education in conflict-affected settings.

3592 Background: Chemotherapy-induced peripheral neuropathy (CIPN) is a frequent dose-limiting toxicity from oxaliplatin that impairs quality of life in gastrointestinal (GI) cancer patients (pts). While strategies to limit exposure exist, their impact on survival remains debated. We evaluated whether reduced oxaliplatin exposure (ROE) maintains survival while mitigating toxicity. Methods: We conducted a systematic review and meta-analysis (PubMed, Embase, Scopus, Web of Science, EBM Reviews) of studies comparing ROE vs standard-duration oxaliplatin-based chemotherapy in GI cancers. ROE was defined as planned limitation of oxaliplatin exposure, including shortened duration (3-4 months), maintenance-based de-escalation, or stop-and-go strategies. Primary endpoints were disease-free survival (DFS) in curative settings, progression-free survival (PFS) in palliative settings, and overall survival (OS). Secondary endpoints included grade ≥3 CIPN and grade ≥3 adverse events (AEs). Random-effects models used Hartung-Knapp-Sidik-Jonkman correction. Heterogeneity was assessed via I² and Cochran’s Q. Results: 24 studies, comprising 15 randomized controlled trials (RCTs) and 9 retrospective cohorts, were included (N = 30,404 pts; ROE: 13,348; control: 17,056). Settings included adjuvant colorectal cancer (CRC; n = 14), metastatic CRC (mCRC; n = 5), gastric cancer (GC) (adjuvant n = 1, metastatic n = 3), and metastatic pancreatic cancer (PDAC) (n = 1). ROE strategies included shortened duration (n = 14), maintenance (n = 8), and stop-and-go (n = 2). In adjuvant CRC, ROE did not compromise DFS (HR 1.07; 95% CI, 0.98-1.16; p = 0.12; I² = 21.7%), including in high-risk subgroups (HR 1.14; 95% CI, 0.93-1.40; p = 0.14; I² = 38.9%); OS was also not different between groups (HR 1.00; 95% CI, 0.94-1.07; p = 0.89; I² = 0%), including high-risk pts (HR 1.01; 95% CI, 0.93-1.10; p = 0.68; I² = 0%). In mCRC, ROE showed no detriment to PFS (HR 1.11; 95% CI, 0.99-1.25; p = 0.07; I² = 0%) or OS (HR 1.06; 95% CI, 0.92-1.23; p = 0.33; I² = 0%). Similarly, in metastatic gastric cancer, PFS (HR 0.82; 95% CI, 0.34-1.99; p = 0.44; I² = 77.3%) and OS (HR 0.90; 95% CI, 0.67-1.21; p = 0.26; I² = 0%) were comparable. Findings remained concordant after restricting the analysis to only RCTs. Pooled analysis was not feasible for PDAC and adjuvant GC studies, but individual study findings were consistent with the above. ROE significantly reduced the risk of grade ≥3 CIPN (OR 0.32; 95% CI, 0.20-0.53; p < 0.001; I² = 80.6%) and overall grade ≥3 AEs (OR 0.65; 95% CI, 0.50-0.86; p = 0.01; I² = 59.9%). Conclusions: Across GI malignancies, ROE was not associated with inferior DFS, PFS, or OS and was associated with lower rates of severe neurotoxicity and high-grade AEs. These findings support planned limitation of oxaliplatin exposure as a strategy to improve the therapeutic index of oxaliplatin-based chemotherapy across disease settings.

PURPOSE Gastroesophageal carcinoma (GEC) is increasingly managed using biomarker-guided therapies. Although both tissue DNA (tDNA) and circulating tumor DNA (ctDNA) testing are used clinically, the concordance of genomic alterations between primary tumors, metastatic sites, and liquid biopsy remains incompletely understood. METHODS We retrospectively analyzed 345 patients with GEC who underwent ctDNA testing at Mayo Clinic. tDNA next-generation sequencing and immunohistochemistry (IHC) for human epidermal growth factor receptor 2 (HER2)/erb-b2 receptor tyrosine kinase 2 ( ERBB2 ) and mismatch repair (MMR) were collected. Concordance was evaluated between ctDNA and tDNA, ctDNA and IHC, and across all three modalities, using 60-day and 30-day intervals. RESULTS Among 345 patients with ctDNA testing, 186 had tDNA testing, and 310 underwent IHC. ctDNA testing showed a shorter turnaround time than tDNA (median 6 v 13 days). The most frequent alteration in ctDNA, primary tDNA, and metastatic tDNA was TP53. Concordance between ctDNA and primary tDNA was ≥78.8% for key genes; between ctDNA and metastatic tDNA, it was ≥84.8%. IHC-ctDNA concordance was higher in metastatic tumors, with 91.1% for HER2/ ERBB2 and 97.7% for mismatch repair (MMR)/microsatellite instability (MSI) compared with 81.1% and 95.8%, respectively, in primary tumors. Triplet concordance for MSI/MMR was 97.6% in primary tumors and 100% in metastatic tumors, while ERBB2 /HER2 showed 84.4% and 93.9% concordance, respectively. ctDNA temporal heterogeneity analysis revealed 14 patients with fluctuating ERBB2 status and 3 with fluctuating MSI-H status. CONCLUSION ctDNA testing demonstrates high concordance with tDNA and IHC and offers faster turnaround. Given its minimally invasive nature and strong concordance with tissue-based testing, ctDNA is a reliable tool for genomic profiling and longitudinal monitoring in GEC.

837 Background: A recent randomized trial suggested that CR may influence ICI activity in patients with lung cancer. However, the same has not been established in GI cancers, where reports have shown mixed results with variable definitions of 'early' vs 'late' IT. We evaluated multiple approaches to assess the impact of CR on first-line ICI in GI malignancies. Methods: This retrospective study included patients from three Mayo Clinic sites (N=455). Both previously reported IT cutoffs and a new cutoff derived from ROC analysis were evaluated. Patients were categorized by the median of all ITs, the median of the first four ITs, and whether ≥20% of ITs occurred before the identified cutoff. Univariate and multivariate Cox regression (adjusting for age, MSI status, type of cancer, metastasis status, number of cycles, and receipt of chemotherapy with ICI) assessed associations with OS. KM analyses were performed to illustrate survival differences. The primary endpoint was OS. Results: When patients were categorized based on whether ≥20% of infusions occurred before 14:00 (ROC-derived cutoff), a significant association with OS was observed. On univariate analysis, early infusion timing was associated with improved survival (HR 2.30, 95% CI 1.58–3.32, p <0.001). This remained significant after multivariable adjustment (HR 2.11, 95% CI 1.41–3.16, p < 0.001). Median OS was 14.2 months in the early group vs 3.8 months in the late group (log-rank p < 0.001). Using previously defined cutoffs, categorization by the median IT of all infusions or the median of the first four infusions did not demonstrate a significant association with OS in either univariate or multivariate Cox regression analyses. Conclusions: These findings highlight the potential role of infusion timing as a chronotherapy factor in GI cancers. Given the retrospective design and heterogeneous population, prospective studies are warranted to validate this signal and clarify its clinical relevance. Baseline demographics of patients by infusion timing (early vs late). Variables Early N=412 (%) LateN=43(%) Total N=455(%) p-value Age <70 249(60.4) 21(48.8) 270 (59.3) 0.1 >70 163(39.6) 22(51.2) 185 (40.7) Gender F 118(28.6) 16(37.2) 134 (29.5) 0.3 M 294(71.4) 27(62.8) 321 (70.5) Cancer Type Gastroesophageal 109 (26.5) 8 (18.6) 117 (25.7) 0.1 Hepatocellular 159 (38.6) 24 (55.8) 183 (40.2) Biliary 86 (20.9) 4 (9.3) 90 (19.8) MSI-H 58 (14.1) 7 (16.3) 65 (14.3) Metastasis No 150 (36.4) 22 (51.2) 172 (37.8) 0.1 Yes 262 (63.6) 21 (48.8) 283 (62.2) Immunotherapy Cycle Number <6 189 (45.9) 33 (76.7) 222 (48.8) <0.001 >6 223 (54.1) 10 (23.3) 233 (51.2)

103 Background: Clinicians spend significant time extracting and synthesizing information to risk-stratify and make adjuvant chemotherapy (AC) recommendations for CRC. By automating parts of this process, LLMs could help reduce documentation burden and variability in decision-making. Methods: We selected 144 stage III, pMMR CRC patients treated at Mayo Clinic (2017–2021). HIPAA-compliant Gemini-2.0-Flash-001 and GPT-4o extracted clinical variables (age, neuropathy grade, pathological stage) from EHRs and generated AC recommendations. Two approaches were compared: (1) a rule-based algorithm with nested if/else statements translating variables into NCCN-based recommendations, and (2) a dynamic LLM agent generating recommendations using a structured prompt informed by NCCN guidelines. Concordance with treating physicians was assessed, with disagreements reviewed by a blinded GI oncologist. Results: The dataset included 144 patients with median age 67 (IQR 66–68), 48.6% female. The LLM pipeline extracted neuropathy grade with 100% accuracy and pathological T/N stages with 99.3% accuracy. Concordance with physician recommendations was 93.1% for the rule-based algorithm and 62.5% for the LLM agent. In discordant cases, blinded adjudication by a GI oncologist favored the algorithm and LLM agent over physicians in most cases (Table 1). Conclusions: This exploratory work shows LLM agents can reliably extract variables and generate evidence-based treatment recommendations for stage III CRC. The high rate of expert preference for LLM recommendations in discordant cases is intriguing but limited by small sample size and possible adjudicator bias. Discordant physician recommendations reflect the complexity of decision-making, including patient preferences, performance status, comorbidities, and subtle findings not fully captured in EHRs. Rather than replacing judgment, we envision LLMs as decision support tools—analogous to an advanced trainee reviewing charts and presenting evidence-based recommendations to the attending physician with ultimate authority. Larger multi-institutional studies with multiple adjudicators are needed to validate these findings and clarify AI’s role in oncology. Patient characteristics, LLM extraction accuracy, and concordance with physician recommendations. Metric Result Total patients 144 Median age (IQR) 67 (66-68) Female (%) 48.6% LLM extraction accuracy – Neuropathy grade 100% LLM extraction accuracy – Pathological T and N stages 99.3% Primary Concordance – Rule-based algorithm vs. physician 93.1% Adjudicator preference of rule-based algorithm over treating physician for discordant cases 100% Concordance – LLM agent vs. physician 62.5% Adjudicator preference of LLM agent over treating physician for discordant cases 82.0%