Pharmacokinetic analysis and simplified uptake measures for tumour lesion [18F]F-AraG PET imaging in patients with non-small cell lung cancer.

INTRODUCTION: The novel positron emission tomography (PET) imaging tracer, [18F]F-AraG, targets activated T-cells, offering a potential means to improve our understanding of immune-oncological processes. The aim of this study was to determine the optimal pharmacokinetic model to quantify tumour lesion [18F]F-AraG uptake in patients with non-small cell lung cancer (NSCLC), and to validate simplified measures at different time intervals against the pharmacokinetic uptake parameter. METHODS: Ten patients with early-stage NSCLC and three patients with advanced NSCLC underwent a dynamic PET scan of minimal 60 min. Venous and/or arterial blood sampling was obtained at maximum seven time points. Tumour lesion time activity curves and metabolite-corrected input functions were analysed using single-tissue reversible (1T2k), two-tissue irreversible (2T3k) and two-tissue reversible (2T4k) plasma input models. Simplified uptake measures, such as standardised uptake value (SUV) and tumour-to-blood (TBR) or tumour-to-plasma ratio (TPR), were evaluated for different time intervals. RESULTS: Whole-blood and plasma radioactivity concentrations showed rapid clearance of [18F]F-AraG. Metabolite analysis revealed a low rate of metabolism, at 70 min p.i., on average, 79% (SD = 9.8%) of the total radioactivity found in blood corresponded to intact [18F]F-AraG. The time activity curves were best fitted by the 2T3k model. Strong positive correlations were found for SUV (body weight (BW), lean body mass (LBM) or body surface area (BSA) corrected), TBR and TPR for any time interval between 20 and 70 min p.i. against the 2T3k-derived Ki. The correlation of TBR at 60-70 min p.i. with 2T3K-derived Ki (r (df = 20) = 0.87, p < 0.01), was stronger than for SUVBW (r (df = 20) = 0.80, p < 0.01). CONCLUSION: Tumour lesion [18F]F-AraG uptake in patients with NSCLC is characterised by a 2T3k model. TBR and TPR show most potential for simplified quantification of tumour lesion [18F]F-AraG uptake in patients with NSCLC.

89Zr-immuno-PET using the anti-LAG-3 tracer [89Zr]Zr-BI 754111: demonstrating target specific binding in NSCLC and HNSCC.

PURPOSE: Although lymphocyte activation gene-3 (LAG-3) directed therapies demonstrate promising clinical anti-cancer activity, only a subset of patients seems to benefit and predictive biomarkers are lacking. Here, we explored the potential use of the anti-LAG-3 antibody tracer [89Zr]Zr-BI 754111 as a predictive imaging biomarker and investigated its target specific uptake as well as the correlation of its tumor uptake and the tumor immune infiltration. METHODS: Patients with head and neck (N = 2) or lung cancer (N = 4) were included in an imaging substudy of a phase 1 trial with BI 754091 (anti-PD-1) and BI 754111 (anti-LAG-3). After baseline tumor biopsy and [18F]FDG-PET, patients were given 240 mg of BI 754091, followed 8 days later by administration of [89Zr]Zr-BI 754111 (37 MBq, 4 mg). PET scans were performed 2 h, 96 h, and 144 h post-injection. To investigate target specificity, a second tracer administration was given two weeks later, this time with pre-administration of 40 (N = 3) or 600 mg (N = 3) unlabeled BI 754111, followed by PET scans at 96 h and 144 h post-injection. Tumor immune cell infiltration was assessed by immunohistochemistry and RNA sequencing. RESULTS: Tracer uptake in tumors was clearly visible at the 4-mg mass dose (tumor-to-plasma ratio 1.63 [IQR 0.37-2.89]) and could be saturated by increasing mass doses (44 mg: 0.67 [IQR 0.50-0.85]; 604 mg: 0.56 [IQR 0.42-0.75]), demonstrating target specificity. Tumor uptake correlated to immune cell-derived RNA signatures. CONCLUSIONS: [89Zr]Zr-BI-754111 PET imaging shows favorable technical and biological characteristics for developing a potential predictive imaging biomarker for LAG-3-directed therapies. TRIAL REGISTRATION: ClinicalTrials.gov , NCT03780725. Registered 19 December 2018.

The Effect of Preanalytical and Physiological Variables on Cell-Free DNA Fragmentation.

BACKGROUND: Assays that account for the biological properties and fragmentation of cell-free DNA (cfDNA) can improve the performance of liquid biopsy. However, preanalytic and physiological differences between individuals on fragmentomic analysis are poorly defined. METHODS: We analyzed the impact of collection tube, plasma processing time, and physiology on the size distribution of cfDNA, their genome-wide representation, and sequence diversity at the cfDNA fragment ends using shallow whole-genome sequencing. RESULTS: Neither different stabilizing collection tubes nor processing times affected the cfDNA fragment sizes, but could impact the genome-wide fragmentation patterns and fragment-end sequences of cfDNA. In addition, beyond differences depending on the gender, the physiological conditions tested between 63 individuals (age, body mass index, use of medication, and chronic conditions) minimally influenced the outcome of fragmentomic methods. CONCLUSIONS: Fragmentomic approaches have potential for implementation in the clinic, pending clear traceability of analytical and physiological factors.

Detection of Circulating Tumor Cells Using the Attune NxT.

Circulating tumor cells (CTCs) have been detected in many patients with different solid malignancies. It has been reported that presence of CTCs correlates with worse survival in patients with multiple types of cancer. Several techniques have been developed to detect CTCs in liquid biopsies. Currently, the only method for CTC detection that is approved by the Food and Drug Administration is CellSearch. Due to low abundance of CTCs in certain cancer types and in early stages of disease, its clinical application is currently limited to metastatic colorectal cancer, breast cancer and prostate cancer. Therefore, we aimed to develop a new method for the detection of CTCs using the Attune NxT-a flow cytometry-based application that was specifically developed to detect rare events in biological samples without the need for enrichment. When healthy donor blood samples were spiked with variable amounts of different EpCAM+EGFR+ tumor cell lines, recovery yield was on average 75%. The detection range was between 1000 and 10 cells per sample. Cell morphology was confirmed with the Attune CytPix. Analysis of blood samples from metastatic colorectal cancer patients, as well as lung cancer patients, demonstrated that increased EpCAM+EGFR+ events were detected in more than half of the patient samples. However, most of these cells showed no (tumor) cell-like morphology. Notably, CellSearch analysis of blood samples from a subset of colorectal cancer patients did not detect CTCs either, suggesting that these blood samples were negative for CTCs. Therefore, we anticipate that the Attune NxT is not superior to CellSearch in detection of low amounts of CTCs, although handling and analysis of samples is easier. Moreover, morphological confirmation is essential to distinguish between CTCs and false positive events.

Ipilimumab plus nivolumab and chemoradiotherapy followed by surgery in patients with resectable and borderline resectable T3-4N0-1 non-small cell lung cancer: the INCREASE trial.

BACKGROUND: The likelihood of a tumor recurrence in patients with T3-4N0-1 non-small cell lung cancer following multimodality treatment remains substantial, mainly due distant metastases. As pathological complete responses (pCR) in resected specimens are seen in only a minority (28-38%) of patients following chemoradiotherapy, we designed the INCREASE trial (EudraCT-Number: 2019-003454-83; Netherlands Trial Register number: NL8435) to assess if pCR rates could be further improved by adding short course immunotherapy to induction chemoradiotherapy. Translational studies will correlate changes in loco-regional and systemic immune status with patterns of recurrence. METHODS/DESIGN: This single-arm, prospective phase II trial will enroll 29 patients with either resectable, or borderline resectable, T3-4N0-1 NSCLC. The protocol was approved by the institutional ethics committee. Study enrollment commenced in February 2020. On day 1 of guideline-recommended concurrent chemoradiotherapy (CRT), ipilimumab (IPI, 1 mg/kg IV) and nivolumab (NIVO, 360 mg flat dose IV) will be administered, followed by nivolumab (360 mg flat dose IV) after 3 weeks. Radiotherapy consists of once-daily doses of 2 Gy to a total of 50 Gy, and chemotherapy will consist of a platinum-doublet. An anatomical pulmonary resection is planned 6 weeks after the last day of radiotherapy. The primary study objective is to establish the safety of adding IPI/NIVO to pre-operative CRT, and its impact on pathological tumor response. Secondary objectives are to assess the impact of adding IPI/NIVO to CRT on disease free and overall survival. Exploratory objectives are to characterize tumor inflammation and the immune contexture in the tumor and tumor-draining lymph nodes (TDLN), and to explore the effects of IPI/NIVO and CRT and surgery on distribution and phenotype of peripheral blood immune subsets. DISCUSSION: The INCREASE trial will evaluate the safety and local efficacy of a combination of 4 modalities in patients with resectable, T3-4N0-1 NSCLC. Translational research will investigate the mechanisms of action and drug related adverse events. TRIAL REGISTRATION: Netherlands Trial Registration (NTR): NL8435 , Registered 03 March 2020.

Association Between PD-L1 Score and the Outcomes of Consolidation Durvalumab in a Large Nationwide Series of Patients With Stage III NSCLC Treated With Chemoradiotherapy.

BACKGROUND: The Pacific trial reported improved outcomes when durvalumab was administered following concurrent chemoradiotherapy (CRT) for stage III NSCLC. Post-hoc subgroup analysis did not show favorable results for PD-L1 negative cases. We compared nationwide survival data with the trial outcomes, and evaluated the influence of PD-L1. PATIENTS AND METHODS: Data from the Netherlands Cancer Registry were queried regarding patients with clinical stage III who underwent CRT, either by concurrent or sequential administration. Predictors for the use of consolidation treatment with durvalumab were evaluated by tabulations and logistic regression analysis. Overall survival (OS) was calculated from start of radiation or start of durvalumab and was stratified by PD-L1 score. RESULTS: Between 2017 and 2021, application of consolidation durvalumab increased from 2% to 21%, 40%, 57%, 62%, respectively. In the period 2020-2021, durvalumab use was more frequent among patients with younger age, concurrent CRT, better performance score and proton radiation, but was irrespective of PD-L1 score. For patients receiving durvalumab (n = 1639), the 4-year OS was 53% overall (95%CI 50-57), and it was 56% (95%CI 52-60) after concurrent CRT. Four-year OS was considerably better for the PD-L1 subgroup ≧50% at 67% (95%CI 59-73), and it was similar for PD-L1 subgroups 0 and 1-49, at 51% (95%CI 42-58) and 46% (95%CI 39-54), respectively. CONCLUSION: In real-world clinical practice, survival outcomes were equivalent to results from trial series. Overall survival in patients with negative PD-L1 was similar to the survival in patients with PD-L1 1-49, questioning the restrictions imposed by the European Medicines Agency.

The development process of 'fit-for-purpose' imaging biomarkers to characterize the tumor microenvironment.

Immune-based treatment approaches are successfully used for the treatment of patients with cancer. While such therapies can be highly effective, many patients fail to benefit. To provide optimal therapy choices and to predict treatment responses, reliable biomarkers for the assessment of immune features in patients with cancer are of significant importance. Biomarkers (BM) that enable a comprehensive and repeatable assessment of the tumor microenvironment (TME), the lymphoid system, and the dynamics induced by drug treatment can fill this gap. Medical imaging, notably positron emission tomography (PET) and magnetic resonance imaging (MRI), providing whole-body imaging BMs, might deliver such BMs. However, those imaging BMs must be well characterized as being 'fit for purpose' for the intended use. This review provides an overview of the key steps involved in the development of 'fit-for-purpose' imaging BMs applicable in drug development, with a specific focus on pharmacodynamic biomarkers for assessing the TME and its modulation by immunotherapy. The importance of the qualification of imaging BMs according to their context of use (COU) as defined by the Food and Drug Administration (FDA) and National Institutes of Health Biomarkers, EndpointS, and other Tools (BEST) glossary is highlighted. We elaborate on how an imaging BM qualification for a specific COU can be achieved.

Comparison of cell-free and small extracellular-vesicle-associated DNA by sequencing plasma of lung cancer patients.

Blood contains multiple analytes that can be used as liquid biopsy to analyze cancer. Mutations have been detected in DNA associated with small extracellular vesicles (sEVs). The genome-wide composition and structure of sEV DNA remains poorly characterized, and whether sEVs are enriched in tumor signal compared to cell-free DNA (cfDNA) is unclear. Here, using whole-genome sequencing from lung cancer patients we determined that the tumor fraction and heterogeneity are comparable between DNA associated with sEV (<200 nm) and matched plasma cfDNA. sEV DNA, obtained with size-exclusion chromatography, is composed of short ∼150-180 bp fragments and long >1000 bp fragments poor in tumor signal. The structural patterns of sEV DNA are related to plasma cfDNA. Mitochondrial DNA is relatively enriched in the sEV fractions. Our results suggest that DNA associated to sEV (including exosomes) is not preferentially enriched in tumor signal and is less abundant than cfDNA.

Stereologic consequences of iatrogenic collapse: The morphology of adenocarcinoma in situ overlaps with invasive patterns. Proposal for a necessary modified classification of pulmonary adenocarcinomas.

Recognizing non-invasive growth patterns is necessary for correct diagnosis, invasive size determination and pT-stage in resected non-small cell lung carcinoma. Due to iatrogenic collapse after resection, the distinction between adenocarcinoma in-situ (AIS) and invasive adenocarcinoma may be difficult. The aim of this study is to investigate the complex morphology of non-mucinous non-invasive patterns of AIS in resection specimen with iatrogenic collapse, and to relate this to follow-up. The effects of iatrogenic collapse on the morphology of collapsed AIS were simulated in a mathematical model. Three dimensional related criteria applied in a modified classification, using also cytokeratin 7 and elastin as additional stains, in two independent retrospective cohorts of primary pulmonary adenocarcinomas ≤3 cm resection specimen with available follow-up information. The model demonstrated that infolding of alveolar walls occurs during iatrogenic collapse and lead to a significant increase in tumor cell heights in maximal collapse areas, compared to less collapsed areas. The morphology of infolded AIS overlaps with patterns described as papillary and acinar adenocarcinoma according to the WHO classification, necessitating an adaptation. The modified classification incorporates recognition of iatrogenic and biologic collapse, tangential cutting effect true invasion and surrogate markers of invasion i.e. grey zone, covering a multilayering falling short of micropapillary, cribriform and solid alveolar filling growth. The use of elastin and CK7 staining aids in the morphologic recognition of iatrogenic collapsed AIS and the distinction from invasive adenocarcinoma. Out of a total of 70 resection specimens 1 case was originally classified as AIS and 9 were reclassified as iatrogenic collapsed AIS. Patients with collapsed AIS showed a 100 % recurrence-free survival after a mean follow-up time of 69.5 months. With the current WHO classification, AIS is overdiagnosed as invasive adenocarcinoma due to infolding. The modified classification facilitates the diagnosis of AIS.

Multi-modal cell-free DNA genomic and fragmentomic patterns enhance cancer survival and recurrence analysis.

The structure of cell-free DNA (cfDNA) is altered in the blood of patients with cancer. From whole-genome sequencing, we retrieve the cfDNA fragment-end composition using a new software (FrEIA [fragment end integrated analysis]), as well as the cfDNA size and tumor fraction in three independent cohorts (n = 925 cancer from >10 types and 321 control samples). At 95% specificity, we detect 72% cancer samples using at least one cfDNA measure, including 64% early-stage cancer (n = 220). cfDNA detection correlates with a shorter overall (p = 0.0086) and recurrence-free (p = 0.017) survival in patients with resectable esophageal adenocarcinoma. Integrating cfDNA measures with machine learning in an independent test set (n = 396 cancer, 90 controls) achieve a detection accuracy of 82% and area under the receiver operating characteristic curve of 0.96. In conclusion, harnessing the biological features of cfDNA can improve, at no extra cost, the diagnostic performance of liquid biopsies.

Challenges and controversies in resectable non-small cell lung cancer: a clinician's perspective.

The treatment landscape of resectable early-stage non-small cell lung cancer (NSCLC) is transforming due to the approval of novel adjuvant and neoadjuvant systemic treatments. The European Medicines Agency (EMA) recently approved adjuvant osimertinib, adjuvant atezolizumab, adjuvant pembrolizumab, and neoadjuvant nivolumab combined with chemotherapy, and the approval of other agents or new indications may follow soon. Despite encouraging results, many unaddressed questions remain. Moreover, the transformed treatment paradigm in resectable NSCLC can pose major challenges to healthcare systems and magnify existing disparities in care as differences in reimbursement may vary across different European countries. This Viewpoint discusses the challenges and controversies in resectable early-stage NSCLC and how existing inequalities in access to these treatments could be addressed.

New systemic treatment paradigms in resectable non-small cell lung cancer and variations in patient access across Europe.

The treatment landscape of resectable early-stage non-small cell lung cancer (NSCLC) is set to change significantly due to encouraging results from randomized trials evaluating neoadjuvant and adjuvant immunotherapy, as well as adjuvant targeted therapy. As of January 2024, marketing authorization has been granted for four new indications in Europe, and regulatory approvals for other study regimens are expected. Because cost-effectiveness and reimbursement criteria for novel treatments often differ between European countries, access to emerging developments may lead to inequalities due to variations in recommended and available lung cancer care throughout Europe. This Series paper (i) highlights the clinical studies reshaping the treatment landscape in resectable early-stage NSCLC, (ii) compares and contrasts approaches taken by the European Medicines Agency (EMA) for drug approval to that taken by the United States Food and Drug Administration (FDA), and (iii) evaluates the differences in access to emerging treatments from an availability perspective across European countries.

How to obtain the image-derived blood concentration from 89Zr-immuno-PET scans.

BACKGROUND: PET scans using zirconium-89 labelled monoclonal antibodies (89Zr-mAbs), known as 89Zr-immuno-PET, are made to measure uptake in tumour and organ tissue. Uptake is related to the supply of 89Zr-mAbs in the blood. Measuring activity concentrations in blood, however, requires invasive blood sampling. This study aims to identify the best delineation strategy to obtain the image-derived blood concentration (IDBC) from 89Zr-immuno-PET scans. METHODS: PET imaging and blood sampling of two 89Zr-mAbs were included, 89Zr-cetuximab and 89Zr-durvalumab. For seven patients receiving 89Zr-cetuximab, PET scans on 1-2 h, 2 and 6 days post-injection (p.i.) were analysed. Five patients received three injections of 89Zr-durvalumab. The scanning protocol for the first two injections consisted of PET scanning on 2, 5 and 7 days p.i. and for the third injection only on 7 days p.i. Blood samples were drawn with every PET scan and the sample-derived blood concentration (SDBC) was used as gold standard for the IDBC. According to an in-house developed standard operating procedure, the aortic arch, ascending aorta, descending aorta and left ventricle were delineated. Bland-Altman analyses were performed to assess the bias (mean difference) and variability (1.96 times the standard deviation of the differences) between IDBC and SDBC. RESULTS: Overall, the activity concentration obtained from the IDBC was lower than from the SDBC. When comparing IDBC with SDBC, variability was smallest for the ascending aorta (20.3% and 17.0% for 89Zr-cetuximab and 89Zr-durvalumab, respectively). Variability for the other regions ranged between 17.9 and 30.8%. Bias for the ascending aorta was - 10.9% and - 11.4% for 89Zr-cetuximab and 89Zr-durvalumab, respectively. CONCLUSIONS: Image-derived blood concentrations should be obtained from delineating the ascending aorta in 89Zr-immuno-PET scans, as this results in the lowest variability with respect to sample-derived blood concentrations.

First exploration of the on-treatment changes in tumor and organ uptake of a radiolabeled anti PD-L1 antibody during chemoradiotherapy in patients with non-small cell lung cancer using whole body PET.

BACKGROUND: In patients with locally advanced unresectable non-small cell lung cancer (NSCLC), durvalumab, an anti-programmed cell death ligand-1 (PD-L1) antibody, has shown improved overall survival when used as consolidation therapy following concurrent chemoradiotherapy (CRT). However, it is unclear whether CRT itself upregulates PD-L1 expression. Therefore, this study aimed to explore the changes in the uptake of the anti PD-L1 antibody [89Zr]Zr-durvalumab in tumors and healthy organs during CRT in patients with NSCLC. METHODS: Patients with NSCLC scheduled to undergo CRT were scanned 7±1 days after administration of 37±1 MBq [89Zr]Zr-durvalumab at baseline, 1-week on-treatment and 1 week after finishing 6 weeks of CRT. First, [89Zr]Zr-durvalumab uptake was visually assessed in a low dose cohort with a mass dose of 2 mg durvalumab (0.13% of therapeutic dose) and subsequently, quantification was done in a high dose cohort with a mass dose of 22.5 mg durvalumab (1.5% of therapeutic dose). Tracer pharmacokinetics between injections were compared using venous blood samples drawn in the 22.5 mg cohort. Visual assessment included suspected lesion detectability. Positron emission tomography (PET) uptake in tumoral and healthy tissues was quantified using tumor to plasma ratio (TPR) and organ to plasma ratio, respectively. RESULTS: In the 2 mg dose cohort, 88% of the 17 identified tumor lesions were positive at baseline, compared with 69% (9/13) for the 22.5 mg cohort. Although the absolute plasma concentrations between patients varied, the intrapatient variability was low. The ten quantitatively assessed lesions in the 22.5 mg cohort had a median TPR at baseline of 1.3 (IQR 0.7-1.5), on-treatment of 1.0 (IQR 0.7-1.4) and at the end of treatment of 0.7 (IQR 0.6-0.7). On-treatment, an increased uptake in bone marrow was seen in three out of five patients together with a decreased uptake in the spleen in four out of five patients. CONCLUSIONS: This study successfully imaged patients with NSCLC with [89Zr]Zr-durvalumab PET before and during CRT. Our data did not show any increase in [89Zr]Zr-durvalumab uptake in the tumor 1-week on-treatment and at the end of treatment. The changes observed in bone marrow and spleen may be due to an CRT-induced effect on immune cells. TRIAL REGISTRATION NUMBER: EudraCT number: 2019-004284-51.

Single-arm trial of neoadjuvant ipilimumab plus nivolumab with chemoradiotherapy in patients with resectable and borderline resectable lung cancer: the INCREASE study.

BACKGROUND: In non-small cell lung cancer (NSCLC), chemoradiotherapy (CRT) yields pathological complete response (pCR) rates of approximately 30%. We investigated using ipilimumab plus nivolumab (IPI-NIVO) with neoadjuvant CRT in resectable, and borderline resectable NSCLC. METHODS: This single-arm, phase-II trial enrolled operable T3-4N0-2 patients with NSCLC without oncogenic drivers. Primary study endpoints were safety, major pathological response (MPR) and pCR. Treatment encompassed platinum-doublet concurrent CRT, IPI 1 mg/kg intravenous and NIVO 360 mg intravenous on day-1, followed by chemotherapy plus NIVO 360 mg 3 weeks later. Thoracic radiotherapy was 50 or 60 Gy, in once-daily doses of 2 Gy. Resections were 6 weeks post-radiotherapy. RESULTS: In a total of 30 patients in the intention-to-treat (ITT) population, grades 3-4 treatment-related adverse events (TRAEs) occurred in 70%, one TRAE grade 5 late-onset pneumonitis on day 96 post-surgery (1/30, 3.3%) occurred, and one non-TRAE COVID-19 death (1/30, 3.3%). pCR and MPR were achieved in 50% (15/30) and 63% (19/30) of the ITT; and in 58% (15/26) and 73% (19/26) of the 26 patients who underwent surgery, respectively. Postoperative melanoma was seen in one non-pCR patient. The R0 rate was 100% (26/26), and no patient failed surgery due to TRAEs. In peripheral blood, proliferative CD8+ T cells were increased, while proliferative regulatory T cells (Tregs) were not. On-treatment, pCR-positives had higher CD8+CD39+ T cells and lower HLA-DR+ Tregs. CONCLUSIONS: Neoadjuvant IPI-NIVO-CRT in T3-4N0-2 NSCLC showed acceptable safety with pCR and MPR in 58% and 73% of operated patients, respectively. No patient failed surgery due to TRAEs. TRIAL REGISTRATION NUMBER: NCT04245514.

Pharmacokinetic analysis of [18F]FAZA in non-small cell lung cancer patients.

PURPOSE: [(18)F]Fluoroazomycin arabinoside (FAZA) is a positron emission tomography (PET) tracer developed to enable identification of hypoxic regions within a tumour. The aims of this study were to determine the optimal kinetic model along with validation of using alternatives to arterial blood sampling for analysing [(18)F]FAZA studies and to assess the validity of simplified analytical methods. METHODS: Dynamic 70-min [(18)F]FAZA PET/CT scans were obtained from nine non-small cell lung cancer patients. Continuous arterial blood sampling, together with manual arterial and venous sampling, was performed to derive metabolite-corrected plasma input functions. Volumes of interest (VOIs) were defined for tumour, healthy lung muscle and adipose tissue generating [(18)F]FAZA time-activity curves (TACs). TACs were analysed using one- and two-tissue compartment models using both metabolite-corrected blood sampler plasma input functions (BSIF) and image-derived plasma input functions (IDIF). RESULTS: The reversible two-tissue compartment model with blood volume parameter (2T4k+VB) best described kinetics of [(18)F]FAZA in tumours. Volumes of distribution (VT) obtained using IDIF correlated well with those derived using BSIF (R(2) = 0.82). Venous samples yielded the same radioactivity concentrations as arterial samples for times >50 min post-injection (p.i.). In addition, both plasma to whole blood ratios and parent fractions were essentially the same for venous and arterial samples. Both standardised uptake value (SUV), normalised to lean body mass, and tumour to blood ratio correlated well with VT (R(2) = 0.77 and R(2) = 0.87, respectively, at 50-60 min p.i.), although a bias was observed at low VT. CONCLUSION: The 2T4k+VB model provided the best fit to the dynamic [(18)F]FAZA data. IDIF with venous blood samples can be used as input function. Further data are needed to validate the use of simplified methods.

Predictive Value of Combined Positive Score and Tumor Proportion Score for Immunotherapy Response in Advanced NSCLC.

Introduction: In advanced-stage NSCLC, tumor proportion score (TPS) is typically used to predict the efficacy of immune checkpoint inhibitors (ICIs). Nevertheless, in other cancer types, the combined positive score (CPS), which covers programmed death-ligand 1 (PD-L1) expression on both tumor and surrounding immune cells, is used. We investigated the predictive value of CPS in comparison to TPS in advanced NSCLC. Methods: A monocenter, retrospective study was performed in patients with advanced NSCLC treated with ICI monotherapy between 2015 and 2021. Hematoxylin and eosin and PD-L1 were stained on baseline tumor biopsy samples to score PD-L1 by both TPS and CPS. Positivity for TPS and CPS was defined as a score of 1% or above. Progression-free survival and overall survival (OS) were assessed for TPS and CPS scores. Results: Among the 187 included patients, PD-L1 positivity was found in 112 patients (59.9%) by TPS and 135 patients (72.2%) by CPS. There was no significant difference in OS between TPS- and TPS+ patients (p = 0.20). Nevertheless, CPS+ patients did have a longer OS than CPS- patients (p = 0.006). OS was superior in both TPS-/CPS+ and TPS+/CPS+ as compared with TPS-/CPS- cases (p = 0.018 and p = 0.015, respectively), whereas no considerable differences in OS were found between TPS-/CPS+ and TPS+/CPS+ cases. Conclusions: This retrospective real-world population study revealed that CPS differentiated OS better than TPS in patients with advanced NSCLC with ICI monotherapy. Remarkably, this was driven by the performance of the TPS-/CPS+ subgroup, indicating that CPS may be a better predictive biomarker for ICI efficacy.

The landscape of cell-free mitochondrial DNA in liquid biopsy for cancer detection.

BACKGROUND: Existing methods to detect tumor signal in liquid biopsy have focused on the analysis of nuclear cell-free DNA (cfDNA). However, non-nuclear cfDNA and in particular mitochondrial DNA (mtDNA) has been understudied. We hypothesize that an increase in mtDNA in plasma could reflect the presence of cancer, and that leveraging cell-free mtDNA could enhance cancer detection. RESULTS: We survey 203 healthy and 664 cancer plasma samples from three collection centers covering 12 cancer types with whole genome sequencing to catalogue the plasma mtDNA fraction. The mtDNA fraction is increased in individuals with cholangiocarcinoma, colorectal, liver, pancreatic, or prostate cancer, in comparison to that in healthy individuals. We detect almost no increase of mtDNA fraction in individuals with other cancer types. The mtDNA fraction in plasma correlates with the cfDNA tumor fraction as determined by somatic mutations and/or copy number aberrations. However, the mtDNA fraction is also elevated in a fraction of patients without an apparent increase in tumor-derived cfDNA. A predictive model integrating mtDNA and copy number analysis increases the area under the curve (AUC) from 0.73 when using copy number alterations alone to an AUC of 0.81. CONCLUSIONS: The mtDNA signal retrieved by whole genome sequencing has the potential to boost the detection of cancer when combined with other tumor-derived signals in liquid biopsies.

Focal 18 F-FDG uptake predicts progression of pre-invasive squamous bronchial lesions to invasive cancers.

INTRODUCTION: Pre-invasive squamous lesions of the central airways can progress into invasive lung cancers. Identifying these high-risk patients could enable detection of invasive lung cancers at an early stage. In this study, we investigated the value of 18 F-fluorodeoxyglucose (18 F-FDG) positron emission tomography (PET) scans in predicting progression in patients with pre-invasive squamous endobronchial lesions. METHODS: In this retrospective study, patients with pre-invasive endobronchial lesions, who underwent an 18 F-FDG PET scan at the VU University Medical Center Amsterdam, between January 2000 and December 2016, were included. Autofluorescence bronchoscopy (AFB) was used for tissue sampling and was repeated every 3 months. The minimum and median follow-up was 3 and 46.5 months. Study endpoints were the occurrence of biopsy proven invasive carcinoma, time-to-progression and overall survival (OS). RESULTS: A total number of 40 of 225 patients met the inclusion criteria of which 17 (42.5%) patients had a positive baseline 18 F-FDG PET scan. A total of 13 of 17 (76.5%) developed invasive lung carcinoma during follow-up, with a median time to progression of 5.0 months (range, 3.0-25.0). In 23 (57.5%) patients with a negative 18 F-FDG PET scan at baseline, 6 (26%) developed lung cancer, with a median time to progression of 34.0 months (range, 14.0-42.0 months, p < 0.002). With a median OS of 56.0 months (range, 9.0-60.0 months) versus 49.0 months (range, 6.0-60.0 months) (p = 0.876) for the 18 F-FDG PET positive and negative groups, respectively. CONCLUSIONS: Patients with pre-invasive endobronchial squamous lesions and a positive baseline 18 F-FDG PET scan were at high-risk for developing lung carcinoma, highlighting that this patient group requires early radical treatment.