Augmented expression of Ki-67 is correlated with clinicopathological characteristics and prognosis for lung cancer patients: an up-dated systematic review and meta-analysis with 108 studies and 14,732 patients

Ameliorating lung fibrosis and pulmonary function in diabetic mice: Therapeutic potential of mesenchymal stem cell

This study aimed to investigate the potential of mesenchymal stem cells (MSCs) in alleviating diabetic lung injury by decreasing inflammation, fibrosis and recovering tissue macrophage homeostasis. To induce pulmonary injuries in an in vivo murine model, we utilized a streptozotocin (STZ), and high-fat diet (HFD) induced diabetic C57 mouse model. Subsequently, human umbilical cord-derived MSCs (hUC-MSCs) were administered through the tail vein on a weekly basis for a duration of 4 weeks. In addition, in vitro experiments involved co-culturing of isolated primary abdominal macrophages from diabetic mice and high glucose-stimulated MLE-12 cells with hUC-MSCs. The objective was to evaluate if hUC-MSCs co-culturing could effectively mitigate cell inflammation and fibrosis. Following hUC-MSCs injection, diabetic mice displayed enhanced pulmonary functional parameters, reduced pulmonary fibrosis, and diminished inflammation. Notably, the dynamic equilibrium of lung macrophages shifted from the M1 phenotype to the M2 phenotype, accompanied by a notable reduction in various indicators associated with inflammation and fibrosis. Results from cell co-culturing experiments further supported this trend, demonstrating a reduction in inflammatory and fibrotic indicators. In conclusion, our findings suggest that hUC-MSCs treatment holds promise in mitigating diabetic pulmonary injury by significantly reducing inflammation, fibrosis and maintain tissue macrophage homeostasis within the lungs. This study sheds light on the therapeutic potential of hUC-MSCs in managing diabetic complications affecting the pulmonary system.

Prognostic heterogeneity of Ki67 in non-small cell lung cancer: A comprehensive reappraisal on immunohistochemistry and transcriptional data

In the present study, the debatable prognostic value of Ki67 in patients with non-small cell lung cancer (NSCLC) was attributed to the heterogeneity between lung adenocarcinoma (LUAD) and lung squamous carcinoma (LUSC). Based on meta-analyses of 29 studies, a retrospective immunohistochemical cohort of 1479 patients from our center, eight transcriptional datasets and a single-cell datasets with 40 patients, we found that high Ki67 expression suggests a poor outcome in LUAD, but conversely, low Ki67 expression indicates worse prognosis in LUSC. Furthermore, low proliferation in LUSC is associated with higher metastatic capacity, which is related to the stronger epithelial-mesenchymal transition potential, immunosuppressive microenvironment and angiogenesis. Finally, nomogram model incorporating clinical risk factors and Ki67 expression outperformed the basic clinical model for the accurate prognostic prediction of LUSC. With the largest prognostic assessment of Ki67 from protein to mRNA level, our study highlights that Ki67 also has an important prognostic value in NSCLC, but separate evaluation of LUAD and LUSC is necessary to provide more valuable information for clinical decision-making in NSCLC.

Implementing circulating tumor DNA as a prognostic biomarker in resectable non-small cell lung cancer

Systemic treatment of resectable non-small cell lung cancer (NSCLC) is evolving with emerging neoadjuvant, perioperative, and adjuvant immunotherapy approaches. Circulating tumor DNA (ctDNA) detection at clinical diagnosis, during neoadjuvant therapy, or after resection may discern high-risk patients who might benefit from therapy escalation or switch. This Review summarizes translational implications of data supporting ctDNA-based risk determination in NSCLC and outstanding questions regarding ctDNA validity/utility as a prognostic biomarker. We discuss emerging ctDNA capabilities to refine clinical tumor-node-metastasis (TNM) staging in lung adenocarcinoma, ctDNA dynamics during neoadjuvant therapy for identifying patients deriving suboptimal benefit, and postoperative molecular residual disease (MRD) detection to escalate systemic therapy. Considering differential relapse characteristics in landmark MRD-negative/MRD-positive patients, we propose how ctDNA might integrate with pathological response data for optimal postoperative risk stratification.

Nomogram for the preoperative prediction of Ki-67 expression and prognosis in stage IA lung adenocarcinoma based on clinical and multi-slice spiral computed tomography features

OBJECTIVE

This study developed and validated a nomogram utilizing clinical and multi-slice spiral computed tomography (MSCT) features for the preoperative prediction of Ki-67 expression in stage IA lung adenocarcinoma. Additionally, we assessed the predictive accuracy of Ki-67 expression levels, as determined by our model, in estimating the prognosis of stage IA lung adenocarcinoma.

MATERIALS AND METHODS

We retrospectively analyzed data from 395 patients with pathologically confirmed stage IA lung adenocarcinoma. A total of 322 patients were divided into training and internal validation groups at a 6:4 ratio, whereas the remaining 73 patients composed the external validation group. According to the pathological results, the patients were classified into high and low Ki-67 labeling index (LI) groups. Clinical and CT features were subjected to statistical analysis. The training group was used to construct a predictive model through logistic regression and to formulate a nomogram. The nomogram's predictive ability and goodness-of-fit were assessed. Internal and external validations were performed, and clinical utility was evaluated. Finally, the recurrence-free survival (RFS) rates were compared.

RESULTS

In the training group, sex, age, tumor density type, tumor-lung interface, lobulation, spiculation, pleural indentation, and maximum nodule diameter differed significantly between patients with high and low Ki-67 LI. Multivariate logistic regression analysis revealed that sex, tumor density, and maximum nodule diameter were significantly associated with high Ki-67 expression in stage IA lung adenocarcinoma. The calibration curves closely resembled the standard curves, indicating the excellent discrimination and accuracy of the model. Decision curve analysis revealed favorable clinical utility. Patients with a nomogram-predicted high Ki-67 LI exhibited worse RFS.

CONCLUSION

The nomogram utilizing clinical and CT features for the preoperative prediction of Ki-67 expression in stage IA lung adenocarcinoma demonstrated excellent performance, clinical utility, and prognostic significance, suggesting that this nomogram is a noninvasive personalized approach for the preoperative prediction of Ki-67 expression.

The Prognostic Importance of Ki-67 in Gastrointestinal Carcinomas: A Meta-analysis and Multi-omics Approach

PURPOSE

This study aimed to determine if Ki-67, a commonly used marker to measure tumor proliferation, is a reliable prognostic factor in various types of gastrointestinal (GI) cancers based on current high-quality multivariable evidence.

METHODS

A comprehensive search was conducted in PubMed, Embase, Scopus, and ISI Web of Science databases to investigate the association between Ki-67 positivity and overall survival (OS) and disease/recurrence-free survival (DFS/RFS) in GI cancers. Heterogeneity was assessed using Chi-square-based Q and I2 analyses and publication bias using funnel plots and Egger's analysis. In addition, Ki-67 levels in different GI cancers were examined by different platforms. The prognostic capability of Ki-67, gene ontology (GO), and pathway enrichment analysis were obtained from GEPIA2 and STRING.

RESULTS

Totally, 61 studies, involving 13,034 patients, were deemed eligible for our evaluation. The combined hazard ratios (HRs) demonstrated the prediction ability of overexpressed Ki-67 for a worse OS (HR: 1.67, P < 0.001; HR: 1.37, P = 0.021) and DFS/RFS (HR: 2.06, P < 0.001) in hepatocellular and pancreatic malignancies, respectively, as confirmed by multi-omics databases. However, similar correlation was not found in esophageal, gastric, and colorectal cancers. Furthermore, most of the associations were identified to be robust based on different subcategories and publication bias assessment. Finally, enriched Ki-67-related genes were found to be involved in various important signaling pathways, such as cell cycle, P53 signaling network, and DNA damage responses.

CONCLUSION

This study supports that Ki-67 can serve as an independent prognostic biomarker for pancreatic and hepatocellular malignancies in clinical settings.

Factors correlating the expression of PD-L1

OBJECTIVE

PD-L1 was an important biomarker in lung adenocarcinoma. The study was to confirm the most important factor affecting the expression of PD-L1 remains undetermined.

METHODS

The clinical records of 1045 lung adenocarcinoma patients were retrospectively reviewed. The High-Resolution Computed Tomography (HRCT) scanning images of all the participants were analyzed, and based on the CT characteristics, the adenocarcinomas were categorized according to CT textures. Furthermore, PD-L1 expression and Ki67 index were detected by immunohistochemistry. All patients underwent EGFR mutation detection.

RESULTS

Multivariate logistic regression analysis revealed that smoking (OR: 1.73, 95% CI: 1.04-2.89, p = 0.004), EGFR wild (OR: 1.52, 95% CI: 1.11-2.07, p = 0.009), micropapillary subtypes (OR: 2.05, 95% CI: 1.46-2.89, p < 0.0001), and high expression of Ki67 (OR: 2.02, 95% CI: 1.44-2.82, p < 0.0001) were independent factors which influence PD-L1 expression. In univariate analysis, tumor size > 3 cm and CT textures of pSD showed a correlation with high expression of PD-L1. Further analysis revealed that smoking, micropapillary subtype, and EGFR wild type were also associated with high Ki67 expression. Moreover, high Ki67 expression was observed more frequently in tumors of size > 3 cm than in tumors with ≤ 3 cm size as well as in CT texture of pSD than lesions with GGO components. In addition, multivariate logistic regression analysis revealed that only lesions with micropapillary components correlated with pSD (OR: 3.96, 95% CI: 2.52-5.37, p < 0.0001).

CONCLUSION

This study revealed that in lung adenocarcinoma high Ki67 expression significantly influenced PD-L1 expression, an important biomarker for immune checkpoint treatment.

The quality and clinical translation of radiomics studies based on MRI for predicting Ki-67 levels in patients with breast cancer

OBJECTIVE

To evaluate the methodological quality of radiomics literature predicting Ki-67 levels based on MRI in patients with breast cancer (BC) and to propose suggestions for clinical translation.

METHODS

In this review, we searched PubMed, Embase, and Web of Science for studies published on radiomics in patients with BC. We evaluated the methodological quality of the studies using the Radiomics Quality Score (RQS). The Cochrane Collaboration's software (RevMan 5.4), Meta-DiSc (v. 1.4) and IBM SPSS (v. 26.0) were used for all statistical analyses.

RESULTS

Eighteen studies met our inclusion criteria, and the average RQS was 10.17 (standard deviation [SD]: 3.54). None of these studies incorporated any of the following items: a phantom study on all scanners, cut-off analyses, prospective study, cost-effectiveness analysis, or open science and data. In the meta-analysis, it showed apparent diffusion coefficient (ADC) played a better role to predict Ki-67 level than dynamic contrast-enhanced (DCE) MRI in the radiomics, with the pooled area under the curve (AUC) of 0.969.

CONCLUSION

Ki-67 index is a common tumor biomarker with high clinical value. Radiomics is an ever-growing quantitative data-mining method helping predict tumor biomarkers from medical images. However, the quality of the reviewed studies evaluated by the RQS was not so satisfactory and there are ample opportunities for improvement. Open science and data, external validation, phantom study, publicly open radiomics database and standardization in the radiomics practice are what researchers should pay more attention to in the future.

ADVANCES IN KNOWLEDGE

The RQS tool considered the radiomics used to predict the Ki-67 level was of poor quality. ADC performed better than DCE in radiomic prediction. We propose some measures to facilitate the clinical translation of radiomics.

Quantitative parameters of static imaging and fast kinetics imaging in 18F-FDG total-body PET/CT for the assessment of histological feature of pulmonary lesions

Background

To investigate the value of quantitative parameters related to static imaging and fast kinetics imaging of total-body (TB) 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in differentiating benign from malignant pulmonary lesions and squamous cell carcinoma (SCC) from adenocarcinoma (AC) and to analyze the correlation of each parameter with the Ki-67 index.

Methods

A total of 108 patients with pulmonary lesions from July 2021 to May 2022 in the Henan Provincial People's Hospital, China, were consecutively recruited for TB 18F-FDG PET/CT in this prospective study. Static imaging parameters maximum standardized uptake value (SUVmax) and fast kinetics imaging parameters transport constant (K1), rate constants (k2), time delay (td), and fractional blood volume (vb) were calculated and compared. The area under the receiver operating characteristic (ROC) curve (AUC), Delong test, Logistic regression analyses, and Pearson correlation were used to assess diagnostic efficacy, find independent predictors and analyse correlations respectively.

Results

Malignant lesions had higher SUVmax and K1 and lower vb than benign lesions, and SCC had higher SUVmax and K1 and lower td and vb than AC (all P<0.05). For the differentiation of benign and malignant lesions, SUVmax, K1, and vb were independent predictors, and AUC (SUVmax + K1+ vb) =0.909 (95% CI: 0.839-0.956), AUC (SUVmax) =0.883 (95% CI: 0.807-0.937), AUC (K1) =0.810 (95% CI: 0.723-0.879), and AUC (vb) =0.746 (95% CI: 0.653-0.825), where AUC (SUVmax + K1+ vb) was significantly different from AUC (K1), AUC (vb) (Z=3.006, 3.965, all P<0.05). For the differentiation of SCC and AC, SUVmax, K1, td, and vb were independent predictors, and AUC (SUVmax + K1+ td + vb) =0.946 (95% CI: 0.840-0.991), AUC (SUVmax) =0.818 (95% CI: 0.680-0.914), AUC (K1) =0.770 (95% CI: 0.626-0.879), AUC (vb) =0.737 (95% CI: 0.590-0.853), and AUC (td) =0.669 (95% CI: 0.510-0.791), where AUC (SUVmax + K1+ td + vb) was significantly different from AUC (SUVmax), AUC (K1), AUC (vb), and AUC (td) (Z=2.269, 2.821, 2.848, and 3.276, all P<0.05). SUVmax and K1 were moderately and mildly positively correlated with the Ki-67 index (r=0.541, 0.452, all P<0.05), respectively.

Conclusions

Quantitative parameters of static imaging and fast kinetics imaging in 18F-FDG total-body PET/CT can be used to differentiate benign from malignant pulmonary lesions and SCC from AC and to assess Ki-67 expression.

CT radiomics model for predicting the Ki-67 proliferation index of pure-solid non-small cell lung cancer: a multicenter study

Purpose

This study aimed to explore the efficacy of the computed tomography (CT) radiomics model for predicting the Ki-67 proliferation index (PI) of pure-solid non-small cell lung cancer (NSCLC).

Materials and methods

This retrospective study included pure-solid NSCLC patients from five centers. The radiomics features were extracted from thin-slice, non-enhanced CT images of the chest. The minimum redundancy maximum relevance (mRMR) and least absolute shrinkage and selection operator (LASSO) were used to reduce and select radiomics features. Logistic regression analysis was employed to build predictive models to determine Ki-67-high and Ki-67-low expression levels. Three prediction models were established: the clinical model, the radiomics model, and the nomogram model combining the radiomics signature and clinical features. The prediction efficiency of different models was evaluated using the area under the curve (AUC).

Results

A total of 211 NSCLC patients with pure-solid nodules or masses were included in the study (N=117 for the training cohort, N=49 for the internal validation cohort, and N=45 for the external validation cohort). The AUC values for the clinical models in the training, internal validation, and external validation cohorts were 0.73 (95% CI: 0.64-0.82), 0.75 (95% CI:0.62-0.89), and 0.72 (95% CI: 0.57-0.86), respectively. The radiomics models showed good predictive ability in diagnosing Ki-67 expression levels in the training cohort (AUC, 0.81 [95% CI: 0.73-0.89]), internal validation cohort (AUC, 0.81 [95% CI: 0.69-0.93]) and external validation cohort (AUC, 0.78 [95% CI: 0.64-0.91]). Compared to the clinical and radiomics models, the nomogram combining both radiomics signatures and clinical features had relatively better diagnostic performance in all three cohorts, with the AUC of 0.83 (95% CI: 0.76-0.90), 0.83 (95% CI: 0.71-0.94), and 0.81 (95% CI: 0.68-0.93), respectively.

Conclusion

The nomogram combining the radiomics signature and clinical features may be a potential non-invasive method for predicting Ki-67 expression levels in patients with pure-solid NSCLC.

Radiomics nomogram for the prediction of Ki-67 index in advanced non-small cell lung cancer based on dual-phase enhanced computed tomography

PURPOSE

To develop a radiomics nomogram based on dual-phase enhanced computed tomography (CT) for predicting the Ki-67 index status in patients with advanced non-small cell lung cancer (NSCLC).

METHODS

137 patients with NSCLC who had undergone dual-phase enhanced CT scans and Ki-67 examination within 2 weeks were retrospectively enrolled between January 2020 and December 2022. Clinical and laboratory data were collected, and the patients were categorized based on low or high expression of Ki-67 index, with a cut-off value of 40%. The cohort was randomly divided into a training group (n = 95) and a testing group (n = 42) at a ratio of 7:3. The least absolute shrinkage and selection operator (LASSO) algorithm was employed to select the most valuable radiomics features from the dual-phase enhanced CT images. Subsequently, a nomogram that incorporated the radiomics score and clinical factors associated with Ki-67 index status was established through univariate and multivariate logistic regression analyses. The predictive performance of the nomogram was evaluated using the area under the curve (AUC).

RESULTS

The AUC values of the radiomics features of artery phase and vein phase CT in the testing group were 0.748 and 0.758, respectively. The AUC of the dual-phase enhanced CT was 0.785, and the AUC of the developed nomogram was 0.859, which was higher than those of the radiomics (AUC, 0.785) and clinical models (AUC, 0.736).

CONCLUSIONS

The radiomics nomogram based on dual-phase enhanced CT images provides a promising method for predicting the Ki-67 index status in patients with advanced NSCLC.

Prognostic value of proliferation, PD-L1 and nuclear size in patients with superior sulcus tumours treated with chemoradiotherapy and surgery

AIMS

The aim of this study was to determine the relationship between proliferative activity, PD-L1 status and nuclear size changes after preoperative chemoradiotherapy (CRT) and the clinical outcome in patients with superior sulcus tumours.

METHODS

Proliferative activity (MIB-1) and PD-L1 status were estimated by immunohistochemistry in the tumour cells of resection specimen in a series of 33 patients with residual tumour after trimodality therapy for a sulcus superior tumour between 2005 and 2014. A morphometric analysis of both pretreatment and post-treatment tumour materials was also performed. Results were related to disease-free survival and overall survival.

RESULTS

Low proliferative activity (<20% MIB-1) was associated with better overall survival: 2-year overall survival of 73% compared with 43% and 25%, respectively, for moderate (MIB-1 20%-50%) and high (MIB-1 >50%) proliferative activity (p=0.016). A negative PD-L1 status (<1% positive tumour cells) was also associated with better overall survival (p=0.021). The mean nuclear size of normal lung tissue pneumocytes was significantly smaller compared with the mean nuclear size of tumour cells of the resection specimens (median difference -38.1; range -115.2 to 16.0; p<0.001). The mean nuclear size of tumour cells did not differ between pretreatment biopsies and resection specimens (median difference -4.6; range -75.2 to 86.7; p=0.14). Nuclear size was not associated with survival (p=0.82).

CONCLUSIONS

Low proliferative activity determined by MIB-1 as well as a negative PD-L1 expression are significantly associated with better overall survival in patients with residual tumour after CRT for superior sulcus tumour.

[Correlation Analysis of Ki67 Expression and EGFR Mutation on the Risk of Recurrence and Metastasis in Postoperative Patients with Stage I Lung Adenocarcinoma]

BACKGROUND

The prognosis of stage I non-small cell lung cancer (NSCLC) is generally good. However, some of the stage I NSCLC patients still may have early recurrence and metastasis, and there is no standard method to screen this part of the population. The aim of this study is to investigate the relationship between Ki67 expression as well as epidermal growth factor receptor (EGFR) mutation and the risk of recurrence in postoperative patients with stage I lung adenocarcinoma.

METHODS

We retrospectively enrolled 118 postoperative patients with stage I lung adenocarcinoma. EGFR mutation was tested using amplification refractory mutation system polymerase chain reaction (ARMS-PCR) , and Ki67 level was detected by immunohistochemistry (IHC), followed by the collection of the patients' clinical characteristics. Kaplan-Meier method, Log-rank test, and Cox proportional hazards regression model were used for the prognostic statistical analysis.

RESULTS

Among the 118 patients, the rate of high Ki67 expression was 43.22% (51/118), which is related to gender, smoking status, surgical method, differentiation degree, and postoperative stage (P<0.05). Meanwhile, EGFR mutation rate was 61.02% (72/118), of which EGFR exon 19 deletion mutation rate was 19.49% (23/118), and the EGFR exon 21 L858R mutation rate was 41.53% (49/118). However, Ki67 expression was not associated with EGFR mutation status (χ2=1.412, P=0.235). Survival analysis showed that high Ki67 expression was inversely associated with disease-free survival (DFS) and overall survival (OS) in stage I lung adenocarcinoma (P<0.05), but EGFR mutation status was not significantly associated with DFS and OS (P>0.05). In the subgroup analysis, the DFS of the EGFR exon 19 deletion group was significantly decreased compared with the EGFR exon 21 L858R mutation group (P=0.031), but there was no significant difference in OS (P=0.308). Multivariate analysis showed that there was statistical significance between Ki67 expression (P=0.001) and DFS in stage I lung adenocarcinoma; Ki67 expression (P=0.03) and gender (P=0.015) were associated with OS in stage I lung adenocarcinoma.

CONCLUSIONS

Ki67 expression is an independent influencing factor for postoperative recurrence and OS of stage I lung adenocarcinoma and it is not significantly associated with EGFR mutation. There is no significant difference between EGFR mutation status and the prognostis of stage I lung adenocarcinoma. However, the prognosis differed in EGFR mutation types; the patients with EGFR exon 19 deletion are at higher risk of recurrence than EGFR exon 21 L858R mutation.

High tumor burden in non-small-cell lung cancer: A review of the literature

BACKGROUND AND AIM

Lung cancer is the leading cause of cancer death worldwide and the majority of the patients have advanced/metastatic disease on presentation. In clinical practice, several biomarkers and clinical factors are taken into account when choosing the best treatment option in advanced non-small-cell lung cancer (NSCLC). One potential marker may be tumor burden (TB). However, this concept is not specifically defined in NSCLC, and usually, it is used as a synonymous for aggressive disease.

METHODS

A non-systematic literature review was conducted. We searched for eligible randomized controlled trials from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials with a cutoff at February 2021. The keywords included non-small-cell lung cancer, tumor burden, aggressive disease, prognosis biomarker, predictive biomarker, and immunotherapy.

RESULTS AND CONCLUSIONS

This review addresses the definition of TB in advanced NSCLC, the pathophysiology of high TB lesions, and the role of TB as a prognosis biomarker.

RELEVANCE FOR PATIENTS

The concept of aggressive disease, as high tumor burden definition, remains poorly defined and rarely considered in clinical research or clinical practice in oncology. The identification of this subgroup of patients could be interesting for defining and optimizing a more aggressive treatment strategy.

Extracellular Vesicles Derived from Lung Cancer Cells Induce Transformation of Normal Fibroblasts into Lung Cancer-Associated Fibroblasts and Promote Metastasis of Lung Cancer by Delivering lncRNA HOTAIR

Human lung cancer (LC) cells A549/H358, normal lung epithelial cells BEAS-2B, and lung normal fibroblasts (NFs) were cultured, followed by transfection of H358 cells with HOTAIR shRNA. Extracellular vesicles (EVs) extracted from H358 cells were identified. The internalization of Dil-labeled-EVs by NFs was tested, and protein levels of cancer-associated fibroblast (CAF) surface markers, inflammatory cytokines, cell proliferation, invasion, and migration, and lncRNA HOTAIR levels were determined. A549 cells were cultured in an H358-EVs-treated conditioned medium of NFs (NFCM), followed by intravenous injection of A549 cells into nude mice. The lesions and Ki-67-positive cells in lung tissues were measured. The results showed that tumor cell-derived EVs (T-EVs) motivated the transformation of NFs into CAFs. Specifically, EVs can be internalized by NFs, and the protein levels of CAF surface markers and inflammation levels were elevated in H358-EVs-treated NFs. The proliferation, invasion, and migration of A549 cells cultured in T-EVs-treated NFCM were increased. H358-EVs carried HOTAIR into NFs and promoted the transformation of NFs into CAFs. Inhibition of HOTAIR partially reversed the promoting effect of H358-EVs on the transformation of NFs into CAFs and invasion and migration of LC cells. T-EVs promoted metastasis of LC in vivo by transforming NFs into CAFs.

State of the Art: Lung Cancer Staging Using Updated Imaging Modalities

Lung cancer is among the most common mortality causes worldwide. This scientific article is a comprehensive review of current knowledge regarding screening, subtyping, imaging, staging, and management of treatment response for lung cancer. The traditional imaging modality for screening and initial lung cancer diagnosis is computed tomography (CT). Recently, a dual-energy CT was proven to enhance the categorization of variable pulmonary lesions. The National Comprehensive Cancer Network (NCCN) recommends usage of fluorodeoxyglucose positron emission tomography (FDG PET) in concert with CT to properly stage lung cancer and to prevent fruitless thoracotomies. Diffusion MR is an alternative to FDG PET/CT that is radiation-free and has a comparable diagnostic performance. For response evaluation after treatment, FDG PET/CT is a potent modality which predicts survival better than CT. Updated knowledge of lung cancer genomic abnormalities and treatment regimens helps to improve the radiologists’ skills. Incorporating the radiologic experience is crucial for precise diagnosis, therapy planning, and surveillance of lung cancer.

Rapid intraoperative Ki-67 immunohistochemistry for lung cancer using non-contact alternating current electric field mixing

OBJECTIVES

Locoregional recurrence of non-small cell lung cancer (NSCLC) occurs even among patients with stage I disease, as a result of tumor proliferative activity. The aim of this study was to evaluate the clinical reliability of a new rapid immunohistochemistry (IHC) technique for assessing malignant potential through detection of tumoral Ki-67 expression.

MATERIALS AND METHODS

The rapid IHC method uses non-contact alternating current (AC) mixing to achieve more rapid/stable staining within 20 min during surgery. First, to investigate the association between clinical outcomes and tumoral Ki-67 labeling with rapid IHC, 21 pairs of surgical patients treated between 2012 and 2020 for pStage IA1-3 NSCLC with/without recurrence were retrospectively reviewed. Second, 40 frozen section (FS) samples in patients with NSCLC for whom radical surgery was planned between April 2021 and February 2022 were deemed eligible for comparison of the clinical performance of conventional IHC and intraoperative rapid Ki-67 IHC with FS.

RESULTS

Detection of tumoral Ki-67 expression using rapid IHC with formalin-fixed, paraffin-embedded (FFPE) blocks was significantly associated with clinical outcomes in R0 pStage IA NSCLC surgical patients, including overall and recurrence-free survival (P = 0.0043 and P < 0.0001, respectively). Levels of Ki-67 expression among resectable NSCLC patients detected using rapid IHC with FS significantly correlated with those detected using conventional FFPE-IHC (p < 0.001). An intraoperative cut-off of > 7.5 % tumor cell Ki-67 positivity accurately predicted pathological stage more advanced than IA3 [P = 0.0185, Odds ratio = 20.477, 95 % confidence interval (CI): 1.660-252.55].

CONCLUSION

Rapid Ki-67 IHC with AC mixing could potentially serve as a clinical tool for intraoperative determination of tumor malignancy status. The present study suggests that segmentectomy for early small NSCLCs is oncologically safe and a reasonable alternative to lobectomy, but only when there is adequate intraoperative selection for primary tumors with low-grade malignancy, which could be verified using intraoperative rapid Ki-67 IHC with FS.

A comparison study of monoexponential and fractional order calculus diffusion models and 18F-FDG PET in differentiating benign and malignant solitary pulmonary lesions and their pathological types

Objective

To evaluate the application value of monoexponential, fractional order calculus (FROC) diffusion models and PET imaging to distinguish between benign and malignant solitary pulmonary lesions (SPLs) and malignant SPLs with different pathological types and explore the correlation between each parameter and Ki67 expression.

Methods

A total of 112 patients were enrolled in this study. Prior to treatment, all patients underwent a dedicated thoracic ¹⁸F-FDG PET/MR examination. Five parameters [including apparent diffusion coefficient (ADC) derived from the monoexponential model; diffusion coefficient (D), a microstructural quantity (μ), and fractional order parameter (β) derived from the FROC model and maximum standardized uptake value (SUVmax) derived from PET] were compared between benign and malignant SPLs and different pathological types of malignant SPLs. Independent sample t test, Mann-Whitney U test, DeLong test and receiver operating characteristic (ROC) curve analysis were used for statistical evaluation. Pearson correlation analysis was used to calculate the correlations between Ki-67 and ADC, D, μ, β, and SUVmax.

Results

The ADC and D values were significantly higher and the μ and SUVmax values were significantly lower in the benign group [1.57 (1.37, 2.05) μm²/ms, 1.59 (1.52, 1.72) μm²/ms, 5.06 (3.76, 5.66) μm, 5.15 ± 2.60] than in the malignant group [1.32 (1.03, 1.51) μm²/ms, 1.43 (1.29, 1.52) μm²/ms, 7.06 (5.87, 9.45) μm, 9.85 ± 4.95]. The ADC, D and β values were significantly lower and the μ and SUVmax values were significantly higher in the squamous cell carcinoma (SCC) group [1.29 (0.66, 1.42) μm²/ms, 1.32 (1.02, 1.42) μm²/ms, 0.63 ± 0.10, 9.40 (7.76, 15.38) μm, 11.70 ± 5.98] than in the adenocarcinoma (AC) group [1.40 (1.28, 1.67) μm²/ms, 1.52 (1.44, 1.64) μm²/ms, 0.70 ± 0.10, 5.99 (4.54, 6.87) μm, 8.76 ± 4.18]. ROC curve analysis showed that for a single parameter, μ exhibited the best AUC value in discriminating between benign and malignant SPLs groups and AC and SCC groups (AUC = 0.824 and 0.911, respectively). Importantly, the combination of monoexponential, FROC models and PET imaging can further improve diagnostic performance (AUC = 0.872 and 0.922, respectively). The Pearson correlation analysis showed that Ki67 was positively correlated with μ value and negatively correlated with ADC and D values (r = 0.402, -0.346, -0.450, respectively).

Conclusion

The parameters D and μ derived from the FROC model were superior to ADC and SUVmax in distinguishing benign from malignant SPLs and adenocarcinoma from squamous cell carcinoma, in addition, the combination of multiple parameters can further improve diagnostic performance. The non-Gaussian FROC diffusion model is expected to become a noninvasive quantitative imaging technique for identifying SPLs.

Correlation of computed tomography quantitative parameters with tumor invasion and Ki-67 expression in early lung adenocarcinoma

The purpose of the study is to investigate the correlation of computed tomography (CT) quantitative parameters with tumor invasion and Ki-67 expression in early lung adenocarcinoma.The study involved 141 lesions in 141 patients with early lung adenocarcinoma. According to the degree of tumor invasion, the lesions were assigned into (adenocarcinoma in situ + minimally invasive adenocarcinoma) group and invasive adenocarcinoma (IAC) group. Artificial intelligence-assisted diagnostic software was used to automatically outline the lesions and extract corresponding quantitative parameters on CT images. Statistical analysis was performed to explore the correlation of these parameters with tumor invasion and Ki-67 expression.The results of logistic regression analysis showed that the short diameter of the lesion and the average CT value were independent predictors of IAC. Receiver operating characteristic curve analysis identified the average CT value as an independent predictor of IAC with the best performance, with the area under the receiver operating characteristic curve of 0.893 (P < .001), and the threshold of -450 HU. Besides, the predicted probability of logistic regression analysis model was detected to have the area under the curve of 0.931 (P < .001). The results of Spearman correlation analysis showed that the expression level of Ki-67 had the highest correlation with the average CT value of the lesion (r = 0.403, P < .001).The short diameter of the lesion and the average CT value are independent predictors of IAC, and the average CT value is significantly positively correlated with the expression of tumor Ki-67.

Expression of Wnt signaling agonists and antagonists in periodontitis and healthy subjects, before and after non-surgical periodontal treatment: A systematic review

Periodontitis is a preventable and treatable multifactorial chronic inflammatory disease that can lead to irreversible periodontal destruction and tooth loss. Wnt signaling and its regulators play an important role in periodontal inflammation, destruction, regeneration, and reconstruction. This systematic review aimed at investigating the involvement of Wnt signaling agonists and antagonists in periodontitis and healthy subjects, before and after periodontal treatment. Electronic searches were carried out using MEDLINE/PubMed, EMBASE, and Cochrane Library databases in addition to hand searches. Studies having different designs assessing the levels of Wnt signaling antagonist and agonist levels in gingival crevicular fluid, serum, and tissue in patients diagnosed with periodontitis or gingivitis, compared with healthy individuals were included. In addition, studies compared these levels in periodontitis patients before and after non-surgical periodontal therapy were also eligible. Sixteen studies met the eligibility criteria. Sclerostin (SOST) has been mainly investigated in the literature (8 publications). Sclerostin (5 studies), Wnt-5a (2 studies), secreted frizzled-related protein 1 (SFRP1) (3 studies), and β-catenin (3 studies) show increased levels in periodontitis compared with periodontal health. Strong correlations between marker levels and periodontal clinical parameters were identified for SOST (5 studies), SFRP1 (2 studies), and β-catenin (2 studies). SOST (3 studies) and SFRP1 (1 study) levels significantly decrease following non-surgical periodontal treatment. The present systematic review demonstrated an association between Wnt signaling agonist and antagonist levels and periodontitis. Wnt agonists and antagonists may serve as valuable diagnostic and prognostic markers for periodontitis onset and progression. Further case-control and longitudinal studies should be conducted for different Wnt signaling agonists and antagonists.

Development and validation of novel radiomics-based nomograms for the prediction of EGFR mutations and Ki-67 proliferation index in non-small cell lung cancer

BACKGROUND

We developed and validated novel radiomics-based nomograms to identify epidermal growth factor receptor (EGFR) mutations and the Ki-67 proliferation index of non-small cell lung cancer.

METHODS

We enrolled 132 patients with histologically verified non-small cell lung cancer from four hospital institutions who underwent computed tomography (CT) scans. EGFR mutations and the Ki-67 proliferation index were measured from tumor tissues. A total of 1,287 radiomic features were extracted, and a three-stage feature selection method was implemented to acquire the most valuable radiomic features. Finally, the radiomic scores and nomograms of the two tasks were established and tested. Receiver operating characteristic curves, calibration curves, and decision curves were used to evaluate their prediction performance and clinical utility.

RESULTS

In task [1], smoking status and histological type were significantly associated with EGFR mutations. After feature selection, 10 features were used to establish radiomic score, which showed good performance [area under the curve (AUC) =0.800] in the validation cohort. The radiomic nomogram had an AUC of 0.798 (95% CI: 0.664 to 0.931) with a C-index of 0.798 in the validation cohort. In task [2], gender, smoking status, histological type, and stage showed a significant correlation with Ki-67 proliferation index expression. A total of 28 features were selected to develop a radiomic score, with an AUC of 0.820 in the validation cohort. The final nomogram showed an AUC of 0.828 (95% CI: 0.703 to 0.953) with a C-index of 0.828 in the validation cohort.

CONCLUSIONS

EGFR mutations and Ki-67 proliferation index in non-small cell lung cancer can be predicted efficiently by the novel radiomic scores and nomograms.

CEA-Ki-67- Pathologic Subtype: An Adjunct Factor for Refining Prognosis in Stage I Pulmonary Adenocarcinoma

Objectives

The prognosis for stage I pulmonary adenocarcinoma is generally good. However, some patients with stage I pulmonary adenocarcinoma have an unexpectedly poor outcome. This warrants consideration of adjunct markers. In this study, we analyze carcinoembryonic antigen, Ki-67, and a pathologic subtype in combination for prognostic evaluation of stage I pulmonary adenocarcinoma. These factors were selected for study as they have been shown to be individually associated with prognosis in many studies.

Methods

A total of 650 patients with stage I pulmonary adenocarcinoma were investigated retrospectively. Each patient was re-staged using standard TNM criteria. Carcinoembryonic antigen (CEA) values were obtained from preoperative blood samples, and Ki-67 was evaluated with tumor tissue immunohistochemistry. Patient clinicopathologic characteristics, survival status, and date of death were obtained from medical records and telephone follow-up.

Results

CEA > 4.4 ng/ml, Ki-67 > 13%, and a solid-micropapillary tumor growth pattern were each independent adverse prognostic markers for 5-year disease specific survival in stage I pulmonary adenocarcinoma. However, in combination, these 3 factors yielded a prognostic value (designated “CEA-Ki-67-pathologic subtype” value). Stage I pulmonary adenocarcinoma of low-risk CEA-Ki-67-pathologic subtype (CKP) value show biologic behavior similar to TNM stage IA1 tumors, while stage I tumors of high-risk CKP value are similar in prognosis to TNM stage II.

Conclusion

The CKP value may be used as an adjunct to the TNM classification, which may yield a more accurately defined prognosis for cases of stage I pulmonary adenocarcinoma. CKP value may identify patients at higher risk who may benefit from adjuvant chemotherapy. Conversely, lower risk CKP values may support avoidance of chemotherapy.

Predicting Ki-67 labeling index level in early-stage lung adenocarcinomas manifesting as ground-glass opacity nodules using intra-nodular and peri-nodular radiomic features

Objectives

To explore the diagnostic value of radiomics in differentiating between lung adenocarcinomas appearing as ground‐glass opacity nodules (GGO) with high‐ and low Ki‐67 expression levels.

Materials and Methods

From January 2018 to January 2021, patients with pulmonary GGO who received lung resection were evaluated for potential enrollment. The included GGOs were then randomly divided into a training cohort and a validation cohort with a ratio of 7:3. Logistic regression (LR), decision tree (DT), support vector machines (SVM), and adaboost (AB) were applied for radiomic model construction. Area under the curve (AUC) of the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of the established models.

Results

Seven hundred and sixty‐nine patients with 769 GGOs were included in this study. Two hundred and forty‐five GGOs were confirmed to be of high Ki‐67 labeling index (LI). In the training cohort, gender, age, spiculation sign, pleural indentation sign, bubble sign, and maximum 2D diameter of the nodule were found to be significantly different between high‐ and low Ki‐67 LI groups (p < 0.05), and spiculation sign and maximum 2D diameter of the nodule were further confirmed to be risk factors for Ki‐67 LI. The radiomic model established using SVM exhibited an AUC of 0.731 in the validation cohort, which was higher than that of the clinical‐radiographic model (AUC = 0.675). Moreover, radiomic model combining both intra‐ and peri‐nodular features showed better diagnostic efficacy than using intra‐nodular features alone (AUC = 0.731 and 0.720, respectively).

Conclusions

The established radiomic model exhibited good diagnostic efficacy in differentiating between lung adenocarcinoma GGOs with high and low Ki‐67 LI, which was higher than the clinical‐radiographic model. Peri‐nodular radiomic features showed added benefits to the radiomic model. As a novel noninvasive method, radiomics have the potential to be applied in the preliminary classification of Ki‐67 expression level in lung adenocarcinoma GGOs.

RBL2/DREAM-mediated repression of the Aurora kinase A/B pathway determines therapy responsiveness and outcome in p53 WT NSCLC

Wild-type p53 is a stress-responsive transcription factor and potent tumor suppressor. P53 activates or represses genes involved in cell cycle progression or apoptosis in order to arrest the cell cycle or induce cell death. Transcription repression by p53 is indirect and requires repressive members of the RB-family (RB1, RBL1, RBL2) and formation of repressor complexes of RB1-E2F and RBL1/RBL2-DREAM. Many aurora kinase A/B (AURKA/B) pathway genes are repressed in a p53-DREAM-dependent manner. We found heightened expression of RBL2 and reduced expression of AURKA/B pathway genes is associated with improved outcomes in p53 wild-type but not p53 mutant non-small cell lung cancer (NSCLC) patients. Knockdown of p53, RBL2, or the DREAM component LIN37 increased AURKA/B pathway gene expression and reduced paclitaxel and radiation toxicity in NSCLC cells. In contrast, pharmacologic inhibition of AURKA/B or knockdown of AURKA/B pathway components increased paclitaxel and IR sensitivity. The results support a model in which p53-RBL2-DREAM-mediated repression of the AURKA/B pathway contributes to tumor suppression, improved tumor therapy responses, and better outcomes in p53 wild-type NSCLCs.

Application of Simultaneous 18 F-FDG PET With Monoexponential, Biexponential, and Stretched Exponential Model-Based Diffusion-Weighted MR Imaging in Assessing the Proliferation Status of Lung Adenocarcinoma

BACKGROUND

Ki-67 proliferation index (PI) is important for providing information on tumor behavior, treatment response, and prognosis. Integrated positron emission tomography/magnetic resonance (PET/MR) may have the potential to assess Ki-67 PI in patients with lung adenocarcinoma.

PURPOSE

To explore the value of simultaneous ¹⁸ F-fluorodeoxyglucose (¹⁸ F-FDG) PET/MR-derived parameters in assessing the proliferation status of lung adenocarcinoma and to determine the best combination of parameters.

STUDY TYPE

Prospective.

POPULATION

Seventy-eight patients with lung adenocarcinoma and with Ki-67 PI.

FIELD STRENGTH/SEQUENCE

3.0 T, simultaneous PET/MRI including diffusion-weighted imaging (DWI) and ¹⁸ F-FDG PET.

ASSESSMENT

DWI-derived parameters, namely, apparent diffusion coefficient (ADC), true diffusion coefficient (D), pseudo diffusion coefficient (D*), perfusion fraction (f), diffusion heterogeneity index (α), and distributed diffusion coefficient (DDC); and PET-derived parameters, namely, maximum standardized uptake value (SUV_max ), metabolic tumor volume (MTV), and total lesion glycolytic volume (TLG), were calculated and compared between the high (>25%) and low (≤25%) Ki-67 PI groups. The correlations between PET-derived parameters and DWI-derived parameters were analyzed.

STATISTICAL TESTS

Student's t-test, Mann-Whitney U test, chi-square test, and receiver operating characteristic (ROC) curves. A P-value <0.05 was considered statistically significant.

RESULTS

The SUV_max , MTV, TLG, ADC, D, and DDC values were significantly different between the high (N = 35) and low Ki-67 PI groups (N = 43). D, SUV_max , and MTV independently predicted the Ki-67 PI status. The combination of D, SUV_max , and MTV had the largest area under the ROC curve (AUC = 0.900), which was significantly larger than the AUC alone of DDC (AUC = 0.725), SUV_max (AUC = 0.815), MTV (AUC = 0.774), or TLG (AUC = 0.783). The perfusion fraction did not correlate with SUV_max , MTV, or TLG (r = -0.03, -0.11, and -0.04, respectively; P = 0.786, 0.348, and 0.733).

DATA CONCLUSION

The combination of D, SUV_max , and MTV may predict Ki-67 PI status. No correlation was observed between perfusion parameters and metabolic parameters.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 2.

Correlation between apparent diffusion coefficient and Ki-67 in different pathological types of lung cancer

BACKGROUND

Computed tomography (CT) is common and valuable non-invasive method to evaluate proliferative activity in lung cancer; however, magnetic resonance (MR) is rarely used in lung cancer. To evaluate whether there were different expression levels of Ki-67 in different pathological types of lung cancer and the correlation between Ki-67 index and apparent diffusion coefficient (ADC) value.

METHODS

The clinical and pathological data of 165 patients with lung cancer confirmed by needle biopsy or surgery were retrospectively evaluated, among whom 54 underwent MR examination. The level of Ki-67 was tested using the international standard IHC 2-step method. Kruskal-Wallis H test was used to compare the different expression level of Ki-67 index of adenocarcinoma, squamous cell carcinoma, and small cell carcinoma, and the least significant difference (LSD) method was used for pair-group comparison. Spearman correlation coefficient was used to analyze the correlation between Ki-67 index and ADC value. All statistical tests were bilateral, and P<0.05 was considered statistically significant.

RESULTS

The median of Ki-67 index in adenocarcinoma, squamous cell carcinoma, and small cell carcinoma were 20 (10, 30), 40 (40, 60), and 70 (60, 80), respectively. There was a statistical difference in the expression level of Ki-67 index in the 3 different pathological types of lung cancer (H=103.762, P=0.000). In 54 cases of lung cancer with MR examination, there was a significant negative correlation between average ADC value and expression level of Ki-67 index (r=-0.506, P=0.000), while there was no correlation between ADC value and Ki-67 index in distinguishing different pathological types of lung cancer.

CONCLUSIONS

The expression level of Ki-67 index was different among different pathological types of lung cancer. The ADC value is correlated with Ki-67 index in lung cancer, which can be used to evaluate the proliferative activity of lung cancer.

The Ki-67 Proliferation Index-Related Nomogram to Predict the Response of First-Line Tyrosine Kinase Inhibitors or Chemotherapy in Non-small Cell Lung Cancer Patients With Epidermal Growth Factor Receptor-Mutant Status

Background: The correlation between Ki-67 and epidermal growth factor receptor (EGFR)- or Kristen rat sarcoma viral oncogene homolog (KRAS)-mutant status in advanced or postoperative-recurrent non-small cell lung cancer (NSCLC) has fewer studies reported, and the prognostic role of Ki-67 with first-line EGFR-tyrosine kinase inhibitors (TKIs) or chemotherapy remains controversial. Methods: A total of 295 patients were tested for EGFR-mutant status in advanced or postoperative-recurrent NSCLC and received first-line EGFR-TKIs or chemotherapy for treatment. Ki-67 expression was retrospectively analyzed by immunohistochemistry. The Kaplan-Meier method was used to calculate survival rates. The multivariate Cox proportional hazards model was used to generate a nomogram. The established nomogram was validated using the calibration plots. Results: The expression levels of Ki-67 were divided into low (<60%, n = 186) and high (≥60%, n = 109) groups, based on the receiver operating characteristic curve. The expression levels of Ki-67 were found to be higher in patients with KRAS mutations when compared to KRAS wildtype, and EGFR wildtype was higher than EGFR mutations. The median overall survival (OS) of the low Ki-67 expression group was significantly longer than that of the high Ki-67 group, no matter in all NSCLC, EGFR mutations, EGFR wildtype, KRAS-mutant status, EGFR-TKIs, or chemotherapy of patients (P < 0.05). Subgroup analysis showed that the KRAS wildtype or EGFR mutations combine with low Ki-67 expression group had the longest median OS than KRAS mutations or EGFR wildtype combine with Ki-67 high expression group (P < 0.05). In the training cohort, the multivariate Cox analysis identified age, serum lactate dehydrogenase (LDH), serum Cyfra211, EGFR mutations, and Ki-67 as independent prognostic factors, and a nomogram was developed based on these covariates. The calibration curve for predicting the 12-, 24-, and 30-month OS showed an optimal agreement between the predicted and actual observed outcomes. Conclusions: The Ki-67 expression-based nomogram can well predict the efficacy of first-line therapy in NSCLC patients with EGFR- or KRAS-mutant status, high expression levels of Ki-67 correlated with a poor prognosis.

Texture features of primary tumor on 18F-FDG PET images in non-small cell lung cancer: The relationship between imaging and histopathological parameters

PURPOSE

The aims of this study were to evaluate the relationships between textural features of the primary tumor on FDG PET images and clinical-histopathological parameters which are useful in predicting prognosis in newly diagnosed non-small cell lung cancer (NSCLC) patients.

METHODS

PET/CT images of ninety (90) patients with NSCLC prior to surgery were analyzed retrospectively. All patients had resectable tumors. From the images we acquired data related to metabolism (SUVmax, MTV, TLG) and texture features of primary tumors. Histopathological tumor types and subgroups, degree of Ki-67 expression and necrosis rates of the primary tumor, mediastinal lymph node (MLN) status and nodal stages were recorded.

RESULTS

Among the two histologic tumor types (adenocarcinoma and squamous cell carcinoma) significant differences were present regarding metabolic parameters, Ki-67 index with higher values and kurtosis with lower values in the latter group. Textural heterogeneity was found to be higher in poorly differentiated tumors compared to moderately differentiated tumors in patients with adenocarcinoma. While Ki-67 index had significant correlations with metabolic parameters and kurtosis, tumor necrosis rate was only significantly correlated with textural features. By univariate and multivariate analyses of the imaging and histopathological factors examined, only gradient variance was significant predictive factor for the presence of MLN metastasis.

CONCLUSIONS

Textural features had significant associations with histologic tumor types, degree of pathological differentiation, tumor proliferation and necrosis rates. Texture analysis has potential to differentiate tumor types and subtypes and to predict MLN metastasis in patients with NSCLC.

Pre-operative Prediction of Ki-67 Expression in Various Histological Subtypes of Lung Adenocarcinoma Based on CT Radiomic Features

Purpose: The aims of this study were to combine CT images with Ki-67 expression to distinguish various subtypes of lung adenocarcinoma and to pre-operatively predict the Ki-67 expression level based on CT radiomic features.

Methods: Data from 215 patients with 237 pathologically proven lung adenocarcinoma lesions who underwent CT and immunohistochemical Ki-67 from January 2019 to April 2021 were retrospectively analyzed. The receiver operating curve (ROC) identified the Ki-67 cut-off value for differentiating subtypes of lung adenocarcinoma. A chi-square test or t-test analyzed the differences in the CT images between the negative expression group (n = 132) and the positive expression group (n = 105), and then the risk factors affecting the expression level of Ki-67 were evaluated. Patients were randomly divided into a training dataset (n = 165) and a validation dataset (n = 72) in a ratio of 7:3. A total of 1,316 quantitative radiomic features were extracted from the Analysis Kinetics (A.K.) software. Radiomic feature selection and radiomic classifier were generated through a least absolute shrinkage and selection operator (LASSO) regression and logistic regression analysis model. The predictive capacity of the radiomic classifiers for the Ki-67 levels was investigated through the ROC curves in the training and testing groups.

Results: The cut-off value of the Ki-67 to distinguish subtypes of lung adenocarcinoma was 5%. A comparison of clinical data and imaging features between the two groups showed that histopathological subtypes and air bronchograms could be used as risk factors to evaluate the expression of Ki-67 in lung adenocarcinoma (p = 0.005, p = 0.045, respectively). Through radiomic feature selection, eight top-class features constructed the radiomic model to pre-operatively predict the expression of Ki-67, and the area under the ROC curves of the training group and the testing group were 0.871 and 0.8, respectively.

Conclusion: Ki-67 expression level with a cut-off value of 5% could be used to differentiate non-invasive lung adenocarcinomas from invasive lung adenocarcinomas. It is feasible and reliable to pre-operatively predict the expression level of Ki-67 in lung adenocarcinomas based on CT radiomic features, as a non-invasive biomarker to predict the degree of malignant invasion of lung adenocarcinoma, and to evaluate the prognosis of the tumor.

Diagnostic, Predictive, and Prognostic Biomarkers in Non-Small Cell Lung Cancer (NSCLC) Management

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite growing efforts for its early detection by screening populations at risk, the majority of lung cancer patients are still diagnosed in an advanced stage. The management of lung cancer has dramatically improved in the last decade and is no longer based on the "one-fits-all" paradigm or the general histological classification of non-small cell versus small cell lung cancer. Emerging options of targeted therapies and immunotherapies have shifted the management of lung cancer to a more personalized treatment approach, significantly influencing the clinical course and outcome of the disease. Molecular biomarkers have emerged as valuable tools in the prognosis and prediction of therapy response. In this review, we discuss the relevant biomarkers used in the clinical management of lung tumors, from diagnosis to prognosis. We also discuss promising new biomarkers, focusing on non-small cell lung cancer as the most abundant type of lung cancer.

A Novel Strategy for the Diagnosis of Pulmonary High-Grade Neuroendocrine Tumor

Correctly diagnosing a histologic type of lung cancer is important for selecting the appropriate treatment because the aggressiveness, chemotherapy regimen, surgical approach, and prognosis vary significantly among histologic types. Pulmonary NETs, which are characterized by neuroendocrine morphologies, represent approximately 20% of all lung cancers. In particular, high-grade neuroendocrine tumors (small cell lung cancer and large cell neuroendocrine tumor) are highly proliferative cancers that have a poorer prognosis than other non-small cell lung cancers. The combination of hematoxylin and eosin staining, Ki-67, and immunostaining of classic neuroendocrine markers, such as chromogranin A, CD56, and synaptophysin, are normally used to diagnose high-grade neuroendocrine tumors; however, they are frequently heterogeneous. This article reviews the diagnostic methods of lung cancer diagnosis focused on immunostaining. In particular, we describe the usefulness of immunostaining by Stathmin-1, which is a cytosolic phosphoprotein and a key regulator of cell division due to its microtubule depolymerization in a phosphorylation-dependent manner, for the diagnosis of high-grade neuroendocrine tumors.

Minimized combinatorial CRISPR screens identify genetic interactions in autophagy

Combinatorial CRISPR-Cas screens have advanced the mapping of genetic interactions, but their experimental scale limits the number of targetable gene combinations. Here, we describe 3Cs multiplexing, a rapid and scalable method to generate highly diverse and uniformly distributed combinatorial CRISPR libraries. We demonstrate that the library distribution skew is the critical determinant of its required screening coverage. By circumventing iterative cloning of PCR-amplified oligonucleotides, 3Cs multiplexing facilitates the generation of combinatorial CRISPR libraries with low distribution skews. We show that combinatorial 3Cs libraries can be screened with minimal coverages, reducing associated efforts and costs at least 10-fold. We apply a 3Cs multiplexing library targeting 12,736 autophagy gene combinations with 247,032 paired gRNAs in viability and reporter-based enrichment screens. In the viability screen, we identify, among others, the synthetic lethal WDR45B-PIK3R4 and the proliferation-enhancing ATG7-KEAP1 genetic interactions. In the reporter-based screen, we identify over 1,570 essential genetic interactions for autophagy flux, including interactions among paralogous genes, namely ATG2A-ATG2B, GABARAP-MAP1LC3B and GABARAP-GABARAPL2. However, we only observe few genetic interactions within paralogous gene families of more than two members, indicating functional compensation between them. This work establishes 3Cs multiplexing as a platform for genetic interaction screens at scale.

Assessment of relationships among clinicopathological characteristics, morphological computer tomography features, and tumor cell proliferation in stage I lung adenocarcinoma

Background

Surgically resected stage I lung adenocarcinoma (ADC) has wide variation in prognosis. It is significant to identify high-risk patients and optimize therapeutic strategy. This study aimed to investigate the relationships among histological grade, serum tumor marker index (TMI), morphological computer tomography (CT) features, and a well-established prognosticator cell proliferation (Ki-67) in stage I ADC.

Methods

Preoperative CT was performed in 182 patients with stage I ADC confirmed by pathology. The Ki-67 expression was acquired by immunohistochemistry. TMI was the square root of standardized serum carcinoembryonic antigen (CEA) and cytokeratin 19 fragments (CYFRA 21-1) values. Tumor shadow disappearance rate (TDR) and other morphological CT features were interpreted by two radiologists. Histological grade, TMI, CT features were statistically evaluated to explore the associations with Ki-67 expression.

Results

In univariate analysis, gender, smoking history, pack-year, histological grade, TNM stage (IA and IB), serum CEA and CYFRA 21-1 status, TMI status, as well as TDR, long-axis diameter, short-axis diameter, lobulation, spiculation, attenuation types, vacuolation, vascular invasion, vascular convergence, thickened bronchovascular bundles, pleural attachment and peripheral fibrosis were significantly associated with Ki-67 expression (all P<0.05). Solid-predominant ADC had the highest Ki-67 expression, followed by micropapillary, papillary and acinar-predominant ADC, while lepidic-predominant ADC had the lowest Ki-67 expression (P<0.001). TDR was negatively correlated with Ki-67 (r =−0.478, P<0.001). Multivariate logistic regression analysis revealed that gender, histological grade, TDR and attenuation types were independent factors associated with Ki-67 expression.

Conclusions

Ki-67 expression differed distinctly according to ADC histological subtypes. High Ki-67 expression is independently associated with male patients of stage I ADC with worse differentiation, lower TDR and solid tumors, which might be of prognostic value for poor prognosis in stage I ADC.

Texture features of primary tumor on 18F-FDG PET images in non-small cell lung cancer: The relationship between imaging and histopathological parameters

OBJECTIVES

The aims of this study were to evaluate the relationships between textural features of the primary tumor on FDG PET images and clinical-histopathological parameters which are useful in predicting prognosis in newly diagnosed non-small cell lung cancer (NSCLC) patients.

MATERIAL AND METHODS

PET/CT images of ninety (90) patients with NSCLC prior to surgery were analyzed retrospectively. All patients had resectable tumors. From the images we acquired data related to metabolism (SUVmax, metabolic tumor volume [MTV] and total lesion glycolysis [TLG]) and texture features of primary tumors. Histopathological tumor types and subgroups, degree of Ki-67 expression and necrosis rates of the primary tumor, mediastinal lymph node (MLN) status and nodal stages were recorded.

RESULTS

Among the 2histologic tumor types (adenocarcinoma and squamous cell carcinoma) significant differences were present regarding metabolic parameters, Ki-67 index with higher values and kurtosis with lower values in the latter group. Textural heterogeneity was found to be higher in poorly differentiated tumors compared to moderately differentiated tumors in patients with adenocarcinoma. While Ki-67 index had significant correlations with metabolic parameters and kurtosis, tumor necrosis rate was only significantly correlated with textural features. By univariate and multivariate analyses of the imaging and histopathological factors examined, only gradient variance was significant predictive factor for the presence of MLN metastasis.

CONCLUSIONS

Textural features had significant associations with histologic tumor types, degree of pathological differentiation, tumor proliferation and necrosis rates. Texture analysis has potential to differentiate tumor types and subtypes and to predict MLN metastasis in patients with NSCLC.

Evaluation of polyhexamethylene guanidine-induced lung injuries by chest CT, pathologic examination, and RNA sequencing in a rat model

Our aim was to correlate chest CT and pathologic findings of polyhexamethylene guanidine phosphate (PHMG)-induced lung injuries in a rat model, to determine whether PHMG exposure causes lung tumors, and to explore genetic alterations according to PHMG exposure under the guidance of CT. A PHMG solution was intratracheally administrated to 40 male rats. Chest CT was carried out in all rats and both lungs were collected for histopathologic evaluation. At 4- and 8-weeks post-instillation, one lobe of the right lung from 3 rats was subjected to RNA sequencing. At least one abnormal CT finding was found in all rats at all weeks. The major CT findings were inflammation, fibrosis, and tumors in the pathologic analysis, where significant changes were observed over time. The lung lesions remained persistent after 8 weeks of PHMG exposure. In the pathologic analysis, the extent/severity of inflammation did not show statistically significant changes over time, whereas the extent/severity of fibrosis increased continuously up to 6 weeks after PHMG exposure and then decreased significantly at 8 weeks. Bronchiolar-alveolar adenomas which have malignant potential were found in 50% of rats at 6 and 8 weeks after PHMG exposure. Also, several genes associated with lung cancer, acute lung injury, and pulmonary fibrosis were detected. Our study revealed that PHMG-induced lung injury and its changes according to the number of weeks after exposure were demonstrated using chest CT and pathologic evaluation. In addition, we showed that PHMG exposure caused lung tumors and genetic alterations according to PHMG exposure under the guidance of CT.

Bioinformatics-Based Identification of HDAC Inhibitors as Potential Drugs to Target EGFR Wild-Type Non-Small-Cell Lung Cancer

Patients with EGFR-mutant non-small-cell lung cancer (NSCLC) greatly benefit from EGFR-tyrosine kinase inhibitors (EGFR-TKIs) while the prognosis of patients who lack EGFR-sensitive mutations (EGFR wild type, EGFR-WT) remains poor due to a lack of effective therapeutic strategies. There is an urgent need to explore the key genes that affect the prognosis and develop potentially effective drugs in EGFR-WT NSCLC patients. In this study, we clustered functional modules related to the survival traits of EGFR-WT patients using weighted gene co-expression network analysis (WGCNA). We used these data to establish a two-gene prognostic signature based on the expression of CYP11B1 and DNALI1 by combining the least absolute shrinkage and selection operator (LASSO) algorithms and Cox proportional hazards regression analysis. Following the calculation of risk score (RS) based on the two-gene signature, patients with high RSs showed a worse prognosis. We further explored targeted drugs that could be effective in patients with a high RS by the connectivity map (CMap). Surprisingly, multiple HDAC inhibitors (HDACis) such as trichostatin A (TSA) and vorinostat (SAHA) that may have efficacy were identified. Also, we proved that HDACis could inhibit the proliferation and metastasis of NSCLC cells in vitro. Taken together, our study identified prognostic biomarkers for patients with EGFR-WT NSCLC and confirmed a novel potential role for HDACis in the clinical management of EGFR-WT patients.

A Noninvasive Assessment of Tumor Proliferation in Lung cancer Patients using Intravoxel Incoherent Motion Magnetic Resonance Imaging

Ki-67 is a nuclear antigen widely used in routine pathologic analyses as a tumor cell proliferation marker for lung cancer. However, Ki-67 expression analyses using immunohistochemistry (IHC) are invasive and frequently influenced by tissue sampling quality. In this study, we assessed the feasibility of noninvasive magnetic resonance imaging (MRI) in predicting the Ki-67 labeling indices (LIs). A total of 51 lung cancer patients, including 42 non-small cell lung cancer (NSCLC) cases and nine small cell lung cancer (SCLC) cases, were enrolled in this study. Quantitative MRI parameters from conventional diffusion-weighted imaging (DWI), intravoxel incoherent motion (IVIM), and diffusion kurtosis imaging (DKI) were obtained, and their correlations with tumor tissue Ki-67 expression were analyzed. We found that the true diffusion coefficient (D value) from IVIM was negatively correlated with Ki-67 expression (Spearman r = -0.76, P < 0.001). The D values in the high Ki-67 group were significantly lower than those in the low Ki-67 group (0.90 ± 0.21 × 10^-3 mm²/s vs. 1.22 ± 0.30 × 10^-3 mm²/s). Among three MRI techniques used, D values from IVIM showed the best performance for distinguishing the high Ki-67 group from low Ki-67 group in receiver operating characteristic (ROC) analysis with an area under the ROC curve (AUROC) of 0.85 (95% CI: 0.73-0.97, P < 0.05). Moreover, D values performed well for differentiating SCLC from NSCLC with an AUROC of 0.82 (95% CI: 0.68-0.90), Youden index of 0.72, and F1 score of 0.81. In conclusion, D values were negatively correlated with Ki-67 expression in lung cancer tissues and can be used to distinguish high from low proliferation statuses, as well as SCLC from NSCLC.

MiR-519d and miR-328-3p Combinatorially Suppress Breast Cancer Progression

Background

MiR-519d and miR-328-3p had tumor-regulatory properties in different cancers, but their combinatorial effects and potential common target in breast cancer had not been fully reported. This research targeted to study the underlying mechanism of how miR-519d and miR-328-3p cooperatively suppressed breast cancer.

Methods

MiR-519d and miR-328-3p expressions in breast cancer tissues and cells were assessed and Ki-67 expression was also checked. DLR assay was executed to verify whether Ki-67 was a common target of miR-519d and miR-328-3p. Western blot, flow cytometry, colony formation, wound healing and transwell assays were applied to examine the inhibitory roles of these two miRNAs on the malignant behaviors of breast cancer cells and the potential molecular mechanism.

Results

Impeded miR-519d and miR-328-3p expressions and enhanced Ki-67 expression were detected in breast cancer tissues and cells. Ki-67 was confirmed as a target of these two miRNAs. MiR-519d and miR-328-3p hampered cell proliferation and blocked cell cycle via binding to Ki-67 and they also suppressed migration and invasion. The combinatorial effects of two miRNAs were much stronger than a single miRNA.

Conclusion

Our findings proved that miR-519d and miR-328-3p played combinatorial anti-cancer roles in breast cancer by directly targeting a common target Ki-67. Our study suggested that these two miRNAs might own the potential to become novel therapeutic biomarkers involved in the diagnosis and therapy of breast cancer.

A method to obtain reproducible Ki-67 indices in lung adenocarcinoma

AIMS

Proliferative activity, evaluated from the Ki-67 index, is a strong prognostic factor in lung adenocarcinoma (LADC). Here, we optimised a procedure to measure the Ki-67 index and establish the best cut-off value.

METHODS AND RESULTS

We examined 342 stage I LADCs for the immunohistochemical expression of Ki-67 using different antibodies, MIB1 and SP6. The results revealed the superior specificity of SP6; therefore, SP6 was used in subsequent analyses. Slides were scanned with a virtual slide system. Using software, tumour cells were counted in a whole tumour. Thereafter, the tumour was evenly subdivided into 0.25-mm² tiles. The frequency of positive cells was counted in each tile of an invasive area or the whole tumour. We calculated the number of tumour cells required to produce a 95% confidence interval (CI) <0.05. Additionally, we calculated coverage probabilities (CP) using two different methods, counting any number or 200 cells per tile. The results showed that we could meet our goal by counting 2000 cells from 10 random tiles (200 cells each) in invasive areas.

CONCLUSIONS

We successfully developed an optimal procedure for determination of the Ki-67 labelling index using an SP6 antibody, which provided CP > 70% and CI of <0.05 in more than 90% of cases. Furthermore, we identified an optimal cut-off value of 0.12 with an alternative of 0.15, based on disease recurrence. This procedure and the cut-off values may be used in the routine pathological diagnosis of LADC.

Proliferative activity is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Differences between MDS and MDS/MPN

The proliferation marker Ki-67 is widely used within the field of diagnostic histopathology as a prognostic marker for solid cancers. However, Ki-67 is hardly used for prognostic and diagnostic purposes in flow cytometric analyses of hematologic neoplasms. In the present study, we investigated to what extent the proliferative activity, as determined by Ki-67 expression, is disturbed in myeloproliferative neoplasms (MPN), myelodysplastic syndrome (MDS), and MDS/MPN diseases. Bone marrow aspirates from 74 patients suffering from MPN, MDS, or MDS/MPN, and aspirates from 50 non-malignant cases were analyzed by flow cytometry for Ki-67 expression in the erythro-, myelo-, and monopoiesis. Ki-67 expression was used to investigate the proliferative activity during the various maturation steps within these hematopoietic cell lineages. In the MPN patient cohort, the proliferative activity of all cell lineages is significantly higher during almost all maturation stages compared to those of the benign control cohort. In the MDS and MDS/MPN cohort, a significantly lower proliferative activity is observed in the early maturation stages. In the MDS/MPN patient cohort, increased proliferative activity is seen in the later stages of the maturation. MDS and MDS/MPN display a distinct pattern in the proliferating fraction of maturing hematopoietic cells. This could become of added value in order to classify these malignancies based on their biological background and behavior, as well as in gaining a better understanding into the pathobiology of these malignancies.

Cutoff of 25% for Ki67 expression is a good classification tool for prognosis in colorectal cancer in the AJCC‑8 stratification

Ki‑67 expression has been widely used in clinical practice as an index to evaluate the proliferative activity of tumor cells. The cutoff for Ki67 expression in order to increase the prognostic value of Ki67 expression in colorectal cancer varies. The present study assessed the relationship between the 25% cutoff for Ki67 expression and prognosis in colorectal cancer in the AJCC‑8 (American Joint Committee on Cancer 8 edition) stratification. The current trial included 1,090 colorectal cancer patients enrolled from 2006 to 2012 at Huzhou Central Hospital. Ki67 expression was classified according to 25% intervals, dividing the patients into four groups. Measurement data were analyzed by ANOVA, and count data by Crosstabs. Bivariate correlation analysis was performed to assess clinicopathological indicators based on Ki67 expression. Disease‑free survival (DFS) and overall survival (OS) based on Ki67 levels were analyzed by the Kaplan‑Meier method. A total of 1,090 patients of the 2,080 enrolled CRC cases were evaluated (52.4%). Invasive depth, tumor differentiation, tumor size, AJCC‑8, positive number of lymph nodes and chemotherapy status showed significant differences in the various Ki67 expression groups (all P<0.05), with significant correlations (Spearman rho: 0.170, 0.456, 0.22, 0.195, 0.514 and ‑0.201, respectively, all P<0.001). DFS and OS for the different Ki67 level groups based on AJCC‑8 stratification were analyzed, and no significance was found in stage IV (P=0.334). DFS and OS survival rates were assessed at different Ki67 expression levels, and no significant differences were found (all P>0.05). Cox regression analysis showed that invasive depth, lymph node metastasis, tumor differentiation, AJCC‑8 and Ki67 were independent factors affecting colorectal cancer (P=0.030, all others P<0.001). In conclusion, a cutoff of 25% for Ki67 expression is a good classification tool. High Ki67 has a close association with poor prognosis in colorectal cancer and independently predicts prognosis in the AJCC‑8 stratification.

Tumor cellular proliferation is associated with enhanced immune checkpoint expression in stage I non-small cell lung cancer

OBJECTIVES

Ki67 is a marker for tumor proliferative activity and is known to have prognostic significance in multiple solid malignancies. We sought to characterize the relationships among Ki67 expression, immune cell infiltration, and immune checkpoint expression in patients with resected non-small cell lung cancer.

METHODS

Specimens of patients undergoing resection of stage I to III non-small cell lung cancer (1997-2012) were analyzed using tissue microarrays. Proliferative index was quantified as the percentage of malignant cells expressing Ki67. Checkpoints expressed on malignant cells (programmed death ligand 1, B7H3, B7H4, indoleamine 2,3-dioxygenase 1) and lymphocytes (T-cell immunoglobulin and mucin-domain containing 3, V-domain suppressor of T-cell activation, tumor necrosis factor receptor superfamily member 4, lymphocyte activation gene 3, inducible T-cell co-stimulator) were analyzed in intratumoral and stromal compartments, respectively. Immune cell densities were quantified in intratumoral and peritumoral compartments in a representative subset.

RESULTS

A total of 190 patients met inclusion criteria. Higher Ki67 expression was noted in squamous cell carcinoma (median 31.4% positive malignant cells vs 15.2% adenocarcinoma, P < .001), advanced-stage tumors (25.7% stages II/III vs 20.8% stage I, P = .013), and poorly differentiated tumors (28.8% vs 15.4% well/moderately, P < .001). Ki67 was positively correlated with intratumoral expression of programmed death ligand 1, B7-H3, and indoleamine 2,3-dioxygenase 1, and elevated stromal expression of lymphocyte activation gene 3 and inducible T-cell co-stimulator. Ki67 expression was inversely associated with intratumoral densities of CD57+ and CD4+ cells. The relationship between Ki67 and checkpoint expression was strongest in stage I tumors. Among patients with stage I, increased Ki67 was independently associated with worse overall survival.

CONCLUSIONS

Increased Ki67 expression is associated with biologically aggressive non-small cell lung cancer, enhanced immune checkpoint expression, and reduced intratumoral immune cell infiltration. These findings were strongest in early-stage disease and warrant further investigation in the context of novel therapeutic agents.

Ki-67/MKI67 as a Predictive Biomarker for Clinical Outcome in Gastric Cancer Patients: an Updated Meta-analysis and Systematic Review involving 53 Studies and 7078 Patients

Gastric cancer (GC) threatens human health worldwide and we performed this meta-analysis to evaluate the clinical value of Ki-67/MKI67 in patients with GC. The combined hazard ratio (HR), odds ratio (OR) and 95% confidence interval (95% CI) were calculated to assess the relationships of Ki-67/MKI67 expression with prognoses and clinicopathological characteristics. Genes co-expressed with MKI67 were collected for Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and protein-protein interaction (PPI) network analyses. In total, 53 studies with 7078 patients were included in this study. The pooled HRs indicated that an elevated expression of Ki-67/MKI67 predicted an unfavorable overall survival (HR: 1.54, 95% CI: 1.33-1.78, P<0.0001) and disease-free survival (HR: 2.28, 95% CI: 1.43-3.64, P<0.0001) in GC patients. Additionally, in patients with advanced GC, a high Ki-67/MKI67 expression was also significantly connected with OS (HR: 1.37, 95% CI: 1.18-1.60, P<0.0001). The combined ORs showed that Ki-67/MKI67 expression was related to TNM stage (stage III/IV versus stage I/II: OR=1.93, 95% CI=1.34-2.78, P<0.0001), tumor differentiation (poor versus well/moderate: OR=1.94, 95% CI=1.32-2.85, P=0.001), lymph node metastasis (yes versus no: OR=1.67, 95% CI=1.23-2.25, P=0.001), distant metastasis (yes versus no: OR=1.67, 95% CI=1.24-2.26, P=0.001) and tumor invasion depth (T3/T4 versus T_is/T1/T2: OR=1.98, 95% CI=1.60-2.44, P<0.0001). The results of GO, KEGG pathway and PPI network analyses indicated that Ki-67/MKI67 may be involved in the development of GC via influencing P53 signaling pathway. Ki-67/MKI67 could be a potential indicator to predict the prognosis of patients with GC and identify high-risk cases. Detecting Ki-67/MKI67 expression in clinic may be helpful in optimizing individual treatment and further improving the survival expectancy of patients with GC.

Can peritumoral radiomics increase the efficiency of the prediction for lymph node metastasis in clinical stage T1 lung adenocarcinoma on CT?

OBJECTIVES

To evaluate the efficiency of radiomics model on CT images of intratumoral and peritumoral lung parenchyma for preoperative prediction of lymph node (LN) metastasis in clinical stage T1 peripheral lung adenocarcinoma patients.

METHODS

Three hundred sixty-six peripheral lung adenocarcinoma patients with clinical stage T1 were evaluated using five CT scanners. For each patient, two volumes of interest (VOIs) on CT were defined as the gross tumor volume (GTV) and the peritumoral volume (PTV, 1.5 cm around the tumor). One thousand nine hundred forty-six radiomic features were obtained from each VOI, and then refined for reproducibility and redundancy. The refined features were investigated for usefulness in building radiomic signatures by mRMR feature ranking method and LASSO classifier. Multivariable logistic regression analysis was used to develop a radiomic nomogram incorporating the radiomic signature and clinical parameters. The prediction performance was evaluated on the validation cohort.

RESULTS

The radiomic signatures using the features of GTV and PTV showed a good ability in predicting LN metastasis with an AUC of 0.829 (95% CI, 0.745-0.913) and 0.825 (95% CI, 0.733-0.918), respectively. By incorporating the features of GTV and PTV, the AUC of radiomic signature increased to 0.843 (95% CI, 0.770-0.916). The AUC of radiomic nomogram was 0.869 (95% CI, 0.800-0.938).

CONCLUSIONS

Radiomic signatures of GTV and PTV both had a good prediction ability in the prediction of LN metastasis, and there is no significant difference of AUC between the two groups. The proposed nomogram can be conveniently used to facilitate the preoperative prediction of LN metastasis in T1 peripheral lung adenocarcinomas.

KEY POINTS

• Radiomics from peritumoral lung parenchyma increase the efficiency of the prediction for lymph node metastasis in clinical stage T1 lung adenocarcinoma on CT. • A radiomic nomogram was developed and validated to predict LN metastasis. • Different scan parameters on CT showed that radiomics signature had good predictive performance.