Arterial stiffness for the early prediction of pre-eclampsia compared with blood pressure, uterine artery Doppler and angiogenic biomarkers: a prospective cohort study

OBJECTIVE

Our aim was to evaluate the ability of arterial stiffness parameters to predict pre-eclampsia early compared with peripheral blood pressure, uterine artery Doppler and established angiogenic biomarkers.

DESIGN

Prospective cohort study.

SETTING

Tertiary care antenatal clinics in Montreal, Canada.

POPULATION

Women with singleton high-risk pregnancies.

METHODS

In the first trimester, arterial stiffness was measured by applanation tonometry, along with peripheral blood pressure and serum/plasma angiogenic biomarkers; uterine artery Doppler was measured in the second trimester. The predictive ability of different metrics was assessed through multivariate logistic regression.

MAIN OUTCOME MEASURES

Arterial stiffness (carotid-femoral pulse wave velocity, carotid-radial pulse wave velocity) and wave reflection (augmentation index, reflected wave start time), peripheral blood pressure, ultrasound indices of velocimetry and circulating angiogenic biomarker concentrations.

RESULTS

In this prospective study, among 191 high-risk pregnant women, 14 (7.3%) developed pre-eclampsia. A first-trimester 1 m/s increase in carotid-femoral pulse wave velocity was associated with 64% increased odds (P < 0.05), and a 1-millisecond increase in time to wave reflection with 11% decreased odds for pre-eclampsia (P < 0.01). The area under the curve of arterial stiffness, blood pressure, ultrasound indices and angiogenic biomarkers was 0.83 (95% confidence interval [CI] 0.74-0.92), 0.71 (95% CI 0.57-0.86), 0.58 (95% CI 0.39-0.77), and 0.64 (95% CI 0.44-0.83), respectively. With a 5% false-positive rate, blood pressure had a sensitivity of 14% for pre-eclampsia and arterial stiffness a sensitivity of 36%.

CONCLUSIONS

Arterial stiffness predicted pre-eclampsia earlier and with greater ability than blood pressure, ultrasound indices or angiogenic biomarkers.

Prognostic biomarkers and clinical outcomes in neuroendocrine prostate cancer (NEPC)

209

Background: NEPC includes both pure small cell carcinoma and mixed tumors with varying degrees of adenocarcinoma and neuroendocrine histology. It arises de novo or is treatment associated (TA) post androgen deprivation therapy. Clinical outcome data and prognostic biomarkers are limited and were thus explored. Methods: Patients with high grade prostate cancer and morphologic and/or immunohistochemical (IHC) NEPC features were included in this retrospective multicentre study. Clinical stage, Gleason score, and serum biomarkers were recorded. Kaplan-Meier method and log-rank test calculated and compared overall survival (OS) from time of NEPC diagnosis.Cox proportional hazards regression assessed prognostic impact of serum biomarkers at diagnosis and de novo vs TA status, adjusting for clinical stage and castration resistance. Results: 135 NEPC cases were identified. 124 (92%) were mixed tumors. 56 (41%) arose de novo. 79 (59%) were TA. 77% of those with a Gleason score (N=85/110) were grade group 5. Median PSA pre-NEPC biopsy was 11.6 ng/mL. At NEPC diagnosis, 19 (14%) had localized disease (median OS 123.0 mo); 33 (24%) non-metastatic castrate-sensitive disease (median OS 42.3 mo); 6 (4%) non-metastatic castrate-resistant disease (median OS 14.3 mo); 35 (26%) metastatic castrate-sensitive disease (median OS 17.6 mo); and 42 (31%) metastatic castrate-resistant disease (median OS 9.6 mo). Median OS for those with visceral metastases was 8.6 mo (95% CI 6.0 – 14.6), compared to patients with non-visceral metastases (11.1 mo; 95% CI 13.7 – 21.5) and no metastases (42.3 mo; 95% CI 47 – 89). Anemia (adjusted HR 1.66; 95% CI 1.05 - 2.16, p = 0.031) and NLR >3 (adjusted HR 1.51; 95% CI 1.01 - 2.52, p = 0.045) were associated with increased risk of death. De novo disease, elevated LDH, serum PSA, and Gleason score were not prognostic. Conclusions: This study identifies NEPC clinical outcomes by stage, with survival poorer than expected in pure prostate adenocarcinoma. Anemia and elevated NLR >3 are prognostic biomarkers that may help risk stratify and guide treatment intensification, including platinum-based chemotherapy. Further biomarker characterization of NEPC through IHC-staining pattern and genomic analysis is currently underway by this group.

Advanced practice physiotherapy care in emergency departments for patients with musculoskeletal disorders: a pragmatic cluster randomized controlled trial and cost analysis

BACKGROUND

Advanced practice physiotherapy (APP) models of care where physiotherapists are primary contact emergency department (ED) providers are promising models of care to improve access, alleviate physicians' burden, and offer efficient centered patient care for patients with minor musculoskeletal disorders (MSKD).

OBJECTIVES

To compare the effectiveness of an advanced practice physiotherapist (APPT)-led model of care with usual ED physician care for persons presenting with a minor MSKD, in terms of patient-related outcomes, health care resources utilization, and health care costs.

METHODS

This trial is a multicenter stepped-wedge cluster randomized controlled trial (RCT) with a cost analysis. Six Canadian EDs (clusters) will be randomized to a treatment sequence where patients will either be managed by an ED APPT or receive usual ED physician care. Seven hundred forty-four adults with a minor MSKD will be recruited. The main outcome measure will be the Brief Pain Inventory Questionnaire. Secondary measures will include validated self-reported disability questionnaires, the EQ-5D-5L, and other health care utilization outcomes such as prescription of imaging tests and medication. Adverse events and re-visits to the ED for the same complaint will also be monitored. Health care costs will be measured from the perspective of the public health care system using time-driven activity-based costing. Outcomes will be collected at inclusion, at ED discharge, and at 4, 12, and 26 weeks following the initial ED visit. Per-protocol and intention-to-treat analyses will be performed using linear mixed models with a random effect for cluster and fixed effect for time.

DISCUSSION

MSKD have a significant impact on health care systems. By providing innovative efficient pathways to access care, APP models of care could help relieve pressure in EDs while providing efficient care for adults with MSKD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05545917 . Registered on September 19, 2022.

Stage migration of testicular germ cell tumours in Alberta, Canada, during the COVID-19 pandemic: a retrospective cohort study

BACKGROUND

An absence of screening recommendations and the rapid progression of testicular germ cell tumours (TGCTs) offer a perspective on the potential impact of the COVID-19 pandemic on cancer presentations. We evaluated the presenting cancer stages of TGCTs in a real-world population before and during the pandemic to assess stage migration.

METHODS

We performed a retrospective review of all new patients with TGCT diagnoses in Alberta, Canada, from Dec. 31, 2018, to Apr. 30, 2021, using the Alberta Cancer Registry. Because potential changes in staging should not occur instantaneously, we used a 6-month lag time from Apr. 1, 2020, for seminomas, and a 3-month lag time for nonseminomas, to compare initial cancer stages at presentation before and during the pandemic. We evaluated monthly rates of presentation by stage and histology. Exploratory outcomes included the largest tumour dimension, tumour markers and, for advanced disease, risk category and treatment setting.

RESULTS

Of 335 patients with TGCTs, 231 were diagnosed before the pandemic and 104 during the pandemic (using a lag time). In total, 18 (7.8%) patients diagnosed before the pandemic presented with stage III disease, compared to 16 (15.4%) diagnosed during the pandemic (relative risk 1.97, 95% confidence interval [CI] 1.05-3.72). We observed no significant differences for secondary outcomes. Without a lag time, the rate ratio for a stage II presentation decreased significantly during the pandemic (0.40, 95% CI 0.21-0.72).

INTERPRETATION

We observed signs of TGCT stage migration during the COVID-19 pandemic, driven by a decline in stage II disease and a potential rise in stage III disease. Management of TGCTs should remain a priority, even during a global pandemic.

Analysis of the role of PI3K-AKT and DNA damage repair (DDR) genomic biomarkers as predictors of clinical outcomes in nonmetastatic castration-resistant prostate cancer (nmCRPC)

175

Background: Clinically relevant outcomes in nmCRPC treated with androgen receptor-axis-targeted therapies (ARAT) may be inferior in patients with tumors harboring mutations bypassing androgen receptor signalling. This final update of a retrospective, multicenter analysis explores the association between genomic mutations in the PI3K-AKT and DDR signalling pathways with ARAT treatment outcomes in nmCRPC patients. Methods: Relevant clinical endpoint were collected for high-risk nmCRPC patients treated with an ARAT at APCaRI affiliated cancer centers, including median metastasis-free survival (MFS), overall survival (OS), PSA decline ≥ 50% (PSA50), and second progression free survival (PFS2). Archival tumor tissue was accessed for next generation gene sequencing, examining for genomic alterations in 500 genes, including those involved in the DDR and the PI3K-AKT signalling pathways. Comparison of outcomes of patients with DDR and PI3K-AKT pathway mutations was conducted using Cox proportional hazards regression using wildtype cases as the reference group, adjusting for PSA doubling time and pelvic lymphadenopathy. Results: Of the 37 patients included, 30 (82%) received apalutamide, 5 (13%) received darolutamide, and 2 (6%) received enzalutamide. 10 patients (27%) had PI3K-AKT pathway mutations (4 PTEN, 3 PIK3Ca, 2 PIK3C2G, 1 PIK3C2b), 8 patients (22%) had DDR gene mutations (3 ATM, 2 CHEK1, 1 BRCA2, 1 CDK12, 1 CHEK2, 1 FANCD2, 1 FANCL), and 1 patient (3%) had 2 MLH1 mutations (microsatellite instability). Of those who had subsequent treatment, 1 received enzalutamide and 5 received abiraterone. Patients with PI3K-AKT pathway mutations had significantly shorter MFS (4.8 mo; HR 4.2; 95% CI 1.2 – 15.0; p = 0.025). Those with DDR mutations had a trend towards shorter MFS (23.3 mo HR 3.7; 95% CI 0.71 – 13.4; p = 0.134). OS data remains immature. 4 (11%) patients did not achieve PSA50, including a patient with 2 MLH1 mutations. Conclusions: This final analysis demonstrates that nmCRPC with PI3K and DDR signalling pathway mutations have poor clinical outcomes when treated with ARAT, likely secondary to decreased reliance on the androgen receptor signalling pathway. These results highlight the potential value of exploring targeted therapies, such as PARP or AKT inhibitors in patients with these mutations.

Association between oncology drug review times and public funding recommendations

99

Background: New oncology drugs undergo detailed review of clinical, economic, and patient data. Thoroughly assessing these data can require lengthy review processes, in the absence of accelerated approval pathways. The aim of this study was to assess how cancer drug review times impact public funding recommendations. Methods: Drugs reviewed by Canada’s health technology assessment body, the pan-Canadian Oncology Drug Review (pCODR), from April 2012 to November 2020 were included in this study. Data was collected including Health Canada approval date, initial and final funding recommendations, treatment intent, drug class, clinical indication (tumour type) and incremental cost-effectiveness ratios (ICER). Univariable and multivariable analyses were used to determine the association between funding recommendations and review times. Results: Of the 227 applications submitted to pCODR, 168 had received positive funding recommendations. Amongst the total drug applications, 24 (14.3%) drugs were intended for the treatment of thoracic cancers, 19 (11.3%) for gastrointestinal cancers, 17 (10.1%) for genitourinary cancers, 17 (10.1%) for breast cancer, and 91 (54.2%) for other tumour sites. Median time from pCODR submission to final recommendation was longer for drugs indicated for the treatment of lung and breast cancer compared to those indicated for treatment of other tumours (223 vs. 212 vs. 203 days, respectively; Kruskal-Wallis p = 0.0322). Drugs with longer review times were more likely to receive a negative pCODR recommendation, even when adjusting for ICER (157 vs 298 days, Wilcoxon p-value = 0.0003). There was no association between positive or negative funding recommendation and tumour type. Conclusions: Oncology drugs with longer review times are less likely to receive recommendation for public funding in Canada. Addressing factors contributing to variance in review times and standardizing the review process can ensure equitable access to cancer drugs.

Pulse-shape discrimination against low-energy Ar-39 beta decays in liquid argon with 4.5 tonne-years of DEAP-3600 data

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

Retrospective cohort analysis of real-world clinical outcomes in nonmetastatic (M0) castration-resistant prostate cancer (CRPC) treated with novel androgen receptor pathway inhibitors (ARPI)

51

Background: The landscape of M0 CRPC has changed with the recent demonstration of metastasis-free survival (MFS) and overall survival (OS) improvements with the use of ARPIs in clinical trial settings. However, the extrapolation of this data to clinical practice is limited by strict exclusion criteria in these trials, including prior or concurrent malignancy, cardiovascular disease, or hypertension. The purpose of this study was to assess real-world outcomes in patients with M0 CRPC treated with ARPIs compared to historical controls. Methods: We designed a retrospective cohort study with the inclusion of patients in Alberta, Canada diagnosed with M0 CRPC between 2001-2020. Via chart review, we identified baseline characteristics, potential confounders, treatment details, and clinical outcomes. The primary outcome of interest was MFS. Secondary outcomes included: second progression-free survival (PFS2) and OS. Median survival times were measured using the Kaplan-Meier method and the log-rank test was used for comparison of outcomes based on ARPI exposure. Cox proportional hazard regression models were used to calculate hazard ratios (HR) accounting for impact of PSA doubling time (PSADT), use of osteoclast inhibiting agents, and presence of pelvic lymphadenopathy. Results: We identified 211 patients across multiple centres in Alberta with M0 CRPC, with 54 having received apalutamide (40/54), enzalutamide (7/54), or darolutamide (7/54). Median age at M0 CRPC diagnosis was 74 years; median PSADT was 4.4 months; and 19% of patients (40/211) had pelvic lymphadenopathy at diagnosis. Median MFS in patients treated with ARPIs was 47.5 months compared to 20.6 months in those not treated with ARPIs (HR, 0.23; 95% confidence interval [CI], 0.11-0.49; p < 0.001). Median PFS2 in ARPI treated patients was 66.3 months compared with 35.6 months (HR, 0.40; 95% CI, 0.18-0.87; p = 0.022). Median OS for patients treated with ARPI was not reached. Conclusions: Given the older age of men with advanced prostate cancer, real-world outcomes that include patients with comorbidities are important adjuncts to the interpretation of clinical trials exploring the benefit of novel therapeutics. Here, we demonstrate that in a real-world, unselected population of men with M0 CRPC, apalutamide, enzalutamide, and darolutamide seem to confer similar MFS and PFS2 benefits to those demonstrated in the SPARTAN, PROSPER, and ARAMIS studies. Real-world OS data remain immature and will be an important addition to these findings.

Sequence decision making for cabazitaxel (Cbz) versus abiraterone (Abt) or enzalutamide (Enz) post-docetaxel (Dtx) in a publicly funded health care system

57

Background: The TROPIC trial demonstrated an overall survival (OS) benefit of Cbz after Dtx in metastatic castrate-resistant prostate cancer (mCRPC). However, the novel anti-androgens (NAA) Abi and Enz have demonstrated similar improvements post-Dtx. The recent CARD trial suggests Cbz may provide the greatest OS benefit in selected patients who were rapid progressors ( < 12 months, RP) on first NAA, however Cbz use and efficacy in the real-world is uncertain. We sought to quantify the real-world use of Cbz and evaluate outcomes post-Dtx. Methods: mCRPC patients who received Dtx at the two tertiary referral centres in the Canadian province of Alberta from October 2012 (Cbz funding approval) to December 31st 2017 were assessed. We examined Cbz eligibility per TROPIC and CARD trial criteria, tracked therapies received, and documented objective and subjective reasoning for therapeutic decisions. OS was measured using the Kaplan-Meier method and the log-rank test was used to compare outcomes. The Chi-Square test was used to compare relative therapy utilization. Results: 463 mCRPC patients received Dtx over the study period, including 83 (18%) for castrate sensitive disease. At Dtx progression, 262 patients (56%) were eligible for Cbz per TROPIC trial criteria, while only 162 (62%) of those were RP on first NAA. Post-Dtx OS was lower among TROPIC-eligible patients receiving Cbz compared to those receiving Abi or Enz (9.1 vs 14.2 months, p = 0.001). This OS difference was not demonstrated among RP patients (11.2 vs 12 months, p = 0.664). The most common reasons for TROPIC ineligibility were Dtx intolerance (13%), serious comorbidities (12%), unacceptable blood counts (11%), performance status (9%) or, for CARD ineligible patients, no progression within 12 months on first NAA (38%). The most common agent immediately post-Dtx was Abi (n = 180, 39%), followed by Enz (n = 129, 28%). Significantly fewer patients (n = 56, 12%) received Cbz immediately post-Dtx (p = 0.001), and 149 (32%) received Cbz overall. First line post-Dtx, 286 patients (62%) did not have a documented discussion about Cbz, and in 172 cases (38%) consideration of Cbz was never documented. Patient choice against Cbz chemotherapy was recorded in 15% of discussions. Conclusions: In a real-world cohort of mCRPC patients, Cbz was a significantly less common choice than Abi or Enz after progression on Dtx. In a majority of these cases, no first line discussion of Cbz was documented, and in documented discussions, patient choice was the driving factor in a minority. OS post-Dtx in patients who met TROPIC trial criteria was lower for those receiving Cbz, noting that, unlike in TROPIC, these patients also received NAAs. This OS difference was not seen in those who also progressed rapidly on first NAA. These data suggest ongoing hesitation towards Cbz use in mCRPC and support careful selection of patients who may obtain benefit.

0682 Evaluation Of An Incentive-based Intervention To Improve 90-day Adherence In Pap-naive Patients

Introduction

Although PAP therapy is the gold standard treatment for obstructive sleep apnea, adherence to treatment is suboptimal. Without sustained therapy adherence, patients are at risk of serious negative health outcomes. The objective of this study was to test whether a digitally delivered monetary and social reward program helped patients new to PAP therapy. Financial incentive schemes are effective in helping patients adhere to difficult medication or therapy plans. Additionally, there is an abundance of evidence that social support is a critical component to long-term health behavior change.

Methods

This prospective, randomized, single site pilot is evaluating the effectiveness of an app-based intervention in helping patients adhere to PAP therapy. The financial incentive design leverages loss aversion, and the social incentive design leverages the strength of close ties and variable reinforcement. The primary endpoint is mean PAP usage at 3 months. Secondary endpoints include Medicare compliance, change in functional status, and baseline scores of perceived disease severity, claustrophobia, coping skills, and health literacy as moderators of the intervention’s effectiveness. Study recruitment is ongoing, with an expected sample size of 150 subjects.

Results

Of the 132 subjects enrolled, 56% are male, 61% are Caucasian, and 65% are married. The mean age is 49.6 ± 12.0 years and mean BMI is 32.4 ± 8.4 kg/m2. Additional demographics such as income level, education level, and number of children along with the primary and secondary endpoints will be presented. A subgroup analysis of the primary endpoint will be generated for subjects identified as strugglers within the first 3 days of usage.

Conclusion

The results of this study will provide insight into methods such as financial and social incentives delivered via a smartphone on initial compliance with PAP therapy, as well as provide more information on the behavioral change associated with beginning PAP therapy.

Support

ResMed

Metastasis-free survival as a predictor of overall survival in non-metastatic castration-resistant prostate cancer

201

Background: Recent trials have shown that apalutamide and enzalutamide can improve metastasis free survival (MFS) in advanced non-metastatic (M0) castrate-resistant prostate cancer (CRPC). MFS is a novel clinical endpoint, demonstrated to be a strong predictor of overall survival (OS) for localized prostate cancer, yet it is unknown if this is also true for M0 CRPC. Our aim was to determine how strongly MFS in M0 CRPC correlates with OS in a real world population. Secondary analyses evaluated whether a rapid PSA-doubling time (PSADT), of ≤10 months, impacts outcomes. Methods: We performed an analysis of patients diagnosed with advanced prostate cancer, followed at the Tom Baker Cancer Centre, in Calgary, Alberta from 2001-2017. Patients were excluded if they did not develop M0 CRPC. MFS and OS were measured using the Kaplan-Meier method and the log-rank test was used to compare outcomes based on PSADT. Correlation between OS and MFS was determined using Pearson Correlation and Kendall’s Tau-B. Results: A total of 1310 patients were identified with advanced prostate cancer, of which 87 developed M0 CRPC. The median age of diagnosis of M0 CRPC was 72 years, with a median Gleason score of 7.0, initial PSA of 10.4, and PSADT of 5.1 months. Only 6 patients were treated with second-generation anti-androgens or chemotherapy. Median MFS and OS after M0 CRPC diagnosis were 44.1 and 83.7 months, respectively. Pearson Correlation between MFS and OS was strong with a coefficient of 0.850 (p < 0.001); with non-parametric Kendall’s Tau, correlation was also strong with a coefficient of 0.632 (p < 0.001). PSADT ≤10 months was identified in 70 patients, and associated with a significantly shorter MFS, compared to a PSADT > 10 months (40.2 vs. 90.4 months; p = 0.001), as well as shorter OS (76.2 vs. 104.3 months; p = 0.008). Conclusions: MFS for M0 CRPC is strongly correlated with OS in a real world population. PSADT of ≤10 months seems to be a useful prognostic tool in estimating MFS and OS in patients with M0 CRPC. MFS was better than expected even in patients with a PSADT of ≤10 months, which may due to our adherence to the biochemical definition of castration-resistant disease, as well as lack of standard imaging intervals in the real world.

First Results from the DEAP-3600 Dark Matter Search with Argon at SNOLAB

This Letter reports the first results of a direct dark matter search with the DEAP-3600 single-phase liquid argon (LAr) detector. The experiment was performed 2 km underground at SNOLAB (Sudbury, Canada) utilizing a large target mass, with the LAr target contained in a spherical acrylic vessel of 3600 kg capacity. The LAr is viewed by an array of PMTs, which would register scintillation light produced by rare nuclear recoil signals induced by dark matter particle scattering. An analysis of 4.44 live days (fiducial exposure of 9.87 ton day) of data taken during the initial filling phase demonstrates the best electronic recoil rejection using pulse-shape discrimination in argon, with leakage <1.2×10^{-7} (90% C.L.) between 15 and 31  keV_{ee}. No candidate signal events are observed, which results in the leading limit on weakly interacting massive particle (WIMP)-nucleon spin-independent cross section on argon, <1.2×10^{-44}  cm^{2} for a 100  GeV/c^{2} WIMP mass (90% C.L.).

Abstract P3-07-08: Quantitative HER family proteins assessment as prognostic and predictive biomarkers in the EGF30008 clinical trial

Background

Combined targeted strategy with letrozole (Le) and lapatinib (La) improves progression-free survival (PFS) in patients with metastatic breast cancer (MBC) co-expressing hormone receptor-positive (HR+) and HER2+ but not in HR+/HER2-negative (HER-) disease (Johnston J Clin Oncol 2009). However, among HER2+ tumors, quantitative levels of HER2 are heterogeneous with a broad dynamic range corresponding to approximately 163.7 to 17446.7 amol/µg as previously reported (Nuciforo SABCS 2014). In addition, within HER2- tumors, quantitative measurement of HER family proteins may identify those patients most likely to benefit from the addition of La to Le. In this retrospective study, we tested the prognostic and predictive ability of HER proteins quantification in clinically HER2+ tumor samples from the EGF30008 study.

Methods

Formalin-fixed paraffin-embedded primary tumor tissues sections from HER2+ MBC population were used. After laser microdissection, tissue lysates were prepared for selected reaction monitoring mass spectrometry (SRM-MS) analysis. Absolute quantitation was accomplished through simultaneous detection of endogenous target and synthetic labeled heavy peptide identical to analytical targets (EGFR, HER2, HER3). HER2 protein levels were correlated with PAM50 molecular subtypes, ERBB2 and ESR1 genes by nCounter. PFS and overall survival (OS) were analyzed by Kaplan–Meier and log-rank test. To determine whether HER2 protein levels were predictive of La benefit, we tested the interaction term of HER2 protein as a continuous variable by treatment arm in a Cox model.

Results

Within the HER2+ study cohort (n=219), 107 had an available tumor block; 84 cases had sufficient material for HER expression measurement by SRM-MS. Average HER2 levels were

2321.1 amol/ug (median, 817.6). HER2 levels were lower in Le+La (n=43; mean, 1761 amol/ug) compared to Le (n=41; mean, 2908 amol/ug) arms, although the difference was non-significant (p=0.108). No expression of EGFR and HER3 was observed. HER2 protein levels were significantly different among PAM50 subtypes with HER2-enriched (HER2E) tumors showing the highest expression followed by Basal-like, Luminal A, Luminal B, and Normal-like (p&lt;0.001). A correlation between HER2 protein, ERBB2 (r=0.5, p&lt;0.001) and ESR1 (r=-0.5, p=0.001) gene expression was found. In patients with disease that expresses HER2 protein levels above the median a trend towards worse PFS (2.9 vs 7.7 months, p=0.092) and OS (21 vs 39 months, p=0.071) were observed. A statistically significant interaction was observed between HER2 protein levels and La treatment for both PFS (p=0.049) and OS (p&lt;0.001). HER2+ tumors with lower expression of HER2 benefited more from La than those with higher expression.

Conclusions

Levels of HER2 protein in HER2+ MBC are extremely heterogeneous. An association between HER2 protein and gene expression by nCounter was observed. HER2E tumors by PAM50 showed the highest levels of HER2 protein. Within the group of HER2+ MBC by standard IHC/FISH, tumors with high HER2 protein had a statistically non-significant worse outcome and do not seem to benefit from La. Further validation of these findings is warranted.

Citation Format: Nuciforo P, Thyparambil S, Galván P, Vilaro M, Jimenez J, Liao W-L, Cecchi F, Blackler A, Press MF, Gagnon R, Ellis C, Hembrough T, Johnston S, Prat A. Quantitative HER family proteins assessment as prognostic and predictive biomarkers in the EGF30008 clinical trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-07-08.

Abstract P2-08-16: Prognostic and predictive abilities of intrinsic subtype in hormone receptor-positive metastatic breast cancer from the EGF30008 phase III clinical trial

Background

Combination of letrozole and lapatinib improved progression-free survival (PFS) compared with letrozole and placebo in patients with hormone receptor-positive (HR+)/HER2+ metastatic breast cancer (MBC), but not HR+/HER2-negative (HER2-) disease (JCO 2009). However, HR+ disease is clinically and biologically heterogeneous with all intrinsic molecular subtypes (Luminal A, Luminal B, HER2-enriched [HER2E] and Basal-like) identified. Here, we tested retrospectively the prognostic and predictive ability of intrinsic subtype in tumor samples of the EGF30008 trial.

Methods

Expression profiling from FFPE tumor tissues was performed on the nCounter platform. Tumors were classified into each intrinsic subtype using the research-based PAM50 classifier (JCO 2009). Cox proportional hazard models for PFS and overall survival (OS) were used to generate point estimates of hazard ratios (HR) and corresponding 95% confidence intervals (CIs). Changes in likelihood ratio χ2 values were used to measure and compare the relative amount of information of each variable. Variables evaluated were: age, prior endocrine therapy, presence of visceral disease, number of metastatic sites, performance status, clinical HER2 status, and treatment. To determine whether the intrinsic subtypes were predictive of lapatinib benefit, we tested the interaction term of subtype by treatment arm in a Cox model that also included the main effects. Kaplan-Meier plots were used to depict the proportion of patients free from progression as a function of time.

Results

Tumor samples from 821 patients (63.8%) were profiled (85.7% primary and 14.3% metastatic tumor samples). Clinical-pathological features of this patient subset were well balanced compared with the original set. Within the entire cohort, all subtypes were identified: Luminal A (46.5%); Luminal B (29.7%); HER2E (7.4%); Basal-like (3.4%) and normal-like (12.9%). Within HER2+ disease, 28.6% of samples were HER2E. Intrinsic subtype was found the strongest prognostic factor independently associated with PFS and OS in all patients, and in patientswith HER2-negative or HER2+ disease (P&lt;0.0001). Median PFS and OS for each subtype within clinically HER2-negative disease were: Luminal A (16.85 and 45.0 months), Luminal B (10.97 and 37.0 months), HER2E (4.67 and 16.0 months) and Basal-like (4.14 and 23.0 months). Within clinically HER2-negative disease (n=644), 16 patients (2.5%) had HER2E disease. Patients with HER2-/HER2E disease benefited from lapatinib (6.5 vs 2.6 months; PFS HR =0.24, 95% CI: 0.07-0.86; P=0.019; HER2E vs not treatment interaction P=0.016). Finally, intrinsic subtype was not predictive of benefit from lapatinib within HER2+ disease.

Conclusions

HR-positive disease is biologically heterogeneous and intrinsic subtypes are strongly prognostic in a first-line MBC setting. HR+/HER2- disease with a HER2E profile may benefit from lapatinib. The clinical value of intrinsic subtyping in HR+ MBC warrants further investigation, but patients with Luminal A/HER2-negative MBC disease might be good candidates for letrozole monotherapy in the first-line setting regardless of visceral disease and number of metastases.

Citation Format: Prat A, Cheang MCU, Galván P, Nuciforo P, Paré L, Adamo B, Viladot M, Press MF, Gagnon R, Ellis C, Johnston S. Prognostic and predictive abilities of intrinsic subtype in hormone receptor-positive metastatic breast cancer from the EGF30008 phase III clinical trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-16.

A metabolomic study reveals novel plasma lyso-Gb3 analogs as Fabry disease biomarkers

Fabry disease is an X-linked, multisystemic lysosomal storage disorder due to alpha-galactosidase A deficiency. It is characterized by the accumulation of glycosphingolipids, mainly globotriaosylceramide (Gb(3)), in biological fluids, vascular endothelium, heart, and kidneys. Treatment by enzyme replacement therapy has been shown to be beneficial in both males and females affected with the disease. In addition to Gb(3), increased concentrations of globotriaosylsphingosine (lyso-Gb(3)) have recently been reported in urine and plasma of Fabry patients. The overall objective of this metabolomic study was to identify and characterize new potential plasma biomarkers in treated and untreated males and females affected with Fabry disease which might better reflect disease severity and progression. We employed a time-of-flight mass spectrometry metabolomic approach using plasma samples of Fabry patients compared to age-matched controls. We found three new lyso-Gb(3) analogs in Fabry patients presenting m/z ratios at 802, 804, and 820. As previously detected by our group, we also found a m/z ratio of 784 corresponding to the lyso-Gb(3) molecule minus two hydrogen atoms. Using exact mass measurements and tandem mass spectrometry, we confirmed that these analogs result from modifications of the lyso-Gb(3) sphingosine moiety. We evaluated the relative plasma concentration by measuring area counts for each lyso-Gb(3) analog. None of these analogs was detected in the majority of healthy controls. The relative concentration of each analog was higher in males compared to female Fabry patients. We demonstrated that mass spectrometry combined to a metabolomic approach is a powerful tool to detect and identify new potential biomarkers.