Citations

Abstract Purpose: Rearranged during transfection (RET) alterations are oncogenic drivers across solid tumors. Selective RET inhibitors (SRI) selpercatinib and pralsetinib have transformed outcomes for patients with RET-altered malignancies. Limited knowledge exists on genomic mechanisms of resistance to SRI. Experimental Design: We established “RETgistry,” a global consortium of patients with advanced RET-altered solid tumors who received SRI and underwent postprogression tissue or plasma biopsies assessed by next-generation sequencing. Frequencies of secondary RET resistance mutations and acquired non-RET gene alterations were determined. Progression-free survival (PFS) and time to treatment discontinuation (TTD) on first SRI were estimated with the Kaplan–Meier method. Results: RETgistry included 109 patients with RET-altered advanced solid tumors (lung, n = 94; thyroid, n = 15) who underwent 143 post-SRI progression biopsies (tissue, 91; plasma, 52). The median PFS and TTD were 13.9 months [95% confidence interval (CI), 10.1–16.6] and 17.3 months (95% CI, 14–20.2), respectively. Secondary RET mutations were detected in 20 (14%) biopsies [lung cancer, 15 (12.4%) and thyroid carcinoma, 5 (22.7%)]. Common acquired off-target alterations involved MET (18.2%; amplification, 15%), TP53 (8.2%), APC (7.6%), KRAS (7.1%), KEAP1 (5.9%), and CDKN2A/B (5.3%). MET alterations were enriched in post-SRI versus pre-SRI specimens (full cohort, 17.6% vs. 2.0%, P = 0.022; lung cancer, 19.1% vs. 2.1%, P = 0.022). Conclusions: The prevalence of secondary RET mutations after SRI was low, underscoring a greater role for off-target resistance. Recurrent acquired alterations involving tumor suppressor genes or upstream regulators of MAPK and PI3K pathways were identified, most commonly MET amplification. Continued efforts to characterize SRI resistance biology are critical to guide the development of novel therapeutic strategies.

TPS256 Background: Currently, there are no biomarkers validated prospectively in randomized studies for resected colon cancer (CC) to determine need for adjuvant chemotherapy (AC). However, circulating tumor DNA (ctDNA) represents a highly specific and sensitive approach (especially with serial monitoring) for identifying minimal/molecular residual disease (MRD) post-surgery in CC patients (pts), and may outperform traditional clinical and pathological features in prognosticating risk for recurrence. CC pts who do not have detectable ctDNA (ctDNA-) are at a much lower risk of recurrence and may be spared the toxicities associated with AC. Furthermore, for CC pts with detectable ctDNA (ctDNA+) who are at a very high risk of recurrence, the optimal AC regimen has not been established. We hypothesize that for pts whose CC has been resected, ctDNA status may be used to risk-stratify for making decisions about AC. Methods: In this prospective phase II/III trial, up to 1,912 pts with resected stage IIB, IIC, and III CC will be enrolled. Based on the post-operative ctDNA status using personalized and tumor-informed assay (Signatera, bespoke assay), those who are ctDNA- (Cohort A) will be randomized to immediate AC with fluoropyrimidine (FP)+oxaliplatin (Ox) for 3-6 mos per established guidelines v serial ctDNA monitoring. Patients who are ctDNA+ post-operatively, or with serial monitoring (Cohort B), will be randomized to FP+Ox v more intensive AC with addition of irinotecan (I) for 6 mos. One cycle of chemotherapy is allowed while awaiting ctDNA testing results for cohort assignment. The primary endpoints for Cohort A are time to ctDNA+ status (phase II) and disease-free survival (DFS) (phase III) in the immediate v delayed AC arms. The primary endpoint for Cohort B is DFS in the FP+Ox v FP+Ox+I arms for both phase II and phase III portions of the trial. Secondary endpoints include prevalence of detectable ctDNA post-operatively, time-to-event outcomes (overall survival and time to recurrence) by ctDNA status, and the assessment of compliance to adjuvant therapy. Biospecimens including archival tumor tissue, as well as post-operative plus serial matched/normal blood samples, will be collected for exploratory correlative research. Active enrollment across the NCTN started in June 2022 with CCTG sites joining in August 2023. Current accrual (as of 9-4-2025): 967/1,912. Drs. Lieu and Dasari contributed equally to the development of this trial. Clinical trial information: NCT05174169 .

Living donor liver transplantation (LDLT) is an established therapy with curative intent for pediatric and adult patients with acute liver failure and end-stage liver disease. Donor safety remains paramount and commences during preoperative evaluation and assessment. Given the importance of the topic, the International Liver Transplantation Society and International Living Donor Liver Transplantation Group consensus conference on Living Liver Donor Safety was convened in March 2025 (Toronto, Canada). Recommendations were based on the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system for assessment of recommendations, and the Danish model of consensus was followed. This report presents 28 recommendations from the working group focused on addressing clinically relevant questions related to the preoperative aspects of living donor safety including assessment of donor acceptability (age, body mass index and hepatic steatosis; medical conditions and contraindications), medical and surgical workup (liver function and procoagulant workup; anatomical considerations and safe remnant), and psychosocial evaluation (timing and team; underlying conditions; non-directed, paired, and anonymous directed donors; urgent living donor workups for acute liver failure).

Abstract Background Gastrointestinal (GI) cancer remains a major global health challenge. This study provides updated 2022 estimates of GI cancer incidence and mortality worldwide, along with projections of incident cases and deaths through 2050 to inform cancer control strategies. Methods In this population‐based study, data from the GLOBOCAN 2022 database were used to examine incidence and deaths associated with GI cancer. By using global demographic projections, this study estimated the projected number of incident cases and deaths until the year 2050. Results By 2050, the global burden of GI cancer is projected to reach 9.06 million incident cases (+85%) and 6.42 million deaths (+93%) from 2022. Increases in incidence are projected for both females (+87%) and males (+83%), as are increases in mortality for both females (+97%) and males (+91%). Whereas the Western Pacific region will have the highest absolute burden, with 3.88 million new cases and 2.79 million deaths, the greatest relative increase is expected in Africa, with incidence and deaths rising by 157% and 160%, respectively. As measured by the Human Development Index (HDI), the steepest increases are projected in low (+151% incidence; +152% deaths) and medium (+112% incidence; +114% deaths) HDI countries. Overall, all GI cancer types are projected to increase, led by pancreatic cancer in incidence (+95%) and colorectal cancer in deaths (+103%). Conclusions GI cancer incidence and deaths are expected to nearly double by 2050, with increases across sexes, cancer types, and regions, especially in lower HDI countries.

Abstract Pick’s disease (PiD) is a rare cause of sporadic frontotemporal dementia, neuropathologically defined by the presence of Pick bodies consisting of aggregates of 3-repeat tau. Given the genetic aetiology of PiD remains unresolved, we assembled the Pick’s disease International Consortium (PIC) to identify susceptibility loci through a genome-wide association study (GWAS). A GWAS was conducted in 294 autopsy confirmed PiD cases and 1,055 controls. Lead variants were annotated using the Functional Mapping and Annotation of GWAS (FUMA) platform, followed by co-localisation analyses using the METABRAIN dataset and statistical finemapping using FINEMAP and SuSiE. After exclusion of 3 cases of MAPT mutations, no variants were associated with risk of PiD at genome-wide significance ( p < 5 × 10 -8 ). The strongest association was on chromosome 4 (4p13, lead SNP rs112161979, OR = 7.53, 95% Confidence Interval (CI) = 3.62-15.65, p = 6.37 × 10 -8 ) followed by chromosome 11 (11p15.4, lead SNP rs66481907, OR = 2.10, 95% CI = 1.54-2.84, p = 1.83 × 10 -6 ). rs112161979 is an intronic SNP in the KCDT8 gene, encoding a potassium channel tetramerization domain that acts as an auxiliary subunit for GABA B receptors, whilst rs66481907 is an intronic SNP in TRIM22 , encoding an E3 ubiquitin-protein ligase. Our GWAS provides the first evidence of possible genetic risk for PiD that implicate the modulation of GABA B receptor signalling and inflammation, in disease pathogenesis. Replication of these findings will be important, but our results suggest that, if present, the genetic risk of PiD beyond MAPT mutations is low.

Abstract How embryonic cells generate large clones of cells in the adult represents a fundamental question in biology. Here using melanocyte stem cells (McSCs) in the zebrafish as a model we explore the function of the master melanocyte transcription factor (MITF) in safeguarding McSCs in embryonic development and their potential to pigment large clones in the adult. MITF is well known is for its role in the specification of melanoblasts from the neural crest (NC) and their differentiation into melanocytes, yet little is known about how this activity shapes the stem cell lineages. Here, we use live imaging coupled with single-cell transcriptomics and lineage tracing to show that MITF ( mitfa in zebrafish) protects the melanocyte stem cell (McSC) fate in zebrafish. Utilizing a temperature sensitive mitfa vc7 mutant, we show that loss of Mitfa activity leads to a surprising premature and aberrant expansion of McSC progeny at the niche during embryogenesis, coupled with novel emergent transcriptional cell states. Linage tracing of McSCs from the embryonic to juvenile stages reveals Mitfa activity is subsequently required in regeneration by Schwann cell-like and melanocyte stem cell progenitors that serve as a reservoir for fast-responding pigment progenitors. Thus, the impact of Mitfa loss on the melanocyte lineage is cell-state and stage-specific. The emergent cell states resulting from mitfa loss may have important implications for understanding how reduced MITF activity contributes to human genetic disease and melanoma.

ABSTRACT Background Isolated chromosome 5/5q losses (–5/5q) without TP53 mutations are associated with favorable outcomes in myeloid neoplasms (MN) with <5% blasts. However, the clinical implication of concurrent −5/5q and TP53 aberrations in MN with ≥5% blasts is poorly understood. Methods Patients with TP53 ‐mutated MN carrying ≥5% blasts assessing the prognostic impact of ‐5/5q on 24‐month overall survival (OS24) were examined. Results Of 587 patients, 515 (88%) exhibited −5/5q overwhelmingly in the context of a complex karyotype (98.3% vs. 61.1% complex karyotype without −5/5q; p < .0001) and multihit TP53 allelic state (88.3% vs. 56.9%; p < .0001). Proportions of patients with blasts ≥20% were comparable between groups with and without −5/5q; p = 0.26. Notably, patients with −5/5q exhibited significantly fewer coalterations; p < .0001. Looking at outcomes, presence of −5/5q was associated with shorter median 24‐month overall survival (7.8 months vs. 11.2 months; p Log‐rank = .012), an effect restricted to subgroups with blasts <20% ( p = .039; N = 163), absent −7/7q ( p = .007; N = 225), or WHO5‐defined single hit allelic state ( p = 0.030; N = 91). Importantly, −5/5q retained independent adverse prognostic significance regardless of TP53 allelic state in a multivariable model. Furthermore, among the subset of 75 (13%) patients undergoing allogeneic stem cell transplantation, −5/5q predicted significantly shorter median 5‐year posttransplant survival (16.2 months vs. median not reached; p Log‐rank = .009). Conclusions These findings emphasize the independent prognostic relevance of chromosome 5/5q losses underscoring the clinical relevance of cytogenetic testing for −5/5q even in this high‐risk cohort.

Living liver donation is a critical component for addressing organ shortage and improving outcomes for patients with end-stage liver disease. As the prevalence of living donor liver transplantation (LDLT) increases worldwide, understanding and optimizing long-term donor health is paramount. The 2025 International Liver Transplantation Society and International Living Donor Liver Transplantation Society (ILTS-iLDLT) Consensus Conference convened experts in the field of liver transplantation to establish evidence-based guidelines focused on the long-term medical, psychological, and social considerations following living liver donation. The aim of this working group was to integrate current evidence and expert consensus on donor follow-up protocols, risk assessment, and management strategies to promote long-term donor health, quality of life, and living liver donor programs globally to safeguard the welfare of this unique population.