Citations

e18807 Background: CUP represents both a diagnostic and a management challenge. Despite improvements through sophisticated imaging modalities, specific and sensitive testing using immunohistochemistry, a concrete determination of the site of origin of the primary tumor can still be a diagnostic challenge Hereby, we described the genomic landscape of patients with CUP treated at our institution. Methods: Retrospective study of patients with CUP treated at Mayo Clinic Rochester MN from 2010 to 2021. Next generation sequencing (NGS) information was abstracted, and alterations were ranked into different levels of actionability following the Onco KB framework. All data were analyzed by the SPSS version 22.0 software (SPSS, Chicago, IL, United States). Results: From a total of 214 patients, we identified 67 (32%) patients in whom NGS was performed. Among patients with available NGS the median age was 64 years (range: 35-86) and 51% were female. the most prevalent histology included adenocarcinoma (39%), carcinoma NOS (31%), and neuroendocrine tumors (12%). NGS on tumor (t-NGS) was available in 56 (84 %) patients, circulating tumor NGS (b-NGS) was available in 12 (18%) patients, and only 1 patient had both testing available. Among the 56 patients with available t-NGS, MSI-high was detected in 9 patients, whereas among the 12 patients with available b-NGS, MSI-high was detected in 8 patients; yielding an MSI-high detection rate of 16% and 67% for t-NGS and b-NGS. In this cohort, there were a total of 474 genomic alterations detected from which 103 (22 %) were able to be ranked into one therapeutic level following the OncoKB framework. Genomic alterations were most observed among patients with carcinoma (n = 50, 48.53%) adenocarcinoma (n = 33, 32.03 %), squamous cell carcinoma (n = 3, 2.91 %) and neuroendocrine tumor (n = 2, 1.94%). Following the OncoKB framework, 39-level 1 genomic alterations were detected in a total of 14 genes. The most common level 1 genomic alterations comprised the BRCA2 (20.51%), NF1 ATM (17.95%) and HER2/NEU (ERBB2) (15.38%) genes. Therapeutic level 2 included 51 genomic alterations in 13 genes of which KRAS (17.65%), BRAF (15.69%), and BRCA2 (15.69%) were the most prevalent mutated genes. Additionally, level R comprised 13 genomic alterations in the following genes: KRAS (69.23) NRAS (23.08%) and PDGFRA (7.69%). Conclusions: CUP are malignancies rich in potentially actionable alterations, and NGS of tissue and blood samples can inform systemic therapy decisions. Alteration-specific targeted therapy may be an option for a substantial proportion of patients. NGS of tumor tissue or blood should be considered for all patients with CUP.

e18803 Background: CUPs are a heterogeneous group of metastatic cancers for which a standardized diagnostic work-up fails to identify the site of origin at the time of diagnosis. CUP accounts for 3%-5% of all cancer diagnoses worldwide, and the natural history of patient with CUP differs from that of patients (pts) with cancer with known primary tumor. Here we report and summarize the clinical features of patients with CUP treated at Mayo Clinic. Methods: Retrospective study of patients treated at Mayo Clinic Rochester MN from 2010 to 2021. Patient demographics, tumor-related variables, treatment-related variables, and clinical data were extracted. Descriptive statistics were used, and all data were analyzed by the SPSS version 22.0 software (SPSS, Chicago, IL, United States). Results: From a total of 214 pts, 207 pts were included, as primary tumor site was identified in 7 patients after initial evaluation. The pts in this study were predominantly white (87%) of female (50.2%) gender with a mean age of 63 (SD: 13) without history of smoking (51%) and either private or public insurance (82.6%). The predominant histology was adenocarcinoma (30%), followed by neuroendocrine neoplasms (27%), and carcinoma NOS (not otherwise specified) (25%). The most prevalent grade in this cohort was grade III with poorly differentiated tumor cells. All pts had diagnostic imaging and the most used imaging modalities included CT (81.2%), and PET-CT (43.5%). In our cohort, the 3 most common sites of metastases included lymph nodes (57.5%), liver (37.8%), lung (34.3%), and bone (23.7%); and in 64% of pts, there was a specific presentation pattern including liver-predominant (24.6%), lymph node-predominant (24.6%), bone-predominant (7.7%), and peritoneal carcinomatosis (7.7%). The majority of pts received systemic therapy (69%) as first line of therapy and the most frequent first line regimens included platinum-doublet (26.5%), gemcitabine-based regimen (20.7%), 5FU-based regimens (18%) and somatostatin analogs (16.7%); whereas salvage radiation and ablation were offered to 11% of pts and surgery to 17%. The median follow-up time was 22 months (IQR: 45) with a median survival time of 23 months and the 3-year cumulative survival rate was 30%. Conclusions: The heterogenous nature of CUPs and lack of specific immunohistochemical signature prevents primary tissue of origin diagnoses in CUP pts. Without the identification of a primary origin site, treatment is restricted to generic chemotherapy with limited benefit as demonstrated in this cohort.

e18802 Background: CUP is a rare cancer with an incidence of 7–12 cases per 100,000/year. CUP is defined as metastatic cancer with no identifiable primary tumor despite comprehensive evaluation. Despite its heterogeneous clinicopathological presentation, the treatment of CUP has primarily been with platinum-based combination chemotherapies but results are poor and survival is short. Here, we describe survival outcomes in real-world dataset of patients with CUP seen at a tertiary referral center. Methods: Retrospective study of patients treated at Mayo Clinic, Rochester MN, from 2010 to 2021. Survival probabilities were estimated with the Kaplan-Meier method. We used Cox proportional hazard regression with forward modeling to explore the association between each variable and death. Overall survival (OS) analysis was conducted in the entire cohort, and it was stratified by histological subtype. For the hypothesis test, we considered p < 0.05 to be statistically significant; all tests were two-sided. All data were analyzed by the SPSS version 22.0 software (SPSS, Chicago, IL, United States). Results: From a total of 214 patients, 198 patients were included in the survival analysis. The patients were predominantly white (87%), female (50.2%), with a mean age of 63 (SD: 13) without history of smoking (51%). The predominant histology was adenocarcinoma (30%), followed by neuroendocrine neoplasms (NEN) (27%), carcinoma NOS (25%), squamous cell carcinoma (SCC) (10%) and non-classifiable tumors (7%). The median follow-up time was 23 months, and medial OS was 23 months in the entire cohort. OS by histology was as follows: 51 months for NEN, 34 months for SCC, 18 months for carcinomas NOS and 11 months for adenocarcinomas (p < 0.001) (fig.1). Similar OS trends were observed when we restricted the analysis to poorly differentiated tumors. The 3- and 5-year cumulative survival by histology were as follows: 7% and 0% for adenocarcinoma, 25% and 8% for carcinoma NOS, 39% and 17% for SCC, and 56% and 22% for NEN. In Cox regression models we did not identify any prognostic factors among patients with adenocarcinoma. Conclusions: Patients with adenocarcinoma of unknown primary possess a considerable challenge and the OS is short. CUP of other histologies have higher OS. This study highlights the need of accurate tumor identification and better treatment, perhaps as a multiomics therapeutic approach.

Abstract Objectives Disease flares in the post–coronavirus disease 2019 (COVID-19) vaccination period represent a prominent concern, though risk factors are poorly understood. We studied these flares among patients with idiopathic inflammatory myopathies (IIMs) and other autoimmune rheumatic diseases (AIRDs). Methods The COVAD-1 and -2 global surveys were circulated in early 2021 and 2022, respectively, and we captured demographics, comorbidities, AIRDs details, COVID-19 infection history and vaccination details. Flares of IIMs were defined as (a) patient self-reported, (b) immunosuppression (IS) denoted, (c) clinical sign directed and (d) with &gt;7.9-point minimal clinically significant improvement difference worsening of Patient-Reported Outcomes Measurement Information System (PROMIS) PROMISPF10a score. Risk factors of flares were analysed using regression models. Results Of 15 165 total respondents, 1278 IIMs (age 63 years, 70.3% female, 80.8% Caucasians) and 3453 AIRDs were included. Flares of IIM were seen in 9.6%, 12.7%, 8.7% and 19.6% patients by definitions (a) to (d), respectively, with a median time to flare of 71.5 (10.7–235) days, similar to AIRDs. Patients with active IIMs pre-vaccination (OR 1.2; 95% CI 1.03, 1.6, P = 0.025) were prone to flares, while those receiving rituximab (OR 0.3; 95% CI 0.1, 0.7, P = 0.010) and AZA (OR 0.3, 95% CI 0.1, 0.8, P = 0.016) were at lower risk. Female gender and comorbidities predisposed to flares requiring changes in IS. Asthma (OR 1.62; 95% CI 1.05, 2.50, P = 0.028) and higher pain visual analogue score (OR 1.19; 95% CI 1.11, 1.27, P &lt; 0.001) were associated with disparity between self-reported and IS-denoted flares. Conclusion A diagnosis of IIMs confers an equal risk of flares in the post–COVID-19 vaccination period to AIRDs, with active disease, female gender and comorbidities conferring a higher risk. Disparity between patient- and physician-reported outcomes represents a future avenue for exploration.

Abstract Objective Flares of autoimmune rheumatic diseases (AIRDs) following COVID-19 vaccination are a particular concern in vaccine-hesitant individuals. Therefore, we investigated the incidence, predictors and patterns of flares following vaccination in individuals living with AIRDs, using global COVID-19 Vaccination in Autoimmune Diseases (COVAD) surveys. Methods The COVAD surveys were used to extract data on flare demographics, comorbidities, COVID-19 history, and vaccination details for patients with AIRDs. Flares following vaccination were identified as patient-reported (a), increased immunosuppression (b), clinical exacerbations (c) and worsening of PROMIS scores (d). We studied flare characteristics and used regression models to differentiate flares among various AIRDs. Results Of 15 165 total responses, the incidence of flares in 3453 patients with AIRDs was 11.3%, 14.8%, 9.5% and 26.7% by definitions a–d, respectively. There was moderate agreement between patient-reported and immunosuppression-defined flares (K = 0.403, P = 0.022). Arthritis (61.6%) and fatigue (58.8%) were the most commonly reported symptoms. Self-reported flares were associated with higher comorbidities (P = 0.013), mental health disorders (MHDs) (P &lt; 0.001) and autoimmune disease multimorbidity (AIDm) (P &lt; 0.001). In regression analysis, the presence of AIDm [odds ratio (OR) = 1.4; 95% CI: 1.1, 1.7; P = 0.003), or a MHD (OR = 1.7; 95% CI: 1.1, 2.6; P = 0.007), or being a Moderna vaccine recipient (OR = 1.5; 95% CI: 1.09, 2.2; P = 0.014) were predictors of flares. Use of MMF (OR = 0.5; 95% CI: 0.3, 0.8; P = 0.009) and glucocorticoids (OR = 0.6; 95% CI: 0.5, 0.8; P = 0.003) were protective. A higher frequency of patients with AIRDs reported overall active disease post-vaccination compared with before vaccination (OR = 1.3; 95% CI: 1.1, 1.5; P &lt; 0.001). Conclusion Flares occur in nearly 1 in 10 individuals with AIRDs after COVID vaccination; people with comorbidities (especially AIDm), MHDs and those receiving the Moderna vaccine are particularly vulnerable. Future avenues include exploring flare profiles and optimizing vaccine strategies for this group.

Abstract Objective COVID-19 vaccines have a favorable safety profile in patients with autoimmune rheumatic diseases (AIRDs) such as idiopathic inflammatory myopathies (IIMs); however, hesitancy continues to persist among these patients. Therefore, we studied the prevalence, predictors and reasons for hesitancy in patients with IIMs, other AIRDs, non-rheumatic autoimmune diseases (nrAIDs) and healthy controls (HCs), using data from the two international COVID-19 Vaccination in Autoimmune Diseases (COVAD) e-surveys. Methods The first and second COVAD patient self-reported e-surveys were circulated from March to December 2021, and February to June 2022 (ongoing). We collected data on demographics, comorbidities, COVID-19 infection and vaccination history, reasons for hesitancy, and patient reported outcomes. Predictors of hesitancy were analysed using regression models in different groups. Results We analysed data from 18 882 (COVAD-1) and 7666 (COVAD-2) respondents. Reassuringly, hesitancy decreased from 2021 (16.5%) to 2022 (5.1%) (OR: 0.26; 95% CI: 0.24, 0.30, P &lt; 0.001). However, concerns/fear over long-term safety had increased (OR: 3.6; 95% CI: 2.9, 4.6, P &lt; 0.01). We noted with concern greater skepticism over vaccine science among patients with IIMs than AIRDs (OR: 1.8; 95% CI: 1.08, 3.2, P = 0.023) and HCs (OR: 4; 95% CI: 1.9, 8.1, P &lt; 0.001), as well as more long-term safety concerns/fear (IIMs vs AIRDs – OR: 1.9; 95% CI: 1.2, 2.9, P = 0.001; IIMs vs HCs – OR: 5.4 95% CI: 3, 9.6, P &lt; 0.001). Caucasians [OR 4.2 (1.7–10.3)] were likely to be more hesitant, while those with better PROMIS physical health score were less hesitant [OR 0.9 (0.8–0.97)]. Conclusion Vaccine hesitancy has decreased from 2021 to 2022, long-term safety concerns remain among patients with IIMs, particularly in Caucasians and those with poor physical function.

Head and neck squamous cell cancers (HNSCCs) represent a diverse group of tumors emerging within different mucosal surfaces of the oral cavity, nasopharynx, oropharynx, larynx, and hypopharynx. HNSCCs share common clinical risk factors and genomic features, including smoking, alcohol, age, male sex, aneuploidy, and TP53 mutations. Viral initiating and contributing events are increasingly recognized in HNSCCs. While both Epstein–Barr Virus (EBV) and human papilloma virus (HPV) are observed, EBV is more frequently associated with nasopharyngeal cancers whereas HPV is associated with oropharyngeal cancers. HNSCCs are associated with high tumor mutational burden and loss of tumor suppressor gene function, especially in TP53 and X-linked genes. Multiple lines of evidence suggest that HNSCCs are subject to immunologic surveillance and immune-induced evolutionary pressure that correlate with negative clinical outcomes. This review will discuss genomic mechanisms related to immune-mediated pressures and propose prognostic and therapeutic implications of detectable immune escape mechanisms that drive tumorigenesis and disease progression.

Abstract Background Recent data showed that the use of direct oral anticoagulants (DOAC) in addition to dual antiplatelet therapy (DAPT) is associated with reduced risk of adverse cardiovascular (CV) outcomes in patients with acute coronary syndrome (ACS) with or without percutaneous coronary intervention (PCI), but It has also been associated with increased risk of bleeding. The data differs among different studies, thus, the CV outcomes associated with use of DOAC therapy plus DAPT are not fully understood. We conducted a meta-analysis to explore the CV and bleeding outcomes of DOAC therapy plus DAPT vs DAPT with or without placebo in patients with ACS Methods We conducted a literature search of studies exploring the use of DAPT plus DOAC therapy with focusing on bleeding and CV outcomes including myocardial infarction (MI), stroke, stent thrombosis, limb thrombosis and VTE using Ovid, Scopus, PubMed, Medline, and EBSCO databases from January 2010 to March 2020. We used the following terms for the literature search: (Aspirin AND Clopidogrel OR Prasugrel OR Ticagrelor) AND (Apixaban OR Rivaroxaban OR Edoxaban OR Dabigatran OR Betrixaban). The efficacy outcome was a composite of CV death, MI and stroke, and the safety outcome was major bleeding. Results 4857 articles were included. Only RCTs and RCTs post-hoc analysis, were included (N=3). We found no significant heterogeneity and lower odds of the efficacy outcome in DOAC plus DAPT (experimental arm) compared to DAPT plus placebo (Control arm), which were unchanged in both the fixed and random effect models (Odds Ratio [OR] 0.87, 95% Confidence Interval [CI]: 0.78–0.97, I2=0%). We found no significant heterogeneity and higher odds of the safety outcome in DOAC plus DAPT (experimental arm) compared to DAPT plus placebo (Control arm) (OR fixed model 3.27, 95% CI: 2.28–4.70; OR random model 3.18, 95% CI: 2.21–4.57; I2=0%). Conclusion DOAC therapy plus DAPT in patients with ACS with or without PCI was associated with a lower rate of CV death, MI and stroke when compared to DAPT alone or with placebo and also associated with significant increase in major bleeding Funding Acknowledgement Type of funding sources: None.

6589 Background: Real-world utilization and comparative effectiveness of direct oral anticoagulants (DOACs), low molecular weight heparin (LMWH) and warfarin for cancer-associated venous thromboembolism (VTE) treatment remains largely unexplored. Methods: De-identified administrative claims data (OptumLabs - Data Warehouse) for adult active cancer patients with acute VTE (1/1/2012-9/30/2019) were assessed for utilization patterns, recurrent VTE, and major bleeding differences between DOACs, LMWH, and warfarin. Patients were followed up till the end of treatment. Patients who crossed over to other anti-coagulants within the follow up period were excluded. Multinomial logistic regression was used to assess predictors of anticoagulant administration. Kaplan-Meier curves were used to evaluate the differences in time to medication discontinuation among the three groups. Propensity score (PS) and inverse probability of treatment weighting were used to balance baseline differences between groups. Standardized difference (SD) was used to assess the balance of covariates after weighting and SD < 10% was considered acceptable. Weighted Cox proportional hazards regression with a robust variance estimator was then used to assess outcomes in PS weighted groups. Results: A total of 5100 patients met the inclusion criteria; 49.3% filled DOACs (n = 2512), 29.2% LMWH (n = 1488), and 28.6% warfarin (n = 1460). Median treatment duration was around 3.2 months for DOACs and warfarin, and 1.8 months for LWMH ( P-value < 0.01). Multinomial regression analysis showed that younger patients were more likely to be prescribed LMWH (OR 0.97 95% CI: 0.97-0.98) as compared to DOACs. Patients with lung (OR 2.07 95% CI: 1.12-3.65; OR 1.87 95% CI: 1.04-3.37), urological (OR: 1.94 95% CI:1.08-3.49; OR: 2.04 95% CI: 1.12-3.73), gynecological (OR 4.25, 95% CI: 2.31-7.82; OR 2.31 95% CI: 1.22-4.39) and colorectal cancer (OR 2.26 95% CI: 1.20-4.32; OR 2.51; 95% CI: 1.32-4.79) were more likely to be prescribed LMWH or warfarin respectively, compared to DOACs. VTE recurrences were more frequent for patients receiving LMWH (HR: 1.47; 95% CI: 1.14-1.90) or warfarin (HR: 1.46; 95% CI: 1.13-1.87) compared to DOACs. LMWH, but not warfarin, was associated with greater major bleeding rates compared to DOACs (HR: 2.27; 95% CI: 1.62-3.20). All-cause mortality rates were also significantly higher for patients receiving LMWH, but not warfarin compared to DOACs (HR: 1.61; 95% CI: 1.15-2.25). Conclusions: Patients with cancer associated VTE remain on anti-coagulation for a remarkably short duration in real-world clinical practice. DOACs and warfarin may offer better compliance than LMWH. Patients receiving DOACs have a lower risk of VTE recurrence, less major bleeding, and improved mortality. Warfarin may still be considered for patients with contraindications to DOACs and non-compliant to LMWH.