Tumor heterogeneity of fibroblast growth factor receptor 3 (FGFR3) mutations in invasive bladder cancer: implications for perioperative anti-FGFR3 treatment

BACKGROUND

Fibroblast growth factor receptor 3 (FGFR3) is an actionable target in bladder cancer. Preclinical studies show that anti-FGFR3 treatment slows down tumor growth, suggesting that this tyrosine kinase receptor is a candidate for personalized bladder cancer treatment, particularly in patients with mutated FGFR3. We addressed tumor heterogeneity in a large multicenter, multi-laboratory study, as this may have significant impact on therapeutic response.

PATIENTS AND METHODS

We evaluated possible FGFR3 heterogeneity by the PCR-SNaPshot method in the superficial and deep compartments of tumors obtained by transurethral resection (TUR, n = 61) and in radical cystectomy (RC, n = 614) specimens and corresponding cancer-positive lymph nodes (LN+, n = 201).

RESULTS

We found FGFR3 mutations in 13/34 (38%) T1 and 8/27 (30%) ≥T2-TUR samples, with 100% concordance between superficial and deeper parts in T1-TUR samples. Of eight FGFR3 mutant ≥T2-TUR samples, only 4 (50%) displayed the mutation in the deeper part. We found 67/614 (11%) FGFR3 mutations in RC specimens. FGFR3 mutation was associated with pN0 (P < 0.001) at RC. In 10/201 (5%) LN+, an FGFR3 mutation was found, all concordant with the corresponding RC specimen. In the remaining 191 cases, RC and LN+ were both wild type.

CONCLUSIONS

FGFR3 mutation status seems promising to guide decision-making on adjuvant anti-FGFR3 therapy as it appeared homogeneous in RC and LN+. Based on the results of TUR, the deep part of the tumor needs to be assessed if neoadjuvant anti-FGFR3 treatment is considered. We conclude that studies on the heterogeneity of actionable molecular targets should precede clinical trials with these drugs in the perioperative setting.

Patterns of individual coping, engagement with social supports and use of formal services among a five-country sample of resilient youth

BACKGROUND

Although resilience among victims of child abuse is commonly understood as a process of interaction between individuals and their environments, there have been very few studies of how children's individual coping strategies, social supports and formal services combine to promote well-being.

METHOD

For this study, we conducted a multi-phase analysis of a qualitative dataset of 608 interviews with young people from five countries using grounded theory strategies to build a substantive theory of young people's service and support use patterns. We started with an analysis of ten interviews (two from each country) and then compared these findings to patterns found in each country's full dataset.

RESULTS

The substantive theory that emerged explains young people's transience between individual coping strategies (cognitive and behavioral), reliance on social supports (family members, peers and teachers), and engagement with formal service providers whose roles are to provide interventions and case management. Young people's patterns of navigation were shown to be contingent upon the individual's risk exposure, his or her individual capacity to cope, and the quality of the formal and informal supports and services that are available and accessible.

CONCLUSION

Differing amounts of formal resources in low-, middle- and high-income countries influence patterns of service use. Implications for better coordination between formal mental health services and social supports are discussed.

Mechanisms of Action of TSHR Autoantibodies

The availability of human monoclonal antibodies (MAbs) to the TSHR has enabled major advances in our understanding of how TSHR autoantibodies interact with the receptor. These advances include determination of the crystal structures of the TSHR LRD in complex with a stimulating autoantibody (M22) and with a blocking type autoantibody (K1-70). The high affinity of MAbs for the TSHR makes them particularly suitable for use as ligands in assays for patient serum TSHR autoantibodies. Also, M22 and K1-70 are effective at low concentrations in vivo as TSHR agonists and antagonists respectively. K1-70 has important potential in the treatment of the hyperthyroidism of Graves' disease and Graves' ophthalmopathy. Small molecule TSHR antagonists described to date do not appear to have the potency and/or specificity shown by K1-70. New models of the TSHR ECD in complex with various ligands have been built. These models suggest that initial binding of TSH to the TSHR causes a conformational change in the hormone. This opens a positively charged pocket in receptor-bound TSH which attracts the negatively charged sulphated tyrosine 385 on the hinge region of the receptor. The ensuing movement of the receptor's hinge region may then cause activation. Similar activation mechanisms seem to take place in the case of FSH and the FSHR and LH and the LHR. However, stimulating TSHR autoantibodies do not appear to activate the TSHR in the same way as TSH.

Abstract P5-02-04: Tumor heterogeneity impairs robustness of Ki67 scoring in breast cancer

Background

A study by Cheang et al. reported that for ER-positive, HER2-negative breast cancer a Ki67 score ≥14% distinguishes Luminal B from Luminal A tumors. The (neo)adjuvant treatment of these Luminal B tumors consists of endocrine treatment and chemotherapy while chemotherapy can be omitted for Luminal A tumors. For the determination of these subtypes, resection specimens and particularly core biopsies in the neoadjuvant setting are used. Since Ki67 scoring is advocated by some to be a marker in deciding if systemic chemotherapy will be given or not, its assessment should be highly reproducible and reliable. I.e, Ki67 assessment should not vary significantly between different laboratories, but also not within the tumor. To test this, we analyzed (1) interlaboratory agreement using whole slides and (2) agreement within a particular tumor using tissue microarrays (TMA) as well as whole slides from surgical specimens.

Material and methods

The first 100 patients from the microarRAy prognoSTics-in-breast-cancER (RASTER) study (n=427) were selected. From each patient clinicopathological characteristics and tumor blocks were available. From each tumor block 2 whole slides were cut for staining in laboratory 1 and 2. Also six single cores were taken to construct 2 tissue microarrays (core 1-3 and core 4-6). Intrinsic subtypes were defined as follows: Luminal A, Luminal B/HER2-, Luminal B/HER2+, HER2-overexpressing, and Basal-like. Experienced pathologists (EG, JS, VTHMBS, JW) performed the scoring.

Results

There were 99 whole slides suitable for analysis. Substantial agreement (κ = 0.723, P&lt;0.001) was demonstrated in discrimination for Ki67 low and high between whole slides stained in laboratory 1 and laboratory 2 with a discordance rate of 13.1% (Table 1). Moderate agreement (κ = 0.595, κ = 0.584, P&lt;0.001) was demonstrated in discrimination of Ki67 low and high between whole slide and core 1-3 and core 4-6 with a discordance rate of 20.3% and 20.8% respectively (Table 2). Substantial agreement (κ = 0.666) was demonstrated for Ki67 expression between core 1-3 and core 4-6.

Table 1. Discordance between laboratories for whole slide Ki67 result  Laboratory 2     &lt;14%≥14%Discordance rate %KappaSign.Laboratory 1&lt;14%56013.10.723&lt;0.001 ≥14%1330   

Table 2. Discordance between whole slide and core biopsies 1-3 and 4-6 for Ki67 result  Whole slide     &lt;14%≥14%Discordance rate %KappaSign.Core 1-3&lt;14%33920.30.595&lt;0.001 ≥14%730   Core 4-6&lt;14%31820.80.584&lt;0.001 ≥14%830   

Conclusion

Tumor heterogeneity results in substantial variation of Ki67 scores between TMA cores and whole slides that may result in considerable differences in distinguishing luminal A from luminal B ER-positive, HER2-negative tumors. This may have far reaching consequences for the choice for (neo)adjuvant treatment.

Citation Format: Matthijs V Nijenhuis, Emilie Groen, Tim J Dekker, Caroline A Drukker, J Sanders, V T Smit, S Linn, E J Rutgers, J Wesseling. Tumor heterogeneity impairs robustness of Ki67 scoring in breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-02-04.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

PI3K/AKT/mTOR pathway activation in primary and corresponding metastatic breast tumors after adjuvant endocrine therapy

Both preclinical and clinical data suggest that activation of the PI3K/AKT/mTOR pathway in response to hormonal therapy results in acquired endocrine therapy resistance. We evaluated differences in activation of the PI3K/AKT/mTOR pathway in estrogen receptor α (ERα) positive primary and corresponding metastatic breast cancer tissues using immunohistochemistry for downstream activated proteins, like phosphorylated mTOR (p-mTOR), phosphorylated 4E Binding Protein 1 (p-4EBP1) and phosphorylated p70S6K (p-p70S6K). For p-mTOR and p-4EBP1, the proportion of immunostained tumor cells (0–100%) was scored. Cytoplasmic intensity (0–3) was assessed for p-p70S6K. The difference between expression of these activated PI3K/AKT/mTOR proteins- in primary and metastatic tumor was calculated and tested for an association with adjuvant endocrine therapy. In patients who had received endocrine therapy (N = 34), p-mTOR expression increased in metastatic tumor lesions compared to the primary tumor (median difference 45%), while in patients who had not received adjuvant endocrine therapy (N = 37), no difference was found. Similar results were observed for p-4EBP1 and p-p70S6K expression. In multivariate analyses, adjuvant endocrine therapy was significantly associated with an increase in p-mTOR (p = 0.01), p-4EBP1 (p = 0.03) and p-p70S6K (p = 0.001), indicating that compensatory activation of the PI3K/AKT/mTOR pathway might indeed be a clinically relevant resistance mechanism resulting in acquired endocrine therapy resistance.

IgE-mediated food allergy--diagnosis and management in New Zealand children

AIM

To summarise the diagnosis and management of IgE-mediated food allergy (FA) in New Zealand children.

METHOD

A review of the scientific literature and subsequent consensus development.

RESULTS

FA is a common problem in New Zealand children with management necessitating accurate diagnosis, appropriate risk management, and reassessment over time.

CONCLUSION

This paper highlights the importance of a structured approach to diagnosis and management of FA in New Zealand children, guided by appropriately skilled health professionals.

Consequences of switching from prophylactic treatment to on-demand treatment in late teens and early adults with severe haemophilia A: the TEEN/TWEN study

Although many people with haemophilia discontinue prophylaxis in their late teens or early adulthood, the consequences of this decision are largely not known. This 18-month, observational, case-controlled, multicentre study evaluated long-term prophylaxis and the consequences of switching from prophylaxis to on-demand treatment in late teens and young adults with severe haemophilia A. Participants with haemophilia (aged 14-29 years) on prophylaxis ≥ 60% of the time for the 5 years before study entry were enrolled into 1 of 2 prospective or 1 retrospective group. Group 1 was prophylaxis, group 2 had voluntarily discontinued prophylaxis ≤ 12 months before study entry and group 3 had voluntarily discontinued prophylaxis ≥ 13 months before study entry. Assessments included bleeding frequency (primary endpoint), Haemo-QoL-A health-related quality of life (HRQoL) scores, Gilbert score, development of target joints, Haemophilia Activities List, Godin Leisure-Time, treatment satisfaction and State-Trait Anxiety Inventory (secondary and exploratory endpoints). Descriptive statistics were provided for all variables. Thirty-eight participants (group 1, n = 22; group 2, n = 5; group 3, n = 11; median age, 19.5 years) were enrolled. The median annualized number of bleeding events was 0, 4.8 and 24 in groups 1, 2 and 3 respectively. HRQoL was lower in participants who discontinued prophylaxis vs. those who remained on prophylaxis. Changes in the remaining secondary and exploratory variables were small, but were generally worse in participants who discontinued prophylaxis. Following a switch from prophylaxis to on-demand therapy, the number of bleeding events increased and HRQoL worsened in late teens and young adults with severe haemophilia A.

Thyrotrophin receptor antibody characteristics in a woman with long-standing Hashimoto's who developed Graves' disease and pretibial myxoedema

CONTEXT

Sequential conversion of Hashimoto's thyroiditis (HT) to Graves' disease (GD) is uncommon. Distinct immune paradigms, paucity of functioning tissue in long-standing HT, and infrequent conversion of blocking (TBAb) to stimulating (TSAb) thyrotrophin receptor antibody (TRAb) may account for this. Molecular and crystal structure analysis helps delineate TSH receptor (TSHR)/TRAb interactions in detail. Such 'fingerprinting' helps determine the behaviour and characteristics of TRAb in longitudinal studies.

PATIENT

An 80-year-old woman taking thyroxine for long-standing HT became hyperthyroid. This persisted despite thyroxine withdrawal - free T3 was 7·3 pmol/l (2·6-5·7) and TSH < 0·01 mU/l (0·2-4·5) and TRAb highly positive. She had a goitre (ultrasound - HT), pretibial myxoedema, with mild inactive Graves' orbitopathy. She had RAI treatment and is on thyroxine replacement.

MEASUREMENTS AND RESULTS

Blood samples at presentation (A) and 1 year (B) showed high TSAb and TPOAb activity but no TBAb. Experiments involving TSHR mutations confirmed that (i) TRAb had stable characteristics over 1 year; (ii) TSHR mutation R255D caused complete inhibition and (iii) R109A caused marked reduction of cAMP production by M22 (TSHR-stimulating human monoclonal antibody) and A and B; (iv) mutations R80A, E107A and K129A while affecting M22 had little effect on A and B.

CONCLUSIONS

The reasons for an immunological paradigm shift in this elderly woman remain speculative. We believe that de-novo TSAb synthesis occurred converting her long-standing HT to GD although the mechanisms responsible remain unexplained. TRAb analysis confirmed stable autoantibody characteristics over 1 year and variable effects of TSHR mutations on TRAb and M22 function.

The role of p21-activated kinase in the initiation of atherosclerosis

BACKGROUND

p21-activated kinase (PAK) has been implicated in the inflammatory activation of endothelial cells by disturbed fluid shear stress, which is the initiating stimulus in atherosclerosis. The study addresses whether PAK1 contributes to inflammatory marker expression in endothelial cells at atherosclerosis-susceptible regions of arteries in vivo.

METHOD

Aortas from WT and PAK1-/- C57BL/6J mice on a normal chow diet were fixed, dissected and processed for immunohistochemistry using a panel of inflammatory markers. We visualized and quantified staining in the endothelium at the greater and lesser curvatures of the arch of aorta, as atherosclerosis-resistant and susceptible regions, respectively.

RESULTS

Fibronectin, VCAM-1 and the activated RelA NF-κB subunit were localized to the lesser curvature and decreased in PAK1-/- mice. The activated RelB NF-κB subunit was also localized to the lesser curvature but was increased in PAK1-/- mice. Low levels of staining for ICAM-1 and the monocyte/macrophage marker Mac2 indicated that overall inflammation in this tissue was minimal.

CONCLUSION

These data show that PAK1 has a significant pro-inflammatory function at atherosclerosis-prone sites in vivo. These effects are seen in young mice with very low levels of inflammation, suggesting that inflammatory activation of the endothelium is primarily biomechanical. Activation involves NF-κB, expression of leukocyte recruitment receptors and fibronectin deposition. These results support and extend in vitro studies demonstrating that PAK contributes to activation of inflammatory pathways in endothelial cells by fluid shear stress.

The Rib Vertebra Angle Difference and its Measurement in 3D for the evaluation of early onset scoliosis

The Rib Vertebra Angle Difference (RVAD) as defined by Mehta (1972) is used to predict the progression of early onset scoliosis. No clear physical significance has been established for this measurement. The purpose of this study was to evaluate the RVAD along the thoracic spine and the equivalent measurement on 3D reconstructions of the spine and rib cage of early onset scoliosis patients in order to determine their relationship with the geometry of the chest wall and evolution along the spine. The RVAD was measured on PA radiographs of 42 infantile scoliotic patients (Cobb &gt;20°) from T4 to T10 according to the method described by Mehta. The RVAD 3D was computed using the same landmarks from the 3D reconstruction generated from the calibrated biplanar radiographs. Cases were divided into Phase I and Phase II using Mehta's classification based on the rib head overlap with the apical vertebral body on coronal plane radiographs. A linear relationship exists between the Metha (2D) and 3D RVAD for both Phase I (r = 0.87) and Phase II (r = 0.78) patients. For more severe deformities (RVAD 3D ≥ 35°), a relationship was found between RVAD 3D and the axial rotation of the thoracic vertebrae (r = 0.51) in Phase II patients. However, no significant relationship exists between axial rotation and RVAD 3D for Phase I patients as well as Mehta's RVAD. Maximal RVAD measurements were located 2 &amp;frac12; levels above the apical vertebra. Results indicated that RVAD 3D provides additional information to Mehta's RVAD on the torsional nature of the deformity. Considering the importance of clinical indices to assess the progression of early onset scoliosis, this study raises some questions on looking solely at the RVAD measured on radiographs at the apical vertebra of Phase I patients and suggests considering also levels above the apex of the scoliotic curve and 3D measurements. Further investigation is required to fully understand the 3D nature of the spine and rib cage deformities.

The use of a single von Willebrand factor-containing, plasma-derived FVIII product in hemophilia A immune tolerance induction: the US experience

BACKGROUND

Inhibitors are a serious complication for patients with severe hemophilia A. Immune tolerance induction (ITI) is the primary method for eradicating these inhibitors. The role of type of concentrate and in particular the use of von Willebrand factor-containing, plasma-derived factor VIII (VWF/pd-FVIII) concentrate in primary or rescue ITI remains unclear.

OBJECTIVES

To report retrospective collection of data on the use of a single VWF/pd-FVIII concentrate in primary and rescue ITI.

METHODS

Retrospective chart review of hemophilia A inhibitor patients at 11 US institutions who received VWF/pd-FVIII concentrate in primary or rescue ITI.

RESULTS

Primary ITI was carried out in eight inhibitor patients with a 75% complete and partial success. Secondary ITI was carried out in 25 inhibitor patients, with 52% attaining complete or partial success.

CONCLUSIONS

This report represents the largest group of primarily pediatric, high-titer inhibitor patients treated with a single VWF/pd-FVIII concentrate. It adds retrospective data to the use of VWF-containing plasma-derived factor VIII concentrate in primary and rescue ITI, particularly in those patients with characteristics of poor response to ITI.