Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study.

Background: Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardised protocol and definition. Methods: We analysed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population attributable risk (PAR) associated with each of the identifed risk factors. Findings: The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington,KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job. Interpretation: Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors. Funding: Wellcome Trust.

Genome-Wide DNA Methylation Profiling as Frontline Diagnostics for Central Nervous System Embryonal Tumors in Hong Kong.

This paper examines the link between CNS tumor biology and heterogeneity and the use of genome-wide DNA methylation profiling as a clinical diagnostic platform. CNS tumors are the most common solid tumors in children, and their prognosis remains poor. This study retrospectively analyzed pediatric patients with CNS embryonal tumors in Hong Kong between 1999 and 2017, using data from the territory-wide registry and available formalin-fixed paraffin-embedded tumor tissue. After processing archival tumor tissue via DNA extraction, quantification, and methylation profiling, the data were analyzed by using the web-based DKFZ classifier (Molecular Neuropathology (MNP) 2.0 v11b4) and t-SNE analysis. Methylation profiles were deemed informative in 85 samples. Epigenetic data allowed molecular subgrouping and confirmed diagnosis in 65 samples, verified histologic diagnosis in 8, and suggested an alternative diagnosis in 12. This study demonstrates the potential of DNA methylation profiling in characterizing pediatric CNS embryonal tumors in a large cohort from Hong Kong, which should enable regional and international collaboration in future pediatric neuro-oncology research.

CT airway remodelling and chronic cough.

RATIONALE: Structural airway changes related to chronic cough (CC) are described in the literature, but so far reported data are rare and non-conclusive. Furthermore, they derive mainly from cohorts with small sample sizes. Advanced CT imaging not only allows airway abnormalities to be quantified, but also to count the number of visible airways. The current study evaluates these airway abnormalities in CC and assesses the contribution of CC in addition to CT findings on the progression of airflow limitation, defined as a decline in forced expiratory volume in 1 s (FEV1) over time. METHODS: A total of 1183 males and females aged ≥40 years with thoracic CT scans and valid spirometry from Canadian Obstructive Lung Disease, a Canadian multicentre, population-based study has been included in this analysis. Participants were stratified into 286 never-smokers, 297 ever-smokers with normal lung function and 600 with chronic obstructive pulmonary disease (COPD) of different severity grades. Imaging parameters analyses included total airway count (TAC), airway wall thickness, emphysema as well as parameters for functional small airway disease quantification. RESULTS: Irrespective of COPD presence, CC was not related to specific airway and lung structure features. Independent of TAC and emphysema score, CC was highly associated with FEV1 decline over time in the entire study population, particularly in ever-smokers (p<0.0001). CONCLUSION: The absence of specific structural CT features independently from COPD presence indicate that other underlying mechanisms are contributing to the symptomatology of CC. On top of derived CT parameters, CC seems to be independently associated with FEV1 decline. TRIAL REGISTRATION NUMBER: NCT00920348.

Combination of sunitinib and 177Lu-labeled antibody cG250 targeted radioimmunotherapy: A promising new therapeutic strategy for patients with advanced renal cell cancer.

Sunitinib is an effective treatment for patients with metastatic Renal Cell Carcinoma (mRCC) but ultimately resistance occurs. The aim of this study was to investigate sunitinib resistance in RCCs and to develop therapeutic combination strategies with targeted radioimmunotherapy (RIT). We studied two RCC models, analyzed Vascular endothelial growth factor (VEGF) and its receptor (VEGFR) and AXL/MET expression and performed therapy studies in Balb/cnu/nu mice combining sunitinib and [177Lu]Lu-cG250 RIT (6.5 MBq/10 µg), specifically targeting RCC cells. pAXL and pMET were expressed in sunitinib-resistant SK-RC-52 and absent in sunitinib-sensitive NU12. NGS evaluation showed that expression of VEGFA, VEGFB, VEGFD, PGF and VEGFR1,2,3 was higher and expression of VEGFC and PDGFA was lower in NU12 than in SK-RC-52. Therapy studies combining sunitinib with [177Lu]Lu-cG250 RIT showed that the best response in mice with "resistant" SK-RC-52 tumors was observed with two cycles of Sunitinib and [177Lu]Lu-cG250 RIT, probably due to increased vascular permeability by sunitinib treatment. In the "sensitive" NU12 model, two cycles of [177Lu]Lu-cG250 RIT and two cycles of combination treatment were equally effective. Enhanced therapeutic efficacy was achieved when two agents ([177Lu]Lu-cG250 RIT and sunitinib) that on their own did not induce satisfactory response levels, are combined. Our findings provide a promising new therapeutic strategy for patients with advanced RCC.

Canine discrimination of ovarian cancer through volatile organic compounds.

Ovarian cancer has a high mortality rate due to its unclear symptomology and the lack of precise early detection tools. If detected in the first stage, over 90% of patients reach remission. As such, developing a reliable method of early detection is crucial in reducing the mortality rate of the disease. One potential method would be to identify specific biomarkers that are unique to ovarian cancer, which could be detected using a blood test. While this can be done using gas chromatography - mass spectrometry (GC-MS), identifying these biomarkers is an enormous task. One way to expedite the process is to utilize trained scent detection canines. In this study, dogs who were previously trained to respond to positive blood samples from ovarian cancer patients were then tested on their ability to recognize samples prepared by micro-preparative gas chromatography (MP-GC) techniques. MP-GC employed a gradient-cooled glass tube connected to the GC outlet to collect GC eluents containing the plasma-derived volatiles in positive blood samples. These post-column fractions were collected at the exit of the GC according to their eluent times (i.e., 0-15 min, 15-25 min and 25-35 min or 0-35 min) and these full or fractional collections were presented to the trained dogs to judge their responses. Dogs' time spent investigating the odor was used as an indication of odor recognition and was significantly longer on the early (0-15 min) and middle (15-25 min) fractions of the ovarian cancer than the late (25-35 min) fraction of plasma odorants or either the negative fractions or distractors odorants. These findings suggest that characteristic odor biomarkers of ovarian cancer for dogs may exist in the relatively small and more volatile compounds. Additionally, variation between dogs suggests that there may be a number of different biomarkers that can be used to identify ovarian cancer.

Multimodal CEA-targeted fluorescence and radioguided cytoreductive surgery for peritoneal metastases of colorectal origin.

In patients with colorectal peritoneal metastases scheduled for cytoreductive surgery, accurate preoperative estimation of tumor burden and subsequent intraoperative detection of all tumor deposits remains challenging. In this study (ClinicalTrials.gov NCT03699332) we describe the results of a phase I clinical trial evaluating [111In]In-DOTA-labetuzumab-IRDye800CW, a dual-labeled anti-carcinoembryonic antigen (anti-CEA) antibody conjugate that enables both preoperative imaging and intraoperative radioguidance and fluorescence imaging. Primary study outcomes are safety and feasibility of this multimodal imaging approach. Secondary outcomes are determination of the optimal dose, correlation between tracer uptake and histopathology and effects on clinical strategy. Administration of [111In]In-DOTA-labetuzumab-IRDye800CW is well-tolerated and enables sensitive pre- and intraoperative imaging in patients who receive 10 or 50 mg of the tracer. Preoperative imaging revealed previously undetected lymph node metastases in one patient, and intraoperative fluorescence imaging revealed four previously undetected metastases in two patients. Alteration of clinical strategy based on multimodal imaging occurred in three patients. Thus, multimodal image-guided surgery after administration of this dual-labeled tracer is a promising approach that may aid in decision making before and during cytoreductive surgical procedures.

Novel VHH-Based Tracers with Variable Plasma Half-Lives for Imaging of CAIX-Expressing Hypoxic Tumor Cells.

Hypoxic areas are present in the majority of solid tumors, and hypoxia is associated with resistance to therapies and poor outcomes. A transmembrane protein that is upregulated by tumor cells that have adapted to hypoxic conditions is carbonic anhydrase IX (CAIX). Therefore, noninvasive imaging of CAIX could be of prognostic value, and it could steer treatment strategies. The aim of this study was to compare variants of CAIX-binding VHH B9, with and without a C-terminal albumin-binding domain with varying affinity (ABDlow and ABDhigh), for SPECT imaging of CAIX expression. The binding affinity and internalization of the various B9-variants were analyzed using SK-RC-52 cells. Biodistribution studies were performed in mice with subcutaneous SCCNij153 human head and neck cancer xenografts. Tracer uptake was determined by ex vivo radioactivity counting and visualized by SPECT/CT imaging. Furthermore, autoradiography images of tumor sections were spatially correlated with CAIX immunohistochemistry. B9-variants demonstrated a similar moderate affinity for CAIX in vitro. Maximal tumor uptake and acceptable tumor-to-blood ratios were found in the SCCNij153 model at 4 h post injection for [111In]In-DTPA-B9 (0.51 ± 0.08%ID/g and 8.1 ± 0.85, respectively), 24 h post injection for [111In]In-DTPA-B9-ABDlow (2.39 ± 0.44%ID/g and 3.66 ± 0.81, respectively) and at 72 h post injection for [111In]In-DTPA-B9-ABDhigh (8.7 ± 1.34%ID/g and 2.43 ± 0.15, respectively). An excess of unlabeled monoclonal anti-CAIX antibody efficiently inhibited tumor uptake of [111In]In-DTPA-B9, while only a partial reduction of [111In]In-DTPA-B9-ABDlow and [111In]In-DTPA-B9-ABDhigh uptake was found. Immunohistochemistry and autoradiography images showed colocalization of all B9-variants with CAIX expression; however, [111In]In-DTPA-B9-ABDlow and [111In]In-DTPA-B9-ABDhigh also accumulated in non-CAIX expressing regions. Tumor uptake of [111In]In-DTPA-B9-ABDlow and [111In]In-DTPA-B9-ABDhigh, but not of [111In]In-DTPA-B9, could be visualized with SPECT/CT imaging. In conclusion, [111In]In-DTPA-B9 has a high affinity to CAIX and shows specific targeting to CAIX in head and neck cancer xenografts. The addition of ABD prolonged plasma half-life, increased tumor uptake, and enabled SPECT/CT imaging. This uptake was, however, partly CAIX- independent, precluding the ABD-tracers for use in hypoxia quantification in this tumor type.

Changes in lung function in European adults born between 1884 and 1996 and implications for the diagnosis of lung disease: a cross-sectional analysis of ten population-based studies.

BACKGROUND: During the past century, socioeconomic and scientific advances have resulted in changes in the health and physique of European populations. Accompanying improvements in lung function, if unrecognised, could result in the misclassification of lung function measurements and misdiagnosis of lung diseases. We therefore investigated changes in population lung function with birth year across the past century, accounting for increasing population height, and examined how such changes might influence the interpretation of lung function measurements. METHODS: In our analyses of cross-sectional data from ten European population-based studies, we included individuals aged 20-94 years who were born between 1884 and 1996, regardless of previous respiratory diagnoses or symptoms. FEV1, forced vital capacity (FVC), height, weight, and smoking behaviour were measured between 1965 and 2016. We used meta-regression to investigate how FEV1 and FVC (adjusting for age, study, height, sex, smoking status, smoking pack-years, and weight) and the FEV1/FVC ratio (adjusting for age, study, sex, and smoking status) changed with birth year. Using estimates from these models, we graphically explored how mean lung function values would be expected to progressively deviate from predicted values. To substantiate our findings, we used linear regression to investigate how the FEV1 and FVC values predicted by 32 reference equations published between 1961 and 2015 changed with estimated birth year. FINDINGS: Across the ten included studies, we included 243 465 European participants (mean age 51·4 years, 95% CI 51·4-51·5) in our analysis, of whom 136 275 (56·0%) were female and 107 190 (44·0%) were male. After full adjustment, FEV1 increased by 4·8 mL/birth year (95% CI 2·6-7·0; p<0·0001) and FVC increased by 8·8 mL/birth year (5·7-12·0; p<0·0001). Birth year-related increases in the FEV1 and FVC values predicted by published reference equations corroborated these findings. This height-independent increase in FEV1 and FVC across the last century will have caused mean population values to progressively exceed previously predicted values. However, the population mean adjusted FEV1/FVC ratio decreased by 0·11 per 100 birth years (95% CI 0·09-0·14; p<0·0001). INTERPRETATION: If current diagnostic criteria remain unchanged, the identified shifts in European values will allow the easier fulfilment of diagnostic criteria for lung diseases such as chronic obstructive pulmonary disease, but the systematic underestimation of lung disease severity. FUNDING: The European Respiratory Society, AstraZeneca, Chiesi Farmaceutici, GlaxoSmithKline, Menarini, and Sanofi-Genzyme.

Imaging carbonic anhydrase IX as a method for monitoring hypoxia-related radioresistance in preclinical head and neck cancer models.

BACKGROUND AND PURPOSE: Tumor hypoxia is an important cause of radioresistance and is associated with poor outcome.SPECT (Single-photon emission computed tomography) imaging enables visualizing tumor characteristics. We investigated the SPECT-radiotracer [111In]-girentuximab-F(ab')2 to image Carbonic Anhydrase IX (CAIX), an enzyme upregulated under hypoxic conditions. MATERIALS AND METHODS: Athymic mice with subcutaneous FaDu or SCCNij202 head and neck squamous cell carcinoma (HNSCC) xenografts were treated with atovaquone or were housed in a hypoxic chamber (8% O2). Next, [111In]-girentuximab-F(ab')2 was injected and 24 h later mice were euthanized for ex vivo biodistribution, autoradiography of the tumor, and immunohistochemical staining of the tumor. Tumor sections were analyzed for hypoxia, CAIX expression, vessels, and perfusion. Also, the effect of atovaquone on microSPECT scans was determined in the FaDu model. RESULTS: Atovaquone decreased CAIX expression by 69% (p = 0.017) compared with control tumors in FaDu, while in the SCCNij202 tumors no difference was observed. Hypoxic breathing did not increase CAIX expression or hypoxia staining in either tumor model, but did affect the necrotic tumor fraction. Ex vivo tracer uptake in the atovaquone treated group did not differ significantly from the control group, despite the difference in CAIX expression. Furthermore, SPECT imaging with [111In]-girentuximab-F(ab')2 did not discriminate atovaquone-treated versus control tumors. CONCLUSION: Atovaquone decreased CAIX expression only in the FaDu tumor model. [111In]-girentuximab-F(ab')2 specifically targets CAIX-expressing areas in HNSCC xenografts, but differences in vessel density and necrosis most likely affected tracer uptake in the tumors and therefore complicated quantification of changes in CAIX expression.

Simlukafusp alfa (FAP-IL2v) immunocytokine is a versatile combination partner for cancer immunotherapy.

Simlukafusp alfa (FAP-IL2v, RO6874281/RG7461) is an immunocytokine comprising an antibody against fibroblast activation protein α (FAP) and an IL-2 variant with a retained affinity for IL-2Rßγ > IL-2 Rßγ and abolished binding to IL-2 Rα. Here, we investigated the immunostimulatory properties of FAP-IL2v and its combination with programmed cell death protein 1 (PD-1) checkpoint inhibition, CD40 agonism, T cell bispecific and antibody-dependent cellular cytotoxicity (ADCC)-mediating antibodies. The binding and immunostimulatory properties of FAP-IL2v were investigated in vitro and compared with FAP-IL2wt. Tumor targeting was investigated in tumor-bearing mice and in a rhesus monkey. The ability of FAP-IL2v to potentiate the efficacy of different immunotherapies was investigated in different xenograft and syngeneic murine tumor models. FAP-IL2v bound IL-2 Rßγ and FAP with high affinity in vitro, inducing dose-dependent proliferation of natural killer (NK) cells and CD4+/CD8+ T cells while being significantly less potent than FAP-IL2wt in activating immunosuppressive regulatory T cells (Tregs). T cells activated by FAP-IL2v were less sensitive to Fas-mediated apoptosis than those activated by FAP-IL2wt. Imaging studies demonstrated improved tumor targeting of FAP-IL2v compared to FAP-IL2wt. Furthermore, FAP-IL2v significantly enhanced the in vitro and in vivo activity of therapeutic antibodies that mediate antibody-dependent or T cell-dependent cellular cytotoxicity (TDCC) and of programmed death-ligand 1 (PD-L1) checkpoint inhibition. The triple combination of FAP-IL2v with an anti-PD-L1 antibody and an agonistic CD40 antibody was most efficacious. These data indicate that FAP-IL2v is a potent immunocytokine that potentiates the efficacy of different T- and NK-cell-based cancer immunotherapies.

Detection of EGFR Activating and Resistance Mutations by Droplet Digital PCR in Sputum of EGFR-Mutated NSCLC Patients.

BACKGROUND: Proof of the T790M resistance mutation is mandatory if patients with EGFR-mutated non-small cell lung cancer (NSCLC) progress under first- or second-generation tyrosine kinase inhibitor therapy. In addition to rebiopsy, analysis of plasma circulating tumor DNA is used to detect T790M resistance mutation. We studied whether sputum is another feasible specimen for detection of EGFR mutations. METHODS: Twenty-eight patients with advanced EGFR-mutated NSCLC were included during stable and/or progressive disease. The initial activating EGFR mutations (exon 19 deletions or L858R mutations) at stable disease and at progressive disease (together with T790M) were assessed in simultaneously collected plasma and sputum samples and detected by droplet digital polymerase chain reaction (ddPCR). RESULTS: Activating EGFR mutations were detected in 47% of the plasma samples and 41% of sputum samples during stable disease, and in 57% of plasma samples and 64% of sputum samples during progressive disease. T790M was detected in 44% of the plasma samples and 66% of the sputum samples at progressive disease. In ddPCR T790M-negative results for both specimens (plasma and sputum), negativity was confirmed by rebiopsy in 5 samples. Concordance rate of plasma and sputum for T790M was 0.86, with a positive percent agreement of 1.0 and a negative percent agreement of 0.80. CONCLUSIONS: We demonstrated that EGFR mutation analysis with ddPCR is feasible in sputum samples. Combination of plasma and sputum analyses for detection of T790M in NSCLC patients with progressive disease increases the diagnostic yield compared with molecular plasma analysis alone.

Soluble ST2 and All-Cause Mortality in Patients with Chronic Obstructive Pulmonary Disease-A 10-Year Cohort Study.

Chronic obstructive pulmonary disease (COPD) is an inflammatory condition with constantly increasing mortality rates. Interleukin (IL)-33 and its decoy receptor, soluble suppression of tumorigenicity 2 (sST2), play a central role in the inflammatory response during infection. sST2 was suggested as a factor in the pathogenesis of COPD and emerged as a predictor of mortality in other non-communicable diseases. The role of sST2 as a predictor of mortality remains unclear in COPD yet. In this cohort study, we measured circulating concentrations of IL-33 and sST2 in the serum of patients with stable COPD (n = 59), patients with acute exacerbation of COPD (n = 29) and smoking (n = 20) and non-smoking controls (n = 20), using commercially available ELISAs, and investigated the prognostic role of sST2 in stable COPD. sST2 levels were significantly higher in COPD patients and smokers compared with non-smoking controls. We identified systolic blood pressure, forced expiratory volume in 1 s (FEV1% predicted), neutrophil count, lactate dehydrogenase and pack-years index as independent predictors of sST2 levels. During a median follow-up time of 10.6 years, 28 patients (47.5%) died. sST2 was an independent predictor of all-cause mortality in patients with COPD with a hazard ratio of 2.9 (95% CI 1.1-8.4, p = 0.035) per one standard deviation after adjustment for age, sex, pack-years, FEV1% predicted and C-reactive protein (CRP). sST2 concentrations are associated with severity of disease and long-term outcome in patients with COPD.

Results of the Austrian National Lung Cancer Audit.

OBJECTIVES: The Austrian Lung Cancer Audit (ALCA) is a pilot study to evaluate clinical and organizational factors related to lung cancer care across Austria. MATERIALS AND METHODS: The ALCA is a prospective, observational, noninterventional cohort study conducted in 17 departments in Austria between September 2013 and March 2015. Participating departments were selected based on an annual case load of >50 patients with lung cancer. RESULTS: The ALCA included 745 patients, representing 50.5% of all newly diagnosed cancer cases during that time period. In 75.8% of patients, diagnosis was based on histology, and in 24.2% on cytology; 83.1% had non-small-cell lung cancer, 16.9% small-cell lung cancer; and only 4.6% had to be classified as not otherwise specified cancers. The median time elapsed between first presentation at hospital and diagnosis was 8 days (interquartile range [IQR]: 4-15; range: 0-132); between diagnosis and start of treatment it was 15 days for chemotherapy (IQR: 9-27; range: 0-83), 21 days (IQR: 10-35; range: 0-69) for radiotherapy, and 24 days (IQR: 11-36; range: 0-138) for surgery, respectively. In 150 patients undergoing surgical treatment, only 3 (2.0%; n = 147, 3 missings) were seen with postoperative restaging indicating unjustified surgery. One-year follow-up data were available for 723 patients, indicating excellent 49.8% survival; however, a wide range of survival between departments (range: 37.8-66.7) was seen. CONCLUSIONS: The ALCA conducted in high case load departments indicated management of lung cancer in accordance with international guidelines, and overall excellent 1-year survival.

Quality of Life and Limitations in Daily Life of Stable COPD Outpatients in a Real-World Setting in Austria - Results from the CLARA Project.

Background: COPD patients suffer from respiratory symptoms and limitations in daily life. We aimed to characterize the impact of disease on overall health, daily life, and perceived well-being in COPD outpatients. Methods: We conducted a national, cross-sectional study among pulmonologists and general practitioners (GPs). The St. George's Respiratory Questionnaire for COPD patients (SGRQ-C) was used. Inclusion criteria were a physician's diagnosis of COPD and age ≥40 years. Subjects with a history of lung surgery, lung cancer or COPD exacerbation within the last four weeks were excluded. Results: Sixty-seven pulmonologists and 6 GPs enrolled 1175 COPD patients. Two hundred forty-eight of those did not fulfill GOLD criteria for COPD (FEV1/FVC <0.7) and 77 were excluded due to missing data. Finally, 850 patients (62.8% men; mean age 66.2 ± 0.3 (SE) years; mean FEV1%pred. 51.5 ± 0.6 (SE)) were analyzed. Last year, 55.4% reported at least one exacerbation, and 12.7% were hospitalized for COPD exacerbation. Mean SGRQ-C total score was 43.1 ± 0.83 (SE) and mean component scores for symptoms, activity and impacts were 55.6, 55.4 and 30.5, respectively. Half of the patients (50.3%) reported not being able to do any sports and 78.7% stated that their respiratory symptoms did not allow them doing anything they would like to do. In patients with less severe COPD (FEV1pred ≥50% and non-frequent exacerbations), global health status was overrated, ie, estimated as better by the physician than by the patient, while it was underrated in more severe COPD. Conclusion: In Austria, the burden of disease in COPD outpatients tends to be underestimated in patients with milder airway obstruction and less exacerbations and overestimated in patients with more severe airway obstruction and frequent exacerbations. Our finding suggests that validated assessment of global health status might decrease these differences of perception.

Pyruvate-lactate exchange and glucose uptake in human prostate cancer cell models. A study in xenografts and suspensions by hyperpolarized [1-13 C]pyruvate MRS and [18 F]FDG-PET.

Reprogramming of energy metabolism in the development of prostate cancer can be exploited for a better diagnosis and treatment of the disease. The goal of this study was to determine whether differences in glucose and pyruvate metabolism of human prostate cancer cells with dissimilar aggressivenesses can be detected using hyperpolarized [1-13 C]pyruvate MRS and [18 F]FDG-PET imaging, and to evaluate whether these measures correlate. For this purpose, we compared murine xenografts of human prostate cancer LNCaP cells with those of more aggressive PC3 cells. [1-13 C]pyruvate was hyperpolarized by dissolution dynamic nuclear polarization (dDNP) and [1-13 C]pyruvate to lactate conversion was followed by 13 C MRS. Subsequently [18 F]FDG uptake was investigated by static and dynamic PET measurements. Standard uptake values (SUVs) for [18 F]FDG were significantly higher for xenografts of PC3 compared with those of LNCaP. However, we did not observe a difference in the average apparent rate constant kpl of 13 C label exchange from pyruvate to lactate between the tumor variants. A significant negative correlation was found between SUVs from [18 F]FDG PET measurements and kpl values for the xenografts of both tumor types. The kpl rate constant may be influenced by various factors, and studies with a range of prostate cancer cells in suspension suggest that LDH inhibition by pyruvate may be one of these. Our results indicate that glucose and pyruvate metabolism in the prostate cancer cell models differs from that in other tumor models and that [18 F]FDG-PET can serve as a valuable complementary tool in dDNP studies of aggressive prostate cancer with [1-13 C]pyruvate.

Cancer-ID: Toward Identification of Cancer by Tumor-Derived Extracellular Vesicles in Blood.

Extracellular vesicles (EVs) have great potential as biomarkers since their composition and concentration in biofluids are disease state dependent and their cargo can contain disease-related information. Large tumor-derived EVs (tdEVs, >1 µm) in blood from cancer patients are associated with poor outcome, and changes in their number can be used to monitor therapy effectiveness. Whereas, small tumor-derived EVs (<1 µm) are likely to outnumber their larger counterparts, thereby offering better statistical significance, identification and quantification of small tdEVs are more challenging. In the blood of cancer patients, a subpopulation of EVs originate from tumor cells, but these EVs are outnumbered by non-EV particles and EVs from other origin. In the Dutch NWO Perspectief Cancer-ID program, we developed and evaluated detection and characterization techniques to distinguish EVs from non-EV particles and other EVs. Despite low signal amplitudes, we identified characteristics of these small tdEVs that may enable the enumeration of small tdEVs and extract relevant information. The insights obtained from Cancer-ID can help to explore the full potential of tdEVs in the clinic.

Ex Vivo Assessment of Tumor-Targeting Fluorescent Tracers for Image-Guided Surgery.

Image-guided surgery can aid in achieving complete tumor resection. The development and assessment of tumor-targeted imaging probes for near-infrared fluorescence image-guided surgery relies mainly on preclinical models, but the translation to clinical use remains challenging. In the current study, we introduce and evaluate the application of a dual-labelled tumor-targeting antibody for ex vivo incubation of freshly resected human tumor specimens and assessed the tumor-to-adjacent tissue ratio of the detectable signals. Immediately after surgical resection, peritoneal tumors of colorectal origin were placed in cold medium. Subsequently, tumors were incubated with 111In-DOTA-hMN-14-IRDye800CW, an anti-carcinoembryonic antigen (CEA) antibody with a fluorescent and radioactive label. Tumors were then washed, fixed, and analyzed for the presence and location of tumor cells, CEA expression, fluorescence, and radioactivity. Twenty-six of 29 tumor samples obtained from 10 patients contained malignant cells. Overall, fluorescence intensity was higher in tumor areas compared to adjacent non-tumor tissue parts (p < 0.001). The average fluorescence tumor-to-background ratio was 11.8 ± 9.1:1. A similar ratio was found in the autoradiographic analyses. Incubation with a non-specific control antibody confirmed that tumor targeting of our tracer was CEA-specific. Our results demonstrate the feasibility of this tracer for multimodal image-guided surgery. Furthermore, this ex vivo incubation method may help to bridge the gap between preclinical research and clinical application of new agents for radioactive, near infrared fluorescence or multimodal imaging studies.

Targeting of radioactive platinum-bisphosphonate anticancer drugs to bone of high metabolic activity.

Platinum-based chemotherapeutics exhibit excellent antitumor properties. However, these drugs cause severe side effects including toxicity, drug resistance, and lack of tumor selectivity. Tumor-targeted drug delivery has demonstrated great potential to overcome these drawbacks. Herein, we aimed to design radioactive bisphosphonate-functionalized platinum (195mPt-BP) complexes to confirm preferential accumulation of these Pt-based drugs in metabolically active bone. In vitro NMR studies revealed that release of Pt from Pt BP complexes increased with decreasing pH. Upon systemic administration to mice, Pt-BP exhibited a 4.5-fold higher affinity to bone compared to platinum complexes lacking the bone-seeking bisphosphonate moiety. These Pt-BP complexes formed less Pt-DNA adducts compared to bisphosphonate-free platinum complexes, indicating that in vivo release of Pt from Pt-BP complexes proceeded relatively slow. Subsequently, radioactive 195mPt-BP complexes were synthesized using 195mPt(NO3)2(en) as precursor and injected intravenously into mice. Specific accumulation of 195mPt-BP was observed at skeletal sites with high metabolic activity using micro-SPECT/CT imaging. Furthermore, laser ablation-ICP-MS imaging of proximal tibia sections confirmed that 195mPt BP co-localized with calcium in the trabeculae of mice tibia.