Citations

269 Background: Sirtuins (SIRT1-7) are class III histone deacetylases with different roles in CRC as tumor suppressive and oncogenic, mainly influencing proliferation, migration, invasion, DNA damage and chemoresistance. In the present study, we explored the association between tumor gene expression of sirtuins and first-line treatment outcomes in mCRC pts. Methods: We evaluated the impact of the tumor gene expression of sirtuin genes ( SIRT1 -7) on treatment outcomes (overall survival: OS; progression free survival: PFS) in 433 pts enrolled in the randomized, phase III CALGB/SWOG 80405 (NCT00265850) trial. RNA extracted from FFPE tumor samples was sequenced using the HiSeq 2500 (Illumina). Subgroup analyses were based on treatment (bevacizumab [bev] (N = 226) vs. cetuximab [cet] (N = 207)). For each gene, expression was divided into tertiles of high, medium and low. The associations between tumor gene expression and outcomes (PFS and OS) were assessed using log-rank test in univariate analysis. Multivariable Cox proportional hazards regression model was used to compute hazard ratios (HR) and 95% confidence intervals while adjusting for baseline characteristics. Treatment-gene interactions were analyzed using the likelihood ratio test. Results: Of the seven genes analyzed, SIRT3 high was associated with both longer PFS (HR: 0.59 [95% CI: 0.46-0.74], P < 0.001) and OS (HR:0.64 [95% CI: 0.50-0.83], P = 0.002) overall. Treatment-gene interaction testing found significant interactions for SIRT1 and SIRT5 with PFS ( P values: 0.021 and 0.016, respectively) and OS ( P values: 0.038 and 0.014, respectively) with targeted therapies (bev vs. cet). Multivariate analysis showed SIRT1 high associated with longer PFS (HR: 0.62 [95% CI: 0.42-0.89], P = 0.014) and OS (HR: 0.59 [95% CI: 0.40-0.89], P = 0.036) in cet-treated pts; in contrast with shorter observed PFS (HR: 1.38 [95% CI: 0.96-1.99], P = 0.22) and OS (HR: 1.31 [95% CI: 0.90-1.93], P = 0.23) in bev-treated pts. SIRT5 high showed similar results and associated with longer PFS (HR: 0.64 [95% CI: 0.45-0.91], P = 0.039) and OS (HR: 0.57 [95% CI: 0.39-0.83], P = 0.013) in cet-treated pts, with no similar associations in bev-treated pts. Conclusions: Our results highlight a potential role for SIRT3 as prognostic and, SIRT1 and SIRT5 as predictive biomarkers for first-line treatment in mCRC, with differential effects based on targeted agents. Significant interaction favored cet treatment in SIRT1 high and SIRT5 high tumors. However, previous reports suggest an opposite role of SIRT5 that has been linked to chemotherapy and/or cet resistance in CRC via the inactivation of succinate dehydrogenase complex subunit A. Therefore, further studies are warranted to dissect the mechanism behind the interaction of SIRT5 with cetuximab activity and establish the potential of targeting SIRT1/5 in CRC.

254 Background: SLFN11 was recently identified as a dominant determinant of response to DNA-damaging anticancer agents. Several studies showed SLFN11 expression led to better sensitivity to topoisomerase inhibitors and PARP inhibitors. However, clinical evidence in mCRC has been lacking. Methods: Two independent cohorts (CALGB/SWOG 80405 trial and a real-world patient [Caris CODEai] cohort) were included in this study. Patients were stratified into SLFN11 -high and -low groups based on the median SLFN11 gene expression levels. Survival outcomes were compared between SLFN11 -high and SLFN11 -low in irinotecan-treated and oxaliplatin-treated patients. Median time was estimated using Kaplan-Meier method and Cox models were used for covariate adjustment. Endpoints of interest were progression-free survival (PFS) and overall survival (OS). Results: In the CALGB/SWOG 80405 trial cohort, 433 patients were included (110 treated with FOLFIRI-based chemotherapy and 323 treated with FOLFOX-based chemotherapy). In patients treated with FOLFIRI-based chemotherapy, SLFN11 -low patients exhibited numerically better PFS (median PFS, 13.4 vs 11.2 months, log-rank p = 0.03, adjusted hazard ratio [HR] = 0.86, 95% confidence interval [CI] 0.55-1.39, p = 0.50) and OS (median OS, 39.6 vs 30.3 months, log-rank p = 0.02, adjusted HR = 0.73, 95% CI 0.46-1.16, p = 0.19) compared to SLFN11 -high patients. In patients treated with FOLFOX-based chemotherapy, SLFN11 -low patients exhibited numerically better PFS (median PFS 11.2 vs 9.8 months, log-rank p = 0.03, adjusted HR = 0.83, 95% CI 0.65-1.05, p = 0.12) and OS (31.1 vs 26.1 months, log-rank p = 0.07, adjusted HR = 0.84, 95% CI 0.65-1.08, p = 0.16) compared to SLFN11 -high patients. No significant interaction was observed between treatment and SLFN11 expression in terms of PFS ( p = 0.69) and OS ( p = 0.44). In the Caris CODEai cohort, a better OS in SLFN11 -low patients than in SLFN11 -high patients was observed in irinotecan-treated patients ( N = 2906) (median OS, 25.5 vs 21.7 months, HR = 0.90, 95% CI 0.82-1.00, p = 0.048). However, no significant difference in OS between SLFN11 -low and SLFN11-high was observed in oxaliplatin-treated patients ( N = 4428) (median OS, 39.5 vs 35.8 months, HR = 0.98, 95% CI 0.90-1.06, p = 0.56). Conclusions: Low SLFN11 expression showed a potential for better prognosis in mCRC patients receiving irinotecan- and oxaliplatin-containing chemotherapies. These findings are not consistently aligned with preclinical data and clinical evidence in other cancer types previously reported. Further investigation is warranted to better understand the biological role and clinical implication of SLFN11 in mCRC.

Abstract Blood-brain barrier (BBB) dysfunction is a key feature of Alzheimer’s disease (AD), particularly in individuals carrying the APOE-ε4 allele. This dysfunction worsens neuroinflammation and hinders the removal of toxic proteins, such as amyloid-beta (Aβ42), from the brain. In post-mortem brain tissues and in animal models, we previously reported that fibronectin accumulates at the BBB predominantly in APOE-ε4 carriers. Furthermore, we found a loss-of-function variant in the fibronectin 1 ( FN1 ) gene significantly reduces aggregated fibronectin levels and decreases AD risk among APOE-ε4 carriers. Yet, the molecular mechanisms downstream of fibronectin at the BBB remain unclear. The extracellular matrix (ECM) plays a crucial role in maintaining BBB homeostasis and orchestrating the interactions between BBB cell types, including endothelia and astrocytes. Understanding the mechanisms affecting the ECM and BBB cell types will be critical for developing effective therapies against AD, especially among APOE-ε4 carriers. Here, we demonstrate that APOE-ε4 , Aβ42, and inflammation drive the induction of FN1 expression in several models including zebrafish, mice, iPSC-derived human 3D astrocyte and 3D cerebrovascular cell cultures, and in human brains. Fibronectin accumulation disrupts astroglial-endothelial interactions and the signalling cascade between vascular endothelial growth factor (VEGF), heparin-binding epidermal growth factor (HBEGF) and Insulin-like growth factor 1 (IGF1). This accumulation of fibronectin in APOE-ε4- associated AD potentiates BBB dysfunction, which strongly implicates reducing fibronectin deposition as a potential therapeutic target for AD. Graphical abstract Accessibility text This image illustrates the effects of different APOE isoforms (ApoE-ε3 and ApoE-ε4) on blood-brain barrier (BBB) integrity, focusing on the molecular interactions between astrocytes and endothelial cells. This figure emphasizes the detrimental effects of ApoE-ε4 on BBB integrity via fibronectin accumulation and altered signaling pathways. The top section provides a schematic overview of the blood-brain barrier, highlighting astrocytes, endothelial cells, and their interface. The left panel represents the ApoE-ε3 condition: Normal fibronectin (FN1) levels support healthy interactions between astrocytes and endothelial cells. Growth factors, including VEGFA, HBEGF, and IGF1, maintain BBB integrity through their respective receptors (VEGFR and EGFR). Green arrows indicate activation of these signaling pathways. The right panel depicts the ApoE-ε4 condition: Elevated fibronectin (FN1) disrupts astrocyte-endothelium interactions. FN1 binds integrins and activates focal adhesion kinase (FAK), inhibiting VEGFA, which is required for endothelial HBEGF that in turn activates IGF1 signaling. Red symbols indicate inhibition of HBEGF, VEGFA, and IGF1 pathways, leading to BBB dysfunction. Highlights APOE-ε4 drives fibronectin deposition in Alzheimer’s, disrupting astrocyte-endothelia interactions. APOE-ε4 and fibronectin co-localize, forming aggregates at blood-brain barrier (BBB). Fibronectin alters the signaling between VEGF, IGF1, and HBEGF impairing BBB function. Reducing fibronectin restores BBB integrity and offsets APOE-ε4 pathology.

285 Background: Immune checkpoint inhibitors (ICIs) have shown limited efficacy in colorectal cancer (CRC) outside of mismatch repair (MMR) deficient/microsatellite instability-high (MSI-H) tumors. Most CRC cases are MMR proficient /microsatellite stable and demonstrate resistance to ICIs, attributed to the tumor microenvironment. Colony Stimulating Factor 1 Receptor (CSF1R), a regulator of tumor-associated macrophages, has emerged as a potential target due to its association with poor prognosis in CRC. Methods: Data from 433 metastatic CRC (mCRC) patients in the CALGB/SWOG 80405 trial were analyzed. CSF1R RNA was extracted from formalin-fixed, paraffin-embedded tumor samples and sequenced. Patients were divided into tertiles of CSF1R expression (high, medium, low). Progression-free survival (PFS) and overall survival (OS) were compared using Kaplan-Meier curves, log-rank tests, and Cox proportional hazards models. Subgroup analyses were conducted based on liver metastases, treatment type (Bevacizumab, Cetuximab, FOLFOX, FOLFIRI), and MSI status. Results: Low CSF1R expression (CSF1R-L) was associated with significantly better survival outcomes. Median PFS was 12.9 months for CSF1R-L, compared to 11.2 and 9.2 months for CSF1R-M and CSF1R-H (p = 0.003). Median OS was 35.8 months for CSF1R-L versus 32.5 and 24.4 months for CSF1R-M and CSF1R-H (p = 0.00086). Stratification by liver metastases showed that CSF1R-L remained a strong prognostic factor only in patients with liver metastases. There were no significant survival differences based on CSF1R expression in bevacizumab-treated patients. However, in cetuximab-treated patients, CSF1R-L tumors had significantly longer PFS (12.9 vs 8.8 months, p = 0.037) and OS (35.8 vs 21.4 months, p = 0.002) than CSF1R-H tumors. Similarly, in FOLFOX-treated patients, CSF1R-L tumors showed longer PFS and OS (p = 0.018 and p = 0.013, respectively), and in FOLFIRI-treated patients, OS was significantly longer for CSF1R-L tumors (42.2 vs 24.7 months, p = 0.022) than CSF1R-H tumors. Conclusions: Our data suggests that CSF1R expression may serve as a prognostic biomarker in CRC, with lower expression potentially linked to improved survival, particularly in patients with liver metastases. These findings warrant further investigation of CSF1R as a possible prognostic and predictive biomarker, as well as a potential therapeutic target in CRC. Clinical trial information: NCT00265850 .

Background Bacteremia is sometimes observed in patients with prosthetic joint infection (PJI), and it is associated with a lower likelihood of infection control. However, the prevalence and association of bacteremia in chronic PJI remain unknown. Questions/purposes (1) What percentage of patients are diagnosed with bacteremia at the time of hospital admission and before surgery for chronic PJI? (2) What clinical factors are associated with positive blood cultures? (3) To what degree are positive blood cultures associated with infection-free implant survival in patients with chronic PJI? Methods This prospective study was conducted at a single academic institution from June 2021 to August 2022. Within the study period, we treated 124 patients for chronic PJI, defined according to the modified Musculoskeletal Infection Society (MSIS) criteria. Of those, we considered patients who underwent revision surgery because of chronic PJI of the hip or knee as potentially eligible. All patients received two blood cultures within 48 hours after admission but before surgery. The second blood culture was performed on the contralateral arm 1 hour after the first was completed. Based on that, 87% (108 of 124) of patients were eligible; 13% (16 of 124) were excluded because of delayed blood sample transfers in 6% (7 of 124) of patients, contaminated samples in 2% (2 of 124), late hematogenous infection in 2% (3 of 124), and antibiotic use within 2 weeks before sampling in 3% (4 of 124). No patients were lost before the minimum study follow-up of 2 years without having reached a study endpoint (reinfection or persistent PJI) or had incomplete datasets, leaving 74% (92 of 124) for analysis here. The median (range) time from the index surgery (previous primary, debridement, or revision procedure) to the current revision for PJI in these patients was 16 months (2 to 180). Of the included patients, 40% (37 of 92) were men, 39% (36 of 92) had PJI of the hip, and 61% (56 of 92) had PJI of the knee. The mean age of patients was 65 ± 13 years, and the mean BMI was 28 ± 3 kg/m2. The interval between two cultures was at least 1 hour, and one culture was taken from each of the patient’s arms. Patients were divided into blood culture–positive and blood culture–negative groups based on preoperative blood culture results. The chi-square test and the independent t-test were used to compare demographic characteristics (gender, age, BMI, and affected joint) and clinical factors (American Society of Anesthesiologists [ASA] classification, hematological tests, comorbidities) between the two groups. Further multivariable logistic regression analysis was performed to assess the factors associated with positive blood cultures, which controlled for potential confounders including age, gender, BMI, and affected joint. The Firth penalized likelihood was employed when there was monotone likelihood in logistic regression analysis to reduce small-sample bias. A Kaplan-Meier curve tracked infection-free implant survival over 30 months, with differences evaluated using the log-rank test. Results Overall, 15% (14 of 92) of patients had positive blood cultures. After adjusting for age, gender, infection site, BMI, and intraoperative isolation of gram-positive cocci, we found that patients classified as ASA III (OR 4 [95% confidence interval (CI) 1 to 21]; p = 0.04) and those who had diabetes (OR 14 [95% CI 3 to 100]; p < 0.001) had a higher odds of positive blood cultures. We found no difference in the Kaplan-Meier estimate for infection-free implant survival at 30 months between those with positive blood cultures (86% [95% CI 76% to 95%]) and those with negative blood cultures (91% [95% CI 88% to 94%]; p = 0.51). Conclusion In this prospective, observational study, we found that chronic PJI can potentially lead to hematogenous dissemination of pathogens, particularly in patients with poor overall health (such as those classified as ASA III and patients diagnosed with diabetes). Therefore, selective preoperative blood cultures may be crucial in helping clinicians implement early intervention measures to prevent the serious consequences of bacteremia in patients with poor baseline health and those with other implanted devices. Larger studies with longer follow-up are needed to further validate these findings, ensure more robust estimates, and conduct comprehensive evaluations of the risk factors associated with positive blood cultures in chronic PJI. Level of Evidence Level II, therapeutic study.

ImportanceChronic obstructive pulmonary disease (COPD) is often undiagnosed. Although genetic risk plays a significant role in COPD susceptibility, its utility in guiding spirometry testing and identifying undiagnosed cases is unclear.ObjectiveTo determine whether a COPD polygenic risk score (PRS) enhances the identification of undiagnosed COPD beyond a case-finding questionnaire (eg, the Lung Function Questionnaire) using conventional risk factors and respiratory symptoms.Design, Setting, and ParticipantsThis cross-sectional analysis of participants 35 years or older who reported no history of physician-diagnosed COPD was conducted using data from 2 observational studies: the community-based Framingham Heart Study (FHS) and the COPD-enriched Genetic Epidemiology of COPD (COPDGene) study.ExposuresModified Lung Function Questionnaire (mLFQ) scores and COPD PRS.Main Outcomes and MeasuresThe primary outcome was spirometry-defined moderate to severe COPD (forced expiratory volume in the first second of expiration/forced vital capacity [FEV1/FVC] &amp;lt;0.7 and FEV1 [percent predicted] &amp;lt;80%). The performance of logistic models was assessed using the PRS, mLFQ score, and PRS plus mLFQ score for predicting spirometry-defined COPD.ResultsAmong 3385 FHS participants (median age, 52.0 years; 45.9% male) and 4095 COPDGene participants (median age, 56.8 years; 55.5% male) who reported no history of COPD, 160 (4.7%) FHS and 775 (18.9%) COPDGene participants had spirometry-defined COPD. Adding the PRS to the mLFQ score significantly improved the area under the curve from 0.78 to 0.84 (P &amp;lt; .001) in FHS, 0.69 to 0.72 (P = .04) in COPDGene non-Hispanic African American, and 0.75 to 0.78 (P &amp;lt; .001) in COPDGene non-Hispanic White participants. At a risk threshold for spirometry referral of 10%, the addition of the PRS to the mLFQ score correctly reclassified 13.8% (95% CI, 6.6%-21.0%) of COPD cases in FHS, but not in COPDGene.Conclusions and RelevanceA COPD PRS enhances the identification of undiagnosed COPD beyond a conventional case-finding approach in the general population. Further research is needed to assess its impact on COPD diagnosis and outcomes.

Abstract Durable T cell immunity against cancer depends on the continual replenishment of effector CD8+ T cells. Thymic output has been correlated with favorable prognosis in cancer patients across a range of ages, suggesting that the thymus is an important source for replenishing T cells capable of controlling cancer progression. However, the effector potential of thymic mature CD8+ T cells and their regulation have not been clearly defined. In this study, we identified the ability of thymic single positive CD8+ T cells to gain effector potential after thymic selection, but they are subject to the regulation of PD-1. We found a previously undisclosed role of PD-1 in limiting both the cytotoxic and exhaustion potential of thymic and peripheral CD8+ T cells. Our results show that although PD-1 inhibition facilitates the expansion of effector CD8+ T cells, effector CD8+ cells gradually lose their antitumor activity within tumor tissues due to advanced exhaustion in the absence of PD-1. Thus, although the preset effector potential in thymic mature CD8+ T cells allows them to rapidly respond to malignant cells in the periphery, PD-1, as a checkpoint, is embedded in the thymic mature CD8+ T cells after positive selection to balance their effector function from exaggeration and exhaustion. Therefore, we propose that a strategy capable of upholding the cytotoxic capacity and avoiding exhaustion of CD8+ T cells during the early stages of PD-1 inhibition therapy is needed to achieve durable antitumor immunity.

Abstract Although social determinants of health (SDoH) investigations have shown limited analyses of socioeconomic and race-ethnic status on certain hematologic malignancies, the impact of factors beyond those across a fuller scope of hematologic cancers remains unknown. The Social Vulnerability Index (SVI), a tool for assessing varied US census–derived sociodemographic factors, allows for the specific quantification of SDoH in dynamic, regional contexts for their associations with hematologic malignancy inequities. To assess the summative influence of varied SDoH factors on hematologic malignancy outcomes and discern which SDoH factors contributed the largest associations toward disparities, 796 005 adults with hematologic malignancies between 1975 to 2017 were identified for this retrospective cohort study. Vulnerability in 15 SDoH factors was measured using composite and subcategory SVI scores geographically matched to patients. Regressions between SVI factors and follow-up time after diagnosis and survival period were performed. Increasing overall SVI correlated with significantly decreased surveillance period in 11 of 14 hematologic malignancies, with decreases upward of 33.4% (39.0-26.0 months for acute lymphocytic leukemia). Increasing SVI significantly associated with decreased survival period across 11 of 14 hematologic malignancies, with decreases upward of 47.2% (89.5-47.3 months for Hodgkin lymphoma). Socioeconomic status and housing and transportation vulnerabilities showed the largest magnitude of contributions, followed by minority language and household composition. Significant decreases in hematologic malignancy prognosis associate with increasing overall SDoH vulnerability in varied sociodemographic contexts in the United States. Furthermore, there are quantifiable differences in which types of SDoH contribute more to trends per malignancy type. These findings demonstrate specific SDoH targets for further research and policy initiatives to combat hematologic malignancy disparity more effectively.