A discrete choice experiment to elicit preferences for a chronic disease screening programme in Queensland, Australia

OBJECTIVE

Patient-centred care, increasingly highlighted in healthcare strategies, necessitates understanding public preferences for healthcare service attributes. We aimed to understand the preferences of the Australian population regarding the attributes of chronic disease screening programmes.

STUDY DESIGN

The preferences were elicited using the discrete choice experiment (DCE) methodology.

METHODS

A DCE was administered to a sample of the Australian general population. Respondents were asked to make choices, each offering two hypothetical screening scenarios defined by screening conduct, quality and accuracy of the test results, cost to the patient, wait time and source of information. Data were analysed using a panel mixed multinomial logit model.

RESULTS

A strong preference for highly accurate screening tests and nurse-led screenings at local health clinics was evident. They expressed disutility for waiting time and out-of-pocket costs but were indifferent about the source of information. Their preference for a nurse-led programme was highlighted by the fact that they were willing to pay $81 and $88 to get a nurse-led programme when they were offered a general practitioner-led and a specialist-led programme, respectively. Furthermore, they were willing to pay $32 to reduce a week of waiting time and $205 for a 95% accurate test compared to a 75% accurate test. Preferences remained consistent irrespective of the respondent's place of residence.

CONCLUSIONS

Our findings highlight the importance of diagnostic test accuracy and nurse-led service delivery in chronic disease screening programmes. These insights could guide the development of patient-centric services by enhancing test accuracy, reducing waiting times and promoting nurse-led care models.

Functional outcomes after Medial Patellofemoral Ligament Reconstruction show inverted J-shaped relation with Body Mass Index

PURPOSE

Medial patellofemoral ligament reconstruction (MPFL-R) is a recognised surgical procedure for the treatment of recurrent patellofemoral instability with excellent outcomes reported. The aim of this study is to determine if body mass index can influence these outcomes.

METHODS

This is a single-centre retrospective analysis of a longitudinal patellofemoral database. Patients with recurrent patellar instability, without patellar alta or severe trochlear dysplasia were treated using a MPFL-R between 2015 and 2019 at The Robert Jones & Agnes Hunt Orthopaedic Hospital. The clinical efficacy following surgery was assessed by Kujula, International Knee Documentation Committee Score (IKDC), and EuroQol-5 score (EQ-5D) at baseline and up to 26 months post-operatively; their safety assessed by complication rate and requirement for further surgery. The effect of Body Mass Index (BMI) on clinical outcome was analysed using linear, curvilinear, and segmented models following propensity score weighting.

RESULTS

A total of 97 patients (97 Knees, mean age 25y) were analysed. Of these, 61 patients had a BMI < 30 kg/m² (mean age 23y, mean BMI 24) of which 7 patients (12.3%) required additional surgery. A further 36 patients had a BMI > 30 kg/m² (mean age 27y, mean BMI 36) of which 2 patients (5.6%) required additional surgery. The re-dislocation rate was 0% in each BMI group. Both groups had a significantly improved mean outcome following surgery, with improvements in mean IKDC above the minimum clinical important differences (MCID) of 20.5. BMI had an inverted J-shaped association with functional outcome, showing peak outcomes at BMI of 20.5 (95% CI 18.5 to 22.4; IKDC and Kujala) or BMI of 28 (EQ-5D index). No evidence for an association between BMI and complication risk was found.

CONCLUSION

BMI influences the functional outcomes in MPFL-R with an inverted J-shaped relation, without evidence it affected the complication or re-dislocation rate. In the absence of patella alta and severe trochlear dysplasia, an isolated MPFL reconstruction is a safe and effective procedure to treat patellar instability, with the best functional outcome in patients with a BMI around 20 to 21.

LEVEL OF EVIDENCE

Level III.

Shark depredation: future directions in research and management

Shark depredation is a complex social-ecological issue that affects a range of fisheries worldwide. Increasing concern about the impacts of shark depredation, and how it intersects with the broader context of fisheries management, has driven recent research in this area, especially in Australia and the United States. This review synthesises these recent advances and provides strategic guidance for researchers aiming to characterise the occurrence of depredation, identify the shark species responsible, and test deterrent and management approaches to reduce its impacts. Specifically, the review covers the application of social science approaches, as well as advances in video camera and genetic methods for identifying depredating species. The practicalities and considerations for testing magnetic, electrical, and acoustic deterrent devices are discussed in light of recent research. Key concepts for the management of shark depredation are reviewed, with recommendations made to guide future research and policy development. Specific management responses to address shark depredation are lacking, and this review emphasizes that a "silver bullet" approach for mitigating depredation does not yet exist. Rather, future efforts to manage shark depredation must rely on a diverse range of integrated approaches involving those in the fishery (fishers, scientists and fishery managers), social scientists, educators, and other stakeholders.

A general swimming response in exhausted obligate swimming fish

Marine organisms normally swim at elevated speeds relative to cruising speeds only during strenuous activity, such as predation or escape. We measured swimming speeds of 29 ram ventilating sharks from 10 species and of three Atlantic bluefin tunas immediately after exhaustive exercise (fighting a capture by hook-and-line) and unexpectedly found all individuals exhibited a uniform mechanical response, with swimming speed initially two times higher than the cruising speeds reached approximately 6 h later. We hypothesized that elevated swimming behaviour is a means to increase energetic demand and drive the removal of lactate accumulated during capture via oxidation. To explore this hypothesis, we estimated the mechanical work that must have been spent by an animal to elevate its swim speed and then showed that the amount of lactate that could have been oxidized to fuel it comprises a significant portion of the amount of lactate normally observed in fishes after exhaustive exercise. An estimate for the full energetic cost of the catch-and-release event ensued.

A general swimming response in exhausted obligate swimming fish

Marine organisms normally swim at elevated speeds relative to cruising speeds only during strenuous activity, such as predation or escape. We measured swimming speeds of 29 ram ventilating sharks from 10 species and of three Atlantic bluefin tunas immediately after exhaustive exercise (fighting a capture by hook-and-line) and unexpectedly found all individuals exhibited a uniform mechanical response, with swimming speed initially two times higher than the cruising speeds reached approximately 6 h later. We hypothesized that elevated swimming behaviour is a means to increase energetic demand and drive the removal of lactate accumulated during capture via oxidation. To explore this hypothesis, we estimated the mechanical work that must have been spent by an animal to elevate its swim speed and then showed that the amount of lactate that could have been oxidized to fuel it comprises a significant portion of the amount of lactate normally observed in fishes after exhaustive exercise. An estimate for the full energetic cost of the catch-and-release event ensued.

Nutrition adequacy, gastrointestinal and hepatic function during extracorporeal membrane oxygenation in critically ill adults: a retrospective observational study

AIMS

To identify clinical and biochemical markers associated with nutrition adequacy and gastrointestinal and liver dysfunction in adults on extracorporeal membrane oxygenation (ECMO).

METHODS

A retrospective, observational, study was conducted at 2 centres in Australia. Adult patients who received ECMO from July 2011 to June 2015 were included. Mode of ECMO used, fluid balance, number of systemic inflammatory response syndrome (SIRS) criteria present, vasoactive-inotropic scores (VIS) and liver function tests (LFTs) were collected for the duration of ECMO until 7 days after ECMO cessation. Multiple regression models were used to determine if the collected variables were associated with nutrition adequacy. The mean LFTs during ECMO were also compared to mean LFTs post ECMO cessation.

RESULTS

During the first 5 days of ECMO commencement, mean nutrition adequacy was 10% higher in the veno-venous (VV) ECMO group than in the veno-arterial (VA) group (95% confidence interval [CI], 2% to 17%). For every 5,000 ml increase of fluid balance, an associated decrease in nutrition adequacy was observed (-8%, 95% CI, -15% to -2%). A doubling of bilirubin and VIS were associated with a mean reduction in nutrition adequacy of -5% (CI -8% to -2%) and -2% (CI, -3% to -1%), respectively.

CONCLUSIONS

In the first 5 days of ECMO commencement, higher nutrition adequacy was associated with the VV mode of ECMO and reduced nutrition adequacy with increased fluid balance, more vasopressor and inotropic support and raised bilirubin. Prospective investigation is required to confirm whether these associations have a causal relationship.

Potential of electric fields to reduce bycatch of highly threatened sawfishes

Sawfishes are among the most threatened families of marine fishes and are susceptible to incidental capture in net fisheries. Since bycatch reduction devices currently used in trawl fisheries are not effective at reducing sawfish catches, new methods to minimise sawfish bycatch are needed. Ideally, these should affect sawfish behaviour and prevent contact with the fishing gear. We tested the effects of electric fields on sawfish behaviour to assess the potential of electric pulses in mitigating sawfish bycatch. Experiments were conducted in a tank where 2 electrodes were suspended in the water column, connected to a pulse generator, and placed across the swimming path of sawfish. Two largetooth sawfish Pristis pristis were tested in control conditions, in the presence of a baseline pulse, and of 5 variations of that pulse where 1 parameter (polarity, voltage, frequency, pulse shape, pulse duration) was altered at a time. Conditional inference trees were used to identify the effects of various parameters (e.g. treatment, individual) on reaction type, reaction distance, twitching presence and duration, and inter-approach times. Sawfish reacted to electric fields, but reaction distances were small (typically <1.2 m), and no field tested consistently led to reactions conducive to escaping from moving nets. The following parameters induced the most response in both individuals: bipolar current, rectangular shaped, 5-10 Hz, ~1500 µs duration, and 100 V. We recommend further research focussing on moving nets, testing a V-shaped electric array preceding the net mouth by at least 5 m, and testing a setup similar to electrotrawling.

Impact of KRAS mutation status on the efficacy of immunotherapy in lung cancer brain metastases

Immune checkpoint inhibitors (ICIs) have resulted in improved outcomes in non-small cell lung cancer (NSCLC) patients. However, data demonstrating the efficacy of ICIs in NSCLC brain metastases (NSCLCBM) is limited. We analyzed overall survival (OS) in patients with NSCLCBM treated with ICIs within 90 days of NSCLCBM diagnosis (ICI-90) and compared them to patients who never received ICIs (no-ICI). We reviewed 800 patients with LCBM who were diagnosed between 2010 and 2019 at a major tertiary care institution, 97% of whom received stereotactic radiosurgery (SRS) for local treatment of BM. OS from BM was compared between the ICI-90 and no-ICI groups using the Log-Rank test and Cox proportional-hazards model. Additionally, the impact of KRAS mutational status on the efficacy of ICI was investigated. After accounting for known prognostic factors, ICI-90 in addition to SRS led to significantly improved OS compared to no-ICI (12.5 months vs 9.1, p < 0.001). In the 109 patients who had both a known PD-L1 expression and KRAS status, 80.4% of patients with KRAS mutation had PD-L1 expression vs 61.9% in wild-type KRAS patients (p = 0.04). In patients without a KRAS mutation, there was no difference in OS between the ICI-90 vs no-ICI cohort with a one-year survival of 60.2% vs 54.8% (p = 0.84). However, in patients with a KRAS mutation, ICI-90 led to a one-year survival of 60.4% vs 34.1% (p = 0.004). Patients with NSCLCBM who received ICI-90 had improved OS compared to no-ICI patients. Additionally, this benefit appears to be observed primarily in patients with KRAS mutations that may drive the overall benefit, which should be taken into account in the development of future trials.

Neutrophil to lymphocyte ratio influences impact of steroids on efficacy of immune checkpoint inhibitors in lung cancer brain metastases

Steroids are often utilized to manage patients with non-small cell lung cancer brain metastases (NSCLCBM). Steroids and elevated neutrophil-to-lymphocyte ratio (NLR) have been associated with decreased overall survival (OS) in patients treated with immune checkpoint inhibitors (ICI). We retrospectively investigated patients treated with ICI after the diagnosis of NSCLCBM at a single tertiary care institution examing the impact of steroids and NLR. Overall survival (OS) and intracranial progression-free survival (PFS) were analyzed. 171 patients treated with ICI for NSCLCBM were included. Thirty-six received steroids within 30 days of the start of ICI, and 53 patients had an NLR ≥ 5 before the start of ICI. Upfront steroids was associated with decreased OS on multivariable analysis (median OS 10.5 vs. 17.9 months, p = .03) and intracranial PFS (5.0 vs. 8.7 months, p = .045). NLR ≥ 5 was indicative of worse OS (10.5 vs. 18.4 months, p = .04) but not intracranial PFS (7.2 vs. 7.7 months, p = .61). When NLR and upfront steroids are modeled together, there is a strong interaction (p = .0008) indicating that the impact of steroids depended on the patient’s NLR. In a subgroup analysis, only in patients with NLR < 4 was there a significant difference in OS with upfront steroids (26.1 vs. 15.6 months, p = .032). The impact of steroids on the efficacy of ICI in patients with NSCLCBM is dependent on the patient's NLR underscoring its importance in these patients. Patients with a low NLR, steroid use decreases the efficacy of ICI. These results can inform clinicians about the impact of steroids in patients treated with ICI.

Sexually dimorphic radiogenomic models identify distinct imaging and biological pathways that are prognostic of overall survival in glioblastoma

BACKGROUND

Recent epidemiological studies have suggested that sexual dimorphism influences treatment response and prognostic outcome in glioblastoma (GBM). To this end, we sought to (i) identify distinct sex-specific radiomic phenotypes-from tumor subcompartments (peritumoral edema, enhancing tumor, and necrotic core) using pretreatment MRI scans-that are prognostic of overall survival (OS) in GBMs, and (ii) investigate radiogenomic associations of the MRI-based phenotypes with corresponding transcriptomic data, to identify the signaling pathways that drive sex-specific tumor biology and treatment response in GBM.

METHODS

In a retrospective setting, 313 GBM patients (male = 196, female = 117) were curated from multiple institutions for radiomic analysis, where 130 were used for training and independently validated on a cohort of 183 patients. For the radiogenomic analysis, 147 GBM patients (male = 94, female = 53) were used, with 125 patients in training and 22 cases for independent validation.

RESULTS

Cox regression models of radiomic features from gadolinium T1-weighted MRI allowed for developing more precise prognostic models, when trained separately on male and female cohorts. Our radiogenomic analysis revealed higher expression of Laws energy features that capture spots and ripple-like patterns (representative of increased heterogeneity) from the enhancing tumor region, as well as aggressive biological processes of cell adhesion and angiogenesis to be more enriched in the "high-risk" group of poor OS in the male population. In contrast, higher expressions of Laws energy features (which detect levels and edges) from the necrotic core with significant involvement of immune related signaling pathways was observed in the "low-risk" group of the female population.

CONCLUSIONS

Sexually dimorphic radiogenomic models could help risk-stratify GBM patients for personalized treatment decisions.

EPID-13. A RETROSPECTIVE ANALYSIS TO STUDY THE SURVIVAL CHARACTERISTICS OF PATIENTS WITH FIRST PROGRESSION OF GLIOBLASTOMA AT THE CLEVELAND CLINIC

BACKGROUND

Glioblastoma (GBM) is the most aggressive primary central nervous system malignancy. The median overall survival is 15 to 18 months with treatment and decreases to nine months after first progression.

METHODS

This is a retrospective study. Data was collected from all patients with first progression of GBM treated at CCF between Jan 2012 to Jan 2020. Eight cohorts of patients were evaluated: Group 1 received cytotoxic chemotherapy, Group 2 received bevacizumab alone, Group 3 received surgical or reirradiation alone, Group 4 were enrolled in clinical trials. Each group was divided into methylated and unmethylated cohorts.

RESULTS

Median overall survival was 12.4 months for patients with first progression of GBM (n= 248). Among the methlylated patients, the median overall survival was 16.5 months for group 1, 13.4 for group 2, 23.7 for group 3, and 17.3 for group 4. Among the unmethylated patients, the Median overall survival was 8.6 months for group 1, 7.7 months for group 2, 11.7 months for group 3 and 10.7 months for group 4. (p= 0.00016). Progression free survival (PFS) was 4.3 months for all patients with first progression of GBM. Among the unmethlylated patients, the PFS was 3.6 months for group 1, 15.3 months for group 2, 4.8 months for group 3, and 6.1 months for group 4. Among the unmethylated patients, the PFS was 2.3 months for group 1, 3.9 months for group 2, 3.8 months for group 3, and 4.4 months for group 4. (p &lt; 0.0001).

CONCLUSION

Patients with first progression of GBM had the best overall survival in the cohort that underwent a surgical or reirradiation. The best progression free survival was for patients who were treated with Bevacizumab if they were methylated and those enrolled in clinical trials if they were unmethylated. The study was statistically significant.

Survival characteristics of patients with first progression of glioblastoma at Cleveland Clinic Foundation

e14526

Background: Glioblastoma (GBM) is the most common primary central nervous system malignancy, with a median overall survival of 14 to 17 months. First progression refers to progressive disease after initial radiation with or without chemotherapy. The median overall survival of patients with the first progression of GBM is nine months. Currently, there is no standard treatment for progressive GBM. Common treatment options include clinical trials, surgical resection, re-irradiation, stereotactic radiosurgery, cytotoxic chemotherapies, bevacizumab, and tumor treating fields. Methods: This retrospective study reviewed 244 patients with the first progression of GBM who were treated at CCF between Jan 2012 to Jan 2020. Statistical analyses included patients who had biopsy-proven GBM, a known MGMT methylation status, a KPS of more than 70 and presented with the first progression on MRI brain. Four cohorts of patients were evaluated: Group 1 received cytotoxic chemotherapy, Group 2 received bevacizumab alone, Group 3 received surgical or radiation therapy alone, Group 4 received experimental treatments. Results: The median overall survival (OS) and progression-free survival (PFS) was 12.4 months (95% CI: 10.9 to 14.3) and 4.3 months (95% CI: 3.9 to 5.4), respectively. The cohorts demonstrate statistical significant differentiation for PFS (p = 0.021) but not OS (p = 0.19). Second progression was noted at a median interval of 5.6 months in Group 4, 4.3 months in Group 2, 3.8 months Group 3 and 3.2 months in Group 1. Conclusions: Patients with the first progression of GBM had a better progression-free survival on experimental clinical trials than those in other cohorts.

CMET-18. IMPACT OF KRAS MUTATION STATUS ON THE EFFICACY OF IMMUNOTHERAPY IN LUNG CANCER BRAIN METASTASES

BACKGROUND

Immunotherapy is increasingly used in patients with non-small cell lung cancer brain metastases (NSCLCBM). KRAS mutations are associated with worse prognosis and there is no FDA approved targeted therapy. KRAS mutations are associated with increased expression of PD-L1. We evaluated the outcomes of NSCLCBM with KRAS mutations treated with immune checkpoint inhibitors (ICI).

METHODS

We reviewed 800 patients with NSCLCBM treated at our tertiary care center. 226 had known KRAS mutational status, 121 of which received immunotherapy. Overall survival (OS) was calculated from either the start of immunotherapy (when both groups received immunotherapy) or from the date of diagnosis of brain metastasis. Kaplan-Meier method and Cox Proportional hazard model were utilized to determine differences in OS and the Chi-square test was utilized to determine differences in PD-L1 expression.

RESULTS

In 109 patients where both KRAS and PD-L1 status were known, KRAS mutations had greater PD-L1 expression (80.1% vs 61.9% positive, p=0.04). There was no difference in OS between KRAS mutant vs KRAS wild-type patients treated with immunotherapy. Median survival from the start of immunotherapy was 15.6 vs 15.5 months respectively (p=0.7), after adjusting for age, KPS, lesion number and extra-cranial metastasis (HR = .91, p=.7). Patients with KRAS mutations treated with immunotherapy versus those who received chemotherapy had a 1-year OS from the diagnosis of brain metastasis of 60.9% vs 38.7% respectively (trending towards significance, p=0.05). KRAS wild-type patients treated with immunotherapy versus those who did not receive immunotherapy had a 1-year OS from the diagnosis of brain metastasis of 61.9% vs 62.5% (p=0.85), respectively.

DISCUSSION

KRAS mutations are associated with increased PD-L1 expression. Use of immunotherapy negates the poor outcomes seen traditionally in patients with NSCLCBM and KRAS mutations and it improves survival compared to use of chemotherapy. Our experience supports the use of immunotherapy in these patients.

CMET-12. EFFICACY OF UPFRONT IMMUNE CHECKPOINT INHIBITORS IN LUNG CANCER BRAIN METASTASIS

INTRO/OBJECTIVE

Immune checkpoint inhibitors (ICI) have improved outcomes in a subset of patients with lung cancer. However, data describing the efficacy of ICI in lung cancer brain metastasis (LCBM) is limited. We analyzed overall survival (OS) in patients with LCBM treated with upfront ICI, defined as having received ICI within 90-days of LCBM diagnosis, compared to non-ICI therapies.

METHODS

We reviewed 665 patients with LCBM diagnosed between 2000 and 2018 at a major tertiary care institution. Of those patients, 240 received ICI, 164 of which received ICI after 90-days and 76 received ICI within 90-days. Propensity score (PS) was calculated by logistic regression model including age, KPS, number of baseline brain lesions, and presence of extra-cranial metastasis (ECM) at time of LCBM diagnosis. OS from LCBM diagnosis between PS matched cohorts were compared using Kaplan-Meier, the Log-Rank test, and Cox proportional hazards models.

RESULTS

Prior to PS matching, median survival between ICI and non-ICI cohorts was not significantly different (10.9 months for both, p=0.81), although more ICI patients had ECM (57.1% vs 40.9%, p=0.006). Following PS matching, the ICI (n=76) and non-ICI (n=76) cohorts had median age (62.4 vs 62.3 years), KPS (80 for both), lesion number (2 for both), and ECM (56.6% for both). Of matched patients, 94% received SRS, 52% received WBRT, and 29% underwent surgical resection. Compared to non-ICI, the ICI cohort had a 2-year OS hazard ratio=0.87 (95% CI=0.58–1.31, p=0.51). Median and 1-year survival were not significantly different between ICI and non-ICI cohorts (median: 10.9 vs 9.1 months; 1-yr: 43.0% vs 42.4%).

CONCLUSION

Patients with LCBM who received ICI within 90-days of their diagnosis did not have improvement in OS compared to patients who received non-ICI therapies. Evaluation of clinical factors that may affect the efficacy and durability of immunotherapy is ongoing and will be presented.

CMET-36. IMMUNOTHERAPY VERSUS STANDARD OF CARE IN MELANOMA BRAIN METASTASES WITH KNOWN BRAF STATUS

INTRO/OBJECTIVE

A mutation of the BRAF protein is seen in approximately 50% of melanoma patients. Immune checkpoint inhibitors (ICI) are standard therapy in melanoma patients independent of a patient’s BRAF status. The primary objective of this study is to investigate the impact of BRAF status in patients treated with ICI compared to non-ICI systemic therapy on overall survival (OS) in patients with melanoma brain metastasis (MBM).

METHODS

We reviewed 351 patients with MBM treated at our tertiary care center between 2000 and 2018. Of these, 144 had known BRAF status, 71 of which were BRAF mutant and 73 were BRAF wild-type. OS was calculated from the date of diagnosis of MBM to compare the efficacy of ICI to other systemic therapies. Many of these patients received multiple lines of treatment including targeted therapies at some point during their care. The log-rank test and Cox proportional hazard model was utilized to determine differences in OS.

RESULTS

Eighty-four percent of patients received local therapy that included either surgery, stereotactic radiosurgery, or whole brain radiation therapy. In BRAF wild-type patients, 40 received ICI and 33 underwent non-ICI systemic therapy with a median survival (5.6 vs 7.1 months) and 2-year survival (28% vs 32%), respectively (p=0.64). Of the BRAF mutant patients, 33 received ICI and 38 did not with a median survival (17.1 vs 9.0 months) and 2-year survival (36% and 19%), respectively (p=0.014). When controlling for age, KPS, ECM, and number of lesions, BRAF mutant MBM patients treated with ICI compared to non-ICI had an OS hazard ratio, HR=0.4 (95% CI=0.21 – 0.78, p=0.0069).

CONCLUSION

ICI therapy in BRAF mutant MBM patients results in improved OS compared to those with non-ICI systemic therapy. No such difference was observed in the BRAF wild-type cohort.

CMET-23. IMPACT OF SYSTEMIC THERAPY IN MELANOMA BRAIN METASTASIS

BACKGROUND

Melanoma is the third most common malignancy that results in brain metastasis and is associated with a median overall survival (OS) of approximately 9 months. In recent years, management of melanoma brain metastases (MBM) by surgery and radiation [stereotactic radiosurgery (SRS) and whole brain radiation therapy (WBRT)] has been bolstered by targeted therapy and immune checkpoint inhibitors (ICI).

METHODS

351 patients, treated for MBM at our tertiary care center from 2000–2018, were grouped into: received chemotherapy, ICI, or targeted therapy. 34% of patients treated with ICI had received other systemic therapies as well as part of their management. OS was calculated from the date of diagnosis of the brain metastases. The Kaplan Meier analysis was utilized to determine median OS and difference in OS was determined by utilizing the Cox proportional hazard model.

RESULTS

The median survival after the diagnosis of brain metastasis was 10.4, 11.96, and 7.06 months in patients who received ICI, chemotherapy and targeted therapy respectively. A multivariate model was developed including the type of systemic therapy, presence of extracranial metastases, age, KPS and number of intracranial lesions. 114 patients underwent SRS alone, 56 underwent SRS and WBRT, 43 underwent SRS and surgical removal, 28 had surgical removal, SRS and WBRT, and 78 had no intracranial therapy. Compared to patients who received chemotherapy, patients who received immunotherapy had a hazard ratio, HR = 0.628 (confidence interval = 0.396 – 0.994, p-value = 0.047). Presence of EC metastases (HR= 1.25, p-value < .001), lower KPS (HR = .97, p-value < .0001) and multiple brain lesions (HR = 1.117, p-value < .0001) were associated with significantly worse OS.

CONCLUSIONS

Addition of ICI significantly improves the OS in MBM compared to chemotherapy. Lower performance status, multiple brain metastases, and EC metastases are associated with poor OS.

PATH-62. QUANTITATIVE ANALYSIS OF SEX-ASSOCIATED MGMT METHYLATION IN NEWLY DIAGNOSED GLIOBLASTOMA

INTRO/OBJECTIVE

Glioblastoma (GBM) and MGMT have been reported to have sexual dimorphism. In multiple studies, including our own population-based cohort analysis, females had higher rates of MGMT methylation and improved methylation-associated progression-free and overall survival outcomes compared to males. MGMT methylation is assessed as a mean of five cysteine-phosphate-guanine (CpG1-5) islands (CpG methylation is highly inversely correlated with MGMT RNA expression). The primary objective of this study was to investigate differences in mean and individual CpG methylation by sex.

METHODS

155 patients who underwent first surgical intervention for newly diagnosed GBM at a single tertiary care institution between 2016 and 2018 were reviewed. Of these, 135 patients had available CpG methylation data determined by a clinically validated test using bisulfate conversion followed by PCR and pyrosequencing. MGMT was defined as methylated if the mean of CpG1-5 ≥ 12. The mean of CpG1-5 and each CpG parameter were compared by sex using the Wilcoxon signed-rank test.

RESULTS

Overall (mean age 62, 34% female, 42% MGMT methylated), the median (IQR) of mean degree of methylation was 4.0% (2–33) and median CpG1-5 ranged from 3.0 to 4.5%. More females (53.3%) were MGMT methylated than males (37.1%). Females had significantly higher rates of mean methylation compared to males (14.0 vs 3.0%, p=0.046). Females also had higher rates of methylation at each CpG island compared to males CpG1(7.0 vs 3.0%, p=0.15), CpG2(8.0 vs 4.0%, p=0.10), CpG3(9.0 vs 4.0%, p=0.23), CpG4(7.0 vs 3.0%, p=0.047), and CpG5(6.0 vs 4.0%, p=0.097).

CONCLUSION

Females had higher rates of mean methylation and methylation of each CpG island compared to males, although only mean and CpG4 methylation values were statistically significant given the limited sample size. Further investigation with a larger cohort is ongoing to elucidate this dimorphism and establish whether sex-specific methylation cut-offs need to be implemented into clinical practice.

PATH-13. SEX-LINKED TUMORAL MGMT STATUS AND OUTCOMES IN NEWLY DIAGNOSED GLIOBLASTOMA

INTRO/OBJECTIVE

Glioblastoma (GBM) and MGMT have been reported to have sexual dimorphism. The primary objective of this study was to analyze the impact and association between sex and MGMT status on progression-free survival (PFS) and overall survival (OS) in patients with newly diagnosed GBM.

METHODS

582 patients with newly diagnosed GBM who underwent first surgical intervention at a single tertiary care institution between 2012 and 2018 were reviewed. Adults with documented methylated (≥ 12) and un-methylated (≤ 7) MGMT status were included. A Kaplan-Meier and Cox proportional hazard models were used to analyze the association between sex and MGMT status on PFS and OS.

RESULTS

464 adult patients (median age 63.4, 36.6% female) had documented MGMT status. Overall rate of MGMT methylated patients was 42.5%, while females were more often methylated than males (52.1% vs 37.4%, p=0.004). MGMT methylated compared to un-methylated females (median: 12.8 vs 7.4 months; 1-yr: 53% vs 27%) had a greater PFS benefit than males (median: 9.6 vs 6.8 months; 1-yr: 44% vs 23%). OS was significantly improved in MGMT methylated compared to un-methylated patients among females (p=0.001) but not among males (p=0.22). Among MGMT methylated patients, females had significantly better OS compared to males (median: 18.7 vs 12.4 months; 2-yr OS: 36.8% vs 24.3%, p=0.03). Although statistically not significant, a similar pattern was observed on PFS (median: 12.8 vs 9.6 months; 1-yr PFS: 52.6% vs 44.4%). Compared to MGMT methylated females, MGMT methylated males had a PFS HR=1.22 (95% CI=0.80 – 1.85, p=0.36), and an OS HR=1.45 (95% CI=1.03 – 2.04, p=0.032).

CONCLUSION

MGMT methylation is more common in females and methylation had a larger impact on both PFS and OS in females compared to males. These analyses highlight the need to further investigate sex differences that can inform clinical management of GBM.

THER-09. IMPACT OF KRAS MUTATION STATUS ON THE EFFICACY OF IMMUNOTHERAPY IN LUNG CANCER BRAIN METASTASES

BACKGROUND: Immunotherapy is increasingly used in patients with non-small cell lung cancer brain metastases (NSCLCBM). KRAS mutations are associated with worse prognosis and there is no FDA approved targeted therapy. KRAS mutations are associated with increased expression of PD-L1. We evaluated the outcomes of NSCLCBM with KRAS mutations treated with immune checkpoint inhibitors (ICI). METHODS: We reviewed 800 patients with NSCLCBM treated at our tertiary care center. 226 had known KRAS mutational status, 121 of which received immunotherapy. Overall survival (OS) was calculated from either the start of immunotherapy (when both groups received immunotherapy) or from the date of diagnosis of brain metastasis. Kaplan-Meier method and Cox Proportional hazard model were utilized to determine differences in OS and the Chi-square test was utilized to determine differences in PD-L1 expression. RESULTS: In 109 patients where both KRAS and PD-L1 status were known, KRAS mutations had greater PD-L1 expression (80.1% vs 61.9% positive, p=0.04). There was no difference in OS between KRAS mutant vs KRAS wild-type patients treated with immunotherapy. Median survival from the start of immunotherapy was 15.6 vs 15.5 months respectively (p=0.7), after adjusting for age, KPS, lesion number and extra-cranial metastasis (HR = .91, p=.7). Patients with KRAS mutations treated with immunotherapy versus those who received chemotherapy had a 1-year OS from the diagnosis of brain metastasis of 60.9% vs 38.7% respectively (trending towards significance, p=0.05). KRAS wild-type patients treated with immunotherapy versus those who did not receive immunotherapy had a 1-year OS from the diagnosis of brain metastasis of 61.9% vs 62.5% (p=0.85), respectively. DISCUSSION: KRAS mutations are associated with increased PD-L1 expression. Use of immunotherapy negates the poor outcomes seen traditionally in patients with NSCLCBM and KRAS mutations and it improves survival compared to use of chemotherapy. Our experience supports the use of immunotherapy in these patients.

THER-10. IMPACT OF BRAF MUTATIONAL STATUS ON THE EFFICACY OF IMMUNOTHERAPY FOR MELANOMA BRAIN METASTASES

BACKGROUND: BRAF mutations occur in 50% of melanoma patients. Targeted agents – BRAF and MEK inhibitors and immunotherapy improve survival of melanoma patients with BRAF mutations. These agents have intracranial efficacy as shown in clinical trials. However, the efficacy of immunotherapies (immune checkpoint blockade) in melanoma brain metastases and the correlation with BRAF status is not as well characterized. METHODS: We reviewed 351 patients with melanoma brain metastases treated at our tertiary care center between 2000 and 2018, 75 of which received immunotherapy with known BRAF mutational status. Two-year, 5-year, and median overall survival (OS) was calculated from the start of immunotherapy to compare the efficacy of immunotherapy in BRAF mutant and BRAF wild type patients using the log-rank test. RESULTS: At the time of diagnosis of brain metastasis, the median age was 61 (23–87) years, median KPS was 80 (50–100), number of intracranial lesions was 2 (1–15), and 79% had extra-cranial metastases. Sixty-three patients were treated with stereotactic radiosurgery (SRS), 27 underwent whole brain radiation (WBRT) and 21 underwent surgery. When treated with immunotherapy, BRAF mutant and BRAF wild type median survival was 15.7 months (95% CI=9.4 – 42.4) and 6.9 (95% CI=4.1– 26.7) months (p-value=0.205), respectively. Two-year BRAF mutant and BRAF wild type survival was 35% (95% CI=21 – 58) and 28% (95% CI=16 – 51), and 5-year survival was 22% (95% CI=10 – 46) and 23% (95% CI=11 – 47), respectively. CONCLUSIONS: Twenty percent of patients with BRAF mutant and BRAF wild-type patients treated with immunotherapy derive a long-term benefit from immunotherapy and multimodality treatment and are alive 5 years from diagnosis of brain metastases. This was rarely seen in the pre-immunotherapy era in melanoma brain metastases. There was no difference in outcome based on the BRAF mutational status with use of immunotherapy in melanoma brain metastases.

THER-16. EFFICACY OF UPFRONT IMMUNE CHECKPOINT INHIBITORS IN LUNG CANCER BRAIN METASTASIS

INTRODUCTION: Immune checkpoint inhibitors (ICI) have resulted in improved outcomes in a subset of patients with lung cancer. However, data describing the efficacy of ICI in lung cancer brain metastasis (LCBM) is limited. We analyzed overall survival (OS) in patients with LCBM treated with upfront ICI, defined as having received ICI within 90 days of LCBM diagnosis, compared to non-ICI therapies. METHODS: We reviewed 665 patients with LCBM who were diagnosed between 2000 and 2018 at a major tertiary care institution. Of those patients, 240 received ICI, 164 of which received ICI after 90 days and 76 received ICI within 90 days. Propensity score (PS) was calculated using a logistic regression model including age, KPS, number of baseline brain lesions, and presence of extra-cranial metastasis (ECM) at the time of BM diagnosis. OS from BM diagnosis between PS matched cohorts were compared using Kaplan-Meier, the Log-Rank test, and Cox proportional hazards model. RESULTS: Prior to PS matching, median survival between ICI and non-ICI cohorts was not significantly different (10.9 months for both, p=0.81), although more ICI patients had ECM (57.1% vs 40.9%, p=0.006). Following PS matching, the ICI (n=76) and non-ICI (n=76) cohorts had a median age (62.4 vs 62.3 years), KPS (80 for both), lesion number (2 for both), and ECM (56.6% for both). Of matched patients, 94% received SRS, 52% received WBRT, and 29% underwent surgical resection. Compared to non-ICI, the ICI cohort has a 2-year OS hazard ratio, HR=0.87 (95% CI=0.58–1.31, p=0.51). Median and 1-year survival were not significantly different between ICI and non-ICI cohorts (median: 10.9 vs 9.1 months; 1-yr: 43.0% vs 42.4%). CONCLUSION: Patients with BM from primary lung cancer who received ICI within 90 days of their BM diagnosis did not have improvement in OS compared to patients who received non-ICI therapies.

THER-13. IMMUNOTHERAPY VERSUS STANDARD OF CARE IN MELANOMA BRAIN METASTASES WITH KNOWN BRAF STATUS

BACKGROUND: A mutation of the BRAF protein is seen in approximately 50% of melanoma patients. Immune checkpoint inhibitors (ICI) are standard therapy in melanoma patients independent of a patient’s BRAF status. The primary objective of this study is to investigate the impact of BRAF status in patients treated with ICI compared to non-ICI systemic therapy on overall survival (OS) in patients with melanoma brain metastasis (MBM). METHODS: We reviewed 351 patients with MBM treated at our tertiary care center between 2000 and 2018. Of these, 144 had known BRAF status, 71 of which were BRAF mutant and 73 were BRAF wild-type. OS was calculated from the date of diagnosis of brain metastasis to compare the efficacy of ICI to other systemic therapies. Many of these patients received multiple lines of treatment including targeted therapies at some point during their care. The log-rank test and Cox proportional hazard model was utilized to determine differences in OS. RESULTS: Eighty-four percent of patients received local therapy that included either surgery, stereotactic radiosurgery or whole brain radiation therapy. In BRAF wild-type patients, 40 received ICI and 33 underwent non-ICI systemic therapy with a median survival (5.6 vs 7.1 months) and 2-year survival (28% vs 32%), respectively (p=0.64). Of the BRAF mutant patients, 33 received ICI and 38 did not with a median survival (17.1 vs 9.0 months) and 2-year survival (36% and 19%), respectively (p=0.014). When controlling for age, KPS, ECM, and number of lesions, BRAF mutant MBM patients treated with ICI compared to non-ICI had an OS hazard ratio, HR=0.4 (95% CI=0.21 – 0.78, p=0.0069). CONCLUSIONS: ICI therapy in BRAF mutant MBM patients results in improved OS compared to those with non-ICI systemic therapy. No such difference was observed in the BRAF wild-type cohort.

THER-02. IMPACT OF SYSTEMIC THERAPY IN MELANOMA BRAIN METASTASIS

BACKGROUND: Melanoma brain metastasis is associated with a median overall survival (OS) of approximately 9 months. In recent years, management of melanoma brain metastases (MBM) by surgery and radiation [stereotactic radiosurgery (SRS) and whole brain radiation therapy (WBRT)] has been bolstered by targeted therapy and immune checkpoint inhibitors (ICI). METHODS: 351 patients, who underwent treatment for MBM at our tertiary care center from 2000 to 2018, were grouped into those that received chemotherapy, ICI, or targeted therapy. Thirty-four percent of patients treated with ICI had received other systemic therapies as well as part of their management. OS was calculated from the date of diagnosis of the brain metastases. The Kaplan Meier analysis was utilized to determine median OS and difference in OS was determined by utilizing the Cox proportional hazard model. RESULTS: The median survival after the diagnosis of brain metastasis was 10.4, 11.96, and 7.06 months in patients who received ICI, chemotherapy and targeted therapy respectively. A multivariate model was developed including the type of systemic therapy, presence of extracranial metastases, age, KPS and number of intracranial lesions. 114 patients underwent SRS alone, 56 underwent SRS and WBRT, 43 underwent SRS and surgical removal, 28 had surgical removal, SRS and WBRT, and 78 had no intracranial therapy. Compared to patients who received chemotherapy, patients who received immunotherapy had a hazard ratio, HR = 0.628 (confidence interval = 0.396 – 0.994, p-value = 0.047). Presence of EC metastases (HR= 1.25, p-value &lt; .001), lower KPS (HR = .97, p-value &lt; .0001) and multiple brain lesions (HR = 1.117, p-value &lt; .0001) were associated with significantly worse OS. CONCLUSIONS: Addition of ICI significantly improves the OS in MBM compared to chemotherapy. Lower performance status, multiple brain metastases, and EC metastases are associated with poor OS.

Absolute lymphocyte count in patients with glioblastoma treated with temozolomide chemoradiation

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Background: Standard glioblastoma (GBM) management includes radiotherapy, chemotherapy, and steroids; all of which can result in immunosuppression and a low absolute lymphocyte count (ALC). Previous literature identified an association between low CD4 and worse progression free survival (PFS) and overall survival (OS). There remains a lack of research addressing predictors of immunosuppression in patients with GBM. The primary objective of this study is to identify the degree of immunosuppression, measured by ALC, in GBM patients receiving concurrent temozolomide chemoradiation (CRT). Secondary objectives include associations between ALC, PFS, and OS, and whether there are any predictors of immunosuppression in patients with GBM. Methods: We retrospectively reviewed 231 newly diagnosed GBM patients who underwent surgery followed by standard of care CRT. We also analyzed the association between ALC and age, sex, MGMT methylation status, and extent of surgical resection. ALC was collected at the time of surgery, CRT start date, and two, four, six, and ten weeks post-CRT start date. Common Terminology Criteria for Adverse Events (CTCAE) protocol version 5.0 was then used to grade low ALC as grade 0, 1, 2, 3, or 4. Results: Of the 231 patients analyzed, 139 were males, 74 underwent gross total resection of the tumor, 129 patients were less than 65 years, and 79 (42.5%) were MGMT methylated. 37 patients had grade 3-4 low ALC. In a univariate analysis, grade 3-4 low ALC at 4 weeks (±14 days) post-CRT start was associated with higher mortality (HR 1.54, P = 0.028) but had no significant association with PFS (HR 1.22, P = 0.29). Logistic regression analysis was used to identify risk factors for grade 3-4 low ALC and its association with survival. None of the risk factors that we tested such as age, gender, type of surgery, or molecular markers including MGMT, IDH, or EGFR were associated with low ALC. Conclusions: Our study demonstrated that patients with ALC grade 3 or 4 at 4 weeks (±14 days) of CRT had a significantly higher mortality (HR 1.54, P = 0.028) but had no significant association with PFS (HR 1.22, P = 0.29).

Albumin levels and Prognostic Nutritional Index in glioblastoma

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Background: Albumin levels are widely used to estimate patients’ nutritional status. Low perioperative albumin levels are associated with worse outcomes. Moreover, Prognostic Nutritional Index (PNI), which is calculated from serum albumin levels and peripheral blood lymphocyte count as follows: PNI = (Albumin x 10) + (0.005 x ALC), has been used to predict both short and long term outcomes in patients with wide variety of tumors. The primary objective of this study was to characterize perioperative albumin levels and PNI in newly diagnosed GBM patients. Secondary objectives included associations between albumin levels and PNI on progression free survival (PFS) and overall survival (OS). Methods: We retrospectively reviewed 568 newly diagnosed GBM patients who underwent surgery followed by standard of care chemoradiation. We analyzed the association between albumin and PNI on age, sex, MGMT methylation status, and extent of surgical resection on PFS and OS using a multivariate Cox proportional hazard model. Results: Of the 568 patients collected, 355 (62.5%) were males, 158 (27.8%) had gross total resection of the tumor, and 197(42.5%) were MGMT methylated. Both albumin and PNI were associated with OS but not PFS. The hazard ratio (HR) for OS among the top 2 quartiles of both albumin level and PNI were significantly higher than the bottom two quartiles. The median albumin level was 4.0 and the median PNI was 40. The point for significant high hazard ratio (HR) was around median value for both Albumin and PNI based on restricted cubic spine Cox regression models. The Kaplan-Meir (KM) estimated median OS was 15.2 months for albumin > 4, and 7.6 for albumin ≤4. The KM estimated median OS was 14.6 months for PNI > 40, and 5.7 for PNI≤40 (P logrank < 0.001 for both). While controlling for other factors that may also be associated with early death including age, gender, surgery type and MGMT status, HR = 1.9 (95% CI = 1.4- = 2.6) for Albumin < 4, and HR = 2.1 (95% CI = 1.5- 3.0) for PNI < 40 compared to their counterpart. Conclusions: Glioblastoma patients with perioperative albumin > 4 had a median OS of 15.2 months and 7.6 months for albumin ≤4, and a median OS of 14.6 months for PNI > 40 and 5.7 months for PNI≤40 (P logrank < 0.001 for both).

Impact of EGFR amplification status in newly diagnosed glioblastoma treated with Stupp protocol

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Background: Standard post-surgical glioblastoma (GBM) treatment, per Stupp protocol, includes six-weeks of concurrent Temozolomide chemoradiation followed by at least six cycles of adjuvant-Temozolomide. Previous investigations into epidermal growth factor receptor (EGFR) amplification as a prognostic factor in GBM have yielded contradicting results, requiring further investigation. The primary aim of this study was to determine the degree to which EGFR amplification, in newly diagnosed GBM, impacted progression free survival (PFS) and overall survival (OS). Methods: Data from 582 patients who underwent surgical intervention for GBM at a tertiary care institution between 2012 and 2018 were analyzed. Only adult patients who underwent treatment per Stupp protocol and had pathological analysis on EGFR and CEP7 were included. Amplification and non-amplification status was calculated by a ratio of EGFR/CEP7 > 2 and < 2, respectively. PFS and OS outcomes were compared using Cox proportional hazard models stratified by surgery type and sex. Results: Of the original 582 patients, 122 were treated per Stupp protocol and had documented EGFR analysis. Of patients who were EGFR amplified, 41 (58.5%) were male and 25 (48.1%) were female (p = 0.38) and median amplification was 1.07 and 1.16 (p < 0.001), respectively. EGFR non-amplified patients had a PFS hazard ratio, HR = 0.70 (95% CI = 0.44 – 1.12, p = 0.14); and an OS HR = 0.60 (95% CI = 0.35 – 1.03, p = 0.065). When the EGFR/CEP7 ratio was stratified by quartile, it was found that Q4 compared to Q1 (Q4 > 6.50 vs 0 < Q1 ≤ 1.06) had a PFS HR = 2.1 (95% CI = 1.11 – 4.07, p = 0.024); and an OS HR = 2.48 (95% CI = 1.10 – 5.60, p = 0.028). Conclusions: There was no statistical difference in prevalence of EGFR amplification by sex. However, despite statistical significance, there was minimal difference in median degree of amplification by sex (0.09). Trends begin to show that patients who were EGFR non-amplified had better PFS and OS outcomes than patients who were EGFR amplified, although this was not statistically significant. Patients with very high EGFR amplification (Q4) had significantly poorer PFS and OS outcomes than patients with very low EGFR amplification (Q1).

Trends and determinants of weight gains among OECD countries: an ecological study

OBJECTIVES

Obesity has become a global issue with abundant evidence to indicate that the prevalence of obesity in many nations has increased over time. The literature also reports a strong association between obesity and economic development, but the trend that obesity growth rates may converge over time has not been examined. We propose a conceptual framework and conduct an ecological analysis on the relationship between economic development and weight gain. We also test the hypothesis that weight gain converges among countries over time and examine determinants of weight gains.

STUDY DESIGN

This is a longitudinal study of 34 Organisation for Economic Cooperation and Development (OECD) countries in the years 1980-2008 using publicly available data.

METHODS

We apply a dynamic economic growth model to test the hypothesis that the rate of weight gains across countries may converge over time. We also investigate the determinants of weight gains using a longitudinal regression tree analysis.

RESULTS

We do not find evidence that the growth rates of body weight across countries converged for all countries. However, there were groups of countries in which the growth rates of body weight converge, with five groups for males and seven groups for females. The predicted growth rates of body weight peak when gross domestic product (GDP) per capita reaches US$47,000 for males and US$37,000 for females in OECD countries. National levels of consumption of sugar, fat and alcohol were the most important contributors to national weight gains.

CONCLUSION

National weight gains follow an inverse U-shape curve with economic development. Excessive calorie intake is the main contributor to weight gains.