Phase II trial of nivolumab and metformin in patients with treatment-refractory microsatellite stable metastatic colorectal cancer

BACKGROUND

Preclinical studies showed metformin reduces exhaustion of tumor-infiltrating lymphocytes and potentiates programmed cell death protein-1 (PD-1) blockade. We hypothesized that metformin with nivolumab would elicit potent antitumor and immune modulatory activity in metastatic microsatellite stable (MSS) colorectal cancer (CRC). We evaluated this hypothesis in a phase II study.

METHODS

Nivolumab (480 mg) was administered intravenously every 4 weeks while metformin (1000 mg) was given orally, two times per day following a 14-day metformin only lead-in phase. Patients ≥18 years of age, with previously treated, stage IV MSS CRC, and Eastern Cooperative Oncology Group 0-1, having received no prior anti-PD-1 agent were eligible. The primary endpoint was overall response rate with secondary endpoints of overall survival (OS) and progression-free survival (PFS). Correlative studies using paired pretreatment/on-treatment biopsies and peripheral blood evaluated a series of immune biomarkers in the tumor microenvironment and systemic circulation using ChipCytometry and flow cytometry.

RESULTS

A total of 24 patients were enrolled, 6 patients were replaced per protocol, 18 patients had evaluable disease. Of the 18 evaluable patients, 11/18 (61%) were women and the median age was 58 (IQR 50-67). Two patients had stable disease, but no patients had objective response, hence the study was stopped for futility. Median OS and PFS was 5.2 months (95% CI (3.2 to 11.7)) and 2.3 months (95% CI (1.7 to 2.3)). Most common grade 3/4 toxicities: Anemia (n=2), diarrhea (n=2), and fever (n=2). Metformin alone failed to increase the infiltration of T-cell subsets in the tumor, but combined metformin and nivolumab increased percentages of tumor-infiltrating leukocytes (p=0.031). Dual treatment also increased Tim3+ levels in patient tissues and decreased naïve CD8+T cells (p=0.0475).

CONCLUSIONS

Nivolumab and metformin were well tolerated in patients with MSS CRC but had no evidence of efficacy. Correlative studies did not reveal an appreciable degree of immune modulation from metformin alone, but showed trends in tumorous T-cell infiltration as a result of dual metformin and PD-1 blockade despite progression in a majority of patients.

Clinical and Prognostic Biomarker Value of Blood-Circulating Inflammatory Cytokines in Hepatocellular Carcinoma

INTRODUCTION

Circulating inflammatory cytokines play critical roles in tumor-associated inflammation and immune responses. Recent data have suggested that several interleukins (ILs) mediate carcinogenesis in hepatocellular carcinoma (HCC). However, the predictive and prognostic value of circulating ILs is yet to be validated. Our study aimed to evaluate the association of the serum ILs with overall survival (OS) and clinicopathologic features in a large cohort of HCC patients.

METHODS

We prospectively collected data and serum samples from 767 HCC patients treated at the University of Texas MD Anderson Cancer Center between 2001 and 2014, with a median follow-up of 67.4 months (95% confidence interval [CI]: 52.5, 83.3). Biomarker association with OS was evaluated by the log-rank method.

RESULTS

The median OS in this cohort was 14.2 months (95% CI: 12, 16.1 months). Clinicopathologic features were more advanced, and OS was significantly inferior in patients with high circulating levels of IL1-R1, IL-6, IL-8, IL-10, IL-15, IL-16, and IL-18.

CONCLUSION

Our study shows that several serum IL levels are valid prognostic biomarker candidates and potential targets for therapy in HCC.

Impact of unemployment on cardiovascular mortality in united states: a nationwide county-level analysis 2010–2019

Background

Unemployment has been linked with a myriad of adverse health outcomes; however, its population-level impact on cardiovascular mortality (CVM), particularly amongst various demographic subgroups, remains understudied.

Purpose

To determine the impact of county unemployment levels on CVM rates, in overall and between different demographic subgroups.

Methods

We utilized the CDC WONDER database tool to retrieve county-level CVM rates for U.S. counties between 2010 and 2019. The County Health Rankings project was used to retrieve data on unemployment levels in each county as well as other characteristics used in an adjusted multivariate model. Generalized linear mixed models using Poisson regression were used to estimate the impact of unemployment on county-level CVM using relative (incidence rate ratios; IRR) and absolute (additional yearly deaths; AYD) measures.

Results

From 2010 to 2019, a total of 2904 U.S. counties (64.2% white; 50.81% female) with data available on CVM and unemployment levels were analyzed. In a multivariate model adjusted for demographic composition, CV risk, socioeconomic, environmental, and healthcare-access factors, unemployment was significantly associated with higher levels of CVM (IRR: 1.026; 95% CI: 1.018 to 1.033; 6.00 AYD). The relative impact of unemployment was strongest in elderly Blacks (IRR: 1.051; 95% CI: 1.029 to 1.074), middle-aged whites (IRR: 1.050; 95% CI: 1.032 to 1.067), and middle-aged females (IRR: 1.046; 95% CI: 1.018 to 1.075). The absolute impact of unemployment was highest in elderly Blacks (AYD: 94.70), elderly Whites (AYD: 35.30), and elderly females (AYD: 32.70). On a relative basis, the impact was more pronounced in the middle-aged (IRR: 1.030; 95% CI: 1.015 to 1.044) compared to the elderly (IRR: 1.022; 95% CI: 1.014 to 1.030), females (IRR: 1.026; 95% CI: 1.017 to 1.036) compared to males (IRR: 1.022; 95% CI: 1.014 to 1.031), and Blacks (IRR: 1.036; 95% CI: 1.016 to 1.057) compared to Whites (IRR: 1.030; 95% CI: 1.022 to 1.038).

Conclusion(s)

Unemployment is significantly associated with county-level CVM, and this impact is most pronounced in vulnerable demographic subgroups, namely females and Blacks. Efforts to reduce unemployment levels may significantly lower the burden of cardiovascular disease, particularly in groups most strongly affected by health disparities.

Funding Acknowledgement

Type of funding sources: None.

Adding troponin to echocardiography improves preoperative abscess detection in infective endocarditis. A REMOVE Trial analysis

Background

Detection of cardiac abscess in patients with infective endocarditis (IE) is important for surgical planning and decision-making. While transesophageal echocardiography (TEE) is the method of choice for abscess detection, in many cases uncertainty remains. Since IE abscesses often affect ventricular muscle, biomarker release may be a helpful adjunct for abscess detection.

Purpose

We assessed the accuracy of TEE and the value of combining it with preoperative measurement of cardiac Troponin (cTn) in the diagnosis of abscess, using surgical inspection as a reference.

Methods

Data collected in the electronic clinical report form for patients included in the prospective, multicenter, randomized, controlled trial (REMOVE Trial) were analyzed. Continuous variables are presented as median (25th–75th percentile) and categorical data as absolute and relative frequencies. The diagnostic performance of TEE was identified by comparing preoperative TEE findings with intraoperative findings. The concordance rate is expressed as a percentage. Receiver operating characteristic (ROC) curve was used to assess the ability of cTn to predict the presence of abscess intraoperatively. Area under curve (AUC) with 95% confidence interval as well as sensitivity and specificity are provided as measures of accuracy. Youden index was used to estimate an optimal cut-off value for cTn.

Results

Among the 282 patients included, 84 had abscesses detected intraoperatively. The sensitivity and specificity of TEE to detect abscess were 58.3% and 86.4%, respectively. cTn-I and cTn-T were measured preoperatively in 113 and 96 patients, respectively. Median cTn-I in patients with abscess was 132 pg/ml (interquartile range (IQR): 54–1528) vs 53 pg/ml (IQR: 17–250) in patients without abscess, p=0.002. Median cTn-T in patients with abscess was 941 pg/ml (IQR: 387–1527) vs 697 pg/ml (IQR: 282–1423) in patients without abscess, p=0.353. The incidence of recent preoperative myocardial infarction was not different between patients with or without abscess (7.1% vs 5.6%, respectively, p=0.593). The AUC for predicting abscess was 0.69 (95% CI: 0.57 to 0.80, p=0.002) and 0.56 (95% CI: 0.43 to 0.69, p=0.353) for preoperative cTn-I and cTn-T, respectively. Optimal cut-offs according to the Youden index are 38 pg/ml for cTn-I and 1632 pg/ml for cTn-T. By adding preoperative cTn-I or cTn-T to the TEE findings, the AUC increased to 0.82 (95% CI: 0.73 to 0.91, p<0.001) and 0.72 (95% CI: 0.59 to 00.84, p=0.001), respectively.

Conclusion

The results suggest that using TEE alone is a poor method for abscess detection in IE. Adding preoperative troponin values to TEE findings significantly improved IE abscess detection.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): The Federal Ministry of Education and Research (BMBF), Germany

Prognostic relevance of mitral regurgitation at different follow-up timepoints after transcatheter aortic valve implantation (TAVI): implications for therapeutic decision making?

Background

Transcatheter aortic valve implantation (TAVI) has developed rapidly in the last decade and is now recommended as state-of-the-art treatment for elderly patients suffering from severe symptomatic degenerative aortic stenosis (AS). The extent of mitral regurgitation (MR) following TAVI is likely to be of prognostic relevance. This raises the question whether treating MR following TAVI improves outcome of patients with significant MR.

Purpose

The current study was aimed to elucidate the prognostic value of MR at different follow-up (FU) timepoints after TAVI in a prospective real-world single-center registry study.

Methods

A total of 445 patients with severe AS, which were treated by transfemoral TAVI, were included and a wide range of clinical, laboratory, functional and imaging parameters were prospectively assessed. Mortality was recorded at 30 days, 1 year and 2 years after TAVI. Complete FU data including echocardiography were available at 6 to 8 weeks (n=334) as well as 6 months (n=235) after TAVI.

Results

All patients (mean age: 78.7±7.3 years, 52% female, mean STS score: 5±3.9%) were successfully treated by transfemoral TAVI using balloon- or self-expanding prostheses and showed mortality rates of 3.6% after 30 days, 16.4% after 1 year and 22.6% after 2 years. Moderate or severe (relevant) MR was detectable in 39% of the patients at baseline, in 27% of patients after 6 weeks (p=0.001) and in 28% of patients after 6 months (p=0.036, compared to baseline). Multivariate analysis identified independent predictors of 2-year mortality: clinical frailty scale and PAPsys at 6 to 8 weeks post-TAVI as well as BNP and relevant MR 6 months post TAVI. Among those parameters, MR after 6 months was the strongest predictor of long-term mortality (OR 3.192, CI 0.971–10.487, p=0.056). Kaplan-Meier survival analysis displayed significantly worse 2-year survival rates in patients suffering from relevant MR at 6 months (12.1% versus 4.8%, p=0.042).

Conclusions

Taken together, this real-life single-center experience underlines the prognostic value of relevant MR 6 months after TAVI with respect to long-term survival. Interestingly, MR was not predictive at the 6 to 8 weeks FU suggesting that early remodeling includes MR with prognostic relevance in those patients. Whether MR treatment, e.g., by transcatheter edge-to-edge repair, will improve patient outcomes post-TAVI has to be tested in prospective trials.

Funding Acknowledgement

Type of funding sources: None.

Tricuspid regurgitation and atrial fibrillation at baseline independently predict two-year survival after transcatheter aortic valve implantation (TAVI)

Background

Transcatheter aortic valve implantation (TAVI) is the accepted state-of-the-art treatment for elderly patients suffering from severe symptomatic aortic stenosis (AS). Co-morbidities at baseline are of great impact not only for individual peri-procedural risk stratification but also for the determination of long-term prognosis. The latter is of certain clinical interest, since a variety of co-existing disorders can be effectively treated in addition to TAVI.

Purpose

The current study aimed to elucidate the prognostic value of a wide range of baseline characteristics and co-morbidities with respect to long-term survival of TAVI patients in a prospective real-world single-center registry study.

Methods

A total of 445 patients with severe AS, which were treated by transfemoral TAVI, were included. A wide range of clinical, laboratory, functional and imaging parameters were prospectively assessed at baseline prior to TAVI. Mortality was recorded at 30 days, 1 year and 2 years after TAVI.

Results

The mean age of patients in this typical TAVI cohort was 78.7±7.3 years, 52% were female and the mean STS score was 5±3.9%. The mortality rates were as follows: 3.6% after 30 days, 16.4% after 1 and 22.6% after 2 years. Multivariate analysis could identify the following independent predictors of 2-year mortality assessed at baseline: sex, age, AS entity other than high-gradient, atrial fibrillation (Afib), renal function, relevant TR, systolic pulmonary artery pressure (PAPsys) and six-minute walk distance (SMWD). Among those, the strongest predictive value could be shown for Afib (OR 2.505, CI 1.509–4.157, p<0.001) and TR (OR 2.179, CI 1.105–4.299, p=0.025). Kaplan-Meier survival analysis displayed significantly worse 2-year survival rates in patients suffering from relevant TR (31.6% versus 17.4%, p<0.001) and Afib (29.4% versus 14.8%, p<0.001).

Conclusions

Taken together, the results of the current study demonstrate the prognostic value of cardiovascular co-morbidities assessed prior to TAVI. We identified relevant TR and Afib as the strongest independent predictors of long-term mortality in our cohort. Since both conditions are effectively treatable, special emphasis should be placed on the question, which patient might benefit from treatment, e.g., by transcatheter edge-to-edge repair of TR or rhythm control, in addition to TAVI.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Else Kröner-Fresenius-Stiftung, Research Program “Else Kröner-Forschungskolleg AntiAge”

Burden and disparities in cardiovascular mortality rates associated with obesity prevalence in United States: county-level analysis from 2010 to 2019

Background

Obesity is a grave public health threat linked to high morbidity and mortality rates. A significant rise in obesity rates amongst U.S. adults and worldwide has been observed in recent decades. Although associations between obesity and cardiovascular mortality (CVM) are well-known, impact and disparities in CVM attributable to obesity at a nationwide community level, aren't well defined.

Purpose

At county level, we sought to evaluate the independent impact of adult obesity on CVM in overall population and within different age, sex, and race/ethnic subgroups.

Methods

Age-adjusted CVM rates (ACVM) between 2010 to 2019, were obtained using Wide-ranging Online Data for Epidemiologic Research tool of Center for Disease Control (CDC). Using the Behavioral risk Factors Surveillance System (BRFSS), obesity rates per county was assessed as the percentage of adult population (age ≥20) that reports a body mass index ≥30 kg/m2. BRFSS, CDC Diabetes Interactive Atlas, census population estimates, environmental public health network and health county ranking project databases, were utilized to acquire county data of demographics, CV risk, socio-environmental, and health care access factors. Poisson multivariate generalized linear mixed models were employed to assess incidence rate ratios (IRR) of ACVM associated with obesity rates. To evaluate the absolute impact of obesity on ACVM, additional yearly deaths (AYD) per 100,000 individuals were calculated. All study analysis were weighted for the relevant county baseline population.

Results

Among 307,045,647 residents (50% women, 12% non-Hispanic blacks, 24% aged 45–64) lived at 2904 US counties in 2010, total 8,157,571 (2.7%) CV deaths occurred between 2010–2019. In fully adjusted model*, high obesity rates significantly associated with high ACVM (IRR: 1.015; 95% CI: 1.008 to 1.022), that translated to 3.5 AYD per 100,000 individuals. In a subgroup analysis, obesity rates associated with a relatively higher ACVM among overall middle aged adults [45 to 64] (IRR: 1.028; 95% CI: 1.018 to 1.037) versus elderly [≥65] (IRR: 1.013; 95% CI: 1.006 to 1.020), and in males (IRR: 1.018; 95% CI: 1.010 to 1.026) versus females (IRR: 1.014; 95% CI: 1.006 to 1.022), and in Hispanics (IRR: 1.035; 95% CI: 1.005 to 1.065) versus non-Hispanic Whites (IRR: 1.020; 95% CI: 1.012 to 1.027). Interestingly, middle aged adults had higher ACVM IRRs as compared to elderly, among males (IRR: 1.022), females (IRR: 1.039), and non-Hispanic Whites (IRR: 1.044) (Figure).

Conclusions

Obesity prevalence is independently associated with high ACVM among different age, sex, and race/ethnic groups, and this impact is most pronounced in Hispanics and the middle-aged group of females and non-Hispanic Whites. More research is needed to further uncover the mechanisms leading to these observations a long with community-level interventions to reduce the burden of this ongoing epidemic, in overall and most impacted population groups.

Funding Acknowledgement

Type of funding sources: None.

Role of local therapy in the management of patients with metastatic anal squamous cell carcinoma: a National Cancer Database study

BACKGROUND

About 10-20% of patients with anal squamous cell carcinoma (SCCa) present with metastatic disease and are usually treated with systemic chemotherapy. However, primary tumor control is crucial as local failure is associated with significant morbidity. Using the largest cohort to date, we report the impact of local therapy on survival among patients with metastatic anal SCCa.

METHODS

Data were collected from US hospitals that contributed to the National Cancer Database (NCDB) between 2004 and 2015. Patients who did not receive palliative systemic chemotherapy were excluded from analysis. Univariate (UVA) and multivariable analyses (MVA) were performed to identify factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used to evaluate the association between tumor/patient characteristics and overall survival (OS).

RESULTS

A total of 1,160 patients were identified over the 12 years of study. Median age was 57 years. Majority were female (64.9%), non-Hispanic Whites (79.1%) and had Charlson-Deyo Score of 0 (83.6%). Most common metastatic sites were liver (25.9%), lung (11.6%) and bone (8.5%). More than 79% of the patients had received radiation to the primary site, and 10.4% underwent surgical resection for local control. Use of local therapy correlated closely with OS on MVA (HR 0.66; 0.55-0.79; P<0.001), with a 12-month and 5-year OS rates of 72.8% and 25.7% respectively, compared with 61.1% and 14.6% for patients treated with chemotherapy only. Poor prognostic factors included male gender (HR 1.44; 1.24-1.67; P<0.001), age >70 years (HR 1.28; 1.02-1.62; P=0.034), lack of health insurance (HR 1.32; 1.02-1.71; P=0.034), and cloacogenic zone location (HR 4.02; 1.43-11.30; P=0.008). There was no benefit from abdominoperineal resection (mOS =19.7 months; HR 1.05; 0.48-2.29; P=0.909), but both local resection of the primary (mOS =24.8 months, HR 0.48; 0.29-0.80; P=0.005) and palliative radiation (mOS =22.6 months; HR 0.66; 0.55-0.79; P<0.001) were associated with improved OS.

CONCLUSIONS

In addition to systemic therapy, resection of the primary tumor or palliative radiation improved OS in patients with anal SCCa. Patients unlikely to benefit from local control were those >70 years of age, male, lack of health insurance and cloacogenic carcinoma.

Abstract 3482: Correlative analysis of metformin and nivolumab combination in treatment-refractory microsatellite stable (MSS) metastatic colorectal cancer (mCRC)

Background: Preclinical results indicate that metformin can modulate immune cell populations in the tumor microenvironment of solid tumors by diminishing exhaustion of CD8+ tumor infiltrating cells and improving T cell responses. Studies also suggest that metformin could complement PD-1 blockade and potentiate its antitumor activity. Previously we reported the results of a phase II trial with metformin and nivolumab and here we report the findings of correlative analysis of the prospectively collected research samples of 18 patients.

Methods: We conducted a phase II trial with nivolumab and metformin in treatment-refractory microsatellite stable (MSS) metastatic colorectal cancer (mCRC). Nivolumab 480 mg IV every 4 weeks and metformin 1000 mg orally twice daily was administered in 28-day cycles following a 14-day metformin only lead-in phase. The primary endpoint was overall response rate (ORR). Secondary endpoints were overall survival (OS) and progression free survival (PFS). Pre-treatment and on-treatment research biopsies and correlative peripheral blood specimens were collected. Paired biopsies obtained at baseline and following treatment with metformin only (n=9) or metformin and nivolumab (n=9) and were stained with a panel of 13 markers using ChipCytometry technology by Canopy Biosciences. Sample was assessed prior to establishing the multiplex assay. 30 out of 36 samples were imaged and analyzed up to 30 Fields of View. Single cell recognition and quantitative biomarker analysis were performed to compare immune cell numbers and population distribution in pre- versus post-treatment samples.

Results: As previously reported, no patients had objective response based on RECIST version 1.1 and the study was stopped after the first stage for futility. Median OS and PFS was 5.1 months [95% CI (2-11.7)] and 2.3 months [95% CI (1.7-2.4)], respectively. Multiplex analysis of tissues from patients receiving lead in with metformin alone revealed fewer effector CD4 T cells and effector and effector memory CD8 T cells after treatment vs. baseline biopsy. Biopsy tissue from patients treated with metformin and nivolumab had lower pAMPK and decreased PDL-1 expression vs. baseline. The combination also increased percentages of leukocytes, effector CD4 T cells, effector and effector memory CD8 T cells as well as levels of PDL1-Tim3+ cells.

Conclusion: In the setting of MSS mCRC, metformin as a single agent did not enhance effector CD4 and CD8 T cell percentages in clinical samples in our patient cohort. Metformin in combination with nivolumab was associated with increased percentages of effector CD4 and CD8 T cells in biopsy specimens, although these improvements did not translate into enhanced clinical endpoints. Analysis of peripheral blood samples are currently underway to corroborate the findings in the tissue samples.

Citation Format: Batoul Farran, Jeffrey M. Switchenko, Lana Khalil, Walid L. Shaib, Brian Olson, Amanda Ruggieri, Christina Wu, Olatunji B. Alese, Maria Diab, Gregory B. Lesinski, Bassel El-Rayes, Mehmet Akce. Correlative analysis of metformin and nivolumab combination in treatment-refractory microsatellite stable (MSS) metastatic colorectal cancer (mCRC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3482.

Telotristat ethyl with PRRT in the treatment of well differentiated neuroendocrine tumors

e16205

Background: Feasibility of telotristat ethyl, a tryptophan hydroxylase inhibitor in serotonin synthesis, in combination with PRRT/lutetium Lu 177 DOTATATE is unclear in well differentiated neuroendocrine tumors (WDNET). We explore real world treatment patterns in patients receiving telotristat and PRRT. Methods: A retrospective study was conducted on 67 patients with a histopathologic diagnosis of WDNET, treated with telotristat and/or PRRT at the Winship Cancer Institute in Emory University from 2018 to 2022. OS and PFS were assessed by Kaplan Meier curves. Descriptive analysis was performed with associations characterized by multi- (MVA) and univariate (UVA) Cox proportional hazards model, t-test, and ANOVA. Results: Of the 67 patients, 44 received PRRT alone and 23 received PRRT with telotristat for carcinoid symptoms. Median age was 69 (range 18-80) with male 57% and white race 65%. 16 (26%), 41 (67%), 4 (7%) had grades 1 (Ki67 < 3%), 2 (3-20%), and 3 (> 20%) disease respectively. The plurality (n = 31, 46%) had primary small bowel (SB) NETs and 40 (65%) underwent primary NET resection. 2 had gastrinomas, 1 VIPoma, and 1 insulinoma. All had liver and 23 (40%) had bone metastases. Most patients received PRRT as 3rd line therapy. 59 (88%) in the entire cohort and 17 (74%) in the telotristat group received 4 doses of PRRT. 15 (17%) in the entire cohort had delayed/dose reduced PRRT. Telotristat was associated with improved diarrhea and decreased serotonin (all p < 0.003). 16 (70%) on telotristat reported improvement in diarrhea and flushing. 5 (17%) had grade 3/4 adverse events while receiving telotristat. Of those, 1 developed hypotension, 1 hypokalemia, 1 myelodysplastic syndrome, 1 febrile neutropenia, and 1 anemia and pursued hospice care after a cerebrovascular event. Median(m) OS, PFS, and follow up were 216, 33, 67 months (mo) for the entire cohort respectively. 6 (26%) died in the telotristat/PRRT group vs 17 (39%) PRRT only. 10 (43%) in the telotristat group progressed vs 18 (41%) in PRRT only. mPFS was 33 mo in telotristat/PRRT and not reached (NR) in PRRT only (p = 0.684). mOS was NR in the telotristat/PRRT group vs 216 mo in PRRT only (p = 0.717). In MVA, OS was associated with primary NET resection (HR 0.232), age > 60 (HR 7.88), SB primary NET (HR 0.097), and PRRT completion (HR 0.062, all p < 0.05). In MVA, PFS was associated with diarrhea (HR 3.7) and small bowel primary NET (HR 0.264, all p < 0.05). In UVA, lower OS and PFS were associated with elevated chromogranin A (CGA) (upper limit 225, HR 3.34, p < 0.02). Initial neutrophil-eosinophil ratio (NER) was associated with OS (HR 21.2) and PFS (HR 10.8) in MVA with optimal cutoff of 35.28 ( both p < 0.02). Conclusions: Patients with primary SB WDNETs and carcinoid symptoms benefited from receiving telotristat/PRRT in our study. CGA, serotonin, and NER are potential biomarkers to assess disease patterns. Multi-institutional studies and further follow up are needed to confirm these findings.

Impact of metformin on clinical outcomes in advanced hepatocellular carcinoma treated with immune checkpoint inhibitors

4118

Background: Non-alcoholic steatohepatitis (NASH) is an emerging etiology for hepatocellular carcinoma (HCC) and contributes to the increasing incidence of HCC worldwide. Patients with NASH often have risk factors of metabolic syndrome including hypertension, obesity, and type 2 diabetes (T2DM). NASH induced HCC has been shown to be associated with less response to immune check point inhibitors (ICIs) in HCC. Anti-diabetic agent metformin has been shown to be associated with improved outcomes in patients treated with ICIs in melanoma and non-small cell lung cancer. However, the impact of metformin on the efficacy of ICIs is not well defined in HCC. The main purpose of this study was to examine the effect of metformin on clinical outcomes in patients with advanced HCC treated with ICIs. Methods: We performed a retrospective analysis of patients with advanced HCC treated with ICIs in first and later-line settings between 2015 and 2021. The primary endpoints were overall survival (OS), progression free survival (PFS), and objective response rate (ORR) as assessed according to Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Patients were stratified based on their usage of metformin. OS and PFS were analyzed using Cox proportional hazard models and Kaplan-Meier analysis with log-rank test. Results: A total of 111 patients met inclusion criteria, 18 patients in the metformin group and 93 patients in the non-metformin group. Most common cause of HCC was viral hepatitis (52%), followed by NASH (29%), alcohol (8%) and other (11%). Baseline characteristics between the two groups were similar except all patients in the metformin group had a diagnosis of T2DM. ORR was 5.6%. (1 partial response) in the metformin group vs 22.6% (5 complete responses, 16 partial responses) in the non-metformin group. Median OS was 45.9 months in the non-metformin group vs 10.8 months in metformin group (HR 1.99, 95% CI 0.95-4.21, p = 0.064). Median PFS of 6.6 months vs 2.5 months (HR 1.75, 95% CI 0.93-3.29, p = 0.077). Moreover, metformin usage was associated with shorter median OS of 10.8 months (HR 1.96, 95% CI 0.75-5.09, p = 0.16) vs 20.9 months among patients with T2DM. OS was significantly worse in patients with poor ECOG performance status 2-3, MELD score 10-23, higher grade tumor histology, AFP > = 400, and use of IO in later lines of therapy. Conclusions: In this retrospective study metformin use was associated with worse clinical outcomes in advanced HCC patients treated with ICIs.

Exploring determinants of antimicrobial prescribing behaviour: a qualitative study using the Theoretical Domains Framework

Introduction

Few qualitative studies have explored determinants of antimicrobial prescribing behaviour in hospitals, and none has made reference to behavioural theories. An understanding of these determinants is required for the successful development and implementation of behaviour change interventions (BCIs) in this area.

Aim

To explore the determinants of clinicians’ antimicrobial prescribing behaviour, using the Theoretical Domains Framework (TDF; a framework of behavioural theories).

Methods

This work was part of a multi-phase explanatory, sequential mixed methods PhD programme of research. This qualitative part involved semi-structured, online (video) interviews via a videoconferencing software programme (Zoom) with clinicians (doctors and pharmacists) based in 12 Hamad Medical Corporation hospitals in Qatar. Clinicians were sampled purposively in strata of gender, profession, years of experience and area of practice. The interview schedule was developed based on a review of published literature (1), previous findings of quantitative research (2) and the TDF to ensure comprehensive coverage of key determinants (including barriers and facilitators) related to clinicians’ antimicrobial prescribing behaviour. Interviews were conducted from December 2020 to February 2021, audio-recorded, transcribed and independently analysed by two research team members using the TDF as an initial coding framework.

Results

Data saturation was achieved after interviewing eight doctors and eight pharmacists from a range of areas of practices and with a variety of experiences. A number of themes, linked to ten TDF domains, were identified as determinants of antimicrobial prescribing behaviour and these determinants were interrelated. In-depth analysis identified several barriers and facilitators that may contribute to inappropriate or appropriate antimicrobial prescribing. Main barriers identified were around hospital guidelines and electronic system deficiencies (environmental context and resources), gaps in the knowledge in relation to guidelines and appropriate prescribing (knowledge), restricted roles/responsibilities of microbiologists and pharmacists (professional role and identity), uncomfortable antimicrobial prescribing decisions (memory, attention and decision processes), as well as professional hierarchies and poor multidisciplinary teamworking/relationships (social influences). “Sometimes, the barrier would be the ego of senior doctors who refuse our evidence-based recommendation and depend on their clinical judgement or experience” (Pharmacist 470, Cardiology). Key facilitators highlighted included guidelines compliance goals and intentions, and the beliefs of consequences of appropriate or inappropriate prescribing. Further education and training sessions, and some changes to guidelines, including accessibility were also considered essential. “We need to seriously consider getting an antibiotic guidelines app which is downloaded to clinicians’ mobile phones. The mobile app is handy, you can access it anytime even at the patient’s bedside” (Doctor 514, Microbiology).

Conclusion

This qualitative study, using a theoretically based approach, has identified that antimicrobial prescribing in hospitals is a complex process influenced by a broad range of behavioural determinants that described specific barriers and facilitators. The in-depth understanding of this complexity provided by this phase of the research may contribute to the design and development of theoretically based BCIs to improve clinicians’ antimicrobial prescribing. Limitations include data collected with online interviews due to the Covid-19 restrictions. This may have excluded some clinicians who did not feel comfortable with or have access to the technology required.

References

(1) Talkhan H, Stewart D, Mcintosh T, Ziglam H, Abdulrouf P, Al-Hail M et al. The use of theory in the development and evaluation of behaviour change interventions to improve antimicrobial prescribing: a systematic review. Journal of Antimicrobial Chemotherapy. 2020;75(9):2394-2410.

(2) Talkhan H, Stewart D, McIntosh T, Ziglam H, Abdulrouf P, Al-Hail M et al. Using the Theoretical Domains Framework to investigate clinicians’ behavioural determinants of antimicrobial prescribing in Qatar. International Journal of Pharmacy Practice. 2021;29(1):i20-i22.

Characteristics and outcomes of patients with multiple synchronous colon cancer primaries

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Background: Patients (pts) with multiple synchronous colon cancer primaries (MCPs) constitute a unique subset of pts with colon cancer. However, there are limited published studies about these pts. The objective of this study is to compare the characteristics and outcomes of pts with MCPs to those with single colon cancer primaries (SCPs) using the largest study population to date. Methods: Data was obtained from the Surveillance, Epidemiology, and End Results (SEER) database between 2004 and 2015. Pts with synchronous MCPs were included and were matched 1:3 with pts with SCPs based on the Coarsened Exact Matching method for age, gender, and race. Only patients with multiple synchronous primaries were included (time since index = 0 months). We excluded pts with a lag time since diagnosis of index primary of 1 month or more. Univariate (UNA) and multivariable (MVA) analyses were performed to identify factors associated with patient outcomes. Kaplan-Meier analyses and Cox proportional hazards models were used to assess the association between tumor/patient characteristics and overall survival (OS). Results: A total of 3322 pts with MCPs and 9966 pts with SCPs were identified. Median age was 71 years. Majority were male (51.5%) and White (80.1%). 73.4% and 69.6% of pts had 12 or more lymph nodes examined for the MCPs and SCPs cohorts, respectively. The SCPs cohort included more T4 stage and more well- and moderately-differentiated histology. OS was significantly shorter in MCPs compared to SCPs (HR 1.29; 1.22-1.36; p < 0.001), with a 5- and 10-year OS rate of 47.8% and 28.2% for the MCPs and 56.4% and 41.6% for the SCPs, respectively, for all stages combined. In the MCPs cohort, the use of adjuvant chemotherapy was associated with an improved survival in AJCC stages II, III, and IV but not stage I. Conclusions: This is the largest study evaluating the impact of MCPs on outcomes. Across stages II to IV, pts with MCPs have a shorter survival than those with SCPs. Pts with stage II MCPs who receive adjuvant chemotherapy derive a survival benefit. Current guidelines do not list multiple synchronous primaries as a high-risk feature for stage II.

Impact of local therapy on survival among patients with metastatic anal squamous cell carcinoma

4

Background: About 10-20% of patients with anal squamous cell carcinoma (SCCa) present with metastatic disease, and are usually treated with systemic chemotherapy. The role of local therapy to control the primary tumor is controversial in this setting. We evaluated survival impact of local therapy in metastatic anal SCCa. Methods: Data were obtained from all US hospitals that contributed to the National Cancer Database (NCDB) between 2004 and 2015. We excluded patients who did not receive palliative systemic chemotherapy. Univariate (UVA) and multivariable analyses (MVA) were performed to identify factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used to assess the association between tumor/patient characteristics and overall survival (OS). Results: 1,160 patients were identified over 12 years. Median age was 57 years. Majority were female (64.9%), non-Hispanic Whites (79.1%) and had Charlson-Deyo Score of 0 (83.6%). Most common metastatic sites were liver (25.9%), lung (11.6%) and bone (8.5%). More than 79% of the patients received radiation to the primary site, and 10.4% underwent surgical resection for local control. Use of local therapy correlated closely with a significant improvement in OS on MVA (HR 0.66; 0.55-0.79; p < 0.001), with a 12-month and 5-year OS rates of 72.8% and 25.7% respectively, compared with 61.1% and 14.6% for patients treated with chemotherapy only. Poor prognostic factors included male gender (HR 1.44; 1.24-1.67; p < 0.001), age > 70 years (HR 1.28; 1.02-1.62; p = 0.034), lack of health insurance (HR 1.32; 1.02-1.71; p = 0.034), and cloacogenic zone location (HR 4.02; 1.43-11.30; p = 0.008). There was no benefit from abdominoperineal resection (mOS = 19.7mos; HR 1.05; 0.48-2.29; p = 0.909), but both local resection of the primary (mOS = 24.8mos, HR 0.48; 0.29-0.80; p = 0.005) and palliative radiation (mOS = 22.6 mos; HR 0.66; 0.55-0.79; p < 0.001) were associated with improved OS. Conclusions: This is the largest reported study on management of de novo stage IV SCCa. The data suggest that local control of the primary tumor through resection or radiation improved OS in patients with anal SCCa. Patients unlikely to benefit from local therapy include age over 70 years, male, lack of health insurance and cloacogenic carcinoma.

Phase Ib/II trial of siltuximab and spartalizumab in patients in metastatic pancreatic cancer

TPS626

Background: Interleukin-6 (IL-6) is associated with carcinogenesis, immune suppression, and poor prognosis in pancreatic adenocarcinoma (PDAC). Preclinical data demonstrated dual inhibition of IL-6 and (programmed death ligand-1) PD-L1 facilitates CD8+ T cell migration into pancreatic tumors and was effective in controlling tumor growth in syngeneic and genetically engineered PDAC mouse models. Siltuximab is a chimeric monoclonal antibody which targets the IL-6 molecule specifically and spartalizumab is a high-affinity ligand-blocking humanized IgG4 antibody against the PD-1 receptor. Based on this preclinical rationale, we developed a phase Ib/II trial to determine the recommended phase II dose (RP2D), evaluate the safety, toxicity profile, preliminary antitumor activity, and immunogenicity of the siltuximab and spartalizumab in patients with previously treated metastatic PDAC. Methods: The phase Ib trial design is standard 3+3. Primary endpoint is to determine RP2D. Siltuximab is administered intravenously (IV) in three dose levels of 6 mg/kg (DL1), 11 mg/kg (DL2), 9 mg/kg (only if 2 DLTs observed on DL2) every 3 weeks with spartalizumab at 300 mg IV every 3 weeks. Eligible patients must have stage IV PDAC who have failed at least one prior therapy age ≥18 years, ECOG PS 0-1, no prior anti PD-1 or anti-PD-L1 agent. After RP2D is established, an expansion phase will enroll 24 patients with PDAC. Pre and on-treatment biopsy will be performed in 24 patients in the expansion cohort for correlative analysis. Pre-treatment and on-treatment peripheral blood samples will be collected from all patients. In the expansion phase patients will receive initial cycle (every 3 weeks) treatment with either spartalizumab or spartalizumab plus siltuximab and then starting cycle 2 all patients receive the combination following the on-treatment research biopsy. This design will enable us to evaluate the immunological effects of spartalizumab alone versus the combination in the tumor microenvironment and peripheral blood. This study was activated in January 2020 and to date 12 patients were enrolled in dose escalation phase. The dose expansion phase has recently started accrual. Clinical trial information: NCT04191421.

OUP accepted manuscript

Background

The survival impact of multi-agent (MAC) compared with single-agent (SAC) adjuvant chemotherapy (AC) in elderly patients with stage III colon cancer (CC) remains controversial. The aim of this study was to compare survival outcomes of MAC and SAC in this population utilizing the National Cancer Database (NCDB).

Patients and Methods

Patients aged ≥70 years with pathological stage III CC diagnosed in 2004-2015 were identified in the NCDB. Univariate and multivariable analyses were conducted, and Kaplan-Meier analysis and Cox proportional hazard models were used to identify associations between MAC vs. SAC and overall survival (OS).

Results

Among 41 707 elderly patients (≥70 years old) with stage III CC, about half (n = 20 257; 48.5%) received AC; the majority (n = 12 923, 63.8%) received MAC. The median age was 79 (range 70-90). The majority were female (n = 11 201, 55.3%), Caucasians (88%) and had moderately differentiated tumor grade (n = 12 619, 62.3%), tumor size >4 cm (11 785, 58.2%), and negative surgical margins (18 496, 91.3%). Low-risk stage III CC constituted 50.6% (n = 10 264) of the study population. High-risk stage III CC was associated with worse OS compared with low-risk disease (HR 0.35, 0.34-0.36, P < .001). Multi-agent chemotherapy was associated with a better 5-year OS compared with SAC (P < .001). High-risk stage III patients who received MAC vs. SAC had an OS of 4.2 vs. 3.4 years, respectively (P < .001). Low-risk stage III patients who received MAC vs. SAC had a median OS of 8.5 vs. 7 years (P < .001). In univariate and multivariable analyses, male sex, positive surgical margin, insurance and facility types, age, year of diagnosis, tumor size, and Charlson-Deyo score of >2 were associated with worse OS (P < .05).

Conclusions

Any adjuvant chemotherapy has a trend of survival benefits. Multi-agent chemotherapy seems to have an enhanced benefit in the 70-75 age group. Multi-agent chemotherapy seemed to have similar efficacy as SAC in those aged >76 years.

Predictive and Prognostic Effects of Primary Tumor Size on Colorectal Cancer Survival

Background

Pathologic staging is crucial in colorectal cancer (CRC). Unlike the majority of solid tumors, the current staging model does not use tumor size as a criterion. We evaluated the predictive and prognostic impact of primary tumor size on all stages of CRC.

Methods

Using the National Cancer Database (NCDB), we conducted an analysis of CRC patients diagnosed between 2010 and 2015 who underwent resection of their primary cancer. Univariate and multivariate analyses were used to identify predictive and prognostic factors, Kaplan-Meier analysis and Cox proportional hazards models for association between tumor size and survival.

Results

About 61,000 patients met the inclusion criteria. Median age was 63 years and majority of the tumors were colon primary (82.7%). AJCC stage distribution was: I - 20.1%; II - 32.1%; III - 34.7% and IV - 13.1%. The prognostic impact of tumor size was strongly associated with survival in stage III disease. Compared to patients with tumors <2cm; those with 2-5cm (HR 1.33; 1.19-1.49; p<0.001), 5-10cm (HR 1.51 (1.34-1.70; p<0.001) and >10cm (HR 1.95 (1.65-2.31; p<0.001) had worse survival independent of other variables. Stage II treated without adjuvant chemotherapy had comparable survival outcomes (HR 1.09; 0.97-1.523; p=0.148) with stage III patients who did, while Stage II patients who received adjuvant chemotherapy did much better than both groups (HR 0.76; 0.67-0.86; p<0.001). Stage III patients who did not receive adjuvant chemotherapy had the worst outcomes among the non-metastatic disease subgroups (HR 2.66; 2.48-2.86; p<0.001). Larger tumors were associated with advanced stage, MSI high, non-rectal primary and positive resection margins.

Conclusions

Further studies are needed to clarify the role of tumor size in prognostic staging models, and how to incorporate it into therapy decisions.

High-Risk Features Are Prognostic in dMMR/MSI-H Stage II Colon Cancer

BACKGROUND

High-risk features, such as T4 disease, bowel obstruction, poorly/undifferentiated histology, lymphovascular, perineural invasion, and <12 lymph nodes sampled, indicate poor prognosis and define high-risk stage II disease in proficient mismatch repair stage II colon cancer (CC). The prognostic role of high-risk features in dMMR/MSI-H stage II CC is unknown. Similarly, the role of adjuvant therapy in high-risk stage II CC with dMMR/MSI-H (≥1 high-risk feature) has not been studied in prospective trials. The aim of this analysis of the National Cancer Database is to evaluate the prognostic value of high-risk features in stage II dMMR/MSI-H CC.

METHODS

Univariate (UVA) and multivariate (MVA) Cox proportional hazards (Cox-PH) models were built to assess the association between clinical and demographic characteristics and overall survival. Kaplan-Meier survival curves were generated with log-rank tests to evaluate the association between adjuvant chemotherapy in high-risk and low-risk cohorts separately.

RESULTS

A total of 2,293 stage II CC patients have dMMR/MSI-H; of those, 29.5% (n = 676) had high-risk features. The high-risk dMMR/MSI-H patients had worse overall survival [5-year survival and 95%CI, 73.2% (67.3-78.1%) vs. 80.3% (76.7-83.5%), p = 0.0001]. In patients with stage II dMMR/MSI-H CC, the high-risk features were associated with shorter overall survival (OS) along with male sex, positive carcinoembryonic antigen, Charlson-Deyo score >1, and older age. Adjuvant chemotherapy administration was associated with better OS, regardless of the high-risk features in dMMR/MSI-H (log-rank test, p = 0.001) or not (p = 0.0006). When stratified by age, the benefit of chemotherapy was evident only in patients age ≥65 with high-risk features.

CONCLUSION

High-risk features are prognostic in the setting of dMMR/MSI-H stage II CC. Adjuvant chemotherapy may improve survival specifically in patients ≥65 years and with high-risk features.

The impact of establishing a regional infective endocarditis (IE) network on pre-operative IE-related complications and on post-operative outcome

Background

Infective endocarditis (IE) requires a high degree of suspicion and advanced level of multidisciplinary management. In 2015, the European guidelines recommended the formation of an endocarditis-team (ET) for optimal treatment of IE. In 2011, we already established an ET within the hospital that was only consulted on demand for certain patients. Since 2015, ET has been increasingly involved in the management of almost all patients with IE. In addition, we established in 2015 a statewide endocarditis- (E) network for the referring hospitals.

Purpose

We investigated the effect of E-network on reducing referral latency and pre-operative IE-related complications. We also investigated the adherence to the ET management recommendations in our hospital and its impact on post-operative stroke and mortality.

Methods

We retrospectively analyzed data from patients operated for IE in our center between 01/2007 and 03/2018. We conducted univariate analysis using Chi-square or Fisher's exact test, Multivariate logistic regression models for in-hospital mortality and post-operative stroke, and Kaplan-Meier estimate of 5-years survival.

Results

Among 630 patients operated for IE in our center, 409 (65%) underwent surgery in the 1st era before 12/2014. S. aureus IE was more frequent in the second era (34% vs 25%, p&lt;0.001). The median time from the onset of symptoms to referral in the 2nd era was halved compared to the first one [7 days (IQR 2–19) vs 15 days (IQR 6–35)]. Patients in the 2nd era were admitted with less IE-related complications, i.e. less preoperative stroke (14% vs 27%, p&lt;0.001), less heart failure (45% vs 69%, p&lt;0.001) less cardiac abscesses (24% vs 34%, p=0.018), less acute renal insufficiency requiring hemodialysis (8% vs 14%, p=0.026). The lack of ET management recommendations was an independent predictor for in-hospital mortality (adjusted OR: 2.13, 95% CI: 1.27–3.53, p=0.004) and post-operative stroke (adjusted OR: 2.23, 95% CI: 1.12–4.39, p=0.02), and was associated with worse 5-years survival (59% compared to 40%, log rank&lt;0.001).

Conclusion

Endocarditis-network led to earlier referral of patients, which resulted in less IE-related complications on admission. Lack of ET management recommendations was an independent predictor for post-operative stroke, in-hospital mortality and was associated with worse 5-years survival.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Increased neutrophil infiltration and lower prevalence of tumor mutation burden and microsatellite instability are hallmarks of RAS mutant colorectal cancers

3563

Background: The tumor microenvironment (TME) of colorectal cancers (CRC) is modulated by oncogenic drivers such as KRAS. The TME comprises a broad landscape of immune infiltration. How tumor genomics associates with the immune cell landscape is less known. We aim to characterize immune cell types in RAS wild-type (WT) and mutant (MT) CRC, and to examine the prevalence of immuno-oncologic (IO) biomarkers (e.g. tumor mutation burden (TMB), PD-L1, MSI-H/dMMR) in these tumors. We performed genomic and transcriptomic analysis to confirm associations of mutant RAS with immune infiltration of the TME conducive to metastasis vs. potential response to immunotherapies. Methods: A total of 7,801 CRC were analyzed using next-generation sequencing on DNA (NextSeq, 592 Genes and WES, NovaSEQ), RNA (NovaSeq, whole transcriptome equencing) and IHC (Caris Life Sciences, Phoenix, AZ). MSI/MMR was tested by FA, IHC and NGS. TMB-H was based on a cut-off of > 10 mutations per MB). Immune cell fraction was calculated by QuantiSeq (Finotello 2019, Genome Medicine). Significance was determined by X2 and Fisher-Exact and p adjusted for multiple comparisons (q) was <0.05. Results: Mutant KRAS was seen in 48% of mCRC tumors; NRAS in 3.7%, HRAS in 0.1%. The distribution was similar in patients < or >= than 50 yrs. In MSS tumors, there was a significantly higher neutrophil infiltration in KRAS MT (median cell fraction 6.6% vs. 5.9%) and NRAS MT (6.9%) overall and also when individual codons were studied. B cells, M2 macrophages, CD8+ T cells, dendritic cells and fibroblasts were lower in KRAS mutant tumors; B cells and M1 macrophages are lower in NRAS (q<0.05). dMMR/MSI-H was significantly more prevalent in RAS WT (9.1%) than in KRAS (2.9%) or NRAS MT (1.8%) tumors, and highest in HRAS MT tumors (60%, q<0.05).TMB-H was more prevalent in RAS WT (11%) than KRAS (5.8%) or NRAS (5.1%) MT, and highest in HRAS MT tumors (70%, all q<0.05). In MSS tumors, KRAS MT tumors showed more TMB-H than WT (3.1% vs. 2.1%, q<0.05), especially in KRAS non 12/13/61 mutations (5.5%, vs. 2.1%, q<0.05) and G12C (4.4%, p<0.05). PD-L1 expression was studied: in MSS tumors, KRAS-G12D (10.4%) and G13 MT (11.8%) showed higher mutation rates than RAS WT tumors (q<0.05). Conclusions: KRAS & NRAS mutations are associated with increased neutrophil abundance, with codon specific differences, while HRAS shows no difference. Overall CD8+ T cells and B cells are less abundant in KRAS & NRAS mutants; substantial variability was seen amongst different protein changes. RAS mutations were more prevalent overall than generally reported, but did not vary by age. These results demonstrate significant differences in the TME of RAS mutant CRC that identify variable susceptibilities to immuno-oncologic agents, and provide further detailed characterization of heterogeneity between RAS variants, at the molecular as well as immunogenic levels.

Clinical features and outcomes of colloid carcinoma of pancreas compared to pancreatic ductal adenocarcinoma

e16259

Background: Colloid carcinoma (CC) of the pancreas is a rare histopathological subtype of ductal adenocarcinoma (PDAC), with poorly defined prognostic factors and therapeutic outcomes. The aim of this study is to characterize the clinicopathological features and evaluate the overall survival (OS) and prognostic factors of patients with pancreatic CC using National Cancer Database (NCDB). Methods: Patients diagnosed with CC of the pancreas and PDAC between 2004 and 2016 were identified from the NCDB using ICD-O-3 morphology (8480/3 for CC and 8140/3 for PDAC) and topography codes (C25). Univariate and multivariable analyses were conducted and Kaplan-Meier analysis and Cox proportional hazards models were used to perform OS analysis. Results: A total of 56,846 patients met the inclusion criteria for the final analysis. Of the total population included, 2,430 patients (4.3%) had CC and 54,416 patients (95.7%) had PDAC. For both, CC and PDAC, there was a male preponderance (52.0%, 52.5%), Caucasians (85.1%, 84%), occurrence above the age of 70 (39.2%, 38.2%), and the most common primary site was the head of the pancreas (50.5%, 53%). For CC, the percentage of pathologic stage III colloid pancreas cancer appeared the lowest (3.5%, 85 patients), compared to stage I (16.7%), stage II (37.8%), and stage IV (42.1%). While in PDAC, the percentage of pathologic stage I (5.94%) and stage III (4.44%) patients was lower than stage II (37.21%) and IV (52.41%). CC and PDAC more frequently presented with < 5cm tumor, at academic or research cancer centers, and diagnosed between 2009 and 2013 compared to 2004–2008 ( p< 0.001). For both CC and PDAC, the majority underwent surgical resection (58%, 53%), systemic chemotherapy (57.8%, 63%) and did not receive radiotherapy (78.8%, 77.6%). A positive surgical margin on pathologic evaluation was associated with worse outcomes for CC and PDAC in both univariate and multivariate analysis (HR 1.61; 1.56–1.66; p< 0.001 and HR 1.43; 1.38–1.48, p< 0.001). CC had a better 1-year overall survival (OS) in all stages compared to PDAC (p < 0.001). In multivariate analysis, mucinous carcinoma histology, female sex, diagnosis between 2004 and 2009, well/moderately differentiated histology, chemotherapy, age at diagnosis less than 60, radiation therapy after surgery, and local surgical procedure of primary site and pancreatectomy (p < 0.001) were associated with better OS compared to PDAC. Colloid histology was associated with better 1-year overall survival (OS) in all stages compared to PDAC (p < 0.001). Conclusions: Colloid carcinoma of pancreas is associated with a better overall survival as compared to pancreatic ductal adenocarcinoma. This is the largest study to address the clinical features and outcomes of colloid carcinoma of pancreas.

Treatment outcomes for stage T1b-2 esophagogastric adenocarcinomas

e16085

Background: Treatment of localized esophageal, gastroesophageal junction (GEJ), and stomach cancer is neoadjuvant therapy with either chemoradiation or chemotherapy followed by surgery. Treatment for T1b-2 stage disease is not well evaluated and this stage is underrepresented in prospective studies. The aim of this study is to evaluate survival outcomes among the three treatment modalities (neoadjuvant chemotherapy (NACT), neoadjuvant chemoradiation (NACRT), and upfront surgery (US)) in this population using the National Cancer Database (NCDB). Methods: Patients (pts) with clinical stage T1b-2N0 and any pathological stage (excluding metastatic) adenocarcinoma of the esophagus, GEJ, and stomach treated with neoadjuvant therapy or upfront surgery, with or without adjuvant chemotherapy (AC), were identified between 2004 and 2015 in the NCDB. Univariate and multivariable analyses were conducted, and Kaplan-Meier analysis and Cox proportional hazard models were used to identify the association between the three treatment modalities and overall survival (OS). Results: A total of 2260 pts were analyzed. The median follow-up was 66.6 months. The median age was 67 years. Most pts were White (86%) and male (77%). 1018 (45%) had moderately-differentiated grade, while 946 (42%) had poorly-differentiated/undifferentiated grade. The most common site of disease was the lower third of esophagus (34.1%). 161 pts (7%) received NACT, of whom 45 pts received AC; 537 pts (24%) received NACRT, of whom 40 pts received AC. 1562 pts (69%) underwent US, of whom 146 pts received AC. US with AC was associated with the best survival, followed by NACT with AC; median OS was 90.1 and 86.8 months for surgery with AC and NACT with AC, respectively. NACRT was associated with the worst survival (39.5 and 40.2 months with and without AC, respectively). The 5-year OS rates were 59.8%, 58.5%, 52.1%, 44.9%, 37.3%, and 37.8%, for US, NACT, and NACRT, with and without AC, respectively. The rate of tumor upstaging was highest in the NACT group, followed by the NACRT group, and lowest in the US group. Postsurgically, 62 (39%) and 48 (30%) pts in the NACT group and 198 (37%) and 161 (30%) pts in the NACRT group had upstaging in their T and N stages, respectively, compared to 214 (13%) and 326 (21%) pts in the US group. For the 1107 pts who also had pathological T1b-2N0 stage disease following US, no difference in survival was observed with or without AC. Conclusions: Upfront surgery with adjuvant chemotherapy and perioperative chemotherapy are associated with the best survival compared to preoperative radiotherapy. This is the largest study to address the best approach for the treatment of T1b-2 stage disease.

Using the Theoretical Domains Framework to investigate clinicians’ behavioural determinants of antimicrobial prescribing in Qatar

Introduction

A recent systematic review by Talkhan et al demonstrated the need for theoretically based behaviour change interventions in this area. [1] For development of such complex interventions, emphasis should be placed on using theory to systematically identify behavioural determinants of antimicrobial prescribing.

Aim

To identify and quantify clinicians’ behavioural determinants of antimicrobial prescribing in Qatar.

Methods

This cross-sectional survey is part of a multi-phase explanatory, sequential mixed methods PhD project in Qatar. Questionnaires were distributed (online and paper based) to all doctors (~4,000) and pharmacists (~400) within Hamad Medical Corporation (HMC, the main healthcare provider). The questionnaire was developed with reference to the Determinants of Implementation Behaviour Questionnaire (a generic questionnaire derived from the 14 theoretical domains of the Theoretical Domains Framework, TDF). [2] Each item was presented as a 5-point Likert scale (scored 5=Strongly agree to 1=Strongly disagree). Personal and practice demographics were also collected for data contextualisation. The draft questionnaire was reviewed for face/content validity by an expert panel of six researchers in Qatar and the UK with experience in the use of the TDF, followed by ‘Think aloud’ testing and piloting. Analysis investigated the behavioural determinants and influential factors through descriptive, principal component analysis (PCA) and inferential analysis. Ethics approval was granted from a UK university and HMC.

Results

In total, 535 responses were received, 339 (63.4%) from doctors and 196 (36.6%) from pharmacists. Respondents were predominantly male, 346 (64.7%). Just over half (n=285, 53.3%) had ≤ 5 years’ experience as health professionals. PCA showed a three component (C) solution with components incorporating a number of questionnaire items labelled: ‘Guidelines compliance’ (C1 with 8 items), ‘Influences on prescribing’ (C2 with 7 items) and ‘Self-efficacy’ (C3 with 5 items) in prescribing/recommendation activity. A scale score for each respondent was calculated through summation of Likert scores for the relevant questionnaire items within each component. These scales had high internal reliability (Cronbach’s alpha all &gt;0.7) showing consistency in response between component items indicating statistical appropriateness for developing scales. The median score (possible scale range, midpoint) for each scale was C1, 32 (8 to 40, 24), C2, 26 (7 to 35, 21) and C3, 20, (5 to 25, 15). By way of example Table 1 shows levels of agreement for items in C2. This shows lower levels of agreement than C1 scale with the median scale score (26) closer to the midpoint (21) indicating that respondents had less positive views. Inferential analysis using these scale scores and free text analysis is in progress.

Conclusion

A theoretical basis was used throughout providing insights to behavioural determinants for the development of a theory-based behaviour change intervention. Preliminary results suggest that social influences, staff development and quality monitoring may be useful targets for behaviour change interventions to improve antimicrobial prescribing practice. Limitations include potential social desirability bias and focus on one healthcare organisation/country in the Middle East which may limit generalisability of findings. More in-depth exploration is required to select and test appropriate linked theory-based behaviour change techniques.

References

1. Talkhan H, Stewart D, McIntosh T, Ziglam H Palli Valapila, A; Moza Sulaiman H, Diab M, Cunningham S. The use of theory in the development and evalu​ation of behaviour change interventions to improve antimicrobial prescribing: a systematic review. J Antimicrob Chemother. 2020;75(9):2394–2410, Available from https://doi.org/10.1093/jac/dkaa154 [Accessed 12 Oct 2020].

2. Huijg JM, Gebhardt WA, Dusseldorp E, Verheijden MW, van der Zouwe N, Middelkoop BJ, Crone MR. Measuring determinants of implementation behaviour: psychometric properties of a questionnaire based on the Theoretical Domains Framework. Implement. Sci. 2014;9(1):33.

Survival outcomes of adjuvant chemotherapy in elderly patients with stage III colon cancer

89

Background: The survival impact of multi-agent (MAC) as compared to single-agent (SAC) adjuvant chemotherapy (AC) in elderly patients with stage III colon cancer (CC) remains controversial. The aim of this study is to evaluate the survival outcome comparing MAC to SAC in this population utilizing the National Cancer DataBase (NCDB). Methods: Patients 70 years and older with pathological stage III CC were identified between 2004 and 2015 from the NCDB using ICD-O-3 morphology and topography codes: 8140-47, 8210-11, 8220-21, 8260-63, 8480-81, 8490, and C18.0-18.8 (without C18.1). Univariate and multivariable analyses were conducted and Kaplan-Meier analysis and Cox proportional hazard models were used to identify the association between MAC vs. SAC and overall survival (OS). Results: A total of 41,707 elderly patients (≥70 years old) with stage III CC were identified. Around half of the patients (n = 20,257; 48.5%) received AC; the majority of whom (n = 12,923, 63.8%) received MAC. The median age was 79 (range 70-90). Of the patients who received AC, the majority were female (n = 11,201, 55.3 %), Caucasians (87.4%) and had a moderately differentiated tumor grade (n = 12,619, 62.3%). Tumor size more than 4 cm was identified in 11,785 (58.2%) patients and 18,496 (91.3%) had negative surgical margins. Low-risk stage III CC constituted 50.6% (n = 10,264) of the study population. High-risk stage III CC was associated with worse OS compared to low-risk disease (p < 0.001). MAC was associated with better 5-year OS compared to SAC (p < 0.001). High-risk stage III patients who received MAC had an OS of 4.2 v. 3.4 years in SAC (p < 0.001). In low risk stage III, patients who received MAC had median OS of 8.5 v. 7 years in SAC (p < 0.001). In Univariate, male sex, positive surgical margin, insurance and facility types, age, year of diagnosistumor size, and Charlson-Deyo Score of > 2 were associated with worse OS (p < 0.05). Conclusions: Multi-agent AC is associated with better survival in stage III CC patients 70 years and older compared to SAC. Enhanced benefit of MAC was shown for both low risk and high risk stage III CC.

Phase II trial of nivolumab and metformin in patients with treatment refractory microsatellite stable metastatic colorectal cancer

95

Background: Preclinical data suggests metformin can improve immune exhaustion of tumor infiltrating lymphocytes and potentiate the effects of PD-1 blockade. By normalizing the hypoxic TME, metformin was shown to improve cytotoxic T cell function and efficacy of anti-PD-1 antibody in highly aggressive B16 melanoma and MC38 colon adenocarcinoma tumor models. Based on this preclinical rationale we conducted a phase II study with nivolumab and metformin combination in treatment refractory MSS metastatic colorectal cancer (mCRC). Methods: Nivolumab 480 mg IV every 4 weeks and Metformin 1000 mg po twice daily was administered in 28-day cycles following a 14-day metformin only lead-in phase.Eligible patients included stage IV metastatic treatment refractory MSS mCRC (patients must have received oxaliplatin, irinotecan, and fluoropyrimidine), age ≥18 years, ECOG PS 0-1, adequate organ function, no prior anti PD-1 agent. The primary endpoint was overall response rate (ORR). Secondary endpoints included overall survival (OS) and progression free survival (PFS). Simon’s two-stage Minimax design was employed (H0: ORR =4%; H1: ORR=15%; alpha = 0.1; power =80%). If ≥1 objective response was observed in the first evaluable 18 patients, 10 additional patients would be included in the cohort. ≥3 objective responders in 28 patients would be required to be considered positive study. Pre-treatment and on-treatment research biopsies and correlative peripheral blood specimens were collected. Results: A total of 24 patients were enrolled, 6 patients were replaced per protocol, and 18 patients had evaluable disease. Of the 18 evaluable patients 11/18 (61%) were female, median age 58 [IQR 50-67]. 2 patients had prolonged stable disease (4 and 10 cycles). No patients had objective response based on RECIST 1.1. Median OS and PFS was 5.1 months [95% CI (2-11.7)] and 2.3 months [95% CI (1.7-2.4)], respectively. Most common grade 3 and 4 toxicities were anemia (n=2) and diarrhea (n=2). Conclusions: In treatment refractory MSS mCRCnivolumab and metformin combination was well tolerated. Two patients achieved stable disease, but no objective response was seen; therefore, the study did not proceed with the second stage of enrollment. Immunologic correlative analysis of this study is ongoing. Clinical trial information: NCT03800602.

Impact of primary tumor size/horizontal extent on survival in colorectal cancer

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Background: Pathologic staging in colorectal cancer (CRC) is crucial in patient management. Data regarding the impact of size/horizontal tumor extent is limited, contradictory and currently excluded from the American Joint Committee on Cancer (AJCC) staging model. However, a previously published SEER analysis showed that AJCC stages I and IIIA have similar 2- and 5- year survival rates, and worse rates for stage II. Using the largest cohort to date, we report the impact of primary tumor size on CRC survival. Methods: Data were obtained from all US hospitals that contributed to the National Cancer Database (NCDB) between 2010 and 2015. Univariate and multivariate analyses were performed to identify factors associated with patient outcome. Kaplan-Meier analysis and Cox proportional hazards models were used to assess the association between tumor/patient characteristics and overall survival (OS). Results: A total of 61,145 patients were identified with a similar gender distribution (M/F:50.9%/49.1%). The mean age was 62.7years (SD+/-14.1) and 82% were non-Hispanic Whites. Majority had colon primary (82.7%) and 82.4% had microsatellite stable (MSS) disease. Distribution across stages I-IV was 20.1%, 32.1%, 34.7% and 13.2% respectively. Among the total study population, AJCC stage correlated closely with OS on multivariate analysis (HR 1.49, 2.29, 8.38 for stages II to IV compared to stage I), while the distinguishing power for tumor size was relatively mild (HR 1.19 and 1.33 for 5-10 cm and >5cm compared to <5cm). Among patients with stage II disease, tumors >10cm were associated with worse survival compared to those <5cm (HR 1.2; 1.03-1.39; p=0.22). Stage III disease also had differential survival rates; patients with tumors 5-10cm (HR 1.21; 1.14-1.28; p<0.001) and >10cm (HR 1.57; 1.37-1.80; p<0.001) had worse survival than those <5cm. Patients with stage II who did not receive adjuvant chemotherapy (CTX) had worse survival outcomes (HR 1.29; 1.08-1.55; p=0.005) compared to stage III disease who did. Accounting for tumor size, there was no statistically significant survival differences between stage I patients and stages II and III patients who received adjuvant chemotherapy. Conclusions: Tumors larger than 10cm have inferior outcomes among patients in the same AJCC stages. Stage II patients without adjuvant CTX did worse than stage III with CTX. Further studies are needed to clarify the role of tumor size in staging models. [Table: see text]

Pancreatic adenocarcinoma: molecular drivers and the role of targeted therapy

Prognosis from pancreatic ductal adenocarcinoma (PDAC) continues to be poor despite the many efforts channeled to improve its management. Although the mainstay treatment is still traditional chemotherapy, recent advances highlighted a promising potential for targeted therapy in the management of this disease. Those advances emphasize the significance of timely genomic profiling of tumor tissue as well as germline testing of patients to identify potential markers of targeted therapy. While targeted therapy is reserved for a relatively small subset of patients with PDAC, ongoing research is uncovering additional markers, and targeted agents, that will hopefully translate to better outcomes for patients.

Gastric cancer: a comprehensive review of current and future treatment strategies

Gastric cancer remains a major unmet clinical problem with over 1 million new cases worldwide. It is the fourth most commonly occurring cancer in men and the seventh most commonly occurring cancer in women. A major fraction of gastric cancer has been linked to variety of pathogenic infections including but not limited to Helicobacter pylori (H. pylori) or Epstein Barr virus (EBV). Strategies are being pursued to prevent gastric cancer development such as H. pylori eradication, which has helped to prevent significant proportion of gastric cancer. Today, treatments have helped to manage this disease and the 5-year survival for stage IA and IB tumors treated with surgery are between 60 and 80%. However, patients with stage III tumors undergoing surgery have a dismal 5-year survival rate between 18 and 50% depending on the dataset. These figures indicate the need for more effective molecularly driven treatment strategies. This review discusses the molecular profile of gastric tumors, the success, and challenges with available therapeutic targets along with newer biomarkers and emerging targets.

Gastric Cancer Heterogeneity and Clinical Outcomes

Gastric adenocarcinoma is a highly aggressive disease with poor overall survival. The aggressive nature of this disease is in part due to the high intra and inter tumoral heterogeneity and also due to the late diagnosis at presentation. Once progression occurs, treatment is more difficult due to the adaptation of tumors, which acquires resistance to commonly used chemotherapeutics. In this report, using publicly available data sets and pathway analysis, we highlight the vast heterogeneity of gastric cancer by investigating genes found to be significantly perturbed. We found several upregulated genes in the diffuse gastric cancer subtypes share similarity to gastric cancer as a whole which can be explained by the increase in this subtype of gastric cancer throughout the world. We report significant downregulation of genes that are underrepresented within the literature, such as ADH7, GCNT2, and LIF1, while other genes have not been explored within gastric cancer to the best of our knowledge such as METTL7A, MAL, CWD43, and SLC2A12. We identified gender to be another heterogeneous component of this disease and suggested targeted treatment strategies specific to this heterogeneity. In this study, we provide an in-depth exploration of the molecular landscape of gastric cancer in order to shed light onto novel areas of gastric cancer research and explore potential new therapeutic targets.

Pharmacotherapeutic strategies for treating pancreatic cancer: advances and challenges

INTRODUCTION

Despite many efforts to improve the outcome of pancreatic ductal adenocarcinoma (PDAC), its prognosis remains poor, which is mostly related to late diagnosis and drug resistance. Improving systemic therapy is considered the major challenge in improving the outcome of this disease.

AREAS COVERED

This review covers novel chemotherapy and targeted agents in the treatment of PDAC, with a focus on advanced stage disease.

EXPERT OPINION

Current frontline therapies used in the treatment of patients with PDAC with favorable performance status are gemcitabine (GEM) and nab-paclitaxel or 5-fluorouracil, leucovorin, irinotecan, and oxaliplatin (FOLFIRINOX). PDAC has a number of genetic mutations that may explain its biological behavior, such as KRAS, p53 and CDK2NA, which occur in more than 90% of cases. Unfortunately, to this day, a specific targeting agent to any of those frequent gene mutations is lacking. Emerging areas of targeted therapies include the DNA repair, stroma, metabolism, and stem cells. Immunotherapy with either vaccines or immune checkpoint inhibitors has not produced any significant improvements in outcome of PDAC. Incorporating different approaches in therapy, including conventional, immunological, and others, is key in offering patients with the best possible care.

S. aureus endocarditis: Clinical aspects and experimental approaches

Infective endocarditis (IE) is a life-threatening disease, caused by septic vegetations and inflammatory foci on the surface of the endothelium and the valves. Due to its complex and often indecisive presentation the mortality rate is still about 30%. Most frequently bacterial microorganisms entering the bloodstream are the underlying origin of the intracardiac infection. While the disease was primarily restricted to younger patients suffering from rheumatic heart streptococci infections, new at risk categories for Staphylococcus (S.) aureus infections arose over the last years. Rising patient age, increasing drug resistance, intensive treatment conditions such as renal hemodialysis, immunosuppression and long term indwelling central venous catheters but also the application of modern cardiac device implants and valve prosthesis have led to emerging incidences of S. aureus IE in health care settings and community. The aetiologic change has impact on the pathophysiology of IE, the clinical presentation and the overall patient management. Despite intensive research on appropriate in vitro and in vivo models of IE and gained knowledge about the fundamental mechanisms in the formation of bacterial vegetations and extracardiac complications, improved understanding of relevant bacterial virulence factors and triggered host immune responses is required to help developing novel antipathogenic treatment strategies and pathogen specific diagnostic markers. In this review, we summarize and discuss the two main areas affected by the changing patient demographics and provide first, recent knowledge about the pathogenic strategies of S. aureus in the induction of IE, including available experimental models of IE used to study host-pathogen interactions and diagnostic and therapeutic targets. In a second focus we present diagnostic (imaging) regimens for patients with S. aureus IE according to current guidelines as well as treatment strategies and surgical recommendations.