A meta-analysis of efficacy and safety data from head-to-head first-line trials of epidermal growth factor receptor inhibitors versus bevacizumab in adult patients with RAS wild-type metastatic colorectal cancer by sidedness

The first-line treatment choice of EGFRIs plus doublet chemotherapy vs. bevacizumab plus doublet chemotherapy remains a topic of interest for patients with left-sided RAS WT mCRC. We conducted a systematic literature review and meta-analysis of clinical trial data published between 2015 and 2024. We evaluated the relative efficacy and safety of first-line EGFRIs plus doublet chemotherapy (FOLFIRI or FOLFOX) vs. bevacizumab plus doublet chemotherapy for patients with RAS WT left-sided mCRC, as well as in all- and right-sided tumors. We identified eight trials with 2624 patients. Five trials reported outcomes by tumor sidedness. In the left-sided population, overall survival (OS) (Hazard Ratio (HR) = 0.80, 95% Confidence Interval (CI): 0.71-0.90) and objective response rate (ORR) (Odds ratio [OR]=1.61, 95% CI: 1.30-1.99) favored EGFRI plus chemotherapy, while no statistically significant differences were observed for progression-free survival (PFS) (HR=0.93, 95% CI: 0.84-1.04) or resection rate (RR). Similar results were found in the all-sided population. In the right-sided population, PFS favored bevacizumab plus chemotherapy (HR=1.45, 95% CI: 1.19-1.78), while no statistically significant differences were observed for OS (HR=1.17, 95% CI: 0.95-1.44), ORR (OR=0.99, 95% CI: 0.69-1.41), and RR. Early tumor shrinkage in the all-sided population favored EGFRI plus chemotherapy (OR=1.72; 95% CI: 1.36-2.17); limited data precluded evaluation by sidedness. Safety was available in 6 trials for all-sided tumors and 1 trial for left-sided tumors, each demonstrating typical class-specific adverse events. This most comprehensive meta-analysis indicates a benefit for first-line EGFRI plus chemotherapy over bevacizumab plus chemotherapy in patients with left-sided RAS WT mCRC.

Systematic Literature Review of the Prevalence and Prognostic Value of Delta-Like Ligand 3 Protein Expression in Small Cell Lung Cancer

BACKGROUND

Delta-like ligand 3 (DLL3), a member of the Notch pathway, has been identified as a potential therapeutic target as it is highly expressed in small cell lung cancer (SCLC), a subtype accounting for 15% of lung cancer cases.

OBJECTIVE

A systematic literature review (SLR) was conducted to understand the prevalence and prognostic impact of DLL3 expression on survival of patients with SCLC and treatment response.

PATIENTS AND METHODS

Systematic literature searches were conducted across multiple databases to capture studies of any SCLC population that evaluated DLL3 expression. Specific outcomes of interest included prevalence of DLL3 expression, method of expression analysis, and impact on outcome, including treatment response and survival (overall, progression-free, disease-free) according to varying levels of DLL3 expression/positivity. Standard risk of bias tools were used to evaluate study quality.

RESULTS

Among the 30 included studies, the most common DLL3 testing method was immunohistochemistry (N = 26, 86.7%). For comparability, results focused on the 13 (22.3%) studies that used the Ventana DLL3 (SP347) immunohistochemistry assay. The prevalence of DLL3 positivity ranged from 80.0-93.5% for studies using a threshold of ≥ 1% of tumor cells (N = 4) and 58.3-91.1% for studies with a ≥ 25% threshold (N = 4). DLL3 expression was generally categorized as high using cutoffs of ≥ 50% (prevalence range: 45.8-79.5%; N = 6) or ≥ 75% (prevalence range: 47.3-75.6%; N = 5) of cells with positivity. Two studies used an H-score of ≥ 150 to define high DLL3 expression with prevalence ranging from 33.3-53.1%. No consistent associations were seen between DLL3 expression level and patient age, sex, smoking history, or disease stage. Two studies reported change in DLL3 expression category (high versus low) before and after chemotherapy. No statistically significant differences were reported between DLL3 expression groups and survival (overall, progression-free, or disease-free) or treatment response.

CONCLUSIONS

There is a high prevalence of DLL3 expression in SCLC. Further research and analytical methods may help to characterize different populations of patients with SCLC based on DLL3 expression. While no significant prognostic factor in the included studies was identified, additional cohort studies using standardized methodology, with longer follow-up, are needed to better characterize any potential differences in patient survival or response by DLL3 expression level in SCLC.

Medically-attended anxiety and depression is increased among newly diagnosed patients with cold agglutinin disease: Analysis of an integrated claim-clinical cohort in the United States

BACKGROUND

Cold agglutinin disease (CAD) is a rare, chronic form of autoimmune hemolytic anemia. Clinical manifestations can include classical complement pathway-mediated chronic hemolysis, anemia, and profound fatigue. Research has shown that patients with other anemias may develop anxiety and depression, but this has not been studied previously in patients with CAD.

METHODS

CAD patients were identified in the Optum Claims-Clinical dataset (between January 1, 2006-June 30, 2016) and matched to comparison patients without CAD by patient factors. Adjusted Cox regression models estimated time to anxiety and depression, defined by three different outcomes: medication use, hospitalization, and therapy related to anxiety and depression. Subset analyses were performed for primary CAD. Patients were followed until they had anxiety and depression, they left the Optum system, death, or the study period ended (June 30, 2016).

RESULTS

Patients with CAD (n = 384) were more likely to have medically attended anxiety and depression (adjusted hazard ratio [aHR]: 1.6; 95% confidence interval [CI]: 1.3-2.1), to be prescribed antidepressants or psychotherapy after their CAD diagnosis (aHR: 1.8; 95% CI: 1.2-2.9), or to be hospitalized for an anxiety and depression-related event along with medication or psychotherapy (aHR: 2.0; 95% CI: 1.4-2.9) relative to matched comparisons (n = 2789), during the follow-up period. Patients with primary CAD were at increased risk for medically attended anxiety and depression (aHR: 1.8; 95% CI: 1.4-2.4), with the highest risk for prescription medication or therapy (aHR: 2.7; 95% CI: 1.6-4.6).

CONCLUSIONS

Our study indicates that medically attended anxiety and depression manifest at a higher rate in CAD patients than in a matched non-CAD cohort. Study findings suggest that CAD patients may experience a greater burden on mental health that may negatively contribute to their overall quality of life. Further investigation on this topic is warranted.

Systematic literature review and meta-analysis on use of Thrombopoietic agents for chemotherapy-induced thrombocytopenia

Background

Currently, there are no approved options to prevent or treat chemotherapy-induced thrombocytopenia (CIT). We performed a systematic literature review and meta-analysis on use of thrombopoietic agents for CIT.

Patients and methods

We searched Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, PubMed, EMBASE, ClinicalTrials.gov, and health technology assessments from January 1995 to March 2021 for studies evaluating thrombopoietic agents for CIT, including recombinant human thrombopoietin (rhTPO), megakaryocyte growth and development factor (MGDF), romiplostim, and eltrombopag. Random effects meta-analyses were conducted for efficacy and safety endpoints.

Results

We screened 1503 titles/abstracts, assessed 138 articles, and abstracted data from 39 publications (14 recombinant human thrombopoietin, 7 megakaryocyte growth and development factor, 9 romiplostim, 8 eltrombopag, and 1 romiplostim/eltrombopag). Random effects meta-analyses of data from multiple studies comparing thrombopoietic agents versus control (comparator, placebo, or no treatment) showed that thrombopoietic agents did not significantly improve chemotherapy dose delays and/or reductions (21.1% vs 40.4%, P = 0.364), grade 3/4 thrombocytopenia (39.3% vs 34.8%; P = 0.789), platelet transfusions (16.7% vs 31.7%, P = 0.111), grade ≥ 2 bleeding (6.7% vs 16.5%; P = 0.250), or thrombosis (7.6% vs 12.5%; P = 0.131). However, among individual studies comparing thrombopoietic agents with placebo or no treatment, thrombopoietic agents positively improved outcomes in some studies, including significantly increasing mean peak platelet counts (186 x 10⁹/L with rhTPO vs 122 x 10⁹/L with no treatment; P < 0.05) in one study and significantly increasing platelet count at nadir (56 x 10⁹/L with rhTPO vs 28 x 10⁹/L with not treatment; P < 0.05) in another study. Safety findings included thrombosis (n = 23 studies) and bleeding (n = 11), with no evidence of increased thrombosis risk with thrombopoietic agents.

Conclusion

Our analyses generate the hypothesis that thrombopoietic agents may benefit patients with CIT. Further studies with well-characterized bleeding and platelet thresholds are warranted to explore the possible benefits of thrombopoietic agents for CIT.

The epidemiology of desmoid tumors in Denmark

INTRODUCTION/AIM

The epidemiology, demographic, clinical, treatment, and healthcare resource utilization (HRU) characteristics of desmoid tumor (DT) patients treated at two sarcoma centers in Denmark is described.

METHODS

Using Danish health registers, we studied DT patients treated at two sarcoma centers between 2009 and 2018. For each patient, ten persons from the general population were randomly matched on birth year, sex, and region of residence.

RESULTS

Of the 179 DT patients identified, 76% were female and the median patient age was 38 years at diagnosis (interquartile range: 31-50). An average annual incidence of DTs over the study period was 3.2 per 1000,000 individuals with the observed annual incidence of DTs ranging from 2.2 (2011) to 4.3 (2017) per 1000,000 individuals. No notable linear time trend in incidence was observed. Anatomical DT sites included extra-abdominal (49%), abdominal wall (40%), and intra-abdominal or retroperitoneal areas (8%). In total, 56% of patients were initially treated surgically. However, while 75% of patients diagnosed with DT between 2009 and 2014 were initially treated surgically, this was true for only 32% of patients diagnosed with DT between 2015 and 2018. A total of 56% of DT patients used chemotherapeutic agents, tyrosine kinase inhibitors, NSAIDs, opioids, antidepressants, or steroids at some point during the three years before their DT diagnoses. In contrast, 70% of surgically treated and 63% of non-surgically treated patients used one of these drugs in the subsequent three years, including NSAIDs (45% surgical vs. 33% non-surgical), opioids (39% surgical vs. 27% non-surgical), and steroids (22% surgical vs. 18% non-surgical). The average number of inpatient and outpatient visits, days of hospitalization, and additional surgical procedures were higher among DT patients than the comparison cohort.

CONCLUSION

DTs are rare but have a large impact on patients' health, HRU, and medication utilization.

Comparison of clinical presentations and burden of respiratory syncytial virus in infants across three distinct healthcare settings in Davidson County, Tennessee

Background:

The burden of respiratory syncytial virus (RSV)-associated acute respiratory illnesses among healthy infants (<1 year) in the inpatient setting is well established. The focus on RSV-associated illnesses in the outpatient (OP) and emergency department (ED) settings are however understudied. We sought to determine the spectrum of RSV illnesses in infants at three distinct healthcare settings.

Methods:

From 16 December 2019 through 30 April 2020, we performed an active, prospective RSV surveillance study among infants seeking medical attention from an inpatient (IP), ED, or OP clinic. Infants were eligible if they presented with fever and/or respiratory symptoms. Demographics, clinical characteristics, and illness histories were collected during parental/guardian interviews, followed by a medical chart review and illness follow-up surveys. Research nasal swabs were collected and tested for respiratory pathogens for all enrolled infants.

Results:

Of the 627 infants screened, 475 were confirmed eligible; 360 were enrolled and research tested. Within this final cohort, 101 (28%) were RSV-positive (IP = 37, ED = 18, and OP = 46). Of the RSV-positive infants, the median age was 4.5 months and 57% had ⩾2 healthcare encounters. The majority of RSV-positive infants were not born premature (88%) nor had underlying medical conditions (92%). RSV-positive infants, however, were more likely to have a lower respiratory tract infection than RSV-negative infants (76% vs 39%, p < 0.001). Hospitalized infants with RSV were younger, 65% required supplemental oxygen, were more likely to have lower respiratory tract symptoms, and more often had shortness of breath and rales/rhonchi than RSV-positive infants in the ED and OP setting.

Conclusion:

Infants with RSV illnesses seek healthcare for multiple encounters in various settings and have clinical difference across settings. Prevention measures, especially targeted toward healthy, young infants are needed to effectively reduce RSV-associated healthcare visits.

Complement-mediated hemolysis persists year round in patients with cold agglutinin disease

BACKGROUND

Cold agglutinin disease (CAD) is a rare autoimmune hemolytic anemia mediated by immunoglobulin M autoantibodies that bind to the "I" antigen on erythrocytes. IgM binding results in either agglutination at ≤37°C, activation of the classical complement pathway, or both. Patients with CAD can have transient agglutination-mediated circulatory symptoms triggered by exposure to cold conditions. Separately, patients with CAD can experience complement-mediated symptoms such as anemia, hemolysis, and fatigue, but the effect of the season on these complement-mediated manifestations of CAD and clinical outcomes is not well understood.

METHODS

Using data from the Optum® de-identified Electronic Health Record dataset, we compared hemoglobin, markers of hemolysis (bilirubin and lactate dehydrogenase [LDH]), and healthcare resource utilization (HRU) between seasons for 594 patients (62% female; 66% aged ≥65 years) with CAD (defined as having CAD-related terms in their clinical notes on ≥3 separate occasions between December 2008 and May 2016). Laboratory parameters and HRU were compared between seasons using multivariate regression models.

RESULTS

Estimated median hemoglobin (9.87 g/dL in summer and 9.86 g/dL in winter; P = 0.944) and bilirubin (1.04 mg/dL in summer and 1.09 mg/dL in winter; P = 0.257) were similar in winter versus summer. While LDH was statistically significantly higher in winter compared with summer (P < 0.001), the estimated median value was above normal for both seasons (309 U/L in summer and 367 U/L in winter). HRU measures and transfusion and thromboembolism rates were similar across seasons.

CONCLUSIONS

Patients with CAD had evidence of persistent chronic hemolysis, HRU, and thromboembolism risk year round.

PD-L1 expression, EGFR and KRAS mutations and survival among stage III unresected non-small cell lung cancer patients: a Danish cohort study

Programmed cell death receptor ligand-1 (PD-L1) expression, KRAS (KRASm) and EGFR (EGFRm) mutations may influence non-small cell lung cancer (NSCLC) prognosis. We aimed to evaluate PD-L1 expression, KRASm, and EGFRm and survival among stage III unresected NSCLC patients. Using Danish registries, we collected data on stage III unresected NSCLC patients diagnosed 2001–2012 and paraffin-embedded tumor tissue from pathology archives. We assessed PD-L1 expression in tumors and tumor-infiltrating immune cells (ICs) by immunohistochemistry (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\ge$$\end{document}≥ 1% threshold for PD-L1+). We genotyped KRAS and EGFR. Follow-up extended from 120 days post-diagnosis to death, emigration, or 31/12/2014. We computed median survival using Kaplan–Meier methods, and hazard ratios (HRs) using Cox regression associating the biomarkers with death, adjusting for confounders. Among 305 patients, 48% had adenocarcinoma; 38% squamous cell carcinoma. Forty-nine percent had PD-L1+ tumors—51% stage IIIA and 26% KRASm. Few (2%) patients had EGFRm. Median survival in months was 14.7 (95% CI = 11.8–17.9) and 13.4 (95% CI = 9.5–16.3) in PD-L1+ and PD-L1− tumors, respectively. KRASm was not associated with death (HR = 1.06, 95% CI = 0.74–1.51 versus wildtype). PD-L1+ tumors yielded a HR = 0.83 (95% CI = 0.63–1.10); PD-L1+ ICs a HR = 0.51 (95% CI = 0.39–0.68). Tumor expression of PD-L1 did not influence survival. PD-L1+ ICs may confer survival benefit in stage III unresected NSCLC patients.

1406. Comparison of Clinical Presentations and Burden of Respiratory Syncytial Virus in Infants Across Three Distinct Healthcare Settings

Background

Respiratory syncytial virus (RSV) accounts for the majority of lower respiratory tract illnesses in hospitalized infants. In the U.S., RSV hospitalizations are well characterized; yet, emergency department (ED) and outpatient (OP) visits are underrecognized. We evaluated the burden of RSV across three distinct healthcare settings during one respiratory season.

Methods

From 12/16/19-4/30/20, we conducted a prospective RSV surveillance study among Davidson County, TN infants under one year who presented to an inpatient (IP), ED, or one of four OP clinics with either fever or any upper respiratory (i.e., cough, earache, nasal congestion, rhinorrhea, sore throat) and/or lower respiratory [i.e., wheezing, crackles, rales, diminished breath sounds, shortness of breath (SOB)] symptoms. Demographic and illness history were collected during parental/guardian interviews, followed by medical chart abstraction. Nasal swabs were collected and tested for RSV using Luminex® NxTAG RPP. Due to the COVID-19 pandemic, on 3/16/20 enrollment at three of the four OP clinics ceased.

Results

A total of 627 infants were screened, of whom 473 (75%) were confirmed eligible, 364 (77%) enrolled, 361 (99%) were tested for RSV of which 101 (28%) were RSV+ (IP=37, ED=18, OP=46) (Figure 1). Compared to RSV-negative subjects, RSV+ subjects were younger (6.6 vs. 4.9 months, p< 0.001), 56% were male and 48% white. By setting, infants in the OP setting were older than those seen in the IP and ED [(p=0.002), Figure 2]. Compared to infants in the OP setting, hospitalized infants were more likely to present with SOB and rhonchi/rales, but less likely to have only upper respiratory symptoms (Figure 3) and be African American (p=0.046). Infants in the IP setting had a higher proportion of clinical RSV diagnostic testing (73%) compared to the ED (39%) and OP (28%) settings (p< 0.001).

Figure 1. Davidson County Infants with RSV by MMWR Week and Healthcare Setting (n=101)

Figure 2. Cumulative Enrollment of Davidson County Infants with RSV by Age in Months and Healthcare Setting (n=101)

Figure 3. Proportion of Davidson County Infants with RSV Showing each Clinical Symptom, by Healthcare Setting

Conclusion

Two-thirds of RSV+ infants sought care from either an OP or ED setting, with nearly all hospitalized infants presenting with both upper and lower respiratory symptoms. The underutilization of diagnostic testing in the OP settings may underestimate the true burden of RSV. Future studies are essential to document the true prevalence of RSV in order to assess the need and impact of new interventions (e.g., immunizations, antivirals).

Disclosures

Danielle A. Rankin, MPH, CIC, Sanofi Pasteur (Grant/Research Support, Research Grant or Support) Zaid Haddadin, MD, CDC (Grant/Research Support, Research Grant or Support)Quidel Corporation (Grant/Research Support, Research Grant or Support)sanofi pasteur (Grant/Research Support, Research Grant or Support) Jon Fryzek, PhD, MPH, EpidStrategies (Employee) Mina Suh, MPH, International Health, EpidStrategies (Employee) Donald S. Shepard, PhD, Sanofi Pasteur (Grant/Research Support) Natasha B. Halasa, MD, MPH, Genentech (Other Financial or Material Support, I receive an honorarium for lectures - it’s a education grant, supported by genetech)Karius (Consultant)Moderna (Consultant)Quidel (Grant/Research Support, Research Grant or Support)Sanofi (Grant/Research Support, Research Grant or Support)

1513. Medically Attended Respiratory Syncytial Virus Hospitalizations (RSVH) and All-Cause Bronchiolitis Hospitalizations (BH) Among Children Aged ≤ 24 Months at RSV Season Start With Higher-Risk Congenital Heart Disease (CHD) Before and After the 2014 American Academy of Pediatrics (AAP) Policy

Background

In 2014, the AAP stopped recommending palivizumab for use in children with hemodynamically significant CHD (hs-CHD) aged 12 to 24 months at the RSV season start. This analysis investigates the impact of the 2014 AAP policy on the contemporary burden of RSVH and BH in children with CHD for whom palivizumab immunoprophylaxis is no longer recommended.

Methods

All children with CHD aged ≤ 24 months at the start of the RSV season and hospitalized for RSV or BH during the 2010-2017 RSV seasons (November-March) were studied. RSVH and BH were defined by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10-CM codes. As there are no ICD codes for hs-CHD, we evaluated the effect of the guidance on higher-risk CHD as defined by ICD codes.¹ Frequency and characteristics of RSVH and BH and disease severity (including intensive care unit [ICU] admission and mechincal ventilation) for these children before and after the 2014 AAP guidance using the Children’s Hospital Association’s Pediatric Health Information System^® (PHIS) data set were described. SAS version 9.4 was used for statistical analysis of this data, with z-tests method used to determine statistical significance.

Results

RSVH significantly increased after 2014 for all higher-risk CHD children aged ≤ 24 months (3.4% [1992 RSVH CHD/59,217 RSVH] before the 2014 guidance and 4.0% [1798 RSVH CHD/45,470 RSVH] after; P< 0.0001) and for the subgroup of children aged 12 to 24 months at the start of the RSV season (0.5% before the guidance and 0.8% after; P< 0.0001). Disease severity as measured by ICU admissions in the 12 to 24 months subgroup also significantly increased after the 2014 guidance (0.2% before the guidance and 0.3% after; P< 0.0001). Mechanical ventilation usage was not statistically significantly increased after the 2014 guidance (P=0.188). A similar pattern of results was found for BH.

Conclusion

RSVH, BH, and associated disease severity significantly increased among higher-risk CHD children aged 12 to 24 months, within the PHIS health system, after the 3 RSV seasons following the 2014 AAP RSV immunoprophylaxis recommendations.

Disclosures

Jaime Fergie, MD, AstraZeneca (Speaker’s Bureau)Sobi, Inc. (Speaker’s Bureau) Tara Gonzales, MD, Sobi, Inc. (Employee) Mina Suh, MPH, International Health, EpidStrategies (Employee) Xiaohui Jiang, MS, EpidStrategies (Employee) Jon Fryzek, PhD, MPH, EpidStrategies (Employee) Adam Bloomfield, MD, FAAP, Sobi, Inc. (Employee)

1507. Clinical Characteristics of Common Respiratory Viruses Detected in Infants Across Different Clinical Settings

Background

Viral acute respiratory infections (ARI) continues to be a significant cause of healthcare visits in young children. We evaluated the clinical presentation and disease severity of common respiratory viruses associated with medically attended ARI in infants.

Methods

We conducted a prospective viral surveillance study in Davidson County, TN. Infants under one year with fever and/or respiratory symptoms were enrolled from the outpatient (OP), emergency department (ED), or inpatient (IP) settings from 12/16/2019 through 4/30/2020. Nasal swabs were collected and tested for common viral pathogens using Luminex® NxTAG Respiratory Pathogen Panel. Demographic and clinical characteristics were collected through parent/guardian interviews and medical chart abstractions.

Results

In total, 364 participants were enrolled, and 361 (99%) had nasal swabs collected and tested. Overall, mean age was 6±3.3 months, 50% were female, 45% White, and 27% Hispanic. Of the 295 (82%) virus-positive specimens; the three most common viruses were rhinovirus/enterovirus (RV/EV), respiratory syncytial virus (RSV), and influenza (flu) [124, 101, and 44, respectively]. Compared to virus-negative infants, virus-positive infants were more likely to have more severe ARI symptoms and to be admitted to the intensive care unit (Table 1). Compared to other virus-positive infants: RV/EV-positive infants were more likely to be White, attend daycare, but less likely to present with respiratory distress, or require oxygen or admission; flu-positive infants were older and more likely to have systemic symptoms rather than ARI symptoms, and RSV-positive infants were more likely to present with respiratory distress, receive oxygen and be hospitalized (Table 1).

Table 1. Demographic and Clinical Characteristics of Study Subjects

Conclusion

The majority of ARI in infants are due to respiratory viruses, with RSV, RV/EV, and flu accounting for over three-quarters of these viruses. The clinical presentations and disease severity differed across the clinical settings and the three main viruses, with RSV being most severe. To decrease the burden of medically attended viral ARI, preventive measures (i.e., developing new vaccines and antivirals), refining current vaccination strategies, and infection control measures are needed.

Disclosures

Zaid Haddadin, MD, CDC (Grant/Research Support, Research Grant or Support)Quidel Corporation (Grant/Research Support, Research Grant or Support)sanofi pasteur (Grant/Research Support, Research Grant or Support) Danielle A. Rankin, MPH, CIC, Sanofi Pasteur (Grant/Research Support, Research Grant or Support) Jon Fryzek, PhD, MPH, EpidStrategies (Employee) Mina Suh, MPH, International Health, EpidStrategies (Employee) Donald S. Shepard, PhD, Sanofi Pasteur (Grant/Research Support) Natasha B. Halasa, MD, MPH, Genentech (Other Financial or Material Support, I receive an honorarium for lectures - it’s a education grant, supported by genetech)Karius (Consultant)Moderna (Consultant)Quidel (Grant/Research Support, Research Grant or Support)Sanofi (Grant/Research Support, Research Grant or Support)

913. Distribution of Respiratory Viral Pathogens in Infants Across Different Clinical Settings from December 2019 to April 2020

Background

Acute respiratory infections (ARI) are a major cause of morbidity and mortality in young children, with viral pathogens being the most common etiologies. However, due to limited and inconsistent clinical diagnostic viral testing in the outpatient (OP) setting compared to the inpatient (IP) setting, the actual burden and distribution of viral pathogens across these clinical settings remain largely underreported. We aimed to evaluate the frequency of common respiratory viruses in medically attended ARI in infants.

Methods

We conducted a prospective viral surveillance study in Davidson County, TN. Eligible infants under one year presenting with fever and/or respiratory symptoms were enrolled from OP, emergency department (ED), or IP settings. Nasal swabs were collected and tested for common viral pathogens using Luminex® NxTAG Respiratory Pathogen Panel and for SARS-CoV-2 using Luminex® NxTAG CoV extended panel.

Results

From 12/16/2019 to 4/30/2020, 364 infants were enrolled, and 361 (99%) had nasal swabs collected and tested. Of those, 295 (82%) had at least one virus detected; rhinovirus/enterovirus (RV/EV) [124 (42%)], respiratory syncytial virus (RSV) [101 (32%)], and influenza (flu) [44 (15%)] were the three most common pathogens detected. No samples tested positive for SARS-CoV-2. Overall, the mean age was 6.1 months, 50% were male, 45% White and 27% Hispanic. Figure 1 shows the total number of PCR viral testing results by month. RSV was the most frequent virus detected in the IP (63%) and ED (37%) settings, while RV/EV was the most common in the OP setting (Figure 2). Figure 3 displays viral seasonality by clinical setting, showing an abrupt decrease in virus-positive cases following the implementation of a stay-at-home order on March 23, 2020 in Nashville, TN.

Distribution of Respiratory Viruses in Different Settings

Distribution of Respiratory Viruses in Different Settings by Season

Conclusion

Most medical encounters in infants are due to viral pathogens, with RSV, RV/EV, and flu being the most common. However, distributions differed by clinical setting, with RSV being the most frequently detected in the IP and ED settings, and second to RV/EV in the OP setting. Continued active viral ARI surveillance in various clinical settings is warranted. Preventative measures such as vaccines and infection control measures deserve study to reduce viral ARI burden.

Disclosures

Zaid Haddadin, MD, CDC (Grant/Research Support, Research Grant or Support)Quidel Corporation (Grant/Research Support, Research Grant or Support)sanofi pasteur (Grant/Research Support, Research Grant or Support) Danielle A. Rankin, MPH, CIC, Sanofi Pasteur (Grant/Research Support, Research Grant or Support) Jon Fryzek, PhD, MPH, EpidStrategies (Employee) Mina Suh, MPH, International Health, EpidStrategies (Employee) Donald S. Shepard, PhD, Sanofi Pasteur (Grant/Research Support) Natasha B. Halasa, MD, MPH, Genentech (Other Financial or Material Support, I receive an honorarium for lectures - it’s a education grant, supported by genetech)Karius (Consultant)Moderna (Consultant)Quidel (Grant/Research Support, Research Grant or Support)Sanofi (Grant/Research Support, Research Grant or Support)

1520. Respiratory Syncytial Virus Hospitalizations (RSVH) and All-Cause Bronchiolitis Hospitalizations (BH) Among Children Aged ≤ 24 Months at the Start of RSV Season With Bronchopulmonary Dysplasia/Chronic Lung Disease of Prematurity (BPD/CLDP) Before and After the 2014 American Academy of Pediatrics (AAP) Policy

Background

The AAP, in 2014, stopped endorsing palivizumab for use in children with BPD/CLDP born at < 32 weeks’ gestational age (wGA) between the ages of 12 to 24 months not requiring medical support during the 6 months before the start of RSV season and all children with BPD/CLDP born at > 32 wGA. We sought to understand the impact of the guidance change on RSVH and BH in children no longer advised for RSV immunoprophylaxis with palivizumab.

Methods

Children with BPD/CLDP aged ≤ 24 months at the RSV season start and hospitalized for RSV or bronchiolitis during the 2010-2017 RSV seasons (November-March) were studied. RSVH, BH, and BPD/CLDP were defined by International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) and ICD-10-CM codes. ICD-9 codes for wGA combine 31 and 32 wGA into one code. Therefore, for BPD/CLDP, we classified group 1 as children aged 12 to 24 months who were born at < 31 wGA and group 2 as those born at ≥ 31 wGA. The Children’s Hospital Association’s Pediatric Health Information System^® (PHIS) data set was used to describe frequency and characteristics of RSVH and BH and disease severity (including intensive care unit [ICU] admission and mechanical ventilation [MV]) before and after the 2014 AAP policy. Statistical analyses were done using z-tests; SAS version 9.4.

Results

Among children with BPD/CLDP, RSVH rates were 1.7% (1035/59,217) before 2014 and 2.1% (973/45,470) after 2014 (P< 0.0001). RSVH rose after the policy change vs before among children with BPD/CLDP in both group 1 (0.40% vs 0.26%; P< 0.0001) and group 2 (0.22% vs 0.14%; P=0.002). Similarly, BH also increased for both group 1 (P< 0.0001) and group 2 (P=0.002) after the guidance change vs before. Although ICU admissions increased significantly for children with BPD/CLDP in both group 1 (P< 0.0001) and group 2 (P=0.0004), use of MV (P=0.002) increased after 2014 for children with BPD/CLDP in group 1 only. Similar results were observed for BH.

Conclusion

This analysis highlights the increase in RSVH, BH, and associated severity among BPD/CLDP subgroups within the PHIS health system after 2014. Further study of long-term complications associated with RSVH in these children is warranted.

Disclosures

Jaime Fergie, MD, AstraZeneca (Speaker’s Bureau)Sobi, Inc. (Speaker’s Bureau) Tara Gonzales, MD, Sobi, Inc. (Employee) Mina Suh, MPH, International Health, EpidStrategies (Employee) Xiaohui Jiang, MS, EpidStrategies (Employee) Jon Fryzek, PhD, MPH, EpidStrategies (Employee) Adam Bloomfield, MD, FAAP, Sobi, Inc. (Employee)

NRG1 fusion-driven cancers: A systematic literature review and meta-analysis

e15605

Background: Neuregulin 1 (NRG1) fusion proteins have recently been identified as oncogenic drivers in diverse cancers with high unmet medical need. We recently reported promising responses in patients with cancers harboring NRG1 fusions treated with the bispecific antibody MCLA-128 (Schram 2019). The objective of this study was for the first time to quantitatively summarize the frequency of tumors harboring NRG1 fusions reported in the published literature. Methods: Neuregulin 1 (NRG1) fusion proteins have recently been identified as oncogenic drivers in diverse cancers with high unmet medical need. We recently reported promising responses in patients with cancers harboring NRG1 fusions treated with the bispecific antibody MCLA-128 (Schram 2019). The objective of this study was for the first time to quantitatively summarize the frequency of tumors harboring NRG1 fusions reported in the published literature. Results: Out of 212 articles identified in the literature as of 31-Jul-2019, 37 met the inclusion criteria and were abstracted. 13 different tumor types were identified as harboring NRG1 fusions including 5 tumor (sub)types which met the criteria for frequency meta-analysis (Table 1). NRG1 fusions were most frequent in pancreatic adenocarcinoma (3.3%, 95% confidence intervals (CI): 0.3-28.7%; apparent enrichment in KRAS WT) and NSCLC (0.8% 95% CI: 0.3-2.7%) with an enrichment in invasive mucinous adenocarcinoma (9.8%, 95% CI: 4.7-19.6%). Statistically significant heterogeneity was observed indicating substantial variation across studies in each analysis. For tumor types that did not meet the criteria for meta-analysis (uterine, renal cell, ovarian, colorectal, head and neck, bladder, prostate and sarcoma) the reported frequency of NRG1 fusions was typically less than 1%. Conclusions: NRG1 fusions are present across a wide range of different solid tumor types, most frequently in NSCLC and PDAC. NRG1 fusion-driven cancers represent a potential tumor-agnostic therapeutic target. The advent of new treatment options and increased genomic testing will allow a more precise estimation of the frequency of NRG1 fusions in cancer. [Table: see text]

2638. Respiratory Syncitial Virus Hospitalizations (RSVH) and All-Cause Bronchiolitis Hospitalizations (BH) Among 29–34 Weeks Gestational Age (wGA) Preterm Infants Before and After the 2014 American Academy of Pediatrics (AAP) Immunoprophylaxis Policy Change Using the Children’s Hospital Association’s Pediatric Health Information System (PHIS)

Background

In 2014, the AAP stopped recommending RSV immunoprophylaxis for otherwise healthy 29–34 wGA preterm infants. This study examined the risk of RSVH and BH among 29–34 wGA infants before the AAP policy change (November 1, 2010–March 31, 2014) and after (November 1, 2014–March 31, 2017) using PHIS hospital-level encounter data from 51 US children’s hospitals.

Methods

The study population included the first November to March RSVH (ICD9 = 79.6, 480.1, 466.11, ICD10 = B97.4, J12.1, J21.0) or BH (RSVH or unspecified bronchiolitis [ICD9 = 466.19, ICD10 = J21.1, J21.8, J21.9]) among infants 6 months of age or younger admitted to a PHIS hospital between November 1, 2010 and March 31, 2017. The proportion of RSVH and BH by wGA categories (22–28 wGA, 29–34 wGA, 35–36 wGA, and term infants [37+ wGA]) were compared in the time period before and after 2014. Frequencies and proportions were calculated overall for all infants and by demographic and clinical factors for 29–34 wGA infants for RSVH and BH, separately. Statistically significant differences before and after the AAP policy were compared using χ 2 test or Wilcoxon rank-sum test, as appropriate.

Results

96,281 infants with BH, including 67,570 with RSVH, were studied. Among infants with known gestational age, the proportions of hospitalizations for RSVH and BH increased after the AAP policy change for all wGA categories, except for term infants (table). Infants 29–34 wGA represented 8.7% of all RSVH before the policy change and 14.2% of all RSVH after the policy change (P < 0.0001). No significant differences were found by gender or co-morbidity for infants 29–34 wGA. Among infants 29–34 wGA, the intensive care unit admission rate increased significantly for RSVH (from 54.5% to 64.2%, P < 0.0001) and BH (from 46.7% to 54.5%, P < 0.0001) after the policy change. The median RSVH length of stay (from 6 to 7 days, P = 0.047) and median adjusted estimated cost (from $14,077 to $16,058, P = 0.038) increased significantly after the policy change.

Conclusion

RSV and all-cause bronchiolitis hospitalizations and their severity increased among preterm infants 29–34 wGA in the 3-year period following the 2014 AAP policy change on RSV immunoprophylaxis.

Disclosures

All authors: No reported disclosures.

Costs Attributable to Arteriovenous Fistula and Arteriovenous Graft Placements in Hemodialysis Patients with Medicare coverage

INTRODUCTION

Hemodialysis (HD) in end-stage renal disease (ESRD) patients requires vascular access (VA) through an arteriovenous fistula (AVF), a prosthetic arteriovenous graft (AVG), or a central venous catheter. While AVF or AVG is commonly used for HD, the economic implications of AVF versus AVG use have not been fully established. We describe the healthcare resource utilization and costs of AVF and AVG use for incident ESRD patients in the United States.

METHODS

This observational cohort study of AVF and AVG placements used data from the United States Renal Data System to identify and follow access placements. AVF and AVG placements after ESRD onset for incident patients from 2012 to 2014 with continuous Medicare primary coverage were included. All-cause and access-related Medicare costs were averaged over the placement lifetime and expressed as per dialysis-month costs.

RESULTS

The analysis included 38,035 AVF placements and 12,789 AVG placements. Total all-cause monthly costs for AVF averaged USD 8,508; mean monthly costs were USD 3,027 for inpatient (IP), USD 3,139 for outpatient (OP), USD 1,572 for physician services, and USD 770 for other care settings. Access-related monthly costs averaged USD 1,699 and represented 20% of all-cause charges for AVFs. Mean all-cause monthly costs for AVG were USD 9,605; by setting monthly costs were USD 3,811 for IP, USD 3,034 for OP, USD 1,881 for physician services and USD 879 for other care settings. Access-related monthly costs averaged USD 2,656 and represented 28% of all-cause charges for AVGs.

DISCUSSION/CONCLUSIONS

This study indicates that costs due to VA are a significant burden on Medicare budgets and on patients. The factors driving access-related utilization and costs merit attention in future research. Both optimizing process of care and discovery innovation may significantly accelerate better stewardship of available healthcare resources.

Prevalence of KRAS, NRAS, and BRAF gene mutations in metastatic colorectal cancer patients: A systematic literature review and meta-analysis

523

Background: A systematic literature review and meta-analysis was conducted to summarize the prevalence of KRAS, NRAS, and BRAF mutations in mCRC patients. These mutations have substantial implications for treatment decisions among mCRC patients. Methods: Multiple databases were searched to identify observational studies and clinical trials (standard of care arms only) that reported mutation status among mCRC patients. Random effects meta-analysis models were used to estimate summary prevalence estimates for each of the mutations. Subgroup and sensitivity analyses were conducted to identify potential sources of heterogeneity in mutation prevalence. Results: The meta-analyses included 275 studies comprising over 77,000 mCRC patients. The summary prevalence estimate was 35.9% for KRAS mutations, 7.1% for BRAF mutations, and 4.1% for NRAS mutations. Female patients had significantly more KRAS and BRAF mutations than males ( KRAS: 42.2% vs. 37.3%, p = 0.011; BRAF: 11.0% vs. 7.9%, p = 0.018), and significant variation by study location was observed for both KRAS (p = 0.025) and BRAF (p = 0.002) mutation prevalence. Conclusions: The prevalence of KRAS, BRAF, or NRAS mutations in mCRC patients varies significantly by gender and study location. compared to patients with wild-type tumors. The results of these analyses are informative for clinicians, patients, and researchers.

The incidence of infusion reactions associated with monoclonal antibody drugs targeting the epidermal growth factor receptor in metastatic colorectal cancer patients: A systematic literature review and meta-analysis

526

Background: Infusion reactions have been reported in studies of metastatic colorectal cancer (mCRC) patients treated with anti-EGFR therapies, including cetuximab and panitumumab, with incidences ranging from 0-33%. A systematic literature review and meta-analysis were conducted to estimate the incidence of infusion reactions in this population and identify variations in this incidence by patient and study characteristics. Methods: Multiple scientific databases were searched to identify observational studies or clinical trials of mCRC patients treated with anti-EGFR therapies that reported rates of infusion reactions, hypersensitivity, or allergy/anaphylaxis. Random effects models were used to meta-analyze the incidence of infusion reactions overall and stratified by therapy, study design, geographic location, KRAS mutation status, and grade of reaction severity. Results: Among 48 studies included in this meta-analysis, the pooled estimate for infusion reaction incidence was 0.049 (95% CI: 0.036 – 0.065), or nearly 5%. Reactions of grades 1 or 2 were more common than reactions of grades 3-5 (0.089 vs. 0.028) No significant variations in infusion reaction incidence were observed by study design, KRAS status, or study location. Conclusions: Infusion reactions occur in approximately 5% of mCRC patients treated with anti-EGFR therapies and the incidence varies significantly by grade and severity. Future studies should consider investigating survival outcomes for only those patients with infusion reactions to determine its prognostic relevance.

Clinical Outcomes of Arteriovenous Access in Incident Hemodialysis Patients with Medicare Coverage, 2012-2014

BACKGROUND

Chronic hemodialysis requires a mode of vascular access through an arteriovenous fistula (AVF), a prosthetic arteriovenous graft (AVG), or a central venous catheter (CVC). AVF is recommended over AVG or CVC due to increased patency and decreased intervention rates for those that mature. AVG are preferred over CVC due to decreased infection and mortality risk. The aims of this study were to evaluate the lifespan of AVF and AVG in maturation, sustained access use, and abandonment.

METHODS

The United States Renal Data System (USRDS), Medicare claims, and CROWNWeb were used to identify access placements. Patients with a first end-stage renal disease (ESRD) service from January 1, 2012 to June 30, 2014 with continuous coverage with Medicare as primary payer and ≥1 AVF or AVG placed after ESRD onset were included. Maturation was defined as the first use of the access for hemodialysis recorded in CROWNWeb. Sustained access use was defined as 3 consecutive months of use without catheter placement or replacement. Accesses that were never used at any time post-placement were considered abandoned.

RESULTS

The cohort included 38,035 AVF placements and 12,789 AVG placements. Sixty-nine percent of AVF and 72% of AVG matured. Fifty-two percent of AVF and 51% of AVG achieved sustained access use. One quarter of AVF and 14% of AVG were abandoned without use as recorded in CROWNWeb.

CONCLUSION

Although considered the gold standard for vascular access, only half of AVF and AVG placements achieved sustained access use. The USRDS database has inherent limitations but provides useful clinical insight into maturation, sustained use, and abandonment.

Characterization of circulating RSV strains among subjects in the OUTSMART-RSV surveillance program during the 2016-17 winter viral season in the United States

Background

Respiratory syncytial virus (RSV) is an established cause of serious lower respiratory disease in infants, elderly and high-risk populations. The OUTSMART surveillance program aims to characterize patient populations and currently circulating RSV strains, and monitor temporal and geographic evolution of RSV F and G proteins in the U.S.

Methods

The OUTSMART 2016–17 study collected RSV-positive samples from 25 RSVAlert^® laboratories from 4 U.S. regions and Puerto Rico during November 2016 through March 2017. Frequencies of A and B subtypes and genotypes were determined for several demographic and geographic variables. To gauge the representativeness of the OUTSMART patients, results were compared to discharge data from the NEDS and NIS databases.

Results

A total of 1,041 RSV-positive samples with associated demographic data were obtained and the RSV F gene and second variable region of the G gene were sequenced. The majority of samples (76.0%) came from children under 2 years old: <1 year (48.4%), 1–2 years (27.6%). The OUTSMART patient sample was similar to NEDS and NIS for age, gender, and geographic location. Both OUTSMART and national RSV cases peaked in January. Of OUTSMART samples, 45.3% were subtype A, 53.7% were subtype B and 1.0% were mixed A and B. The percentage of RSV B cases increased with increasing age. Hospitalization (length of hospital stay, LOS, >24 hrs) occurred in 29.0% of patients of which 52.0% had RSV B. Outpatients (LOS <24 hrs) were 64.4% of total of which 73.3% were diagnosed in the ER and discharged, while only 6% were diagnosed in other outpatient settings.

Conclusions

The OUTSMART 2016–17 study was representative of the U.S. RSV experience. Geographic and temporal information from the RSV surveillance program will be used to establish a molecular baseline of RSV F and G sequence variability and to help inform development of novel agents for RSV prophylaxis and treatment.

Abstract 4212: PD-L1 expression, EGFR and KRAS mutations in unresectable stage III non-small cell lung cancer (NSCLC) patients

Background: Anti-PD-L1 therapy may improve prognosis in advanced NSCLC. We examined the relation of PD-L1 expression, KRAS and EGFR mutations, with survival in unresectable stage III NSCLC patients.

Methods: We obtained data on unresectable stage III NSCLC patients (defined via TNM AJCC staging and without surgery up to 120 days after diagnosis) diagnosed 2001-2012. We retrieved medical data from Danish population-based registries and paraffin-embedded tumor tissue from pathology archives. We assessed PD-L1 expression using the Ventana IHC (SP263) validated assay. We genotyped KRAS and EGFR using PCR-based kits. Follow-up began at NSCLC diagnosis and continued to death, emigration, or 31/12/2014. We used Cox regression to compute hazard ratios (HRs) and associated 95% confidence intervals (95%CI) for PD-L1, EGFR, and KRAS.

Results: Among 305 patients, 183 (60%) were men, 167 (55%) were aged &gt;65 years at diagnosis and none used immunotherapy; 148 (49%) had adenocarcinoma, 117 (38%) squamous histology, 96 (31.5%) had PD-L1 positive tumors (&gt;=25%), 6 (2%) had EGFR mutations, and 69 (23%) had KRAS mutations. Among PD-L1 positive tumors, 55% had stage IIIA, 45% IIIB disease; 1% had EGFR and 34% had KRAS mutations. Among PD-L1 negative tumors, 54% had stage IIIA and 46% IIIB; 3% had EGFR and 16% had KRAS mutations. Median survival was similar in patients with KRAS wild-type and KRAS mutations (Hazards ratio (HR)=1.07; 95% CI=0.76-1.51). Patients with an EGFR mutation had a lower non-statistically significant risk of death (HR=0.75; 95% CI=0.28-2.06). Tumor cell positivity for PD-L1 (&gt;=25% versus &lt;25%) yielded an HR=0.80 (95%CI=0.60-1.07). Immune cell positivity for PD-L1 &gt;=1% and &gt;=25% yielded HRs of 0.50 (95%CI=0.39-0.66) and 0.45 (95%CI=0.30-0.67), respectively. Tumor infiltration by immune cells with PD-L1 measured as a continuous variable yielded an HR=0.96 (95%CI=0.93-0.99).

Conclusion: Our findings suggest that PD-L1 expression and EGFR mutations, but not KRAS mutations, are associated with survival in this real-world Danish study of unresectable Stage III NSCLC patients.

Citation Format: Deirdre Cronin-Fenton, Tapashi Dalvi, Elizabeth Hedgeman, Mette Norgaard, Lars Pedersen, Hanh Hansen, Jon Fryzek, Jill Walker, Anders Mellemgaard, Torben Rasmussen, Norah Shire, James Riggas, Danielle Potter, Stephen Hamilton-Dutoit, Henrik Sørensen. PD-L1 expression, EGFR and KRAS mutations in unresectable stage III non-small cell lung cancer (NSCLC) patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4212.

Prevalence of RAS and BRAF mutations in metastatic colorectal cancer (mCRC) patients by tumor location

681

Background: There is evidence to suggest that tumor biology and pathology differ for right- and left-sided colon tumors which may affect treatment efficacy and clinical outcomes. Therefore, we conducted a systematic review and meta-analysis of the available scientific literature to summarize the prevalence of RAS and BRAF mutations by primary tumor location and to identify potential sources of heterogeneity in mutation prevalence. Methods: This study was conducted in accordance with PRISMA guidelines. Using comprehensive search strings, several medical research databases were queried and relevant variables abstracted including tumor mutation prevalence, study country, metastasis site, tissue source, study design, study dates, median age of the cohort, mutation assessment method, and length of follow-up. Results: Final abstraction was performed on 40 articles, 36 observational studies and 4 randomized trials. Most studies were from Europe (n = 16), followed by Asia (n = 11), USA, (n = 7), Australia (n = 3), and the remaining 3 were conducted in multiple countries. The proportion of males in each study ranged from 37% to 72%, and the mean age ranged from 55 to 76 years. The prevalence of all RAS mutations was significantly higher among right-sided colon tumors than left-sided colon tumors (44%, 95% Confidence Interval [CI]: 38 – 50% vs 34%, 95% CI: 29 – 38%; p = 0.009). BRAF mutation prevalence was also higher in right-sided tumors (16.1%, 95% CI: 13.1 – 19.6% vs 4.4%, 95% CI: 3.4 – 5.8%; p < 0.0001). Conclusions: This systematic review and meta-analysis found that mutation prevalence varied by primary tumor right- or left-sided location among mCRC patients. Some of this variation may be explained by study characteristics such as mutation assessment method, country and length of follow-up. Further research will help to better understand treatment and outcome implications of tumor sidedness and mutation prevalence.

Programmed cell death receptor ligand 1 (PD-L1) expression: Epidermal growth factor receptor (EGFR) and Kirsten RAS (KRAS) mutations in second-line therapy (2L) non-small cell lung cancer (NSCLC) patients—A Danish cohort study

e20523

Background: In NSCLC patients who received 2L therapy, we examined the association of PD-L1 expression, mutations in KRAS and EGFR and survival. Methods: 2L NSCLC patients diagnosed during 2001-2012 and with sufficient archival tumour tissue were selected from the Danish Lung Cancer Group Registry. We retrieved patient data from population-based medical registries, and paraffin-embedded tumor tissue from pathology archives. We assessed PD-L1 expression using the Ventana IHC (SP263) validated assay (using 25% cutoff for positivity), and genotyped KRAS and EGFR via PCR-based kits. Follow-up was from the start of 2L therapy to death, emigration, or 31/12/2014. We used Cox regression to compute hazard ratios (HR) and associated 95% confidence intervals (95%CI) for PD-L1, EGFR and KRAS. Results: Among 368 patients, 204 (55%) were men, 250 (68%) were aged >60 years at diagnosis, and 95% were ever-smokers. 233 (63%) had adenocarcinoma, 90 (24%) had PD-L1 positive tumors, 28 (8%) had EGFR mutations, and 113 (31%) had KRAS mutations. In the PD-L1 positive tumors, 7% had EGFR and 37% KRAS mutations, respectively. In the PD-L1 negative tumors, 9% had EGFR and 32% KRAS mutations, respectively. Patients with KRAS mutations had shorter survival compared with wild-type patients. Survival was longer for patients with EGFR mutations compared with wildtype patients. PD-L1 expression did not correlate with survival (Table). Conclusions: Our findings suggest that EGFR and KRAS mutations, but not PD-L1 expression, correlate with survival in 2L NSCLC patients. [Table: see text]

Respiratory syncytial virus hospitalization risk in the second year of life by specific congenital heart disease diagnoses

Children with hemodynamically significant congenital heart disease (CHD) are at elevated risk of morbidity and mortality due to respiratory syncytial virus (RSV) disease compared to their healthy peers. Previous studies have demonstrated lower RSV hospitalization risk among all children with CHD at 12-23 months of age versus 0-11 months of age. However, RSV hospitalization risk at 12-23 months of age by specific CHD diagnosis has not been characterized. Both case-control and cohort studies were conducted using data from the US National Inpatient Sample from 1997 to 2013 to characterize relative risk of RSV hospitalization among children 12-23 months of age with CHD. Related CHD diagnoses were combined for analysis. Hospitalizations for RSV and unspecified bronchiolitis were described by length of stay, mechanical ventilation use, mortality, and total charges. Over the 17-year period, 1,168,886 live birth hospitalizations with CHD were identified. Multiple specific CHD conditions had an elevated odds ratio or relative risk of RSV hospitalization. Mean total RSV hospitalization charges were significantly higher among children with CHD relative to those without CHD ($19,650 vs $7,939 in 2015 dollars) for this period. Compared to children without CHD, children with Ebstein's anomaly, transposition of the great arteries, aortic stenosis, heterotaxia, and aortic arch anomalies had 367-, 344-, 203-, 117- and 47-fold increased risk of inpatient RSV mortality, respectively. Unspecified bronchiolitis hospitalization odds and relative risk across CHD diagnoses were similar to those observed with RSV hospitalization; however, unspecified bronchiolitis hospitalizations were associated with shorter mean days of stay and less frequently associated with mechanical ventilation or mortality. Among children with more severe CHD diagnoses, RSV disease remains an important health risk through the second year of life. These data can help inform decisions regarding interventions to protect children with CHD from severe RSV disease during their second year of life.

Heterogeneous populations driven by clinical practice: A case example comparing enzalutamide (ENZA) and bicalutamide (BIC)

e571

Background: Comparative real-world insurance claims data (RWD) analysis can be used to compare homogeneous cohorts (to avoid selection bias). Since the National Comprehensive Cancer Network guidelines recommend ENZA for metastatic castration-resistant prostate cancer (PC) and BIC for localized PC, it was of interest to evaluate these 2 heterogeneous cohorts as the ENZA cohort, being further advanced in the disease, has a worse prognosis than the BIC cohort. Here, we describe the results of a post hoc analysis on the ENZA and BIC cohorts to confirm the heterogeneity of demographics presented in a published study (Behl A et al. J Clin Oncol. 2016;34:235). Methods: The RWD captured enrollees with PC, claims for ENZA or BIC from 09/01/2012–12/31/2014, and at least 6 mo of continuous enrollment prior to the index date. After replicating methods from Behl et al using Truvan, we explored the balance of demographics in baseline periods greater than 6 mo. Differences in demographics and the post hoc analysis were compared. Results: Behl et al reported balanced age between the ENZA (73.1±10.0 y) and BIC (71.4±10.5 y) cohorts. However, 90% (531/592) of the ENZA cohort were metastatic vs 35% (1917/5524) of the BIC cohort. The Quan-Charlson comorbidity index was higher for the ENZA (5.6±2.1 y) than BIC (3.2±2.1 y) cohort. In the ENZA cohort, abiraterone acetate (ABI) or BIC utilization in the baseline period was higher (53%) than in the BIC cohort (0%). When the baseline period was greater than 6 mo, per our post hoc analysis, prior use of ABI or BIC increased to 68% for the ENZA cohort and remained unchanged in the BIC cohort. Conclusions: Despite results from the Behl analysis, the ENZA and BIC cohorts were dissimilar; ENZA patients had more advanced disease (metastatic disease; received ≥ 1 therapy) than BIC patients. Comparison of such heterogeneous populations can lead to biased estimates of treatment effects. Analyses lacking appropriate measures of prognostic variables that guide treatment decisions should be cautiously interpreted. Further analysis is required to identify best practices for using RWD and to address confounding driven by clinical practice.

Hospitalizations for Respiratory Syncytial Virus Among Adults in the United States, 1997-2012

BACKGROUND

Respiratory syncytial virus (RSV) is an established cause of serious lower respiratory disease in children, but the burden in adults is less well studied.

METHODS

We conducted a retrospective study of hospitalizations among adults ≥20 years from the 1997-2012 National Inpatient Sample. Trends in RSV admissions were described relative to unspecified viral pneumonia admissions. Hospitalization severity indicators were compared among immunocompromised RSV, non-immunocompromised RSV, and influenza admissions.

RESULTS

An estimated 28237 adult RSV hospitalizations occurred, compared with 652818 influenza hospitalizations; 34% were immunocompromised individuals. Respiratory syncytial virus and influenza patients had similar age, gender, and race distributions, but RSV was more often diagnosed in urban teaching hospitals (73.0% for RSV vs 34.6% for influenza) and large hospitals (71.9% vs 56.4%). Respiratory syncytial virus hospitalization rates increased from 1997 to 2012, particularly for those ≥60, increasing from 0.5 to 4.6 per 100000, whereas unspecified pneumonia admission rates decreased significantly (P < .001). Immunocompromised patients with RSV hospitalization had significantly higher inpatient mortality (P = .013), use of mechanical ventilation (P = .016), mean length of stay (LOS) (P < .001), and mean cost (P < .001) than non-immunocompromised RSV hospitalizations. Overall, RSV hospitalizations were more severe than influenza hospitalizations (6.2% mortality for RSV vs 3.0% for influenza, 16.7% vs 7.2% mechanical ventilation, mean LOS of 6.0 vs 3.6 days, and mean cost of $38828 vs $14519).

CONCLUSIONS

Respiratory syncytial virus hospitalizations in adults are increasing, likely due to increasing recognition and diagnosis. The burden of RSV in adults deserves attention. Although there are fewer hospitalizations than influenza, those that are diagnosed are on average more severe.

Trends in Respiratory Syncytial Virus and Bronchiolitis Hospitalization Rates in High-Risk Infants in a United States Nationally Representative Database, 1997-2012

Background

Respiratory syncytial virus (RSV) causes significant pediatric morbidity and is the most common cause of bronchiolitis. Bronchiolitis hospitalizations declined among US infants from 2000‒2009; however, rates in infants at high risk for RSV have not been described. This study examined RSV and unspecified bronchiolitis (UB) hospitalization rates from 1997‒2012 among US high-risk infants.

Methods

The Kids’ Inpatient Database (KID) infant annual RSV (ICD-9 079.6, 466.11, 480.1) and UB (ICD-9 466.19, 466.1) hospitalization rates were estimated using weighted counts. Denominators were based on birth hospitalizations with conditions associated with high-risk for RSV: chronic perinatal respiratory disease (chronic lung disease [CLD]); congenital airway anomalies (CAA); congenital heart disease (CHD); Down syndrome (DS); and other genetic, metabolic, musculoskeletal, and immunodeficiency conditions. Preterm infants could not be identified. Hospitalizations were characterized by mechanical ventilation, inpatient mortality, length of stay, and total cost (2015$). Poisson and linear regression were used to test statistical significance of trends.

Results

RSV and UB hospitalization rates were substantially elevated for infants with higher-risk CHD, CLD, CAA and DS without CHD compared with all infants. RSV rates declined by 47.0% in CLD and 49.7% in higher-risk CHD infants; no other declines in high-risk groups were observed. UB rates increased in all high-risk groups except for a 22.5% decrease among higher-risk CHD. Among high-risk infants, mechanical ventilation increased through 2012 to 20.4% and 13.5% of RSV and UB hospitalizations; geometric mean cost increased to $31,742 and $25,962, respectively, and RSV mortality declined to 0.9%.

Conclusions

Among high-risk infants between 1997 and 2012, RSV hospitalization rates declined among CLD and higher-risk CHD infants, coincident with widespread RSV immunoprophylaxis use in these populations. UB hospitalization rates increased in all high-risk groups except higher-risk CHD, suggesting improvement in the health status of higher-risk CHD infants, potentially due to enhanced surgical interventions. Mechanical ventilation use and RSV and UB hospitalization costs increased while RSV mortality declined.

International burden of chronic kidney disease and secondary hyperparathyroidism: a systematic review of the literature and available data

The international burden of secondary hyperparathyroidism (SHPT) is unknown, but it may be estimable through the available chronic kidney disease and SHPT literature. Structured reviews of biomedical literature and online data systems were performed for selected countries to ascertain recent estimates of the incidence, prevalence, and survival of individuals with CKD and SHPT. International societies of nephrology were contacted to seek additional information regarding available data. Estimates were abstracted from 35 sources reporting estimates of CKD in 25 countries. Population prevalence estimates of CKD stages 3-5 in adults ranged from approximately 1 to 9% (China, Mexico, resp.). Estimates of the population prevalence of maintenance dialysis therapy ranged from 79 per million population (pmp; China) to 2385 pmp (Japan); incidence rates ranged from 91 pmp (United Kingdom) to 349 pmp (United States). Prevalence of SHPT among stage 5D populations was highly variable and dependent upon the disease definition used. Among the few nations reporting, approximately 30-50% of stage 5D patients had serum parathyroid hormone levels >300 pg/mL. Reported incidence and prevalence estimates across the individual nations were variable, likely reflecting differing population demographics, risk factors, etiologies, and availability of treatment through all stages of CKD.

Epidemiology of myelofibrosis, essential thrombocythemia, and polycythemia vera in the European Union

BACKGROUND

Primary myelofibrosis (PMF), essential thrombocythemia (ET), and polycythemia vera (PV) are BCR ABL-negative myeloproliferative neoplasms (MPN). Published epidemiology data are scarce, and multiple sources are needed to assess the disease burden.

METHODS

We assembled the most recent information available on the incidence and prevalence of myelofibrosis (MF), ET, and PV by conducting a structured and exhaustive literature review of the published peer-reviewed literature in EMBASE and by reviewing online documentation from disease registries and relevant health registries in European countries. The search was restricted to human studies written in English or French and published between January 1, 2000, and December 6, 2012.

RESULTS

Eleven articles identified from EMBASE, three online hematology or oncology registries, and two Web-based databases or reports were used to summarize epidemiological estimates for MF, PV, and ET. The incidence rate of MF ranged from 0.1 per 100,000 per year to 1 per 100,000 per year. Among the various registries, the incidence of PV ranged from 0.4 per 100,000 per year to 2.8 per 100,000 per year, while the literature estimated the range of PV incidence to be 0.68 per 100,000 to 2.6 per 100,000 per year. The estimated incidence of ET was between 0.38 per 100,000 per year and 1.7 per 100,000 per year. While a few studies reported on the MPNs' prevalences, it is difficult to compare them as various types of prevalence were calculated (point prevalence vs. period prevalence) and standardization was made according to different populations (e.g., the world population and the European population).

CONCLUSION

There is a wide variation in both prevalence and incidence estimates observed across European data sources. Carefully designed studies, with standardized definitions of MPNs and complete ascertainment of patients including both primary and secondary MFs, should be conducted so that estimates of the population aimed to receive novel treatments for these neoplasms are better understood assist public health planning and provide valuable information about the burden of illness to policy makers, funding agencies, resource planners, healthcare insurers, and pharmaceutical manufacturers.

A multisource approach to improving epidemiologic estimates: application to global B-cell malignancies

The compilation of comprehensive, worldwide epidemiologic data can inform hypotheses on cancer etiology and guide future drug development. These statistics are reported by a multitude of sources using varying methods; thus, compiling a complete database of these statistics is a challenge. To this end, this paper examined the usefulness of a novel, multisource approach—extracting data from the peer-reviewed literature, online reports, and query systems from cancer registries and health agencies and directly contacting cancer registry personnel—for building a comprehensive, multinational epidemiologic cancer database. The major B-cell malignancies were chosen as the cancer subtype to test this approach largely because their epidemiology has not been well characterized in the peer-reviewed literature. We found that a multisource approach yields a more comprehensive epidemiologic database than what would have been possible with the use of literature searches alone. In addition, our paper revealed that cancer registries vary considerably in their methodology, comprehensiveness, and ability to gather information on specific B-cell malignancy subtypes. Collectively, this paper demonstrates the feasibility and value of a multisource approach to gathering epidemiologic data.

An ecological study of cancer mortality rates in high altitude counties of the United States

To test the hypothesis that sustained, increased hemoglobin levels as measured by residence in high altitudes lead to an increase of malignant cancer deaths, we performed an assessment of U.S. cancer mortality rates for people residing in high altitude counties compared with those in counties with altitudes close to sea level. This included a graphical analysis of mortality rates for all cancers, female breast cancer, respiratory system cancer (RSC) and non-Hodgkin lymphoma (NHL), computation of standardized mortality ratios (SMRs) and Poisson regression modeling. Overall, our ecological evaluation showed statistically significantly reduced SMRs and rate ratios (RRs) for high altitude residents compared to sea level residents. For the causes of death categories examined, we found no evidence that persons residing in high altitude counties are at an elevated risk of cancer mortality compared with persons living close to sea level. Our results corroborate previous altitude studies of cancer mortality.

Abstract P3-07-08: Recent trends in the characteristics of patients with distant stage breast cancer in the United States Surveillance, Epidemiology and End Stage Disease (SEER) program

Objectives. Even though advances in screening and contemporary diagnostic techniques have led to earlier detection, a proportion of breast cancer patients are still diagnosed with distant stage disease. The objective of this research was to describe the changing demographic and clinical characteristics of patients with distant stage breast cancer.

Methods. We identified women aged 20 years or older who were diagnosed with distant stage primary breast cancer between 1995 and 2009 with non-missing hormone receptor (HR) status in the SEER 18 Registry (1973–2009) database. As staging systems changed across the years of the study, we opted to use the SEER historic stage in our analyses. Trends in demographic and clinical characteristics were evaluated by time period of diagnosis (1995–1999, 2000–2004, 2005–2009) and HR status (HR+ includes ER+/PR+, ER+/PR- and ER−/PR+; HR− includes ER−/PR− only). Statistically significant changes were examined using the Cochran Armitage test.

Results. A total of 30,161 women with distant stage breast cancer were identified. Over the 15 years, the incidence rate (IR) of distant stage disease was stable (10.6 to 10.9 per 100,000 pys), as well as the proportion of HR+ cases (68%).

Age did not vary significantly over time; 55% of the HR+ cases and 45% of the HR- cases were 60 years or older. The proportion of Black and Hispanic patients increased significantly over time (18 to 24% for HR+; 24 to 33% for HR−) -as did the proportion of patients diagnosed with grades I and II cancers (44 to 54% for HR+; and 16 to 20% for HR−). The proportion of ductal histologic diagnoses was stable over time, at 77% among HR+ cases and 93% among HR- cases in 2005–2009. Cancer-directed surgeries (from 63 to 47% for HR+; 72 to 56% for HR−) and radiation therapies (43 to 37% for HR+; 42 to 38% for HR−) became less common over the time. Information on chemotherapy/systemic therapies is unavailable in this dataset.

Conclusions. Although, incidence rate of distant stage breast cancer was stable over a time, there was a higher proportion of diagnosis of grade I/II stage cancer cases potentially due to earlier cancer detections by screening programs. The growing proportion of minorities suggested that screening programs be adjusted to the changing demographics in the United States.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-07-08.

The burden of immune thrombocytopenia in adults: evaluation of the thrombopoietin receptor agonist romiplostim

BACKGROUND

Immune thrombocytopenia (ITP) is a chronic, immune-mediated disease characterized by a transient or long-lasting decrease in platelet counts. ITP is associated with numerous serious clinical consequences. Discussed here are clinical aspects of ITP, the humanistic and economic burden of ITP, and current treatment options with a focus on romiplostim, a thrombopoietin (TPO) receptor agonist. The aim of this review is to provide decision-makers with the background information necessary to evaluate the value of romiplostim.

SCOPE

PubMed was searched for relevant, English-language papers published from January 2006 through November 2011 relating to the epidemiology and treatment options of chronic ITP, and, focusing on the TPO mimetic romiplostim, patient-reported outcomes (PRO) and economic burden. Recent select conference abstracts were also reviewed.

FINDINGS

The initial clinical management of ITP (e.g., corticosteroids, immunoglobulins) is often associated with adverse events and recommended for short-term use only. Splenectomy, a potentially curative second-line treatment, is associated with increased risks of bleeding and infection, and patients often require additional long-term drug intervention. ITP and its sequelae are associated with a substantial burden on patients' health-related quality-of-life (HRQoL) and increased medical costs. Use of TPO receptor agonists in ITP patients may represent a more efficient use of healthcare resources than existing therapies.

CONCLUSION

While this literature review is not a systematic review, e.g., it considers only approved therapies and published literature written in English, it provides a comprehensive overview of the clinical, humanistic, and economic factors that should be considered in treating ITP, particularly with new agents such as romiplostim. Among the limited number of safe and effective therapies currently available for chronic ITP, highly effective and well-tolerated medications such as romiplostim may reduce the healthcare resource utilization associated with ITP while improving patients' HRQoL.

P4-11-19: Healthcare Resource Utilization among Breast Cancer Patients with Bone Metastases and Skeletal-Related Events: A Population-Based Cohort Study in Denmark (1997 - 2009)

Background

The healthcare resource utilization (HRU) of breast cancer patients who develop bone metastases and skeletal-related events (SREs) has not been well-characterized. Our objective was to describe the HRU associated with SREs in a large population-based cohort of Danish breast cancer patients with bone metastases and one or more SRE.

Methods: We identified women diagnosed with incident breast cancer from January 1, 1997 through December 31, 2006 using the Danish Cancer Registry. We followed this cohort of patients for development of subsequent bone metastases and SREs identified through the Danish National Registry of Patients through December 31, 2009. SREs were defined as pathologic fracture, spinal cord compression, and radiation or surgery to bone. Among patients with only one SRE, the HRU period, composed of all HRU occurring within a 90-day period after the SRE and within a two-week diagnostic period prior to the SRE, was assessed. For patients with multiple SREs (each one separated by less than 90 days), the HRU period, composed of all HRU occurring within a two-week diagnostic period prior to the first SRE up until 90 days after the last SRE, was described. Patients may have had multiple HRU periods if SREs were separated by more than 90 days. The HRU summarized included number of inpatient hospitalizations, length of hospitalization stay, outpatient physician visits, emergency room visits, and procedures.

Results: We identified 1,148 patients with bone metastases and SREs among 38,485 breast cancer patients. The mean age at breast cancer diagnosis for those who developed bone metastases and SREs was 59 years (SD, 13 years) and the majority (72%) of patients had multiple SREs during the first HRU period. Approximately 20% to 30% of patients with single and multiple SREs, respectively, died within the first HRU period. Overall, length of hospitalization was longest for patients with spinal cord compression followed by patients with pathologic fracture. In general, patients with multiple SREs had higher HRU compared to those with a single SRE in the first HRU period, particularly in length of hospitalization stay.

Conclusion: SREs secondary to bone metastases are serious events. In Denmark, high HRU was observed in all patients with SREs, but especially in those with multiple SREs, where increased lengths of hospitalization were observed.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-11-19.

Incidence of myelodysplastic syndromes within a nonprofit healthcare system in western Washington state, 2005-2006

Myelodysplastic syndromes (MDS) incidence is unclear because of historical lack of population-based registration and possibly because of underdiagnosis. We conducted a study to evaluate completeness of MDS registration in the Seattle-Puget Sound region of the Surveillance, Epidemiology, and End Results (SEER) program-which has reported the highest rates among the SEER registries since mandatory reporting of MDS began in 2001. We identified incident MDS cases of any age that occurred within a nonprofit healthcare system in western Washington State in 2005 or 2006 through the local SEER registry or by relevant diagnostic code followed by medical chart review to classify these patients as unlikely, possible, or definite/probable MDS. We calculated age-standardized incidence rates for all identified MDS cases and for case groups based on identification method, and we summarized medical histories of the MDS patients. MDS incidence in our study population was estimated as 7.0 per 100,000 person-years in 2005-2006 when combining MDS cases identified by SEER and definite/probable cases identified by chart review, which was similar to the rate of 6.9 reported by our local SEER registry. The addition of possible MDS cases identified from chart review increased the rate to 10.2 per 100,000. MDS patients frequently had previous cancer diagnoses (25%) and comorbidities such as high blood pressure and diabetes. Our investigation suggests that although reporting of confirmed MDS diagnoses in our region appears complete, MDS incidence is likely underestimated because of omission of cases who are symptomatic but do not receive definitive diagnoses.

Epidemiology of paediatric immune thrombocytopenia in the General Practice Research Database

This study assessed the incidence of immune thrombocytopenia (ITP) and characteristics associated with ITP in the paediatric population using the General Practice Research Database (GPRD). Two hundred and fifty-seven paediatric ITP patients were identified out of 1145 incident patients with ITP recorded between 1990 and 2005. The age-specific incidence for ITP in paediatric patients was 4.2 per 100,000 person-years (PY) [95% confidence interval (CI): 3.7-4.8 per 100,000 PY], with a statistically significantly higher incidence in boys compared to girls aged 2-5 years [9.7 (95% CI: 7.5-12.2) per 100,000 PY vs. 4.7 (95% CI: 3.2-6.6) per 100,000 PY, respectively]. By contrast, among teenagers aged 13-17 years, the overall incidence was lower [2.4 (95% CI: 1.7-3.3) per 100,000 PY] with a similar incidence in girls and boys. There was a relationship between age and sex with ITP incidence, suggesting that patterns of disease burden differ among children and teenagers. Evidence of an infection or immunization shortly before ITP diagnosis was apparent in 52 (20.2%) and 22 (8.6%) of the 257 paediatric ITP patients, respectively. Two deaths were observed during the study period. ITP is an important although rarely fatal disease in paediatric patients and its aetiology remains unexplained in the majority of cases.

Use of electronic medical records in oncology outcomes research

Oncology outcomes research could benefit from the use of an oncology-specific electronic medical record (EMR) network. The benefits and challenges of using EMR in general health research have been investigated; however, the utility of EMR for oncology outcomes research has not been explored. Compared to current available oncology databases and registries, an oncology-specific EMR could provide comprehensive and accurate information on clinical diagnoses, personal and medical histories, planned and actual treatment regimens, and post-treatment outcomes, to address research questions from patients, policy makers, the pharmaceutical industry, and clinicians/researchers. Specific challenges related to structural (eg, interoperability, data format/entry), clinical (eg, maintenance and continuity of records, variety of coding schemes), and research-related (eg, missing data, generalizability, privacy) issues must be addressed when building an oncology-specific EMR system. Researchers should engage with medical professional groups to guide development of EMR systems that would ultimately help improve the quality of cancer care through oncology outcomes research.

The Incidence of Bone Metastases and Skeletal-Related Events in Breast Cancer Patients: A Population-Based Cohort Study in Denmark (1999 – 2007)

Background Breast cancer (BrCa) is the most commonly diagnosed cancer among women in the industrialized world. More than half of women presenting with metastatic BrCa develop bone metastases. Bone metastases increase the risk of skeletal-related events (SREs), defined as radiation to bone, pathologic fractures, spinal cord compression, bone surgery, or altered antineoplastic therapy to treat bone pain. Both bone metastases and SREs are associated with unfavorable prognosis and greatly affect quality of life. To date, the epidemiology of the subgroup of BrCa patients who develop bone metastases and/or SREs has not been well-characterized. Our objective was to estimate the one- and five-year incidence of bone metastases and SREs in a large population cohort of newly-diagnosed BrCa patients in Denmark (population ∼ 5.4 million inhabitants). Methods We identified women diagnosed with BrCa (International Classification of Diseases, 10th Revision (ICD-10) code C50.x.) from January 1, 1999 through December 31, 2007, with follow-up through April 2008. We retrieved this data from Denmark's National Registry of Patients (NRP), which includes records from all Danish hospitals. We also identified bone metastases (ICD-10 code C79.5) and recorded SREs. The Kaplan-Meier method was used to estimate time to bone metastases and time to first SRE. We also calculated 1- and 5-year incidence rates (IR) of bone metastases and first SRE in newly-diagnosed BrCa patients. Results We identified 35,941 BrCa patients from the NRP. The median age at diagnosis was 62 years (range, 18-104 years). A total of 1,494 (4%) patients developed bone metastases during follow-up, and of these, 712 developed an SRE. The distribution of SREs by type were 394 (55%) with radiation to the bone, 133 (19%) with pathological or osteoporotic fracture, 42 (6%) with bone surgery, and 143 (20%) with spinal cord compression. The 1-year IR of bone metastases was 13.7 [95% confidence interval (CI): 12.5-15.0] per 1000 person-years (P-Y). The 1-year IR of SREs among patients with bone metastases was 55 times that of the 1-year IR of bone metastases in BrCa patients at 759.2 (95% CI: 662.0-870.5) per 1000 P-Y. After five years of follow-up, the incidence curves plateaued at approximately 4% and 48% for bone metastases and SREs, respectively (Figures 1 and 2). Conclusions Among breast cancer patients with bone metastases, there was a strong tendency towards development of SREs within a year of bone metastases diagnosis; however, this phenomenon stabilized beyond 5 years of bone metastases diagnosis.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2051.

Heparin use and venous thromboembolism (VTE) among cancer patients receiving chemotherapy with a prior history of VTE

6616

Background: Heparin is an effective treatment option for the prevention of venous thromboembolism (VTE) in cancer patients on chemotherapy. To date, information on the use of both low molecular weight heparin (LMWH) and non-LMWH in cancer patients receiving chemotherapy that have had a prior VTE is lacking. We evaluated heparin treatment patterns as well as the incidence of VTE in a cohort of cancer patients receiving chemotherapy, who have had a VTE prior to their cancer diagnosis. Methods: We conducted a retrospective cohort study using a large claims database representing the U.S. commercially-insured population. The cohort included all patients 18–64 years old from 2000 to 2007 who were diagnosed with cancer, were on chemotherapy, and who had a VTE occurring up to 12 months before cancer (n=331). We defined a diagnosis of cancer as two ICD-9 claims 30 days apart or more. A combination of ICD-9, HCPCS, and CPT codes were used to capture chemotherapy treatment after cancer. A VTE was identified by a single ICD-9 claim of 415.1, 451.2, 451.81, 451.9, 453.1, 453.2, 453.8, or 453.9. VTE claims occurring within 6 months of the index claim were considered part of the same VTE event. A patient was considered to have a VTE after cancer if they had a VTE claim that occurred both after the cancer diagnosis and at least 6 months beyond the most recent pre-cancer index VTE date. Results: Fifty-one percent of cancer patients with a history of VTE were prescribed an anticoagulant (n = 171). Fewer patients took LMWH compared to non-LMWH (6.7% versus 27.8%) while a portion took both (17.2%). A VTE after cancer was experienced by 49.1% of those on any kind of anticoagulant, 45.4% of those taking LMWH, 43.5% of those taking non-LMWH, and 59.6% of those who had taken both types. Fewer VTEs were reported among those taking no anticoagulants (29.4%). Conclusions: Approximately half of all cancer patients receiving chemotherapy were receiving heparin, with a smaller proportion using only LMWH. Even with prophylaxis, VTE recurs in half of cancer patients with a VTE history who receive chemotherapy. Recurrent VTE is a serious risk despite heparin or LMWH prophylaxis.

[Table: see text]

Prevalence of early-stage prostate and estrogen receptor positive (ER+) breast cancer patients receiving primary androgen deprivation therapy (ADT) and aromatase inhibitors (AIs) in the United States (U.S.)

e22126

Background: AIs and ADT are used to prevent recurrence of breast and prostate cancers but have been shown to accelerate bone loss. We estimated the prevalence of early-stage ER+ breast and prostate cancer patients on hormone therapy in the U.S., as this is not well-described in the literature. Methods: Data from the Surveillance, Epidemiology, and End Results (SEER) Program, published literature, clinical practice, and a large claims database were used. We began with the American Cancer Society's estimated number of new breast and prostate cancer cases for the year 2008. We then assessed the number of patients with localized/regional disease and ER+ tumors and those receiving primary ADT (both chemical and surgical) or AI therapy by applying proportions from SEER, published literature, clinical practice, and the claims database. Using these incident case counts, we calculated the 5-year prevalence using appropriate cohort-specific survival rates to sum the number of new and surviving cases over a 5-year period. Results: The estimated 5-year prevalence of early-stage ER+ breast cancer for women aged ≥50 years in the U.S. was 607,411, of which 293,904 (48.4%) were on AI therapy based on the claims database. However, because this data source was limited to women aged <65 years, we also used estimates from clinical practice to capture AI use for women of all ages. Based on clinical practice, 402,637 (66.3%) to 460,156 (75.8%) of early-stage ER+ breast cancer patients were on AI therapy. For early-stage prostate cancer, the estimated 5-year prevalence for all ages was 1,024,238, of which 141,451 (13.8%) were on primary ADT. However, these figures may underestimate current usage of hormone therapies, as our data and the literature show increasing trends in ADT and AI use for early-stage disease. Conclusions: Based on a combination of population-based data and the published literature, approximately half of all early-stage ER+ breast cancer patients and a modest proportion of early-stage prostate cancer patients are on hormone therapy in the U.S.

[Table: see text]