McGary, Alyssa

The use of normothermic machine perfusion (NMP) over static cold storage in liver transplantation has been shown to reduce posttransplant risks of early allograft dysfunction, primary nonfunction, and ischemic cholangiopathy, and its increasing use has played a role in the expanded utilization of marginal livers. While studies have demonstrated improved clinical outcomes using NMP over static cold storage preservation, real-time intraoperative data reflecting the quality and viability of NMP livers is limited. This retrospective, single-center study compared NMP versus static cold storage livers in first-time recipients of liver transplants through the evaluation of synthetic coagulation function as measured by thromboelastography and conventional coagulation testing. Secondarily, transfusion utilization between the 2 cohorts was reviewed. One hundred eighty-six recipients of liver transplants receiving allografts from donors after circulatory death were included in the study, of which 99 (53%) allografts were preserved in static cold storage, and 87 (47%) allografts were placed on the TransMedics Organ Care System. Study findings showed NMP livers supported with the TransMedics Organ Care System were associated with increased synthetic coagulation function and less excess fibrinolysis in the postreperfusion period compared to static cold storage livers, and that these findings were better reflected in real-time with thromboelastography monitoring versus conventional coagulation testing. Following reperfusion, there was a significant decrease in the transfusion of blood products in the NMP group compared with that in the static cold storage group. Overall, we determined that the use of intraoperative thromboelastography can provide real-time data to assess one aspect of reperfusion liver quality and viability.

ImportanceMeasurable residual disease (MRD) refers to the presence of disease at low levels not detected by conventional pathologic analysis. The association of MRD status as a surrogate end point of clinical outcome in chronic lymphocytic leukemia (CLL) has not been established in the era of targeted agents. Assessing the association of MRD with progression-free survival (PFS) may improve its role as a surrogate marker and allow its use to accelerate drug development.ObjectiveTo assess the association between MRD and PFS in CLL using data from prospective clinical trials that studied targeted agents or obinutuzumab-based treatment.Data SourcesClinical studies on CLL were identified via searches of PubMed, Embase, Scopus, and Web of Science from inception through July 31, 2023.Study SelectionProspective, single-arm, and randomized clinical trials that assessed targeted agents or obinutuzumab-based treatment and reported PFS by MRD status were included. Studies with insufficient description of MRD information were excluded.Data Extraction and SynthesisStudy sample size, median patient age, median follow-up time, line of treatment, MRD detection method and time points, and survival outcomes were extracted.Main Outcomes and MeasuresAnalyses of survival probabilities and hazard ratios (HRs) were conducted for PFS according to MRD status. Meta-analyses were performed using a random-effects model.ResultsA total of 11 prospective clinical trials (9 randomized and 2 nonrandomized) including 2765 patients were analyzed. Achieving undetectable MRD (uMRD) at 0.01% was associated with an HR of 0.28 (95% CI, 0.20-0.39; P < .001) for PFS. Median PFS was not reached in both groups (uMRD vs MRD), but the estimated 24-month PFS was better in the uMRD group (91.9% [95% CI, 88.8%-95.2%] vs 75.3% [95% CI, 64.7%-87.6%]; P < .001). The association of uMRD with PFS was observed in subgroup analyses in the first-line treatment setting (HR, 0.24; 95% CI, 0.18-0.33), relapsed or refractory disease setting (HR, 0.34; 95% CI, 0.16-0.71), and trials using time-limited therapy (HR, 0.28; 95% CI, 0.19-0.40).Conclusions and RelevanceThe findings of this systematic review and meta-analysis suggest that assessing MRD status as an end point in clinical trials and as a surrogate of PFS may improve trial efficiency and potentially allow for accelerated drug registration.

1597 Background: The impact of COVID19 pandemic on patient health beliefs and healthcare systems has adversely affected mammographic breast cancer screening (MBCS) during the initial stages of the pandemic. The aims of our study were to determine whether the initial decrease in MBCS rates persisted or if there was a rebound in later stages and to quantify the impact on urban and rural populations. Methods: This retrospective observational study analyzed data from March 2017 to March 2023 to assess whether eligible women received annual MBCS during this timeframe. We included women aged 40-75 years, drawn from the integrated Mayo Clinic system, encompassing nearly 60 primary care practices in Arizona, Florida, Iowa, Minnesota, and Wisconsin, representing a broad cross-section of the United States (US) population. US census data was utilized to classify a county as urban or rural. We divided the study period into 4 categories:1) pre-COVID-19 pandemic (March 1, 2017-March 10, 2020), 2) early pandemic (March 11, 2020-March 10, 2021; pre-vaccination period), 3) mid- pandemic (March 11, 2021-March 10, 2022; delta and omicron variant dominant period), and 4) late pandemic (March 11, 2022-March 1, 2023; recovery period). Utilizing the Poisson regression model, we compared the incidence rate ratio (IRR) for rates of MBCS across the 4 predefined time periods. Multivariable modeling was performed to assess the significance of MBCS rates with urbanicity while controlling for the year (2017-2022) and age. Results: By race and ethnicity, the women in this cohort were White (92%), Black (3.1%), Asian (3%) and other (1.9%). The median age was 57 years and the cohort included 239, 804 women aged 40-75 years. MBCS rates was 49.2% in 2017, 47.1% in 2018, 46.4% in 2019, and decreased to 42.1% in 2020 and improved to 44.7% in 2021 and 43.8% in 2022. Compared with the pre-COVID-19 pandemic period, there was a significant decrease in MBCS rate in the early pandemic (IRR= 0.886, 95% CI 0.879, 0.892, p<0.001). Though the MBCS rate improved in the mid-pandemic period, it remained below the pre-pandemic level (IRR=0.941, 95% CI 0.934, 0.948, p<0.001). Similarly, during the late stage of the pandemic, the MBCS rate remained lower than the pre-pandemic level (IRR=0.922, 95% CI 0.915, 0.928, p<0.001). Rural counties had a lower MBCS rate compared with urban counties (IRR = 0.936, 95% CI 0.931, 0.941, p<0.001). Conclusions: This study confirms the negative impact of the early COVID-19 pandemic on MBCS, and it revealed its persistent effect, as the current MBCS rate remains below the pre-pandemic rate. These findings were more evident in rural counties. Factors contributing to the long-lasting impact are being analyzed with the intent to develop and implement targeted solutions to improve the MBCS rate.

AbstractObjectiveFirst bite syndrome (FBS) is a rare complication of transoral surgery (TOS) for oropharyngeal cancer (oropharyngeal squamous cell carcinoma [OPSCC]). Risk factors for developing this complication are not well described. In this study, we attempt to identify risks for developing FBS in TOS.Study DesignRetrospective chart review.SettingTertiary care medical center.MethodsThis study was exempted by the Mayo Clinic institutional review board. We performed a review from January 2017 to November 2022 of all patients who underwent TOS for OPSCC by a single provider. Exclusion criteria included less than 6 months follow up, prior treatment of head and neck cancer, or incomplete records. Demographic data, comorbidities, tumor characteristics, surgical details, adjuvant treatment details, functional outcomes, and oncologic outcomes were assessed. Fisher's Exact test and Kruskal‐Wallis rank sum test were used to identify significant variables, and multivariable logistic regression was used to address confounding.ResultsOne hundred and one patients were identified. Eighty‐nine met the inclusion criteria. The mean follow‐up was 34 months (median 33). Seven patients (7.9%) developed FBS. Palatine tumor primary (P = .041), resection of styloglossus/stylopharyngeus (P = .039), and parapharyngeal fat manipulation (P = .015) were associated with the presence of FBS. After adjusting for tumor location, manipulation of parapharyngeal fat maintained significance (P = .025). T and N staging, tumor volume, adjuvant radiation, and ligation of lingual/facial arteries were not associated with the development of FBS. Eighty‐six percent (6/7) of patients had a resolution of FBS at an average of 11.3 months.ConclusionManipulation of the parapharyngeal space is independently associated with developing FBS in TOS in our cohort. Further confirmatory studies are warranted.

AbstractBackgroundVelopharyngeal insufficiency (VPI) is a known complication of transoral surgery (TOS) for oropharyngeal HPV‐mediated squamous cell carcinoma. Controversy exists regarding adequate resection margins for balancing functional and oncologic outcomes.MethodsThis retrospective study was exempted by the IRB. Patients who underwent TOS from January 2017 to October 2022 were included. Patient characteristics, treatment details, and oncologic and functional outcomes were evaluated.ResultsFifty‐five patients were included. Mean and median follow‐up was 34 months. 98% of patients were AJCC stage I/II. Recurrence‐free survival was 96% with no local recurrences.Univariate analysis demonstrated an association between VPI and pT stage (p = 0.035), medial pterygoid resection (p = 0.049), and palatal attachment sacrifice (p < 0.001). Multivariate analysis showed sacrifice of the palatal attachments remained a significant risk for VPI (p = 0.009).ConclusionLoss of soft palate pharyngeal attachments is an independent risk factor for VPI. When oncologically appropriate, the palatal attachments to the pharynx may be preserved.

175 Background: Alterations to mismatch repair (MMR) genes such as MLH1, MSH2, MSH6, and PMS2, can lead to microsatellite instability-high (MSI-H) tumors. MMR mutations can be inherited in Lynch syndrome (LS) but can also be a result of de novo alterations resulting in MSI-H malignancies. Treatment with immune checkpoint inhibitors (ICIs) have been shown to improve survival in such patients (pts) compared to systemic chemotherapy. However, there is a paucity of information in the literature with respect to outcomes of pts with germline vs somatic MMR mutations in MSI-H colorectal cancer (CRC). Furthermore, the presence of underlying BRAF mutation confers resistance to chemotherapy in pts with CRC, however data regarding outcomes with immunotherapy in such pts with MSI-H CRC is lacking. Methods: Pt records from the Mayo Clinic (AZ, MN, FL) between 2008-2023 denoted as MSI-H CRC, were included for retrospective review. Pt demographics, treatment courses, and genomic profiles were collected. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method. Outcome differences between sub-groups were accessed with the log rank test and univariate analyses were assessed with Cox-regression. Results: A total of 81 pt records were identified (n = 18 LS, n = 63 non-LS). Stage IV disease was found in 28% of LS pts vs 59% of non-LS pts at diagnosis. Pembrolizumab was the most common ICI selected for metastatic CRC pts for both LS and non-LS pts (65% vs 94%) with median treatment duration for each group 11.7 vs 8.8 months. There were no differences in OS or PFS for any stage between LS vs non-LS. Median OS for all patients was 82 months. For all stage IV patients, median OS was 44 months, and median PFS was 19 months. Interestingly, for stage IV pts treated with immunotherapy, tumors that harbored BRAF V600E mutation (n = 21) vs BRAF wild type (n = 20) had a significantly lower median OS 19 vs 113 months (HR = 2.69, p = 0.043) as well as median PFS 12 vs 95 months (HR = 2.48, p = 0.041). Conclusions: In this study, we found that patient treated with ICIs have similar outcomes in the presence of germline vs. somatic MMR mutations in MSI-H CRC. The presence of an associated BRAF V600E mutation, which occurs in non-LS MSI-H CRC conferred worse outcomes.

Introduction: Achieving undetectable measurable residual disease (uMRD) following treatment has shown significant prognostic value in several hematological malignancies. In chronic lymphocytic leukemia (CLL), uMRD is associated with improved outcomes in the era of chemoimmunotherapy (CIT). However, the role of measurable residual disease (MRD) in the context of novel agents such as Bruton tyrosine kinase inhibitors (BTKi) and/or BCL2 inhibitors (e.g. venetoclax) is uncertain. To address this question, we conducted a systematic review of the literature and performed a comprehensive meta-analysis of trials that included novel agents to evaluate the association between MRD status after treatment and PFS in patients with CLL. Methods: We conducted a comprehensive search of PubMed, EMBASE, Scopus, and Web of Science focusing on CLL trials reporting MRD and its association with PFS. Results were independently screened by two reviewers. Inclusion criteria included prospective phase 3 trials involving a novel agent in one of the treatment arms, while studies with incomplete information on MRD status related to PFS, reviews, abstracts, and retrospective analyses were excluded. The initial search identified 185 studies in PubMed and 402 studies in EMBASE. After applying prespecified criteria, a total of 10 phase 3 trials were included in our analysis. We extracted sample size, patient age, follow-up time, time point and tissue of MRD assessment, MRD cut-off and rate, performance status and molecular status when available. We only considered treatment arms with complete MRD information. The comparison involved patients who achieved uMRD with those exhibiting detectable MRD. When available, hazard ratios (HR) and confidence intervals (CI) were used to evaluate the relationship between MRD status and PFS. If not, we used Kaplan-Meier (KM) curves from both uMRD and MRD subgroups and extracted the coordinates points of the curves using DigitizeIt software (version 2.5.10, I. Bormann) and using the number at risk provided we estimated the HRs and CIs. A meta-analysis was performed using a random effects model from the R package metafor (Viechtbauer, W. (2010). Conducting meta-analyses in R with the metafor package. Journal of Statistical Software, 36(3), 1-48). The pooled hazard ratio estimates, and the corresponding 95% CI and prediction intervals (PI) were reported. Funnel and Baujat plots were generated to assess study heterogeneity and bias. All analysis was performed using R version 4.1.2 (R Foundation for Statistical Computing, Vienna, Austria). Results: A total of 10 phase 3 trials, encompassing 14 treatment arms and involving 3152 patients, met the stringent inclusion criteria. All but one study used a uMRD cut-off of &lt; 0.01%. Detailed information on the treatment arms and key trial characteristics is presented in Table 1. Notably, ten treatment arms were derived from first-line treatment trials, while the remaining arms pertained to the relapsed/refractory population. Only two trials (4 treatment arms) assessed MRD using next generation sequencing (NGS), while the rest used multicolor flow cytometry (MFC) (9 treatment arms) and allele-specific oligonucleotides polymerase chain reaction (ASO-PCR) (2 treatment arms). All but 3 trials assessed MRD in both bone marrow (BM) and peripheral blood (PB). One trial (2 treatment arms) was excluded from the met-analysis due to higher MRD cut-off. All studies included in the meta-analysis measured uMRD (&lt;0.01) versus MRD. The PFS pooled HR estimate for achieving uMRD at 0.01 cut off from the meta-analysis was 0.32 (95% CI [0.22, 0.45]), with minimal bias observed on the Funnel Plot. Conclusions: In this comprehensive meta-analysis, comprising 9 phase 3 trials, achieving uMRD was strongly associated with PFS. These findings further establish the prognostic role of MRD in CLL management and its potential use as a surrogate marker in clinical trials. As the body of evidence on MRD in CLL continues to grow, it becomes imperative to standardize the optimal time point, methodology, and tissue for MRD assessment. Substantial heterogeneity in these aspects underscores the necessity for unified guidelines to ensure the accurate and consistent evaluation of MRD status in clinical practice.

e19078 Background: MECOM (EVI1) rearrangements in MDS/AML are rare and carry an unfavorable prognosis. Although allogeneic stem cell transplantation (allo-HSCT) may prolong survival, factors impacting outcomes are not known. We conducted a retrospective analysis of patients with MECOM (EVI1) to associate clinicopathologic variables with prognosis. Methods: This study was approved by the Mayo Clinic IRB. Patients >18 years of age with MDS or AML and MECOM EVI1 at Mayo Clinic between 01/2012 and 12/2022 were included. Response was defined by ELN criteria. Intensive chemotherapy was defined as 7+3 or high dose cytarabine. Non-intensive chemotherapy included hypomethylating agents with or without venetoclax. Median overall survival (OS) and median leukemia free survival (LFS) were estimated using the Kaplan-Meier method. Outcome differences between sub-groups and univariate analyses were assessed with Cox regression. Results: Sixty patients met criteria for inclusion. Sixty-three percent (n = 38) were male and the median age at diagnosis was 67.8 yrs (range, 56 – 75). Eighty percent had AML (n = 48) and 18% had MDS (n = 11). Sixty-seven percent of patients had secondary AML/MDS (n = 40). Inv(3)/t(3;3) was present in 65% (n = 39) and t(3;21) was present in 12% (n = 7). Thirty-eight percent (n = 23) of patients had cooccurring monosomy 7 or 7q deletion and 5% had complex karyotype (n = 3). SF3B1 was the most common cooccurring mutation in 31% (n = 10), followed by KRAS in 19% (n = 6). Thirty-eight percent of patients (n = 23) received intensive chemotherapy. Complete response (CR) rates were 36% with intensive treatment (n = 8) and 4% with non-intensive treatment (n = 1; p = 0.007). Thirty percent (n = 18) underwent SCT (78% in CR1 and 22% in CR2) and of those, myeloablative conditioning (MAC) was used in 38% while 61% received reduced intensity conditioning (RIC). The mOS in the entire cohort was 11 months (95% CI 6.2, 17). Patients who received a SCT had longer mOS compared to patients who did not (19 vs 6.2 months, HR = 0.31, 95% CI 0.16,0.64; p = 0.001). AML-MRC was a poor prognostic factor in the HCST group for OS (HR = 4.23, 95% CI 1.02, 17.5, p = 0.047). Intensive vs. non-intensive chemotherapy, response prior to transplant (CR vs. no CR), or having 2 or more mutations on NGS did not significantly impact OS or LFS. Conclusions: In line with previous reports, allo-HSCT was associated with improved survival outcomes. Our results showed a high frequency of secondary AML/MDS, but only AML-MRC was associated with decreased survival outcomes. Regardless of therapy type, outcomes were poor. Novel therapies are urgently needed for these patients.