Downregulation of hsa_circTLK1 represses non-small cell lung cancer progression by regulating miR-876-3p/SRSF7 axis.

Background: This study clarified the expression of cicrTLK1 in non-small cell lung cancer (NSCLC) and explored its role in cancer growth, metastasis and immune escape, providing a potential molecular target and theoretical basis for NSCLC treatment. Methods: The expression levels of circTLK1, miR-876-3p and SRSF7 were determined by RT-qPCR assay. The localization of circTLK1 in NSCLC cells was determined by FISH assay. EdU and cell plate clone formation assay were applied to explore cell proliferation. Wound healing test and Transwell assay were applied to measure the migration and invasion ability. Cell apoptosis rate was detected by FCM assay. Western blotting assay was adopted to measure the protein expression of SRSF7. Dual-luciferase reporter gene assay was applied to assess the interaction between miR-876-3p and circTLK1, and between miR-876-3p and SRSF7. The ability of cirTLK1 to regulate tumor formation in vivo was examined by tumor transplantation experiments in nude mice. Results: The relative expression of circTLK1 was increased in NSCLC cell lines. Knockdown of circTLK1 prohibited the proliferation, migration, and invasion, and promoted apoptosis rate, but miR-876-3p inhibitor reversed the effects of circTLK1 knockdown. In addition, silencing of circTLK1 overtly restrained the growth of transplanted tumors in vivo, and inhibited immune escape. In addition, circTLK1 interacted with miR-876-3p, and SRSF7 was concluded to be the target gene of miR-876-3p. Conclusion: In this study, we researched the inhibitory effect of circTLK1knockdown on NSCLC progression and immune escape, and further elucidated the potential regulatory mechanism of circTLK1/miR876-3p/SRSF7 axis.

Observational study to characterize treatment-resistant depression in Germany, France and the United Kingdom: analysis of real-world data collected through a survey of healthcare professionals.

OBJECTIVE: This study describes treatment patterns, productivity, healthcare resource utilization and previous episodes of depression for patients with treatment-resistant depression (TRD). METHODS: In this cross-sectional study, a quantitative survey was administered to 225 healthcare providers (HCPs) distributed evenly across Germany, France and the UK from July to August 2021. Each HCP was asked to answer based on medical records of five patients with TRD, defined as patients failing to respond to two or more treatments of adequate dose and duration in the same episode of major depressive disorder (MDD), which provided a sample size of 1125 patients. RESULTS: Of the 1125 patients with TRD, 73.2% had two or more previous episodes of MDD, 46.3% had a history of suicidal ideation and 24.8% had attempted suicide. Only 26.8% of patients were employed either full-time or part-time. During the most recent/current TRD episode, 45.5% of patients received five or more lines of treatment, and 46.0% remained on monotherapy. For multiple pharmacological treatments, too many distinct combinations were used to discern trends. Overall, 60.6% of patients had at least one mental health-related hospitalization in the last 12 months; 35.0% had two or more hospitalizations. Half of TRD patients saw a doctor five or more times per year for their depression. CONCLUSIONS: This study addresses the knowledge gap about treatment patterns and healthcare utilization in real-world practice for TRD patients in three European countries. It provides data that potentially could inform treatment guideline development and optimize patient-perceived benefits from the treatment of TRD.

Clinicopathological Characteristics and Molecular Phenotypes of Primary Hepatic Lymphoma.

Primary hepatic lymphoma (PHL) is a rare malignant tumor, occurring in 0.016% of non-Hodgkin's lymphoma (NHL). The common histological subtype is diffuse large B-cell lymphoma (DLBCL). Due to the rarity of tumor, clinicopathological characteristics and molecular phenotypes of PHL are limited. Seven patients with PHL (primary liver DLBCL) and 13 cases of liver involvement by DLBCL diagnosed between 2014 and 2021 in our hospital were included. The genetic features were also compared between the two groups by next-generation sequencing (NGS). Differential gene expression and pathway enrichment analysis were also performed. There were some discrepancies on presenting symptoms, pathological characteristics, laboratory data, and prognosis between PHL and DLBCL-liver groups. No same mutation was found between PHL and DLBCL-liver groups by NGS. Differential gene expression analysis discovered some up- and downregulated genes in PHL compared with the DLBCL-liver group. Upregulated genes were enriched in metabolic pathways, and downregulated genes were enriched in the HTLV-1 infection pathway. PHL is a distinct entity, with unique molecular features compared to liver involvement of systemic lymphoma. Kaplan-Meier analysis showed that the prognosis of the PHL group was better than that of the DLBCL-liver group. Understanding the clinicopathological and molecular features of PHL would help to direct clinical treatment.

Comparative Efficacy of Umeclidinium/Vilanterol Versus Other Bronchodilators for the Treatment of Chronic Obstructive Pulmonary Disease: A Network Meta-Analysis.

INTRODUCTION: Few randomised controlled trials (RCTs) have directly compared long-acting muscarinic antagonist/long-acting ß2-agonist (LAMA/LABA) dual maintenance therapies for patients with chronic obstructive pulmonary disease (COPD). This systematic literature review and network meta-analysis (NMA) compared the efficacy of umeclidinium/vilanterol (UMEC/VI) versus other dual and mono-bronchodilator therapies in symptomatic patients with COPD. METHODS: A systematic literature review (October 2015-November 2020) was performed to identify RCTs ≥ 8 weeks long in adult patients with COPD that compared LAMA/LABA combinations against any long-acting bronchodilator-containing dual therapy or monotherapy. Data extracted on changes from baseline in trough forced expiratory volume in 1 s (FEV1), St George's Respiratory Questionnaire (SGRQ) total score, Transitional Dyspnoea Index (TDI) focal score, rescue medication use and moderate/severe exacerbation rate were analysed using an NMA in a frequentist framework. The primary comparison was at 24 weeks. Fixed effects model results are presented. RESULTS: The NMA included 69 full-length publications (including 10 GSK clinical study reports) reporting 49 studies. At 24 weeks, UMEC/VI provided statistically significant greater improvements in FEV1 versus all dual therapy and monotherapy comparators. UMEC/VI provided similar improvements in SGRQ total score compared with all other LAMA/LABAs, and significantly greater improvements versus UMEC 125 µg, glycopyrronium 50 µg, glycopyrronium 18 µg, tiotropium 18 µg and salmeterol 50 µg. UMEC/VI also provided significantly better outcomes versus some comparators for TDI focal score, rescue medication use, annualised moderate/severe exacerbation rate, and time to first moderate/severe exacerbation. CONCLUSION: UMEC/VI provided generally better outcomes compared with LAMA or LABA monotherapies, and consistent improvements in lung function (measured by change from baseline in trough FEV1 at 24 weeks) versus dual therapies. Treatment with UMEC/VI may improve outcomes for symptomatic patients with COPD compared with alternative maintenance treatments.

Bronchodilators are medicines that open the airways, allowing patients with chronic obstructive pulmonary disease (COPD) to breathe more easily. There are two different types of bronchodilators, namely long-acting muscarinic antagonists (LAMAs) and long-acting ß₂-agonists (LABAs), which can be used on their own or combined (LAMA/LABAs). Only a few clinical trials have compared different LAMA/LABA combinations with each other, so it is unclear which LAMA/LABA combination provides the greatest benefits for patients.In this study, we used network meta-analysis to compare a LAMA/LABA combination medicine called umeclidinium and vilanterol (UMEC/VI) with other LAMAs and LABAs used alone or in combination to treat patients with COPD. Network meta-analysis is a way of comparing two or more medicines by analysing data from many studies. We systematically searched for evidence from clinical trials in adult patients with COPD that were at least 8 weeks long and that compared LAMA/LABA combinations with a LAMA, a LABA, or another LAMA/LABA combination. We analysed data from 49 clinical trials that met these criteria.We found that patients treated with UMEC/VI had better lung function than patients treated with alternative LAMA/LABA combinations or bronchodilators used on their own. Patients treated with UMEC/VI had better quality of life than those receiving some other treatments, but not all. All the medicines we compared had similar side effects.Our results suggest that treating patients with COPD with UMEC/VI might improve their lung function and quality of life more than alternative bronchodilators.

Antibacterial Copolypeptoids with Potent Activity against Drug Resistant Bacteria and Biofilms, Excellent Stability, and Recycling Property.

The preparation of a type of innovative cationic copolypeptoid antimicrobials containing various hydrophobic moieties that resemble both structure and membrane-lytic antibacterial mechanism of natural antimicrobial peptides (AMPs) is reported. By finely tuning the hydrophilic/hydrophobic balance, the polypeptoids exhibit a wide spectrum of antibacterial activity against both Gram-positive bacteria and Gram-negative bacteria with the lowest minimum inhibitory concentration (MIC) at only 2 µg mL-1 , whereas they also show low haemolytic properties. In particular, high selectivity (>128) is achieved from the polymers with butyl moieties. Moreover, the polypeptoids can readily inhibit the formation of biofilms and effectively eradicate the bacteria embedded in the mature biofilms, which is superior to many natural AMPs and vancomycin. Unlike conventional antibiotics, the polypeptoids possess potent activity against drug-resistant bacteria without visible resistance development after repeated usage. Notably, the polypeptoid antimicrobials not only have inherently fast bactericidal properties and excellent stability against incubation with human plasma, but also show excellent in vivo antibacterial effect. The prepared antimicrobials, coated onto magnetic nanospheres show recycling properties and enhanced antibacterial activity as combined with near-infrared (NIR)-induced photothermal antibacterial therapy.

A province-wide HIV initiative to accelerate initiation of treatment-as-prevention and virologic suppression in British Columbia, Canada: a population-based cohort study.

BACKGROUND: In 2010, HIV treatment as prevention (TasP), encompassing widespread HIV testing and immediate initiation of free antiretroviral treatment (ART), was piloted under the Seek and Treat for Optimal Prevention of HIV/AIDS initiative (STOP) in British Columbia, Canada. We compared the time from HIV diagnosis to treatment initiation, and from treatment initiation to first virologic suppression, before (2005-2009) and after (2010-2016) the implementation of STOP. METHODS: In this population-based cohort study, we used longitudinal data of all people living with an HIV diagnosis in BC from 1996 to 2017. We included those aged 18 years or older who had never received ART and had received an HIV diagnosis in the 2005-2016 period. We defined the virologic suppression date as the first date of at least 2 consecutive test results within 4 months with a viral load of less than 200 copies/mL. Negative binomial regression models assessed the effect of STOP on the time to ART initiation and suppression, adjusting for confounders. All p values were 2-sided, and we set the significance level at 0.05. RESULTS: Participants who received an HIV diagnosis before STOP (n = 1601) were statistically different from those with a diagnosis after STOP (n = 1700); 81% versus 84% were men (p = 0.0187), 30% versus 15% had ever injected drugs (p < 0.0001), and 27% versus 49% had 350 CD4 cells/µL or more at diagnosis (p < 0.0001). The STOP initiative was associated with a 64% shorter time from diagnosis to treatment (adjusted mean ratio 0.36, 95% confidence interval [CI] 0.34-0.39) and a 21% shorter time from treatment to suppression (adjusted mean ratio 0.79, 95% CI 0.73-0.85). INTERPRETATION: In a population with universal health coverage, a TasP intervention was associated with shorter times from HIV diagnosis to treatment initiation, and from treatment initiation to viral suppression. Our results show accelerating progress toward the United Nations' 90-90-90 target of people with HIV who have a diagnosis, those who are on antiretroviral therapy and those who are virologically suppressed, and support the global expansion of TasP to accelerate the control of HIV/AIDS.

The impact of lookback windows on the prevalence and incidence of chronic diseases among people living with HIV: an exploration in administrative health data in Canada.

BACKGROUND: We described the impact of different lengths of lookback window (LW), a retrospective time period to observe diagnoses in administrative data, on the prevalence and incidence of eight chronic diseases. METHODS: Our study populations included people living with HIV (N = 5151) and 1:5 age-sex-matched HIV-negative individuals (N = 25,755) in British Columbia, Canada, with complete follow-up between 1996 and 2012. We measured period prevalence and incidence of diseases in 2012 using LWs ranging from 1 to 16 years. Cases were deemed prevalent if identified in 2012 or within a defined LW, and incident if newly identified in 2012 with no previous cases detected within a defined LW. Chronic disease cases were ascertained using published case-finding algorithms applied to population-based provincial administrative health datasets. RESULTS: Overall, using cases identified by the full 16-year LW as the reference, LWs ≥8 years and ≥ 4 years reduced the proportion of misclassified prevalent and incidence cases of most diseases to < 20%, respectively. The impact of LWs varied across diseases and populations. CONCLUSIONS: This study underscored the importance of carefully choosing LWs and demonstrated data-driven approaches that may inform these choices. To improve comparability of prevalence and incidence estimates across different settings, we recommend transparent reporting of the rationale and limitations of chosen LWs.

Efficacies and Toxicities of Seven Chemotherapy Regimens for Advanced Hodgkin Lymphoma.

Background/Aims: Hodgkin Lymphoma (HL) has become one of the most treatable cancers, with more than 80% patients in the advanced stage being cured through improvement of therapeutic regimens. Nevertheless, some treatments were accompanied with toxicities. Methods: In the current study, a network meta-analysis (NMA) was conducted to compare the efficacies and toxicities of different chemotherapy regimens for advanced Hodgkin lymphoma (HL). We reviewed PubMed and EMBASE databases from inception to May 2018, and identified randomized controlled trials (RCTs) in which advanced HL patients received chemotherapy. Fourteen eligible RCTs published between 1992 and 2017 were enrolled in this NMA. These studies included a total of 5,964 HL patients, and assessed at least one of seven different chemotherapy regimens. Direct and indirect evidence was combined to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs), and to establish a surface under the cumulative ranking (SUCRA) curve. Results: A cluster analysis was performed to evaluate efficacies and toxicities of different regimens. The COPP + ABVD (cyclophosphamide + vincristine + procarbazine + prednisone + doxorubicin + bleomycin + vinblastine + dacarbazine) regimen had the highest SUCRA partial response and overall remission rate values, while the ABVD regimen resulted in the lowest incidences of anemia, thrombocytopenia, neutropenia, and leucopenia. Conclusion: Cluster analysis revealed that COPP + ABVD had the best efficacy against advanced HL among the seven regimens, and ABVD had the lowest toxicity.

Assessment and Prognostic Value of Immediate Changes in Post-Ablation Intratumor Density Heterogeneity of Pulmonary Tumors via Radiomics-Based Computed Tomography Features.

OBJECTIVES: To retrospectively observe the instantaneous changes in intratumor density heterogeneity after microwave ablation (MWA) of lung tumors and to determine their prognostic value in predicting treatment response and local tumor progression (LTP). METHODS: Pre- and post-MWA computed tomography (CT) images of 50 patients (37-males; 13-females; mean-age 65.9 ± 9.7y, 39 primary and 11 metastasis) were analyzed to evaluate changes in intratumor density. Global, regional, and local scale radiomics features were extracted to assess intratumor density heterogeneity. In four to six weeks, chest enhanced CT was used as the baseline evaluation of treatment response. The correlations between the parametric variation immediately after ablation and the visual score of ablation response (Rvisu) were analyzed by nonparametric Spearman correlation analysis. The 1-year LTP discrimination power was assessed using the area under the receiver operating characteristic (ROC) curves. A Cox proportional hazards regression model was used to identify the independent prognostic features. RESULTS: Although no significant volume changes were observed after ablation, the radiomics parameters changed in different directions and degrees. The mean intensity value from baseline CT image was 30.3 ± 23.2, and the post-MWA CT image was -60.9 ± 89.8. The ratio of values change was then calculated by a unified formulation. The largest increase (522.3%) was observed for cluster prominence, while the mean CT value showed the largest decline (321.4%). The pulmonary tumors had a mean diameter of 3.4 ± 0.8 cm. Complete ablation was documented in 36 patients. Significant correlations were observed between Rvisu and quantitative features. The highest correlations were observed for changes in local features after MWA, with r ranging from 0.594 to 0.782. LTP developed in 22 patients. The Cox regression model revealed Δcontrast% and response score as independent predictors (Δcontrast%: odds ratio [OR]=5.61, p=0.001; Rvisu: OR=1.73, p=0019). ROC curve analysis showed that Δcontrast% was a better predictor of 1-year LTP. with higher sensitivity (83.5% vs. 71.2%) and specificity (87.1% vs. 76.8%) than those for Rvisu. CONCLUSIONS: The changes in intratumor density heterogeneity after MWA could be characterized by analysis of radiomics features. Real-time density changes could predict treatment response and LTP in patients with pulmonary tumors earlier, especially for tumors with larger diameters.

Correlation of IL-6 and JAK2/STAT3 signaling pathway with prognosis of nasopharyngeal carcinoma patients.

IL-6 is reported to be the main upstream activator, instead of the downstream target of JAK2/STAT3. This study is intended to explore the correlation of IL-6 and JAK2/STAT3 signaling pathway with clinicopathological features and prognosis in nasopharyngeal carcinoma (NPC). First, NPC tissues and normal nasopharyngeal epithelial tissues were obtained from 117 NPC patients. Next, we detected expression levels of IL-6 in serum and those of STAT3, p-STAT3, JAK2, p-JAK2 and CyclinD1 in tissues. A follow-up was conducted in all the patients and the survival was analyzed. To verify the correlation of IL-6 and JAK2/STAT3 pathway, CNE-1 and SUNE1 NPC cells were interpreted with IL-6 and JAK2/STAT3 signaling pathway inhibitor AG490 to detect cell viability, migration and invasion. We observed thatIL-6 increased in serum of NPC patients. The expressions of IL-6, STAT3, p-STAT3, JAK2, p-JAK2 and CyclinD1 in NPC tissues were higher and correlated with TNM stage and lymph node metastasis (LNM). Survival rates were reduced in patients with positive expressions of IL-6, STAT3, p-STAT3, JAK2, p-JAK2 and CyclinD1. LNM and positive expressions of IL-6 and p-STAT3 were risk factors for poor prognosis of NPC. Besides, recombinant human IL-6 promoted cell proliferation, invasion and migration while AG490 inhibited cell proliferation, invasion and migration in CNE-1 and SUNE1 NPC cells. The results demonstrated that increased IL-6 expression and the activated JAK2/STAT3 signaling pathway had effects on prognosis and reduced the survival time in NPC patients, which provide a potential target for the treatment of NPC.

Efficacy and safety of CT-guided microwave ablation for stage T1a renal cell carcinoma in patients with a solitary kidney.

OBJECTIVE: To retrospectively evaluate early clinical outcomes of percutaneous microwave ablation (MWA) for stage T1a renal cell carcinomas (RCCs) in solitary kidney patients. MATERIALS AND METHODS: 15 solitary kidney patients with 16 stage T1a N0M0 biopsy-proved RCCs underwent CT-guided percutaneous microwave ablation between October 2016 and July 2020. The patients were followed up with contrast-enhanced computed tomography or magnetic resonance imaging at 1, 3, and 6 months and every 6 months thereafter. Serum creatinine levels of each patient pre MWA, 1 day after MWA and the most recent record were collected. Technical effectiveness, local recurrence, survival rates and complications were accessed. RESULTS: Complete ablation was achieved in all 16 tumors (100%) including 13 clear cell carcinomas and 3 papillary carcinomas. Within the follow-up time (median: 24 months) no tumor recurrence or major complication was detected. No significant change in serum creatinine level was noted. The cancer-specific survival rate was 100% (15 of 15), and 1-, 2-, and 3-year overall survival rates were 100%, 93.3%, and 93.3%, respectively. CONCLUSION: Percutaneous MWA is an effective and safe treatment option for stage T1a RCCs in solitary kidney patients; it can achieve high complete ablation rate in selected lesions of appropriate size and location.

Overdose mortality is reducing the gains in life expectancy of antiretroviral-treated people living with HIV in British Columbia, Canada.

BACKGROUND: A remarkable reduction in AIDS-related mortality has been achieved through the widespread use of triple combination antiretroviral therapy, considerably increasing the life expectancy of people living with HIV (PLWH). However, these survival gains are now at risk in North America due to an unprecedented public health emergency: the deadly drug overdose epidemic. Drug overdoses are now the leading cause of unintentional death in British Columbia (BC), Canada and the United States due to synthetic opioids (e.g., fentanyl) in illegal markets. This manuscript aimed to estimate the effect of overdose mortality on life expectancy and identify covariates associated with the hazard for overdose mortality in the presence of competing risk among PLWH in BC. METHODS: Those eligible were aged ≥20 years, initiated antiretroviral therapy from 1-Apr-1996 to 30-Dec-2017, and were followed until 31-Dec-2017, last contact or death date. We estimated the potential gains in life expectancy from abridged life tables. We modelled the association between covariates and the cause-specific hazard for overdose mortality, accounting for mortality of other causes as a competing risk. RESULTS: Among the 10,362 PLWH, 3% experienced overdose mortality. The life expectancy at age 20 increased by 8.7 years from 2002-2007 to 2008-2013 compared to only 3.0 years from 2008-2013 to 2014-2017. The potential gain in life expectancy was 3.3 years at age 20 during the ongoing overdose epidemic (2014-2017). There were gender differences in life expectancies throughout the study period. People who have ever injected drugs, women and viral load monitoring non-compliance were key covariates associated with an increased hazard of overdose mortality. CONCLUSION: Survival gains among PLWH have been considerably reduced due to the ongoing overdose epidemic.

Association of radiomic features with epidermal growth factor receptor mutation status in non-small cell lung cancer and survival treated with tyrosine kinase inhibitors.

Since the discovery of the fact that tyrosine kinase inhibitors could improve progression-free survival for patients with advanced non-small cell lung cancer compared with traditional chemotherapy, it has been extremely important to identify epidermal growth factor receptor mutation status in treatment stratification. Although lack of sufficient biopsy samples limit the precise detection of epidermal growth factor receptor mutation status in clinical practice, and it is difficult to identify the sensitive patients who confer favorable response to tyrosine kinase inhibitors. An increasing number of scholars tried to deal with these problems using methods based on the non-invasive imaging including computed tomography and PET to find the association with epidermal growth factor receptor mutation status and survival treated with tyrosine kinase inhibitor in non-small cell lung cancer. Although the conclusions have not reached a consensus, quantitative and high-throughput radiomics have brought us a new direction and might successfully help identify patients undergoing tyrosine kinase inhibitors who could get significant benefits.

The impact of intratumoral metabolic heterogeneity on postoperative recurrence and survival in resectable esophageal squamous cell carcinoma.

OBJECTIVE: To evaluate the impact of intratumoral metabolic heterogeneity measured by 18F-FDG PET imaging on postoperative recurrence and survival for patients with esophageal squamous cell carcinoma (ESCC). RESULTS: AUC-CSH, metabolic tumor volume and pN-stage were significant prognostic factors for RFS. Additionally, tumor recurrence of the low AUC-CSH group (≤ 0.478) was 3 times higher than high group (P = 0.015). The median OS of patients with advanced AJCC stage or low AUC-CSH was also significantly shorter than that of patients with stage I & II or high AUC-CSH (P = 0.021, 0.009). Multivariate analysis identified the AUC-CSH to be the only significant risk factor for postoperative recurrence and overall survival in whole-group and stage III patients. MATERIALS AND METHODS: 116 ESCC patients who underwent staging 18F-FDG PET-CT scan and surgical resection were reviewed. The metabolic parameters were assessed as follows: maximum standardized uptake value (SUVmax), metabolic tumor volume, and the area under the curve of the cumulative SUV-volume histogram (AUC-CSH), which is known to reflect the intratumoral metabolic heterogeneity. Regression analyses were used to identify clinicopathological and imaging variables associated with relapse-free survival (RFS) and overall survival (OS). CONCLUSIONS: Intratumoral metabolic heterogeneity characterized by AUC-CSH can predict postoperative recurrence and survival in patients with resectable ESCC.

Dynamic CT imaging of volumetric changes in pulmonary nodules correlates with physical measurements of stiffness.

BACKGROUND AND PURPOSE: A major challenge in CT screening for lung cancer is limited specificity when distinguishing between malignant and non-malignant pulmonary nodules (PN). Malignant nodules have different mechanical properties and tissue characteristics ('stiffness') from non-malignant nodules. This study seeks to improve CT specificity by demonstrating in rats that measurements of volumetric ratios in PNs with varying composition can be determined by respiratory-gated dynamic CT imaging and that these ratios correlate with direct physical measurements of PN stiffness. METHODS AND MATERIALS: Respiratory-gated MicroCT images acquired at extreme tidal volumes of 9 rats with PNs from talc, matrigel and A549 human lung carcinoma were analyzed and their volumetric ratios (δ) derived. PN stiffness was determined by measuring the Young's modulus using atomic force microscopy (AFM) for each nodule excised immediately after MicroCT imaging. RESULTS: There was significant correlation (p=0.0002) between PN volumetric ratios determined by respiratory-gated CT imaging and the physical stiffness of the PNs determined from AFM measurements. CONCLUSION: We demonstrated proof of concept that PN volume changes measured non-invasively correlate with direct physical measurements of stiffness. These results may translate clinically into a means of improving the specificity of CT screening for lung cancer and/or improving individual prognostic assessments based on lung tumor stiffness.

Early Change in Metabolic Tumor Heterogeneity during Chemoradiotherapy and Its Prognostic Value for Patients with Locally Advanced Non-Small Cell Lung Cancer.

INTRODUCTION: To observe the early change of metabolic tumor heterogeneity during chemoradiotherapy and to determine its prognostic value for patients with locally advanced non-small cell lung cancer (NSCLC). METHODS: From January 2007 to March 2010, 58 patients with NSCLC were included who were received 18F-fluorodeoxyglucose (18F-FDG) PET/CT before and following 40 Gy radiotherapy with the concurrent cisplatin-based chemotherapy (CCRT). Primary tumor FDG uptake heterogeneity was determined using global and local scale textural features extracted from standardized uptake value (SUV) histogram analysis (coefficient of variation [COV], skewness, kurtosis, area under the curve of the cumulative SUV histogram [AUC-CSH]) and normalized gray-level co-occurrence matrix (contrast, dissimilarity, entropy, homogeneity). SUVmax and metabolic tumor volume (MTV) were also evaluated. Correlations were analyzed between parameters on baseline or during treatments with tumor response, progression-free survival (PFS), and overall survival (OS). RESULTS: Compared with non-responders, responders showed significantly greater pre-treatment COV, contrast and MTV (AUC = 0.781, 0.804, 0.686, respectively). Receiver-operating-characteristic curve analysis showed that early change of tumor textural analysis serves as a response predictor with higher sensitivity (73.2%~92.1%) and specificity (80.0%~83.6%) than baseline parameters. Change in AUC-CSH and dissimilarity during CCRT could also predict response with optimal cut-off values (33.0% and 28.7%, respectively). The patients with greater changes in contrast and AUC-CSH had significantly higher 5-year OS (P = 0.008, P = 0.034) and PFS (P = 0.007, P = 0.039). In multivariate analysis, only change in contrast was found as the independent prognostic factor of PFS (HR 0.476, P = 0.021) and OS (HR 0.519, P = 0.015). CONCLUSIONS: The metabolic tumor heterogeneity change during CCRT characterized by global and local scale textural features may be valuable for predicting treatment response and survival for patients with locally advanced NSCLC.

Robust Intratumor Partitioning to Identify High-Risk Subregions in Lung Cancer: A Pilot Study.

PURPOSE: To develop an intratumor partitioning framework for identifying high-risk subregions from (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) and computed tomography (CT) imaging and to test whether tumor burden associated with the high-risk subregions is prognostic of outcomes in lung cancer. METHODS AND MATERIALS: In this institutional review board-approved retrospective study, we analyzed the pretreatment FDG-PET and CT scans of 44 lung cancer patients treated with radiation therapy. A novel, intratumor partitioning method was developed, based on a 2-stage clustering process: first at the patient level, each tumor was over-segmented into many superpixels by k-means clustering of integrated PET and CT images; next, tumor subregions were identified by merging previously defined superpixels via population-level hierarchical clustering. The volume associated with each of the subregions was evaluated using Kaplan-Meier analysis regarding its prognostic capability in predicting overall survival (OS) and out-of-field progression (OFP). RESULTS: Three spatially distinct subregions were identified within each tumor that were highly robust to uncertainty in PET/CT co-registration. Among these, the volume of the most metabolically active and metabolically heterogeneous solid component of the tumor was predictive of OS and OFP on the entire cohort, with a concordance index or CI of 0.66-0.67. When restricting the analysis to patients with stage III disease (n=32), the same subregion achieved an even higher CI of 0.75 (hazard ratio 3.93, log-rank P=.002) for predicting OS, and a CI of 0.76 (hazard ratio 4.84, log-rank P=.002) for predicting OFP. In comparison, conventional imaging markers, including tumor volume, maximum standardized uptake value, and metabolic tumor volume using threshold of 50% standardized uptake value maximum, were not predictive of OS or OFP, with CI mostly below 0.60 (log-rank P>.05). CONCLUSION: We propose a robust intratumor partitioning method to identify clinically relevant, high-risk subregions in lung cancer. We envision that this approach will be applicable to identifying useful imaging biomarkers in many cancer types.

Intra-tumour 18F-FDG uptake heterogeneity decreases the reliability on target volume definition with positron emission tomography/computed tomography imaging.

INTRODUCTION: This study aims to explore whether the intra-tumour (18) F-fluorodeoxyglucose (FDG) uptake heterogeneity affects the reliability of target volume definition with FDG positron emission tomography/computed tomography (PET/CT) imaging for nonsmall cell lung cancer (NSCLC) and squamous cell oesophageal cancer (SCEC). METHODS: Patients with NSCLC (n = 50) or SCEC (n = 50) who received (18)F-FDG PET/CT scanning before treatments were included in this retrospective study. Intra-tumour FDG uptake heterogeneity was assessed by visual scoring, the coefficient of variation (COV) of the standardised uptake value (SUV) and the image texture feature (entropy). Tumour volumes (gross tumour volume (GTV)) were delineated on the CT images (GTV(CT)), the fused PET/CT images (GTV(PET-CT)) and the PET images, using a threshold at 40% SUV(max) (GTV(PET40%)) or the SUV cut-off value of 2.5 (GTV(PET2.5)). The correlation between the FDG uptake heterogeneity parameters and the differences in tumour volumes among GTV(CT), GTV(PET-CT), GTV(PET40%) and GTV(PET2.5) was analysed. RESULTS: For both NSCLC and SCEC, obvious correlations were found between uptake heterogeneity, SUV or tumour volumes. Three types of heterogeneity parameters were consistent and closely related to each other. Substantial differences between the four methods of GTV definition were found. The differences between the GTV correlated significantly with PET heterogeneity defined with the visual score, the COV or the textural feature-entropy for NSCLC and SCEC. CONCLUSIONS: In tumours with a high FDG uptake heterogeneity, a larger GTV delineation difference was found. Advance image segmentation algorithms dealing with tracer uptake heterogeneity should be incorporated into the treatment planning system.