A concurrent, deep learning-based computer-aided detection system for prostate multiparametric MRI: a performance study involving experienced and less-experienced radiologists.

OBJECTIVES: To evaluate the effect of a deep learning-based computer-aided diagnosis (DL-CAD) system on experienced and less-experienced radiologists in reading prostate mpMRI. METHODS: In this retrospective, multi-reader multi-case study, a consecutive set of 184 patients examined between 01/2018 and 08/2019 were enrolled. Ground truth was combined targeted and 12-core systematic transrectal ultrasound-guided biopsy. Four radiologists, two experienced and two less-experienced, evaluated each case twice, once without (DL-CAD-) and once assisted by DL-CAD (DL-CAD+). ROC analysis, sensitivities, specificities, PPV and NPV were calculated to compare the diagnostic accuracy for the diagnosis of prostate cancer (PCa) between the two groups (DL-CAD- vs. DL-CAD+). Spearman's correlation coefficients were evaluated to assess the relationship between PI-RADS category and Gleason score (GS). Also, the median reading times were compared for the two reading groups. RESULTS: In total, 172 patients were included in the final analysis. With DL-CAD assistance, the overall AUC of the less-experienced radiologists increased significantly from 0.66 to 0.80 (p = 0.001; cutoff ISUP GG ≥ 1) and from 0.68 to 0.80 (p = 0.002; cutoff ISUP GG ≥ 2). Experienced radiologists showed an AUC increase from 0.81 to 0.86 (p = 0.146; cutoff ISUP GG ≥ 1) and from 0.81 to 0.84 (p = 0.433; cutoff ISUP GG ≥ 2). Furthermore, the correlation between PI-RADS category and GS improved significantly in the DL-CAD + group (0.45 vs. 0.57; p = 0.03), while the median reading time was reduced from 157 to 150 s (p = 0.023). CONCLUSIONS: DL-CAD assistance increased the mean detection performance, with the most significant benefit for the less-experienced radiologist; with the help of DL-CAD less-experienced radiologists reached performances comparable to that of experienced radiologists. KEY POINTS: • DL-CAD used as a concurrent reading aid helps radiologists to distinguish between benign and cancerous lesions in prostate MRI. • With the help of DL-CAD, less-experienced radiologists may achieve detection performances comparable to that of experienced radiologists. • DL-CAD assistance increases the correlation between PI-RADS category and cancer grade.

Inferior vena cava-syndrome.

Inferior vena cava syndrome (IVCS) is caused by agenesis, compression, invasion, or thrombosis of the IVC, or may be associated with Budd-Chiari syndrome. Its incidence and prevalence are unknown. Benign IVCS is separated from malignant IVCS. Both cover a wide clinical spectrum reaching from asymptomatic to highly symptomatic cases correlated to the underlying cause, the acuity, the extent of the venous obstruction, and the recruitment and development of venous collateral circuits. Imaging is necessary to determine the underlying cause of IVCS and to guide clinical decisions. Interventional therapy has changed the therapeutic approach in symptomatic patients. This article provides an overview over IVCS and focuses on interventional therapeutic methods and results.

Superior vena cava syndrome.

The superior vena cava syndrome (SVCS) is caused by compression, invasion, and/or thrombosis of the superior vena cava and/or the brachiocephalic veins. Benign SVCS is separated from malignant SVCS. SVCS comprises a broad clinical spectrum reaching from asymptomatic cases to rare life-threatening emergencies with upper airway obstruction and increased intracranial pressure. Symptoms are correlated to the acuity and extent of the venous obstruction and inversely correlated to the development of the venous collateral circuits. Imaging is necessary to determine the exact underlying cause and to guide further interventions. Interventional therapy has widely changed the therapeutic approach in symptomatic patients. This article provides an overview over this complex syndrome and focuses on interventional therapeutic methods and results.

Gene expression profiling of homologous recombination repair pathway indicates susceptibility for olaparib treatment in malignant pleural mesothelioma in vitro.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a tumour arising from pleural cavities with poor prognosis. Multimodality treatment with pemetrexed combined with cisplatin shows unsatisfying response-rates of 40%. The reasons for the rather poor efficacy of chemotherapeutic treatment are largely unknown. However, it is conceivable that DNA repair mechanisms lead to an impaired therapy response. We hypothesize a major role of homologous recombination (HR) for genome stability and survival of this tumour. Therefore, we analysed genes compiled under the term "BRCAness". An inhibition of this pathway with olaparib might abrogate this effect and induce apoptosis. METHODS: We investigated the response of three MPM cell lines and lung fibroblasts serving as a control to treatment with pemetrexed, cisplatin and olaparib. Furthermore, we aimed to find possible correlations between response and gene expression patterns associated with BRCAness phenotype. Therefore, 91 clinical MPM samples were digitally screened for gene expression patterns of HR members. RESULTS: A BRCAness-dependent increase of apoptosis and senescence during olaparib-based treatment of BRCA-associated-protein 1 (BAP1)-mutated cell lines was observed. The gene expression pattern identified could be found in approx. 10% of patient samples. Against this background, patients could be grouped according to their defects in the HR system. Gene expression levels of Aurora Kinase A (AURKA), RAD50 as well as DNA damage-binding protein 2 (DDB2) could be identified as prognostic markers in MPM. CONCLUSIONS: Defects in HR compiled under the term BRCAness are a common event in MPM. The present data can lead to a better understanding of the underlaying cellular mechanisms and leave the door wide open for new therapeutic approaches for this severe disease with infaust prognosis. Response to Poly (ADP-ribose)-Polymerase (PARP)-Inhibition could be demonstrated in the BAP1-mutated NCI-H2452 cells, especially when combined with cisplatin. Thus, this combination therapy might be effective for up to 2/3 of patients, promising to enhance patients' clinical management and outcome.

Pathogenic and targetable genetic alterations in 70 urachal adenocarcinomas.

Urachal cancer (UrC) is a rare but aggressive malignancy often diagnosed in advanced stages requiring systemic treatment. Although cytotoxic chemotherapy is of limited effectiveness, prospective clinical studies can hardly be conducted. Targeted therapeutic treatment approaches and potentially immunotherapy based on a biological rationale may provide an alternative strategy. We therefore subjected 70 urachal adenocarcinomas to targeted next-generation sequencing, conducted in situ and immunohistochemical analyses (including PD-L1 and DNA mismatch repair proteins [MMR]) and evaluated the microsatellite instability (MSI) status. The analytical findings were correlated with clinicopathological and outcome data and Kaplan-Meier and univariable/multivariable Cox regression analyses were performed. The patients had a mean age of 50 years, 66% were male and a 5-year overall survival (OS) of 58% and recurrence-free survival (RFS) of 45% was detected. Sequence variations were observed in TP53 (66%), KRAS (21%), BRAF (4%), PIK3CA (4%), FGFR1 (1%), MET (1%), NRAS (1%), and PDGFRA (1%). Gene amplifications were found in EGFR (5%), ERBB2 (2%), and MET (2%). We detected no evidence of MMR-deficiency (MMR-d)/MSI-high (MSI-h), whereas 10 of 63 cases (16%) expressed PD-L1. Therefore, anti-PD-1/PD-L1 immunotherapy approaches might be tested in UrC. Importantly, we found aberrations in intracellular signal transduction pathways (RAS/RAF/PI3K) in 31% of UrCs with potential implications for anti-EGFR therapy. Less frequent potentially actionable genetic alterations were additionally detected in ERBB2 (HER2), MET, FGFR1, and PDGFRA. The molecular profile strengthens the notion that UrC is a distinct entity on the genomic level with closer resemblance to colorectal than to bladder cancer.

Telomerase reverse transcriptase (TERT) promoter mutations are rare in urachal cancer.

High rates of telomerase reverse transcriptase (TERT) promoter mutations have recently been described in urothelial carcinoma (UC). Unlike UC in the bladder, adenocarcinomas account for the majority of urachal cancer (UrC) cases. As data in UrC is unclear, we analyzed TERT promoter mutations in a large cohort of UrC for its differential diagnostic, clinicopathological and prognostic significance. UrC cases from six academic centers were analyzed for c.-146C>T (C250T) and c.-124C>T (C228T) TERT promoter mutations by PCR and Sanger sequencing. Clinicopathological and survival data were collected. The cohort consisted of 15 men (56%) and 12 women (44%) with a median age of 50 years including 23 adenocarcinomas, two squamous cell carcinomas (SCC), one UC and one undifferentiated carcinoma. In one case of (mucinous) urachal adenocarcinoma a C228T mutation was detected (1/23; 4%), like in a case of SCC in addition to one C250T mutation in the UC case. TERT promoter mutations are very rare in urachal adenocarcinomas (unlike in UC) with differential diagnostic implications. Additionally, the low TERT promoter mutation rate in urachal adenocarcinomas is more comparable to colorectal adenocarcinomas than to UC, giving further support to recent genetic findings and therapeutic considerations.

Real-time lymphography by indocyanine green fluorescence: improved navigation for regional lymph node staging.

OBJECTIVES: Lymphatic imaging is an important step for the identification of lymphonodal positive disease in solid malignancies. Various methods have been established to detect positive lymph nodes, but the available diagnostic tools leave some inherent drawbacks. The aim of this study was to validate the indocyanine green (ICG) guided approach for transcutaneous and transmesenterial navigation with accurate lymph vessel and node identification for regional lymph node staging in solid malignancies. METHODS: After institutional review board approval, a planar fluorescence imaging system was applied for lymphography and lymph node detection using ICG. A total of 96 patients were recruited and subject to fluorescence navigation for axillary (n = 46), inguinal (n = 16), and mesenterial (n = 34) visualization to analyze technical and clinical feasibility of the method after regional lymph node dissection and the applicability. RESULTS: Overall fluorescence imaging identified lymphatic vessels and the SLN in 92 out of 96 patients (detection rate: 96%) after a mean injection of 7 mg ICG. Sensitivity based on fluorescent emission of ICG navigation was 95.6% in 65 out of 68 patients with lymph node dissection. All solid tumors were feasible for fluorescence-guided navigation with a broad spectrum. CONCLUSION: Fluorescence-guided real-time lymphography with navigation to regional lymph nodes enables accurate visualization for a broad spectrum of different solid tumors with potential lymphonodal spread. In addition, the technique can be applied for lymphography in non-malignant diseases. With reference to the broad application spectrum, institutional investment in camera equipment can be justified.

Early Metabolic Response by PET Predicts Sensitivity to Next-Line Targeted Therapy in EGFR-Mutated Lung Cancer with Unknown Mechanism of Acquired Resistance.

Targeted therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has established the precision oncology paradigm in lung cancer. Most patients with EGFR-mutated lung cancer respond but eventually acquire resistance. Methods: Patients exhibiting the EGFR p.T790M resistance biomarker benefit from sequenced targeted therapy with osimertinib. We hypothesized that metabolic response as detected by 18F-FDG PET after short-course osimertinib identifies additional patients susceptible to sequenced therapy. Results: Fourteen patients with EGFR-mutated lung cancer and resistance to first- or second-generation EGFR TKI testing negatively for EGFR p.T790M were enrolled in a phase II study. Five patients (36%) achieved a metabolic 18F-FDG PET response and continued osimertinib. In those, the median duration of treatment was not reached (95% CI, 24 mo to not estimable), median progression-free survival was 18.7 mo (95% CI, 14.6 mo to not estimable), and median overall survival was 41.5 mo. Conclusion: Connecting theranostic osimertinib treatment with early metabolic response assessment by PET enables early identification of patients with unknown mechanisms of TKI resistance who derive dramatic clinical benefit from sequenced osimertinib. This defines a novel paradigm for personalization of targeted therapies in patients with lung cancer dependent on a tractable driver oncogene.

Epiphyseal stress fractures of finger phalanges in adolescent climbing athletes: a 3.0-Tesla magnetic resonance imaging evaluation.

OBJECTIVES: To study the value of 3.0-Tesla magnetic resonance imaging for baseline and follow-up assessment of epiphyseal finger phalanx stress fractures in a collective of 7 consecutive adolescent climbing athletes. MATERIALS AND METHODS: Baseline MRI was performed in 8 fingers of 7 adolescent athletes (mean age 13.8 years, female:male = 2:5) with clinically suspected stress fracture of the fingers acquired during climbing sports. Follow-up MRI was performed after functional therapy with training interruption for 6 weeks (n = 6) and 12 weeks (n = 1). Images were analysed retrospectively and independently by two readers using an MRI grading score from 0 (no pathology) to 4 (bone marrow oedema and clear depiction of a sharp fracture line with surrounding inflammatory soft tissue reaction). RESULTS: A total of 8 baseline and 7 follow-up MRIs were analysed. In 7 out of 8 fingers a stress fracture line Salter-Harris III and in all fingers a bone marrow oedema were diagnosed at the epiphyseal base of the middle phalanx. The average grading score was 3.37 in the initial MRI and 1.43 in the follow-up MRI indicating fracture healing in all fingers. Kappa value for interobserver variability was 0.86, representing almost perfect interobserver agreement. CONCLUSIONS: 3-T MRI is a promising diagnostic technique for baseline assessment of epiphyseal finger phalanx stress fractures and for follow-up evaluation of fracture healing.

Elastic behaviour of orientation-correlated grains in multiphase aggregates.

Diffraction elastic constants (DEC) describe the elastic response of a sub-set of orientation correlated grains which share a common lattice vector. DEC reflect the elastic behaviour of the single crystal constituents through their dependence on grain orientation. DEC furthermore depend on the behaviour of the polycrystal aggregate both through the dependence on preferred orientation and through the average elastic interaction of the grains in the sub-set with their surroundings. The latter is also known as grain-matrix interaction which is grain shape dependent. Both dependencies can make the DEC uniquely sensitive to the elastic effects of the grain shape, texture, and phase composition. Several micro-mechanical models are explored with respect for use both in calculating diffraction elastic constants and overall elastic constants. Furthermore, it is shown how discrete data from electron backscatter diffraction on grain shape, grain orientations, and neighbouring grains can be used for DEC calculations. Lastly, the inverse problem of calculating single crystal elastic constants from DEC is discussed in detail. All calculations discussed in this work can be verified using the freely available computer program IsoDEC.

Molecular Markers Are Associated with Onset of Radioiodine Refractoriness in Patients with Papillary Thyroid Carcinoma.

The onset of radioiodine-refractory thyroid carcinoma (RR-TC) is a negative predictor of survival and has been linked to the presence of BRAFV600E mutations in papillary thyroid cancer. We aimed to identify further genetic alterations associated with RR-TC. Methods: We included 38 patients with papillary thyroid cancer who underwent radioiodine imaging and 18F-FDG PET/CT after total thyroidectomy. The molecular profile was assessed by next-generation sequencing. The time to the onset of RR-TC for different genetic alterations was compared using the log-rank test. Results: The median onset to RR-TC was 0.7 and 19.8 mo in patients with and without, respectively, telomerase reverse transcriptase promoter mutations (P = 0.02) and 1.7 and 19.8 mo in patients with and without, respectively, a tumor protein 53 mutation (P < 0.01). This association was not observed for BRAFV600E mutations (P = 0.49). Conclusion: Our data show a significant association between the onset of RR-TC and mutations in telomerase reverse transcriptase promoter and tumor protein 53, indicating the need for a more extensive diagnostic workup in these patients. Certain genetic changes put patients with thyroid cancer at risk of developing cancer spread that does not respond to radioiodine therapy.

A Phase II Study of Nab-Paclitaxel and Gemcitabine as First-Line Therapy in Patients with Cholangiocarcinoma Ineligible for Cisplatin-Based Chemotherapy (NACHO).

INTRODUCTION: Gemcitabine and cisplatin is the standard first-line systemic treatment in patients with advanced cholangiocarcinoma (CCA). However, a substantial number of patients do not qualify for cisplatin due to comorbidities or poor performance status. The phase II pilot study NACHO evaluated the efficacy of nab-paclitaxel (125 mg/m2) and gemcitabine (1000 mg/m2) given on days 1, 8, and 15 every 4 weeks as first-line therapy in patients with advanced CCA ineligible for cisplatin-based chemotherapy. METHODS: Patients with any comorbidity precluding cisplatin therapy, such as renal impairment, impaired hearing, increased risk or history for thromboembolic events, intolerance of extensive hydration, or significant cardiovascular disease were eligible. Primary endpoint was overall response rate (ORR) per RECIST 1.1. Secondary endpoints were progression-free survival (PFS), overall survival (OS), safety, and patient reported outcome. RESULTS: From December 2016 to July 2017, 10 patients were prospectively enrolled and treated. The ORR with nab-paclitaxel/gemcitabine was 50%, the disease control rate (DCR) was 90%. Median PFS was 5.7 months (95% CI: 5.3-6.1), and median OS was 7.8 months (95% CI: 5.4-10.2). In total, 13 SAEs were documented without any new safety signals. There were 14 grade 3-4 treatment-related adverse events (TRAEs) in 10 patients of the ITT population. Exploratory subgroup analyses including known prognostic markers were performed. CONCLUSIONS: The NACHO trial supports safety and efficacy of nab-paclitaxel and gemcitabine in patients with advanced CCA ineligible for cisplatin-based therapy and should be further evaluated in a larger prospective trial.

Favorable survival outcomes in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer sequentially treated with a tyrosine kinase inhibitor and osimertinib in a real-world setting.

PURPOSE: EGFR tyrosine kinase inhibitor (TKI) therapy in EGFR-mutated lung cancer is limited by acquired resistance. In half of the patients treated with first/second-generation (1st/2nd gen) TKI, resistance is associated with EGFR p.T790M mutation. Sequential treatment with osimertinib is highly active in such patients. Currently, there is no approved targeted second-line option for patients receiving first-line osimertinib, which thus may not be the best choice for all patients. The present study aimed to evaluate the feasibility and efficacy of a sequential TKI treatment with 1st/2nd gen TKI, followed by osimertinib in a real-world setting. METHODS: Patients with EGFR-mutated lung cancer treated at two major comprehensive cancer centers were retrospectively analyzed by the Kaplan-Meier method and log rank test. RESULTS: A cohort of 150 patients, of which 133 received first-line treatment with a first/second gen EGFR TKI, and 17 received first-line osimertinib, was included. Median age was 63.9 years, 55% had ECOG performance score of ≥ 1. First-line osimertinib was associated with prolonged progression-free survival (P = 0.038). Since the approval of osimertinib (February 2016), 91 patients were under treatment with a 1st/2nd gen TKI. Median overall survival (OS) of this cohort was 39.3 months. At data cutoff, 87% had progressed. Of those, 92% underwent new biomarker analyses, revealing EGFR p.T790M in 51%. Overall, 91% of progressing patients received second-line therapy, which was osimertinib in 46%. Median OS with sequenced osimertinib was 50 months. Median OS of patients with p.T790M-negative progression was 23.4 months. CONCLUSION: Real-world survival outcomes of patients with EGFR-mutated lung cancer may be superior with a sequenced TKI strategy. Predictors of p.T790M-associated resistance are needed to personalize first-line treatment decisions.

GenoType CM Direct® and VisionArray Myco® for the Rapid Identification of Mycobacteria from Clinical Specimens.

M. tuberculosis is the single infectious agent responsible for most deaths worldwide outside of pandemics. Diseases due to non-tuberculous mycobacteria (NTM) are increasing in many regions of the world. The two molecular assays GenoType CM direct® (GTCMd) (Bruker, Billerica, MA, USA) and VisionArray Myco® (VAM) (ZytoVision, Bremerhaven, Germany) are based on the DNA/DNA hybridization technique, and allow for the identification of tuberculous and the most clinically relevant non-tuberculous mycobacterial species from clinical specimens. We evaluated the performance of both assays for the identification of mycobacteria from 65 clinical specimens of 65 patients and compared it with the results of conventional culture. Based on conventional culture that recovered 37 mycobacterial isolates including 11 tuberculous and 26 NTM isolates, sensitivity, specificity, positive predictive value and negative predictive value were 89.2%, 81.5%, 86.8% and 84.6% for GTCMd and 73.0%, 96.3%, 96.4% and 72.2% for VAM. Additionally, GTCMd identified mycobacteria from five and VAM from one culture-negative sample. Both assays identified a mycobacterium in one sample overgrown by other microorganisms. Two M. abscessus subsp. abscessus isolates grown from culture were identified as M. chelonae by GTCMd assay. In conclusion, both assays improve the rapid identification of mycobacteria directly from clinical specimens.

Proteasomal Processing Immune Escape Mechanisms in Platinum-Treated Advanced Bladder Cancer.

In recent years, the number and type of treatment options in advanced bladder cancer (BC) have been rapidly evolving. To select an effective therapy and spare unnecessary side effects, predictive biomarkers are urgently needed. As the host's anti-cancer immune response is by far the most effective system to impede malignant tumor growth, immune system-based biomarkers are promising. We have recently described altered proteasomal epitope processing as an effective immune escape mechanism to impair cytotoxic T-cell activity. By altering the neoantigens' characteristics through different proteasomal peptide cleavage induced by non-synonymous somatic mutations, the ability for T-cell activation was decreased ("processing escapes"). In the present study, we analyzed primary chemo-naïve tissue samples of 26 adjuvant platinum-treated urothelial BC patients using a targeted next-generation sequencing panel followed by the epitope determination of affected genes, a machine-learning based prediction of epitope processing and proteasomal cleavage and of HLA-affinity as well as immune activation. Immune infiltration (immunohistochemistries for CD8, granzyme B, CD45/LCA) was digitally quantified by a pathologist and clinico-pathological and survival data were collected. We detected 145 epitopes with characteristics of a processing escape associated with a higher number of CD8-positive but lower number of granzyme B-positive cells and no association with PD-L1-expression. In addition, a high prevalence of processing escapes was associated with unfavorable overall survival. Our data indicate the presence of processing escapes in advanced BC, potentially creating a tumor-promoting pro-inflammatory environment with lowered anti-cancerous activity and independence from PD-L1-expression. The data also need to be prospectively validated in BC treated with immune therapy.

Transcriptome-Wide Gene Expression Profiles from FFPE Materials Based on a Nuclease Protection Assay Reveals Significantly Different Patterns between Synovial Sarcomas and Morphologic Mimickers.

BACKGROUND: Transcriptome profiling provides large data on tumor biology, which is particularly valuable in translational research and is becoming more and more important for clinical decision-making as well. RNA sequencing is considered to be the gold standard for this. However, FFPE material, as the most available material in routine pathology, has been an undefeatable obstacle for RNAseq. Extraction-free nuclease protection assays have the potential to be a reliable alternative method for large-scale expression profiling. The aim of this study was to validate and test the basic feasibility, technical applicability robustness, and reliability of the HTG transcriptome profiling (HTP) assay on clinical tumor samples. METHODS: FFPE samples from 44 synovial sarcomas (SyS) and 20 spindle cell sarcomas (SpcS) were used. The HTP assay was performed on 10 µm thin FFPE slides. After nuclease protection in the HTG Edge Seq System, libraries were generated for sequencing on an Illumina NextSeq 500 platform. Fastq data were parsed and then analyzed by using the HTG analysis platform EdgeSeq REVEAL. Immunohistochemistry was performed to validate the expression of TLE1. RESULTS: The technical application of the HTP Panel revealed robust and reliable results with 62 samples, and only 2 samples failed due to an incomplete digestion of gDNA. The analysis, performed at the analysis platform REVEAL, showed 5964 genes being significantly differentially expressed between SpcS and SyS. In particular, overexpression of the known marker TLE1 in synovial sarcoma could be recovered, which underlines the reliability of this system. DISCUSSION: Transcriptome profiling gets more and more important for tumor research and diagnostics. Among other established technologies, the HTP Panel has shown to be a feasible method to get robust and reliable results. Thereby, this method needs very few sample-input by getting a success-rate of 96.88%, which indicates the upper average range, compared to other technologies working with FFPE tissue. CONCLUSION: The nuclease protection assay-based HTP Panel is a feasible method for adequate transcriptome profiling with low sample input and therefore is suitable for further research of biomarkers.

Plasma Sequencing for Patients with GIST-Limitations and Opportunities in an Academic Setting.

Circulating tumor DNA (ctDNA) from circulating free DNA (cfDNA) in GIST is of interest for the detection of heterogeneous resistance mutations and treatment monitoring. However, methodologies for use in a local setting are not standardized and are error-prone and difficult to interpret. We established a workflow to evaluate routine tumor tissue NGS (Illumina-based next generation sequencing) panels and pipelines for ctDNA sequencing in an academic setting. Regular blood collection (Sarstedt) EDTA tubes were sufficient for direct processing whereas specialized tubes (STRECK) were better for transportation. Mutation detection rate was higher in automatically extracted (AE) than manually extracted (ME) samples. Sensitivity and specificity for specific mutation detection was higher using digital droplet (dd)PCR compared to NGS. In a retrospective analysis of NGS and clinical data (133 samples from 38 patients), cfDNA concentration correlated with tumor load and mutation detection. A clinical routine pipeline and a novel research pipeline yielded different results, but known and resistance-mediating mutations were detected by both and correlated with the resistance spectrum of TKIs used. In conclusion, NGS routine panel analysis was not sensitive and specific enough to replace solid biopsies in GIST. However, more precise methods (hybridization capture NGS, ddPCR) may comprise important research tools to investigate resistance. Future clinical trials need to compare methodology and protocols.

Rebiopsy in advanced non-small cell lung cancer, clinical relevance and prognostic implications.

INTRODUCTION: Rebiopsies of non-small cell lung cancers (NSCLC) are mainly performed to (i) cover the evolution of potentially amenable resistance mechanisms against a targeted therapy, and (ii) to identify new therapeutic targets which were not detected in the initial diagnostic biopsy. Comprehensive systematic analyses evaluating the value of rebiopsies are missing. METHODS: Clinical databases from two large comprehensive cancer center networks were queried following prespecified criteria to identify prospectively entered NSCLC cases with at least one rebiopsy at disease progression. Clinicopathological and biomarker findings including multigene sequencing were correlated with clinical outcomes. RESULTS: From a total of 17,477 stage IV NSCLC patients, a cohort of 403 evaluable patients undergoing at least one rebiopsy of a primary tumor or metastasis was retrieved. Changes in biomarker profiles as compared to baseline were observed in 48.9%. In 31.3% of cases, findings of potential therapeutic relevance were revealed, including 18 patients (4.4%) with a targetable marker only detected at rebiopsy. New findings were more frequent (greater than50%) in NSCLC with EGFR/ALK/ROS1 alterations, including mutations of the dominant oncogene, TP53 mutations, and MET or ERBB2 amplifications. Patients undergoing rebiopsy exhibited superior overall survival compared to a control group, irrespective of presence (HR 0.28) or absence (HR 0.20, both p < 0.001) of a therapeutically targetable aberration. CONCLUSIONS: Rebiopsies at progression of advanced NSCLC are strongly supported by a high rate of clinically relevant findings. Current clinical practice selects a patient population with exceptional outcomes, which merits further characterization.

The evolution of dependent medical care in the U.S. Army.

There is great focus within the military medical community regarding the ever growing cost of medical care overall and dependent care specifically. A great deal of discussion relates to the delivery of care through a growing military-civilian partnership, where an increased amount of health care will be referred to an ever growing network of civilian providers. The U.S. military establishment now stands at an important crossroad leading into the future of dependent care. However, the special concerns, which arise from the responsibility of caring for military dependents, are not a solely recent phenomenon. Ever since the establishment of a permanent standing U.S. Army in the late 1700s, there have been families in need of medical treatment. Although changes occurred continuously, the development and evolution of policies regulating the delivery of medical care to dependants can be divided into three periods. The first is the longest and ranges from the establishment of the Army until the year 1900. The second period spans from 1900 to the post-Korean War year of 1956. The third and final period is from 1956 to 1975. Special changes and advances in each of these periods have served to shape the face of dependent care in today's Army Medical Department.

Polyclonal on- and off-target resistance mutations in an EML4-ALK positive non-small cell lung cancer patient under ALK inhibition.

Treatment of advanced stage anaplastic lymphoma kinase (ALK) positive non-small cell lung cancer (NSCLC) with ALK tyrosine kinase inhibitors (TKIs) has been shown to be superior to standard platinum-based chemotherapy. However, secondary progress of disease frequently occurs under ALK inhibitor treatment. The clinical impact of re-biopsies for treatment decisions beyond secondary progress is, however, still under debate. Here, we report on two novel subsequent polyclonal on- and off-target resistance mutations in a patient with ALK-fused NSCLC under ALK inhibitor treatment. A 63-year-old male patient with an advanced stage EML4-ALK fused pulmonary adenocarcinoma was initially successfully treated with the second-generation ALK inhibitor alectinib and upon progressions subsequently with brigatinib, lorlatinib and chemoimmunotherapy (CIT). Progress to alectinib was associated with a so far undescribed ALK mutation (p.A1200_G1201delinsW) which was, however, tractable by brigatinib. An off-target KRAS-mutation (p.Q61K) occurred in association with subsequent progression under second-line TKI treatment. Third-line lorlatinib showed limited efficacy but chemoimmunotherapy resulted in disappearance of the KRAS mutant clone and clinical tumor control for another eight months. In conclusion, we suggest molecular profiling of progressive tumor disease also for ALK-positive NSCLC to personalize treatment in a subgroup of ALK-positive patients.