The (o-p-o)-Terphenyl Embedded Calix[2]phyrin(2.2.1.1.1) and Its Cu(II) Complex

The introduction of a higher arene unit as a structural motif is unprecedented in calixphyrin chemistry. Herein, the syntheses, spectral and structural characterization of heretofore anonymous terphenylene unit (o-p-o) incorporated calixphyrin with fused sp2 meso carbons is reported. The explicitly tailored macrocyclic core is utilized to stabilize the Cu(II) metal ion. The molecular structures of the calixbenziphyrin and Cu(II) complex are unambiguously confirmed by single-crystal X-ray analysis. Moreover, theoretical supports uphold experimental conclusions.

Liquid Biopsy for Detection of Pancreaticobiliary Cancers by Functional Enrichment and Immunofluorescent Profiling of Circulating Tumor Cells and Their Clusters

Circulating tumor cells (CTCs) have historically been used for prognostication in oncology. We evaluate the performance of liquid biopsy CTC assay as a diagnostic tool in suspected pancreaticobiliary cancers (PBC). The assay utilizes functional enrichment of CTCs followed by immunofluorescent profiling of organ-specific markers. The performance of the assay was first evaluated in a multicentric case-control study of blood samples from 360 participants, including 188 PBC cases (pre-biopsy samples) and 172 healthy individuals. A subsequent prospective observational study included pre-biopsy blood samples from 88 individuals with suspicion of PBC and no prior diagnosis of cancer. CTCs were harvested using a unique functional enrichment method and used for immunofluorescent profiling for CA19.9, Maspin, EpCAM, CK, and CD45, blinded to the tissue histopathological diagnosis. TruBlood® malignant or non-malignant predictions were compared with tissue diagnoses to establish sensitivity and specificity. The test had 95.9% overall sensitivity (95% CI: 86.0-99.5%) and 92.3% specificity (95% CI: 79.13% to 98.38%) to differentiate PBC (n = 49) from benign conditions (n = 39). The high accuracy of the CTC-based TruBlood test demonstrates its potential clinical application as a diagnostic tool to assist the effective detection of PBC when tissue sampling is unviable or inconclusive.

CTP-based estimated ischemic core: A comparative multicenter study between Olea and RAPID software

BACKGROUND AND PURPOSE

CTP is increasingly used to assess eligibility for endovascular therapy (EVT) in patients with large vessel occlusions (LVO). There remain variability and inconsistencies between software packages for estimation of ischemic core. We aimed to use heterogenous data from four stroke centers to perform a comparative analysis for CTP-estimated ischemic core between RAPID (iSchemaView) and Olea (Olea Medical).

METHODS

In this retrospective multicenter study, patients with anterior circulation LVO who underwent pretreatment CTP, successful EVT (defined TICI ≥ 2b), and follow-up MRI included. Automated CTP analysis was performed using Olea platform [rCBF < 25% and differential time-to-peak (dTTP)>5s] and RAPID (rCBF < 30%). The CTP estimated core volumes were compared against the final infarct volume (FIV) on post treatment MRI-DWI.

RESULTS

A total of 151 patients included. The CTP-estimated ischemic core volumes (mean ± SD) were 18.7 ± 18.9 mL on Olea and 10.5 ± 17.9 mL on RAPID significantly different (p < 0.01). The correlation between CTP estimated core and MRI final infarct volume was r = 0.38, p < 0.01 for RAPID and r = 0.39, p < 0.01 for Olea. Both software platforms demonstrated a strong correlation with each other (r = 0.864, p < 0.001). Both software overestimated the ischemic core volume above 70 mL in 4 patients (2.6%).

CONCLUSIONS

Substantial variation between Olea and RAPID CTP-estimated core volumes exists, though rates of overcalling of large core were low and identical. Both showed comparable core volume correlation to MRI infarct volume.

Advent and features of pyriporphyrinoids: an overview of a pyridine-based porphyrin analogue

Pyriporphyrinoids have recently attracted a significant proliferation of attention due to their versatile characters, which stem from structural motifs in which the pyridine moiety is involved. The evolution of pyriporphyrin chemistry revealed the subtle modifications of the macrocyclic core that tweak the electronic structure as compared to the parental macrocycle. The amendment of π-electronic organization inside the core manifests exceptional photophysical and coordination properties that cover a vast range of seemingly contradictory fields. In fundamental chemistry, the pyridine unit acts as a modulator of π-conjugated porphyrinoid systems, resulting in aromaticity swapping. From the applied chemistry perspective, these macrocycles are primarily utilized as (i) sensors, (ii) NIR absorbing photoacoustic dyes, (iii) electrochemical catalysts, (iv) singlet biradicaloid generation and (v) contributors to generate metal complexes with intriguing binding modes. Surprisingly, despite their prominence, pyriporphyrinoids are inadequately investigated, while pyridine unit-embedded calixphyrin, calixpyridinopyrrole and calixpyridine are barely reported. This review article illustrates the controlled formation of specific porphyrinic scaffolds with pyridine unit(s) and diverse functionalized heterocyclic and/or carbocyclic building block(s), and demonstrates a substantial influence on the macrocyclic properties.

Comprehensive Update and Review of Clinical and Imaging Features of SMART Syndrome

Stroke-like migraine attacks after radiation therapy (SMART) syndrome is a delayed complication of cranial irradiation, with subacute onset of stroke-like symptoms including seizures, visual disturbance, speech impairment, unilateral hemianopsia, facial droop, and aphasia, often associated with migraine-type headache. The diagnostic criteria were initially proposed in 2006. However, the diagnosis of SMART syndrome is challenging because clinical symptoms and imaging features of SMART syndrome are indeterminate and overlap with tumor recurrence and other neurologic diseases, which may result in inappropriate clinical management and unnecessary invasive diagnostic procedures. Recently, various imaging features and treatment recommendations for SMART syndrome have been reported. Radiologists and clinicians should be familiar with updates on clinical and imaging features of this delayed radiation complication because recognition of this entity can facilitate proper clinical work-up and management. This review provides current updates and a comprehensive overview of the clinical and imaging features of SMART syndrome.

Crowd cluster data in the USA for analysis of human response to COVID-19 events and policies

We provide data on daily social contact intensity of clusters of people at different types of Points of Interest (POI) by zip code in Florida and California. This data is obtained by aggregating fine-scaled details of interactions of people at the spatial resolution of 10 m, which is then normalized as a social contact index. We also provide the distribution of cluster sizes and average time spent in a cluster by POI type. This data will help researchers perform fine-scaled, privacy-preserving analysis of human interaction patterns to understand the drivers of the COVID-19 epidemic spread and mitigation. Current mobility datasets either provide coarse-level metrics of social distancing, such as radius of gyration at the county or province level, or traffic at a finer scale, neither of which is a direct measure of contacts between people. We use anonymized, de-identified, and privacy-enhanced location-based services (LBS) data from opted-in cell phone apps, suitably reweighted to correct for geographic heterogeneities, and identify clusters of people at non-sensitive public areas to estimate fine-scaled contacts.

Accurate prostate cancer detection based on enrichment and characterization of prostate cancer specific circulating tumor cells

BACKGROUND

The low specificity of serum PSA resulting in the inability to effectively differentiate prostate cancer from benign prostate conditions is a persistent clinical challenge. The low sensitivity of serum PSA results in false negatives and can miss high-grade prostate cancers. We describe a non-invasive test for detection of prostate cancer based on functional enrichment of prostate adenocarcinoma associated circulating tumor cells (PrAD-CTCs) from blood samples followed by their identification by immunostaining for pan-cytokeratins (PanCK), prostate specific membrane antigen (PSMA), alpha methyl-acyl coenzyme-A racemase (AMACR), epithelial cell adhesion molecule (EpCAM), and common leucocyte antigen (CD45).

METHODS

Analytical validation studies were performed to establish the performance characteristics of the test using VCaP prostate cancer cells spiked into healthy donor blood (HDB). The clinical performance characteristics of the test were evaluated in a case-control study with 160 known prostate cancer cases and 800 healthy males, followed by a prospective clinical study of 210 suspected cases of prostate cancer.

RESULTS

Analytical validation established analyte stability as well as acceptable performance characteristics. The test showed 100% specificity and 100% sensitivity to differentiate prostate cancer cases from healthy individuals in the case control study and 91.2% sensitivity and 100% specificity to differentiate prostate cancers from benign prostate conditions in the prospective clinical study.

CONCLUSIONS

The test accurately detects PrAD-CTCs with high sensitivity and specificity irrespective of stage, serum PSA or Gleason score, which translates into low risks of false negatives or overdiagnosis. The high accuracy of the test could offer advantages over PSA based prostate cancer detection.

Rh(I) and Organo-Rh(III) Complexes of meso-Triarylbiphenylcorrole

Rhodium complexes of biphenylcorrole are reported, and the molecular structures of the complexes are unambiguously confirmed by single-crystal X-ray analysis. The adj-CCNN core of the dicarbacorrole efficiently stabilizes a rhodium metal ion in its two different oxidation states. It is pertinent to point out that the Rh(I) metal complex attains square-planar geometry while organo-Rh(III) forms an octahedral complex. Furthermore, density functional theory studies corroborate the experimental findings.

Dynamic Contrast-Enhanced MRI Parameters and Normalized ADC Values Could Aid Differentiation of Skull Base Osteomyelitis from Nasopharyngeal Cancer

BACKGROUND AND PURPOSE

The skull base osteomyelitis sometimes can be difficult to distinguish from nasopharyngeal cancer. This study aimed to investigate the differences between skull base osteomyelitis and nasopharyngeal cancer using dynamic contrast-enhanced MR imaging and normalized ADC values.

MATERIALS AND METHODS

This study included 8 and 12 patients with skull base osteomyelitis and nasopharyngeal cancer, respectively, who underwent dynamic contrast-enhanced MR imaging and DWI before primary treatment. Quantitative dynamic contrast-enhanced MR imaging parameters and ADC values of the ROIs were analyzed. Normalized ADC parameters were calculated by dividing the ROIs of the lesion by that of the spinal cord.

RESULTS

The rate transfer constant between extravascular extracellular space and blood plasma per minute (Kep) was significantly lower in patients with skull base osteomyelitis than in those with nasopharyngeal cancer (median, 0.43 versus 0.57; P = .04). The optimal cutoff value of Kep was 0.48 (area under the curve, 0.78; 95% CI, 0.55-1). The normalized mean ADC was significantly higher in patients with skull base osteomyelitis than in those with nasopharyngeal cancer (median, 1.90 versus 0.87; P < .001). The cutoff value of normalized mean ADC was 1.55 (area under the curve, 0.96; 95% CI, 0.87-1). The area under the curve of the combination of dynamic contrast-enhanced MR imaging parameters (Kep and extravascular extracellular space volume per unit tissue volume) was 0.89 (95% CI, 0.73-1), and the area under the curve of the combination of dynamic contrast-enhanced MR imaging parameters and normalized mean ADC value was 0.98 (95% CI, 0.93-1).

CONCLUSIONS

Quantitative dynamic contrast-enhanced MR imaging parameters and normalized ADC values may be useful in differentiating skull base osteomyelitis and nasopharyngeal cancer. The combination of dynamic contrast-enhanced MR imaging parameters and normalized ADC values outperformed each measure in isolation.

A novel application of a bioactive material as a pit and fissure sealant: in vitro pilot study evaluating the sealing ability and penetration

PURPOSE

To compare the sealing ability and penetration of a bioactive material used as pit and fissure sealant to those of glass ionomer sealant.

METHODS

This was an in vitro experimental study conducted on 20 permanent teeth. For Group I of ten teeth, ACTIVA BioACTIVE-Base/Liner was applied as a sealant on pits and fissures, and the remaining ten teeth of Group II were sealed using glass ionomer cement. After thermocycling, the apex of the teeth was sealed using composite resin and they were immersed in 1% methylene blue solution, buffered at pH 7 for 24 h. Longitudinal sections were obtained from each tooth for evaluating the sealing ability and penetration, using a binocular light microscope at 4 × magnification. The obtained data were subjected to analysis using the Chi-square test and independent t test.

RESULTS

The comparison of the sealing ability and sealant penetration, between the two groups, showed statistically no significant difference (p = 0.104 and p = 1.0, respectively).

CONCLUSION

Bioactive material as a pit and fissure sealant, performed on par with glass ionomer sealant in terms of tested properties like sealing ability and penetration.

Multi-analyte liquid biopsies for molecular pathway guided personalized treatment selection in advanced refractory cancers: A clinical utility pilot study

Purpose

The selection of safe and efficacious anticancer regimens for treatment of patients with broadly refractory metastatic cancers remains a clinical challenge. Such patients are often fatigued by toxicities of prior failed treatments and may have no further viable standard of care treatment options. Liquid Biopsy-based multi-analyte profiling in peripheral blood can identify a majority of drug targets that can guide the selection of efficacious combination regimens.

Patients and methods

LIQUID IMPACT was a pilot clinical study where patients with advanced refractory cancers received combination anticancer treatment regimens based on multi-analyte liquid biopsy (MLB) profiling of circulating tumor biomarkers; this study design was based on the findings of prior feasibility analysis to determine the abundance of targetable variants in blood specimens from 1299 real-world cases of advanced refractory cancers.

Results

Among the 29 patients in the intent to treat (ITT) cohort of the trial, 26 were finally evaluable as per study criteria out of whom 12 patients showed Partial Response (PR) indicating an Objective Response Rate (ORR) of 46.2% and 11 patients showed Stable Disease (SD) indicating the Disease Control Rate (DCR) to be 88.5%. The median Progression-Free Survival (mPFS) and median Overall Survival (mOS) were 4.3 months (95% CI: 3.0 - 5.6 months) and 8.8 months (95% CI: 7.0 - 10.7 months), respectively. Toxicities were manageable and there were no treatment-related deaths.

Conclusion

The study findings suggest that MLB could be used to assist treatment selection in heavily pretreated patients with advanced refractory cancers.

Differentiation of Skull Base Chondrosarcomas, Chordomas, and Metastases: Utility of DWI and Dynamic Contrast-Enhanced Perfusion MR Imaging

BACKGROUND AND PURPOSE

Differentiation of skull base tumors, including chondrosarcomas, chordomas, and metastases, on conventional imaging remains a challenge. We aimed to test the utility of DWI and dynamic contrast-enhanced MR imaging for skull base tumors.

MATERIALS AND METHODS

Fifty-nine patients with chondrosarcomas, chordomas, or metastases between January 2015 and October 2021 were included in this retrospective study. Pretreatment normalized mean ADC and dynamic contrast-enhanced MR imaging parameters were calculated. The Kruskal-Wallis H test for all tumor types and the Mann-Whitney U test for each pair of tumors were used.

RESULTS

Fifteen chondrosarcomas (9 men; median age, 62 years), 14 chordomas (6 men; median age, 47 years), and 30 metastases (11 men; median age, 61 years) were included in this study. Fractional plasma volume helped distinguish all 3 tumor types (P = .003, <.001, and <.001, respectively), whereas the normalized mean ADC was useful in distinguishing chondrosarcomas from chordomas and metastases (P < .001 and P < .001, respectively); fractional volume of extracellular space, in distinguishing chondrosarcomas from metastases (P = .02); and forward volume transfer constant, in distinguishing metastases from chondrosarcomas/chondroma (P = .002 and .002, respectively) using the Kruskal-Wallis H test. The diagnostic performances of fractional plasma volume for each pair of tumors showed areas under curve of 0.86-0.99 (95% CI, 0.70-1.0); the forward volume transfer constant differentiated metastases from chondrosarcomas/chordomas with areas under curve of 0.82 and 0.82 (95% CI, 0.67-0.98), respectively; and the normalized mean ADC distinguished chondrosarcomas from chordomas/metastases with areas under curve of 0.96 and 0.95 (95% CI, 0.88-1.0), respectively.

CONCLUSIONS

DWI and dynamic contrast-enhanced MR imaging sequences can be beneficial for differentiating the 3 common skull base tumors.

538 Peer MRCS Teaching Among Surgical Trainees in the East Midlands Deanery, UK

Background

During the covid-19 pandemic, the East Midlands South Deanery ran virtual peer-MRCS OSCE teaching. We analysed two surveys to understand the impact of peer-MRCS teaching on surgical trainees in this region.

Method

One survey was completed by peer-MRCS teachers who delivered sessions in 2020–2021. The second survey was completed by prospective MRCS OSCE candidates. Responses were anonymised.

Results

7 / 8 peer teachers and 13/17 prospective learners completed the surveys. 6/7 peer-teachers had previous experience and prior teacher-training ranged from day courses to university degrees. All peer-teachers felt that peer-MRCS teaching enabled them to refresh their anatomy knowledge. 0/7 peer-teachers preferred to deliver practical-skills teaching.

Passion for teaching was identified as a motivating factor by all peer teachers. This was further supported by the general consensus (5/7) for peer teachers preferring feedback that is focused on self-development rather than conveying appreciation. Majority (12/13) of peer learners also preferred to give feedback focused on teacher development and felt they were more likely (7/13) to provide accurate feedback for peer-sessions when compared to formal teaching sessions run by the deanery.

Majority of participating prospective MRCS OSCE candidates (12/13) expressed an interest in peer-MRCS teaching. Low stress environment and cost effectiveness were the top reasons why prospective peer learners preferred virtual peer MRCS teaching.

Conclusions

Overall peer-MRCS teaching in this cohort suggests advantages to both peer-teachers and learners with the potential to improve teaching skills and clinical knowledge among surgical trainees.

Normalized Parameters of Dynamic Contrast-Enhanced Perfusion MRI and DWI-ADC for Differentiation between Posttreatment Changes and Recurrence in Head and Neck Cancer

BACKGROUND AND PURPOSE

Differentiating recurrence from benign posttreatment changes has clinical importance in the imaging follow-up of head and neck cancer. This study aimed to investigate the utility of normalized dynamic contrast-enhanced MR imaging and ADC for their differentiation.

MATERIALS AND METHODS

This study included 51 patients with a history of head and neck cancer who underwent follow-up dynamic contrast-enhanced MR imaging with DWI-ADC, of whom 25 had recurrences and 26 had benign posttreatment changes. Quantitative and semiquantitative dynamic contrast-enhanced MR imaging parameters and ADC of the ROI and reference region were analyzed. Normalized dynamic contrast-enhanced MR imaging parameters and normalized DWI-ADC parameters were calculated by dividing the ROI by the reference region.

RESULTS

Normalized plasma volume, volume transfer constant between extravascular extracellular space and blood plasma per minute (K ^trans), area under the curve, and wash-in were significantly higher in patients with recurrence than in those with benign posttreatment change (P = .003 to <.001). The normalized mean ADC was significantly lower in patients with recurrence than in those with benign posttreatment change (P < .001). The area under the receiver operating characteristic curve of the combination of normalized dynamic contrast-enhanced MR imaging parameters with significance (normalized plasma volume, normalized extravascular extracellular space volume per unit tissue volume, normalized K ^trans, normalized area under the curve, and normalized wash-in) and normalized mean ADC was 0.97 (95% CI, 0.93-1).

CONCLUSIONS

Normalized dynamic contrast-enhanced MR imaging parameters, normalized mean ADC, and their combination were effective in differentiating recurrence and benign posttreatment changes in head and neck cancer.

Accurate Screening for Early-Stage Breast Cancer by Detection and Profiling of Circulating Tumor Cells

BACKGROUND

The early detection of breast cancer (BrC) is associated with improved survival. We describe a blood-based breast cancer detection test based on functional enrichment of breast-adenocarcinoma-associated circulating tumor cells (BrAD-CTCs) and their identification via multiplexed fluorescence immunocytochemistry (ICC) profiling for GCDFP15, GATA3, EpCAM, PanCK, and CD45 status.

METHODS

The ability of the test to differentiate BrC cases (N = 548) from healthy women (N = 9632) was evaluated in a case-control clinical study. The ability of the test to differentiate BrC cases from those with benign breast conditions was evaluated in a prospective clinical study of women (N = 141) suspected of BrC.

RESULTS

The test accurately detects BrAD-CTCs in breast cancers, irrespective of age, ethnicity, disease stage, grade, or hormone receptor status. Analytical validation established the high accuracy and reliability of the test under intended use conditions. The test detects and differentiates BrC cases from healthy women with 100% specificity and 92.07% overall sensitivity in a case-control study. In a prospective clinical study, the test shows 93.1% specificity and 94.64% overall sensitivity in differentiating breast cancer cases (N = 112) from benign breast conditions (N = 29).

CONCLUSION

The findings reported in this manuscript support the clinical potential of this test for blood-based BrC detection.

Idiopathic granulomatous mastitis: experience at a New York hospital

INTRODUCTION

Idiopathic granulomatous mastitis (IGM) often mimics breast cancer. Presentation includes pain, palpable mass, suppuration or suspicious imaging. Widely reported in Asia and the Middle East, IGM is diagnosed after excluding specific granulomatous mastitis (SGM). Aetiology remains unknown. Lactation, prolactinaemia, ethnicity, autoimmune disease and Corynebacteria are associated. Treatment is controversial and the prevalence rising. Surgery and non-operative treatments including antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), steroids, methotrexate and observation have advocates.

METHODS

A retrospective chart review of 63 patients with IGM from 2008 to 2018 was undertaken focusing on birthplace, age, clinical presentation, wound cultures, imaging, treatments and outcomes.

RESULTS

Sixty-one of 63 patients were Hispanic; 53 were Mexican-born women aged 23-46. Clinical presentation included pain, painful mass, painless mass, suppuration and abnormal imaging. Some 31/61 ultrasound examinations and 17/33 mammograms were deemed Breast Imaging Reporting and Data System (BI-RADS) score 4 or 5. Management included antibiotics (43), incision and drainage (24), NSAIDs (29), steroids (8), lumpectomy (18) and observation (12). Some 12/20 patients with painless masses resolved with observation, 3 received NSAIDs, 2 received steroids and 3 underwent lumpectomies. Antibiotics resolved 8/43 cases, 5 needed incision and drainage, 26 received NSAIDs, 6 received steroids and 5 underwent lumpectomies. Nineteen patients had indolent disease or recurrence.

CONCLUSIONS

Excluding malignancy is critical, treatment challenging and recurrence common in IGM. A preponderance of patients were Mexican-born, similar to other reports from the USA. Over 50% of IGM cases had suspicious BI-RADS scores. Best management remains a challenge and ranges from observation to lumpectomy.

Prediction of Wound Failure in Patients with Head and Neck Cancer Treated with Free Flap Reconstruction: Utility of CT Perfusion and MR Perfusion in the Early Postoperative Period

BACKGROUND AND PURPOSE

Free flap reconstruction in patients with head and neck cancer carries a risk of postoperative complications, and radiologic predictive factors have been limited. The aim of this study was to assess the factors that predict free flap reconstruction failure using CT and MR perfusion.

MATERIALS AND METHODS

This single-center prospective study included 24 patients (mean age, 62.7 [SD, 9.0] years; 16 men) who had free flap reconstruction from January 2016 to May 2018. CT perfusion and dynamic contrast-enhanced MR imaging with conventional CT and MR imaging were performed between 2 and 4 days after the free flap surgery, and the wound assessments within 14 days after the surgery were conducted by the surgical team. The parameters of CT perfusion and dynamic contrast-enhanced MR imaging with conventional imaging findings and patient demographics were compared between the patients with successful free flap reconstruction and those with wound failure as appropriate. P < .05 was considered significant.

RESULTS

There were 19 patients with successful free flap reconstruction and no wound complications (mean age, 63.9 [SD, 9.5] years; 14 men), while 5 patients had wound failure (mean age, 58.0 [SD, 5.7] years; 2 men). Blood flow, blood volume, MTT, and time maximum intensity projection (P = .007, .007, .015, and .004, respectively) in CT perfusion, and fractional plasma volume, volume transfer constant, peak enhancement, and time to maximum enhancement (P = .006, .039, .004, and .04, respectively) in dynamic contrast-enhanced MR imaging were significantly different between the 2 groups.

CONCLUSIONS

CT perfusion and dynamic contrast-enhanced MR imaging are both promising imaging techniques to predict wound complications after head and neck free flap reconstruction.

Prognostic Factors of Stroke-Like Migraine Attacks after Radiation Therapy (SMART) Syndrome

BACKGROUND AND PURPOSE

Prognostic factors of stroke-like migraine attacks after radiation therapy (SMART) syndrome have not been fully explored. This study aimed to assess clinical and imaging features to predict the clinical outcome of SMART syndrome.

MATERIALS AND METHODS

We retrospectively reviewed the clinical manifestations and imaging findings of 20 patients with SMART syndrome (median age, 48 years; 5 women) from January 2016 to January 2020 at 4 medical centers. Patient demographics and MR imaging features at the time of diagnosis were reviewed. This cohort was divided into 2 groups based on the degree of clinical improvement (completely versus incompletely recovered). The numeric and categoric variables were compared as appropriate.

RESULTS

There were statistically significant differences between the completely recovered group (n = 11; median age, 44 years; 2 women) and the incompletely recovered group (n = 9; median age, 55 years; 3 women) in age, months of follow-up, and the presence of steroid treatment at diagnosis (P = .028, .002, and .01, respectively). Regarding MR imaging features, there were statistically significant differences in the presence of linear subcortical WM susceptibility abnormality, restricted diffusion, and subcortical WM edematous changes in the acute SMART region (3/11 versus 8/9, P = .01; 0/11 versus 4/9, P = .026; and 2/11 versus 7/9, P = .022, respectively). Follow-up MRIs showed persistent susceptibility abnormality (11/11) and subcortical WM edematous changes (9/9), with resolution of restricted diffusion (4/4).

CONCLUSIONS

Age, use of steroid treatment at the diagnosis of SMART syndrome, and MR imaging findings of abnormal susceptibility signal, restricted diffusion, and subcortical WM change in the acute SMART region can be prognostic factors in SMART syndrome.

ADC for Differentiation between Posttreatment Changes and Recurrence in Head and Neck Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Previous studies reported that the ADC values of recurrent head and neck cancer lesions are lower than those of posttreatment changes, however, the utility of ADC to differentiate them has not been definitively summarized and established.

PURPOSE

Our aim was to evaluate the diagnostic benefit of ADC calculated from diffusion-weighted imaging in differentiating recurrent lesions from posttreatment changes in head and neck cancer.

DATA SOURCES

MEDLINE, Scopus, and EMBASE data bases were searched for studies.

STUDY SELECTION

The review identified 6 prospective studies with a total of 365 patients (402 lesions) who were eligible for the meta-analysis.

DATA ANALYSIS

Forest plots were used to assess the mean difference in ADC values. Heterogeneity among the studies was evaluated using the Cochrane Q test and the I² statistic.

DATA SYNTHESIS

Among included studies, the overall mean of ADC values of recurrent lesions was 1.03 × 10^-3mm²/s and that of the posttreatment changes was 1.51 × 10^-3mm²/s. The ADC value of recurrence was significantly less than that of posttreatment changes in head and neck cancer (pooled mean difference: -0.45; 95% CI, -0.59-0.32, P < .0001) with heterogeneity among studies. The threshold of ADC values between recurrent lesions and posttreatment changes was suggested to be 1.10 × 10^-3mm²/s.

LIMITATIONS

Given the heterogeneity of the data of the study, the conclusions should be interpreted with caution.

CONCLUSIONS

The ADC values in recurrent head and neck cancers are lower than those of posttreatment changes, and the threshold of ADC values between them was suggested.

Pretreatment ADC Histogram Analysis as a Prognostic Imaging Biomarker for Patients with Recurrent Glioblastoma Treated with Bevacizumab: A Systematic Review and Meta-analysis

BACKGROUND

The mean ADC value of the lower Gaussian curve (ADC_L) derived from the bi-Gaussian curve-fitting histogram analysis has been reported as a predictive/prognostic imaging biomarker in patients with recurrent glioblastoma treated with bevacizumab; however, its systematic summary has been lacking.

PURPOSE

We applied a systematic review and meta-analysis to investigate the predictive/prognostic performance of ADC_L in patients with recurrent glioblastoma treated with bevacizumab.

DATA SOURCES

We performed a literature search using PubMed, Scopus, and EMBASE.

STUDY SELECTION

A total of 1344 abstracts were screened, of which 83 articles were considered potentially relevant. Data were finally extracted from 6 studies including 578 patients.

DATA ANALYSIS

Forest plots were generated to illustrate the hazard ratios of overall survival and progression-free survival. The heterogeneity across the studies was assessed using the Cochrane Q test and I² values.

DATA SYNTHESIS

The pooled hazard ratios for overall survival and progression-free survival in patients with an ADC_L lower than the cutoff values were 1.89 (95% CI, 1.53-2.31) and 1.98 (95% CI, 1.54-2.55) with low heterogeneity among the studies. Subgroup analysis of the bevacizumab-free cohort showed a pooled hazard ratio for overall survival of 1.20 (95% CI, 1.08-1.34) with low heterogeneity.

LIMITATIONS

The conclusions are limited by the difference in the definition of recurrence among the included studies.

CONCLUSIONS

This systematic review with meta-analysis supports the prognostic value of ADC_L in patients with recurrent glioblastoma treated with bevacizumab, with a low ADC_L demonstrating decreased overall survival and progression-free survival. On the other hand, the predictive role of ADC_L for bevacizumab treatment was not confirmed.

Recent Advances in the Design and Syntheses of Porphyrinoids by Embedding Higher Analogues of Arene and Pyridine Units

Due to enthralling applications in various fields and augmenting fundamental wisdom, π-conjugated macrocycles in general and porphyrin systems in particular are constantly explored. Subtle modifications of porphyrin structure can amend the rudimentary properties. Pursuing innovative properties provides impetus to underpin arene or pyridine moiety embedded porphyrin derivatives. There have been several reviews related to arene incorporated carbaporphyrinoids; however, recent developments of porphyrin analogues by introducing higher analogues of arenes and pyridine units are not adequately inspected. This mini-review mainly focuses on biphenyl, bipyridine, terphenyl, and mixed arene pyridine embedded porphyrin analogues and their coordination chemistry.

Response to pazopanib-based combination regimen in a case of FGFR3 amplified gastric adenocarcinoma

Angiogenesis inhibitors (AGI) are not presently used for the treatment of gastric cancers. This report demonstrates that angiogenesis inhibitor can be safely and effectively used in combination with cytotoxic anti-cancer agents for treatment of Gastric cancers.

Diagnostic Role of Diffusion-Weighted and Dynamic Contrast-Enhanced Perfusion MR Imaging in Paragangliomas and Schwannomas in the Head and Neck

BACKGROUND AND PURPOSE

Distinguishing schwannomas from paragangliomas in the head and neck and determining succinate dehydrogenase (SDH) mutation status in paragangliomas are clinically important. We aimed to assess the clinical usefulness of DWI and dynamic contrast-enhanced MR imaging in differentiating these 2 types of tumors, as well as the SDH mutation status of paragangliomas.

MATERIALS AND METHODS

This retrospective study from June 2016 to June 2020 included 42 patients with 15 schwannomas and 27 paragangliomas (10 SDH mutation-positive and 17 SDH mutation-negative). ADC values, dynamic contrast-enhanced MRI parameters, and tumor imaging characteristics were compared between the 2 tumors and between the mutation statuses of paragangliomas as appropriate. Multivariate stepwise logistic regression analysis was performed to identify significant differences in these parameters.

RESULTS

Fractional plasma volume (P ≤ .001), rate transfer constant (P = .038), time-to-maximum enhancement (P < .001), maximum signal-enhancement ratio (P < .001) and maximum concentration of contrast agent (P < .001), velocity of enhancement (P = .002), and tumor characteristics including the presence of flow voids (P = .001) and enhancement patterns (P = .027) showed significant differences between schwannomas and paragangliomas, though there was no significant difference in ADC values. In the multivariate logistic regression analysis, fractional plasma volume was identified as the most significant value for differentiation of the 2 tumor types (P = .014). ADC values were significantly higher in nonhereditary than in hereditary paragangliomas, while there was no difference in dynamic contrast-enhanced MR imaging parameters.

CONCLUSIONS

Dynamic contrast-enhanced MR imaging parameters show promise in differentiating head and neck schwannomas and paragangliomas, while DWI can be useful in detecting SDH mutation status in paragangliomas.

Assessment of MR Imaging and CT in Differentiating Hereditary and Nonhereditary Paragangliomas

BACKGROUND AND PURPOSE

Head and neck paragangliomas have been reported to be associated with mutations of the succinate dehydrogenase enzyme family. The aim of this study was to assess whether radiologic features could differentiate between paragangliomas in the head and neck positive and negative for the succinate dehydrogenase mutation.

MATERIALS AND METHODS

This single-center retrospective review from January 2015 to January 2020 included 40 patients with 48 paragangliomas (30 tumors positive for succinate dehydrogenase mutation in 23 patients and 18 tumors negative for the succinate dehydrogenase mutation in 17 patients). ADC values and tumor characteristics on CT and MR imaging were evaluated by 2 radiologists. Differences between the 2 cohorts in the diagnostic performance of ADC and normalized ADC (ratio to ADC in the medulla oblongata) values were evaluated using the independent samples t test. P < .05 was considered significant.

RESULTS

ADC_mean (1.07 [SD, 0.25]/1.04 [SD, 0.12] versus 1.31 [SD, 0.16]/1.30 [SD, 0.20]× 10^-3 mm²/s by radiologists 1 and 2; P < .001), ADC_maximum (1.49 [SD, 0.27]/1.49 [SD, 0.20] versus 2.01 [SD, 0.16]/1.87 [SD, 0.20] × 10^-3 mm²/s; P < .001), normalized ADC_mean (1.40 [SD, 0.33]/1.37 [SD, 0.16] versus 1.73 [SD, 0.22]/1.74 [SD, 0.27]; P < .001), and normalized ADC_maximum (1.95 [SD, 0.37]/1.97 [SD, 0.27] versus 2.64 [SD, 0.22]/2.48 [SD, 0.28]; P < .001) were significantly lower in succinate dehydrogenase mutation-positive than mutation-negative tumors. ADC_minimum, normalized ADC_minimum, and tumor characteristics were not statistically significant.

CONCLUSIONS

ADC is a promising imaging biomarker that can help differentiate succinate dehydrogenase mutation-positive from mutation-negative paragangliomas in the head and neck.

Concordancy of immunocytochemistry profiling of circulating tumor cells with immunohistochemistry for analysis of therapeutically relevant biomarkers

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Background: Immunohistochemistry (IHC) profiling of tumor tissue is the present standard for evaluation of therapeutically relevant biomarkers such as ER, PR, HER2, AR, ARv7, PD-L1 and MMR for selection of targeted, endocrine and checkpoint inhibitor therapy selection. However, this critical analysis is dependent on availability of tumor tissue obtained by an invasive biopsy. Challenges to this analysis include insufficient tumor tissue and inability to perform a repeat biopsy to obtain fresh tumor tissue. We have previously described an approach for negative enrichment of Circulating Tumor Cells (CTCs) from peripheral blood and for Immunocytochemistry (ICC) profiling of these CTCs for detection of diagnostically relevant tissue of origin and subtype specific markers, concordant with tumor tissue analysis. Methods: In the present study, we determined concordance between tumor tissue (HPE) and CTCs (ICC) for ascertaining the status of therapeutically relevant markers ER, PR, HER2, AR, ARv7 PD-L1 and MMR. We evaluated 201 matched pairs of tumor tissue (FFPE blocks) and CTCs obtained from peripheral blood. Results: Among the 743 paired assays on matched tumor tissue and CTCs, concordance (positive or negative) was observed in 651 matched pairs (87.6%). The concordance was 82.9% for ER, 100% for PR, 90.2 % for Her2, 93.8% for AR, 90% for Arv7, 85.1% and 87.6% for PD-L1 clones 22c3 and 28-8, and 85.6% for MMR (MLH1, MSH2, MSH6, and PMS2). Conclusions: The study findings indicate that ICC analysis of CTCs may be able to substitute IHC analysis of tumor tissue for profiling of therapeutically relevant markers. This approach may have application in cases where tumor tissue may be limiting and / or where an invasive biopsy to obtain tumor tissue may be unviable.

From bad to worse: airline boarding changes in response to COVID-19

Airlines have introduced a back-to-front boarding process in response to the COVID-19 pandemic. It is motivated by the desire to reduce passengers' likelihood of passing close to seated passengers when they take their seats. However, our prior work on the risk of Ebola spread in aeroplanes suggested that the driving force for increased exposure to infection transmission risk is the clustering of passengers while waiting for others to stow their luggage and take their seats. In this work, we examine whether the new boarding processes lead to increased or decreased risk of infection spread. We also study the reasons behind the risk differences associated with different boarding processes. We accomplish this by simulating the new boarding processes using pedestrian dynamics and compare them against alternatives. Our results show that back-to-front boarding roughly doubles the infection exposure compared with random boarding. It also increases exposure by around 50% compared to a typical boarding process prior to the outbreak of COVID-19. While keeping middle seats empty yields a substantial reduction in exposure, our results show that the different boarding processes have similar relative strengths in this case as with middle seats occupied. We show that the increased exposure arises from the proximity between passengers moving in the aisle and while seated. Such exposure can be reduced significantly by prohibiting the use of overhead bins to stow luggage. Our results suggest that the new boarding procedures increase the risk of exposure to COVID-19 compared with prior ones and are substantially worse than a random boarding process.

3-D Cryptand Like Normal and Doubly N-Confused Calixbenzophyrins: Synthesis and Structural Studies

The three-dimensional (3-D) cryptand-like normal and doubly-N-confused calixbenzophyrins embedded with phenyl rings in the macrocyclic skeleton are successfully synthesized from single starting materials. These structural isomers are characterized by spectral studies and unambiguously confirmed by crystal analyses.

Abstract PS2-40: Analytical and clinical validation of the trucheck™ platform for diagnostic triaging of symptomatic cases suspected of breast cancer

Background: trucheckTM is a non-invasive micro-biopsy-like approach for diagnostic triaging of symptomatic individuals suspected of Breast Cancer. trucheckTM is based on the detection of Circulating Ensembles of Tumor Associated Cells (C-ETACs: EpCAM+, Pan-CK+, CD45±) of Breast Cancer origin (GCDFP15+, GATA3+); such C-ETACs are ubiquitous in blood samples of patients with Breast Cancer and unexpected in asymptomatic individuals as well as in individuals with Benign Breast conditions. Methods: Analytical validation was performed using control cell lines for EpCAM (SKBR-3), Pan-CK (SKBR-3), CD45 (PBMCs), GCDFP15 (SKBR-3) and GATA3 (MCF-7) respectively. Known amounts of control cells were spiked into healthy donor blood and their recovery rates determined by immunocytochemistry (ICC) to establish Sensitivity, Specificity, Accuracy, Limit of Detection, Linearity and Precision. Clinical Validation was performed using 15 mL peripheral blood collected from 1,527 participants. An initial Retrospective Clinical Pre-validation was performed using blood samples collected from 547 known cases of Breast Cancer and 19 known cases of other (non-Breast) solid organ Cancers. In a subset of 20 Breast Cancer cases with metastases to the Lungs or Liver, C-ETACs were evaluated for markers associated Lung (Napsin-A, TTF-1, p40) and Liver (Hep-Par 1, Glypican-3) primaries. Prospective Clinical Validation was performed on blood samples collected prior to any invasive procedure from 961 symptomatic cases suspected of Breast Cancer. Results: Analytical Validation based on recovery of spiked control cells indicated 94.0% Sensitivity, 100% Specificity, 97.0% Accuracy, 93.2% - 96.7% Precision and significant linearity (R2≥0.99) for all ICC markers. Clinical Pre-validation indicated 89.4% Sensitivity and 100% Specificity. C-ETACs from the known Breast Cancer cases with Lung and Liver metastases were negative for Lung- and Liver-cancer specific ICC markers, respectively, while C-ETACs from non-Breast Cancer samples were negative for Breast Cancer-specific ICC markers. In the Prospective Clinical Validation, histopathological evaluation (HPE) of biopsied tumor tissue indicated Breast Cancer in 848 cases and benign conditions in 113 of the 961 suspected symptomatic cases. C-ETAC-based trucheckTM approach had 91.9% Sensitivity, 98.3% Specificity and 96.9% Accuracy. Conclusion: Analytical and Clinical Validation data establish the viability of C-ETAC-based trucheckTM for diagnostic triaging of symptomatic individuals suspected of Breast Cancer. Individuals positive for Breast Cancer-specific C-ETACs can be prioritized for further clinical procedures whereas C-ETAC negative individuals can be considered for alternate diagnoses.

Citation Format: Dadasaheb Akolkar, Darshana Patil, Pradip Fulmali, Pooja Fulmali, Revati Patil, Kiran Bendale, Archana Adhav, Shoeb Patel, Shabista Khan, Raja Dasarathan, Vishal Ranjan, Rohit Chougule, Pradyumna Shejwalkar, Akshay Ainwale, Mohini Garte, Rahul Sonawane, Madhav Purane, Yogeshwar Chaudhari, Prajakta Sagar, Shubhangi Nerkar, Vineet Datta, Cynthe Sims, Prashant Kumar, Ajay Srinivasan, Rajan Datar. Analytical and clinical validation of the trucheck™ platform for diagnostic triaging of symptomatic cases suspected of breast cancer [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS2-40.

Abstract PS3-13: Non-invasive screening for breast cancer risk based on circulating ensembles of tumor associated cells

Background: Common modalities for breast cancer screening include self-breast examination (SBE) for detection of palpable lumps as well as Mammography scans for detection of suspicious nodules or masses. While both approaches have low specificity, SBE has lower sensitivity for early stage cancers while mammography is associated with radiation exposure risks. A blood-based non-invasive approach for determination of breast cancer risk in asymptomatic individuals can facilitate early detection and improve prognosis and survival. Circulating Ensembles of Tumor Associated Cells (C-ETACs) are heterotypic clusters of malignant cells which originate in a tumor and are ubiquitously detected in peripheral blood of individuals with solid organ cancers. We present findings from two large-cohort prospective observational studies showing the suitability of C-ETACs for non-invasive, non-radiological screening for breast cancer. Methods: 15 ml of peripheral blood was collected from 14,962 female volunteers among whom 832 were suspected cases of breast cancer and 14,962 were asymptomatic individuals with age-associated risk of breast cancer. The 832 suspected cases underwent a foundational (first diagnostic) biopsy following collection of blood while the 14,962 asymptomatic individuals underwent a mammography scan following collection of blood. Peripheral blood mononuclear cells (PBMCs) were isolated from all blood samples and treated with an epigenetically activating treatment medium which exerts selective cytotoxicity towards non-malignant hematolymphoid cells and allows survival of apoptosis resistant malignant cells and their clusters (C-ETACs). C-ETACs were defined as clusters of 3 or more cells which were EpCAM+, PanCK+ and CD45+/-. Results: Among the 832 suspected cases, 779 were eventually diagnosed with breast cancer and 53 with benign breast conditions. C-ETACs were detected in 701 / 779 cases of breast cancer (90.0% sensitivity) with comparable detection rates in metastatic (365/408 = 89.5%) as well as non-metastatic (336/371 = 90.6%). C-ETACs were also detected in 1 / 53 (1.9%) cases of benign breast tumor. Among the asymptomatic cohort of 14,130, C-ETACs were detected in 657 cases (4.7%), which included 509 / 10,859 (4.7%) individuals with BIRADS 1 and in 148 / 3,271 (4.5%) of individuals with BIRADS ≥2. These individuals have been advised clinical follow-up. Conclusions: We show that C-ETACs are ubiquitous in breast cancers and rare in individuals with benign conditions as well as asymptomatic individuals. Being derived from the tumor mass, C-ETACs are specific for cancer and thus provide direct visual evidence of malignancy in cancer cases and risk of malignancy in asymptomatic cases. The non-invasive nature of the approach is well suited for screening of large asymptomatic populations for breast cancer.

Citation Format: Dadasaheb Akolkar, Darshana Patil, Pradip Fulmali, Pooja Fulmali, Revati Patil, Archana Adhav, Shoeb Patel, Sachin Apurwa, Sushant Pawar, Harshal Bodke, Vishal Ranjan, Rohit Chougule, Pradyumna Shejwalkar, Shabista Khan, Raja Dhasarathan, Pradip Devhare, Sanket Patil, Vineet Datta, Cynthe Sims, Stefan Schuster, Jatinder Bhatia, Chirantan Bose, Ajay Srinivasan, Rajan Datar. Non-invasive screening for breast cancer risk based on circulating ensembles of tumor associated cells [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-13.

Abstract PS4-36: Non-invasive evaluation of chemoresistance in breast cancers using circulating tumor associated cells

Background: Despite the development of Checkpoint Inhibitor Treatments (Immunotherapy) and Targeted anticancer agents, cytotoxic (chemotherapy) agents remain the mainstay of breast cancer treatments. However, treatment failure is often encountered in breast cancers owing to innate or acquired chemoresistance. Real time monitoring of inherent or incipient chemoresistance is an unmet need to minimize or prevent treatment failures and improve outcomes. However, prior efforts to determine chemoresistance have used tumor tissue or explants and are hence not suitable for repetitive monitoring. We present findings from a large cohort perspective observational study which shows that Circulating Tumor Associated Cells (CTACs) be isolated in sufficient numbers from peripheral blood and can be profiled in vitro for chemoresistance characteristics. Methods: 15 ml of peripheral blood was obtained from 1410 breast cancer patients, of whom 719 were treatment naïve and 691 had received prior systemic therapies. Matched tumor tissue was obtained by a biopsy (post-blood collection) in a subset of 68 cases. Peripheral blood mononuclear cells (PBMCs) were isolated from all blood samples and treated with an epigenetically activating treatment medium which exerts selective cytotoxicity towards non-malignant hematolymphoid cells and allows survival of apoptosis resistant malignant CTACs, which were defined as cells which were EpCAM+, PanCK+ and CD45+/-. Viable Tumor Derived Cells (TDCs) were harvested from biopsied tumor tissue (N=68). CTACs and TDCs were treated in vitro with cytotoxic chemotherapy agents that are used in Standard of Care (SoC) treatment protocols for breast cancer as single agents or in combinations. In 68 cases, concordance in Chemoresistance Profiles (CRP) was determined between CTACs and corresponding TDCs. In 681 pretreated cases, CRP of CTACs evaluated cumulative (innate and acquired) resistance following prior exposure to chemotherapy agents. In 685 therapy naïve cases, CRP of CTACs evaluated innate chemoresistance towards chemotherapy agents. Results: Among the 68 paired samples of CTACs and TDCs, there were 733 unique combinations of CTAC-TDC-drug, among which 366 pairs (50%) were concordant for chemo-resistance, 336 pairs (46%) were concordant for absence of resistance, and 31 pairs (4%) showed absence of concordance leading to a cumulative concordance of 96% in CRP between TDC and CTACs. Among the 681 pretreated cases, resistance towards ≥1 anticancer agents was observed in 67% of the samples. Among the 685 therapy naïve cases, resistance towards ≥1 anticancer agents was observed in 39% of the samples. Conclusion: The present study shows that sufficient CTACs can be harvested from peripheral blood for meaningful non-invasive chemoresistance profiling and that the resistance profiles of CTACs are concordant with that of tumor tissue. The present approach can identify innate as well as acquired chemoresistance and can guide selection of appropriate therapies. This approach can facilitate real time monitoring of chemoresistance and therapeutic course correction to minimize the risk of treatment failures.

Citation Format: Darshana Patil, Dadasaheb Akolkar, Sanket Patil, Vishakha Mhase, Sachin Apurwa, Sushant Pawar, Rutuja Bhave, Mahesh Ukade, Samruddhi Raut, Harshal Bodke, Shabista Khan, Raja Dhasarathan, Vineet Datta, Stefan Schuster, Cynthe Sims, Jatinder Bhatia, Chirantan Bose, Ajay Srinivasan, Rajan Datar. Non-invasive evaluation of chemoresistance in breast cancers using circulating tumor associated cells [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS4-36.

Development and validation of a multigene variant profiling assay to guide targeted and immuno therapy selection in solid tumors

We present data on analytical validation of the multigene variant profiling assay (CellDx) to provide actionable indications for selection of targeted and immune checkpoint inhibitor (ICI) therapy in solid tumors. CellDx includes Next Generation Sequencing (NGS) profiling of gene variants in a targeted 452-gene panel as well as status of total Tumor Mutation Burden (TMB), Microsatellite instability (MSI), Mismatch Repair (MMR) and Programmed Cell Death-Ligand 1 (PD-L1) respectively. Validation parameters included accuracy, sensitivity, specificity and reproducibility for detection of Single Nucleotide Alterations (SNAs), Copy Number Alterations (CNAs), Insertions and Deletions (Indels), Gene fusions, MSI and PDL1. Cumulative analytical sensitivity and specificity of the assay were 99.03 (95% CI: 96.54-99.88) and 99.23% (95% CI: 98.54% - 99.65%) respectively with 99.20% overall Accuracy (95% CI: 98.57% - 99.60%) and 99.7% Precision based on evaluation of 116 reference samples. The clinical performance of CellDx was evaluated in a subsequent analysis of 299 clinical samples where 861 unique mutations were detected of which 791 were oncogenic and 47 were actionable. Indications in MMR, MSI and TMB for selection of ICI therapies were also detected in the clinical samples. The high specificity, sensitivity, accuracy and reproducibility of the CellDx assay is suitable for clinical application for guiding selection of targeted and immunotherapy agents in patients with solid organ tumors.

New signatures of the spin gap in quantum point contacts

One dimensional semiconductor systems with strong spin-orbit interaction are both of fundamental interest and have potential applications to topological quantum computing. Applying a magnetic field can open a spin gap, a pre-requisite for Majorana zero modes. The spin gap is predicted to manifest as a field dependent dip on the first 1D conductance plateau. However, disorder and interaction effects make identifying spin gap signatures challenging. Here we study experimentally and numerically the 1D channel in a series of low disorder p-type GaAs quantum point contacts, where spin-orbit and hole-hole interactions are strong. We demonstrate an alternative signature for probing spin gaps, which is insensitive to disorder, based on the linear and non-linear response to the orientation of the applied magnetic field, and extract a spin-orbit gap ΔE ≈ 500 μeV. This approach could enable one-dimensional hole systems to be developed as a scalable and reproducible platform for topological quantum applications.

In one-dimensional systems, the combination of a strong spin-orbit interaction and an applied magnetic field can give rise to a spin-gap, however experimental identification is difficult. Here, the authors present new signatures for the spin-gap, and verify these experimentally in hole QPCs.

Tetrakis-(N-methyl-4-pyridinium)-porphyrin as a diamagnetic chemical exchange saturation transfer (diaCEST) MRI contrast agent

Easily synthesizable tetrakis-(N-methyl-4-pyridinium)-porphyrin as a diaCEST agent that shows nearly pH independent good contrast in a wide range of pH.

A case report of androgen receptor inhibitor therapy in recurrent high-grade serous ovarian cancer

Ovarian cancer is common gynaecological malignancy and a leading cause of death among women. Despite the advances in treatment strategies, majority of patients present with recurrence after first- or second-line treatment. Targeted therapy that has proven to be effective in other advanced or metastatic solid tumors have also demonstrated its efficacy in ovarian cancer. Recent studies have shown that the androgen receptor (AR) signalling is involved in pathogenicity and progression of cancer. Current observations suggest AR could be a potential target in managing the disease. In this case report we present a patient with high grade serous ovarian cancer (HGSOC) with multiple relapses with excellent disease control on AR inhibition with bicalutamide.

Liquid biopsy and multi-analyte testing guided treatment of HER2 positive periampullary adenocarcinoma with durable complete response after trastuzumab based therapy

Periampullary adenocarcinomas are rare neoplasm that originates from the pancreatic head, the ampulla of vater, the distal bile duct or the duodenum. Surgical resection followed by adjuvant therapy is considered as the standard of care treatment for these carcinomas. Despite several advances in diagnostics and therapeutics, only 5% of these patients have an overall survival of five years or more. Currently, there is a dearth of viable therapeutic targets for this disease. The role of HER2 in cancer biology has been studied extensively in several tumour subtypes, and HER2 based targeted therapies have shown to have therapeutic benefits on different cancers. In this case report, we present a case of HER2 positive distal common bile duct carcinoma – a subtype of periampullary carcinoma with multiple relapses where multi-analyte testing with Encyclopedic Tumor Analysis (ETA) (Exacta^®) identified amplification and over expression of HER2 gene which was used as a potential target to treat the patient with trastuzumab. Synchronous in vitro chemosensitivity profiling on Circulating Tumor Asscociated Cells (C-TACs) isolated from blood aided us to design the personalized chemotherapeutic regimen with cyclophosphamide and methotrexate. The combination of trastuzumab with cyclophosphamide and methotrexate yielded excellent treatment response with the patient remaining in complete response till the last follow-up. Our study suggests HER2 directed therapy as a potent pathway for treatment in the subset of HER-2 amplified distal common bile duct carcinomas.

BIOM-35. MULTI ANALYTE ASSAY FOR NON-INVASIVE DIAGNOSIS OF BRAIN TUMORS

The diagnosis of Central Nervous System (CNS) malignancies such as Gliomas in individuals presenting with Intracranial Space Occupying Lesions (ICSOL) is based on histopathological examination (HPE) of tumor tissue obtained by an invasive brain biopsy. However, brain biopsies are resource intensive and are associated with procedural risks such as haemorrhage, morbidity and mortality. The present study evaluated a non-invasive approach for diagnosis of CNS-M in symptomatic individuals based on evaluation of circulating tumor analytes in peripheral blood. The non-invasive multi-platform approach for diagnosis of CNS-M included Immunocytochemistry (ICC) profiling and Fluorescence in situ Hybridization (FISH) of Circulating Tumor Cells (CTCs) and Digital Droplet PCR (ddPCR) of cell-free tumor DNA (ctDNA) and exosomal mRNA. Performance characteristics of each platform were evaluated using blood and tissue samples from 445 individuals including 227 known cases of CNS-M, 47 known cases of benign CNS conditions (CNS-B), 141 known cases of other cancers with brain metastases (OTH-M) and 30 asymptomatic individuals (ASYM). In a set of 37 samples from individuals with radiological ICSOL, suspected of malignancy (CNS-S) complete diagnostic work-up was performed with ICC, FISH and ddPCR. Glial CTCs were detected in 88.8% of 227 CNS-M and undetectable in 89.4% of 47 CNS-B or 100% of 141 OTH-M, indicating high sensitivity and specificity, respectively. The multi-analyte approach discerned CNS-M from CNS-B as well as OTH-M with 91.7% accuracy and accurately inferred lineage in 84.6% of cases. This non-invasive multi-analyte approach can diagnose CNS-M with an accuracy not inferior to standard HPE, can substitute invasive biopsies in most cases and is particularly helpful in cases where a biopsy is not viable.