Citations

Background: Chordoma is a rare primary tumor originating from embryonic notochord remnants, with limited systemic therapeutic options due to a poor understanding of its genomic landscape. This study aims to characterize the genetic alterations in chordoma using a large national patient-level genomic repository, the AACR Project GENIE, to identify potential therapeutic targets and improve disease modeling. Methods: A retrospective analysis of chordoma samples was conducted using the AACR Project GENIE database. Targeted sequencing data were analyzed for recurrent somatic mutations, tumor mutational burden, and chromosomal copy number variations, with significance set at p < 0.05. Results: Frequent mutations were observed in genes associated with SWI/SNF complex affecting chromatin remodeling (SETD2, PBRM1, ARID1A). Mutations were also common among the TERT promoter regions, and cell cycle regulation (CDKN2A). Significant co-occurrences were identified among PBRM1, BRCA2, and KMT2D mutations. CDKN2A/B deletions were enriched in metastatic tumors, and pediatric cases demonstrated distinct mutation profiles compared to adults. Conclusions: This study provides a genomic profile of chordoma, identifying key mutations and potential therapeutic targets. These findings highlight the roles of chromatin remodeling and cell cycle pathways in chordoma biology, offering insights for future precision medicine approaches and therapeutic interventions.

OBJECTIVE Spinal cord cavernous malformations (SCCMs) are rare vascular malformations with a capricious prognosis. Given the eloquent nature of the spinal cord, considerable surgical morbidity may be encountered. Therefore, conservative management has emerged as a valid alternative, especially for incidental lesions diagnosed on ubiquitous imaging. The aim of this systematic review and meta-analysis was to evaluate the safety and efficacy of surgical versus conservative management of SCCMs. METHODS Following PRISMA guidelines, this study included articles published in full-text form comparing the outcomes following conservative and surgical management of SCCMs. Collected variables included the total number of patients, spine level, resection, myelotomy, follow-up duration, bleeding, motor weakness, pain, bladder and/or bowel dysfunction, and neurological improvement or deterioration after discharge. The primary outcome of interest was long-term functional outcome. RESULTS Eleven articles comprising 515 patients were included, of whom 343 (66.6%) underwent resection and 172 (33.4%) were managed conservatively. Patients who underwent surgery were more likely to have preoperative motor deficits, hemorrhagic episodes, and bladder and/or bowel dysfunction, indicating increased disease severity. Resection was associated with significantly improved long-term functional outcomes (OR 3.27, 95% CI 1.72–6.24) compared with conservative management. There was no significant difference between the two groups regarding odds of long-term clinical deterioration (OR 1.03, 95% CI 0.35–3.03). However, the risk of hemorrhagic episodes during follow-up was higher in the conservative group (17.3%) compared with the surgical group (1.69%). The odds of hemorrhage during follow-up were lower in the surgical group, although not statistically significant (OR 0.24, 95% CI 0.05–1.05). CONCLUSIONS This study highlights that while surgical management of SCCMs is associated with better long-term functional outcomes and reduced risk of recurrent hemorrhage, treatment decisions must be carefully tailored to the individual patient, particularly given the potential risks associated with surgery. Conservative management, although less invasive, carries a nonnegligible risk of hemorrhage during follow-up, warranting close monitoring. These findings parallel management strategies used for brainstem cavernomas, for which surgery is reserved for cases with low surgical risk and worsening neurological symptoms. However, the limitations of current data, including selection bias and heterogeneity in reporting, emphasize the need for a multi-institutional registry to better define the natural history of SCCMs and inform future management strategies.

614 Background: Liver transplantation (LT) offers a 5-year survival exceeding 70% for selected patients with hepatocellular carcinoma (HCC). Immune checkpoint inhibitors (ICIs) may be used to downstage or bridge to transplantation. This study aims to evaluate the safety of ICIs prior to LT. Methods: Multicenter retrospective study, involving 9 centers, included adults who received ICIs and, subsequent LT, between 2019 and 2023. The ICI cohort was matched by age, sex, liver diseases and transplant date (1:3) with a similar cohort of HCC transplanted patients that did not receive ICIs. Results: The ICI cohort included 45 patients (Table part 1). The most common underlying liver diseases were viral. 15.5% of patients had macrovascular invasion and, 62.2% multifocal disease. The most commonly used ICI was nivolumab (75.6%), followed by atezolizumab-bevacizumab (17.8%). The median follow up was 32.5 months (17.4 - 47.6). The median ICI duration was 147 days (129.5-276.5), with a median interval of 58 days (22–193) between the last ICI dose and LT. There were 8 (17.8%) cases of graft rejection, 2 steroid-resistant leading to 1 graft failure. There were 4 (8%) HCC recurrences. During follow-up there were 6 deaths, 2 related to HCC recurrence and 4 non liver related. When compared with 135 non-ICI cohort patients, there were no differences within the groups (Table part 2). Importantly, we found no significant differences in crude rejection rates (p=0.5). Conclusions: Our study suggest that ICI treatment prior to LT is safe. ICI rejection primarily occurs in the acute post-transplant period (within 3 months), with a low risk of death due to graft failure. Further clinical trials are needed. Part 1: ICI cohort descriptive analysis. N (%); Median (IQR); Part 2: Comparison between cohorts. N (%); Mean (SD). (part 1) ICI-cohort n=45 General data Male 38 (84.4) Age 61.2 (7.6) Etiology of liver diseases Hepatitis C 17 (37.8)Hepatitis B 6 (13.3)MASLD 6 (13.3)Viral +Alcohol 5 (11.1)Alcohol 3 (6.7)Autoimmune 3 (6.7)Other 3 (6.7)Combined viral 2 (4.4) Largest tumor (mm) 39 (22) Macrovascular invasion 7 (15.5) Multifocal 28 (62.2) Locoregional therapy 36 (80.0) Number of locoregional therapies 2 (2) Immunotherapy Nivolumab 34 (75.6) Atezolizumab/bevacizumab 8 (17.8) Pembrolizumab 1 (2.2) Nivolumab+pembrolizumab 1 (2.2) PD1 inhibitor clinical trial 1 (2.2) Days of ICI treatment 147 (203) Radiological tumor response ICI No 17 (37.8) Transplant Deceased donor 43 (95.6) Washout period (days) 58 (171) Induction therapy (anti-thymoglobulin) 8 (17.8) Outcomes Rejection Biopsy proven 8 (17.8) 8 (100) Time to rejection (days) 43 (102) Graft failure Rejection 2 (4.4)1 (2.2) HCC recurrence 4 (8) Deaths 6 (13.3) Follow up Since transplant (months) 32.5 (30.2) (part 2) ICI-cohort (n=45) Non-ICI cohort (n= 135) P Post transplant rejection rate 8 (17.8) 32 (23.7) 0.53 Time to rejection (days) 180.1 (SD 218) 62.2 (SD 62.8) 0.25 Overall deaths 6 (13.3) 10 (7.4) 0.36