Histological subtypes of lung adenocarcinoma have differential ¹⁸F-fluorodeoxyglucose uptakes on the positron emission tomography/computed tomography scan

The application of Raman spectroscopy for the diagnosis and monitoring of lung tumors

Raman spectroscopy is an optical technique that uses inelastic light scattering in response to vibrating molecules to produce chemical fingerprints of tissues, cells, and biofluids. Raman spectroscopy strategies produce high levels of chemical specificity without requiring extensive sample preparation, allowing for the use of advanced optical tools such as microscopes, fiber optics, and lasers that operate in the visible and near-infrared spectral range, making them increasingly suitable for a wide range of medical diagnostic applications. Metal nanoparticles and nonlinear optical effects can improve Raman signals, and optimized fiber optic Raman probes can make real-time, in vivo, single-point observations. Furthermore, diagnostic speed and spatial accuracy can be improved through the multimodal integration of Raman measurements and other technologies. Recent studies have significantly contributed to the improvement of diagnostic speed and accuracy, making them suitable for clinical application. Lung cancer is a prevalent type of respiratory malignancy. However, the use of computed tomography for detection and screening frequently reveals numerous smaller lung nodules, which makes the diagnostic process more challenging from a clinical perspective. While the majority of small nodules detected are benign, there are currently no direct methods for identifying which nodules represent very early-stage lung cancer. Positron emission tomography and other auxiliary diagnostic methods for non-surgical biopsy samples from these small nodules yield low detection rates, which might result in significant expenses and the possibility of complications for patients. While certain subsets of patients can undergo curative treatment, other individuals have a less favorable prognosis and need alternative therapeutic interventions. With the emergence of new methods for treating cancer, such as immunotherapies, which can potentially extend patient survival and even lead to a complete cure in certain instances, it is crucial to determine the most suitable biomarkers and metrics for assessing the effectiveness of these novel compounds. This will ensure that significant treatment outcomes are accurately measured. This review provides a comprehensive overview of the prospects of Raman spectroscopy and its applications in the diagnosis and analysis of lung tumors.

Maximum amplitude and mean platelet volume in the blood as biomarkers to detect lung adenocarcinoma cancer featured with ground-glass nodules

Objectives

The development and progression of malignancies are closely linked to hypercoagulability. As an early type of lung adenocarcinoma, ground glass nodules (GGNs) have been detected increasingly. Blood Maximum amplitude (MA) and mean platelet volume (MPV) are related to various conditions of hypercoagulability. Therefore, the role of MA and MPV in diagnosing lung adenocarcinoma cancer featured with GGNs was investigated in this case-control study.

Methods

The analyzed data of this study is derived from GGNs patients and healthy individuals in West China (Airport) Hospital Sichuan University. The differences between GGNs patients and healthy individuals were determined by one-way ANOVA, logistic regression or chi-squared test. The accuracy of diagnostic was performed by receiver operating characteristic curve (ROC). The relative mRNA expressions were studied by RT-qPCR.

Results

470 patients diagnosed with GGNs which benign lesions (BN group) are inflammatory and malignant lesions (LC group) are adenocarcinoma in stage IA, and 235 healthy subjects (HC group) were enrolled in this study. Levels of MA and MPV were increased in LC group compared with BN and HC group ( p < 0.001, p < 0.001). When we combined MA and MPV, MA and MPV presented a sensitivity (SEN) of 0.809 and a specificity (SPE) of 0.774. And the area under the curve (AUC) increased to 0.871 (0.837–0.900) when confidence interval was 95%.

Conclusion

This study demonstrates that there have been systemic changes in coagulation disorders in the pathogenesis of GGNs. The diagnostic ability to different lung adenocarcinoma cancer featured with GGNs from benign or healthy controls can be improved by the combination of MA and MPV. Maximum amplitude and MPV may be used as biomarkers to detect lung adenocarcinoma cancer featured with GGNs.

The prognostic relationship of 18F-FDG PET/CT metabolic and volumetric parameters in metastatic ALK + NSCLC

OBJECTIVE

The aim of this study is to determine the role of metabolic and volumetric parameters obtained from 18Fluorine-Fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) imaging on progression-free survival (PFS) and overall survival (OS) in patients with advanced nonsquamous cell lung carcinoma (NSCLC) with anaplastic lymphoma kinase (ALK) rearrangement.

METHODS

Pre and post-treatment PET/CT images of the ALK + NSCLC patients between January 2015 and July 2020 were evaluated. The highest standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) values were obtained from pre-tyrosine kinase inhibitor (TKI) basal PET/CT (PETpre) and post-TKI PET/CT (PETpost) images. Total MTV (tMTV) and total TLG (tTLG) values were calculated by summing MTV and TLG values in all tumor foci. The change (Δ) in pSUVmax, pMTV, pTLG, tMTV and tTLG before and after treatment was calculated.The relationship of these parameters with OS and PFS was analyzed.

RESULTS

tTLGpre, tMTVpre, pTLGpre, pMTVpre, ∆SUVmax, ∆tMTV and ∆tTLG values were found to be associated with OS; ∆tMTV, ∆tTLG, tTLGpre, tMTVpre, pTLGpre and pMTVpre were associated with PFS. The cutoff values in both predicting OS and PFS were calculated as -31.6 and 391.1 for ∆tMTV and tTLGpre, respectively. In Cox regression analysis, ∆tMTV and stage for OS and ∆tMTV and tTLGpre for PFS were obtained as prognostic factors.

CONCLUSIONS

Metabolic and volumetric parameters, especially TLG values in the whole body before treatment and change in whole body MTV value, obtained from PET/CT may be useful in predicting prognosis and determining treatment strategies for patients with advanced ALK + NSCLC.

The value of diffusion kurtosis imaging, diffusion weighted imaging and 18F-FDG PET for differentiating benign and malignant solitary pulmonary lesions and predicting pathological grading

Objective

To explore the value of PET/MRI, including diffusion kurtosis imaging (DKI), diffusion weighted imaging (DWI) and positron emission tomography (PET), for distinguishing between benign and malignant solitary pulmonary lesions (SPLs) and predicting the histopathological grading of malignant SPLs.

Material and methods

Chest PET, DKI and DWI scans of 73 patients with SPL were performed by PET/MRI. The apparent diffusion coefficient (ADC), mean diffusivity (MD), mean kurtosis (MK), maximum standard uptake value (SUV_max), metabolic total volume (MTV) and total lesion glycolysis (TLG) were calculated. Student’s t test or the Mann–Whitney U test was used to analyze the differences in parameters between groups. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy. Logistic regression analysis was used to evaluate independent predictors.

Results

The MK and SUV_max were significantly higher, and the MD and ADC were significantly lower in the malignant group (0.59 ± 0.13, 10.25 ± 4.20, 2.27 ± 0.51[×10^-3 mm²/s] and 1.35 ± 0.33 [×10^-3 mm²/s]) compared to the benign group (0.47 ± 0.08, 5.49 ± 4.05, 2.85 ± 0.60 [×10^-3 mm²/s] and 1.67 ± 0.33 [×10^-3 mm²/s]). The MD and ADC were significantly lower, and the MTV and TLG were significantly higher in the high-grade malignant SPLs group (2.11 ± 0.51 [×10^-3 mm²/s], 1.35 ± 0.33 [×10^-3 mm²/s], 35.87 ± 42.24 and 119.58 ± 163.65) than in the non-high-grade malignant SPLs group (2.46 ± 0.46 [×10^-3 mm²/s], 1.67 ± 0.33[×10^-3 mm²/s], 20.17 ± 32.34 and 114.20 ± 178.68). In the identification of benign and malignant SPLs, the SUV_max and MK were independent predictors, the AUCs of the combination of SUV_max and MK, SUV_max, MK, MD, and ADC were 0.875, 0.787, 0.848, 0.769, and 0.822, respectively. In the identification of high-grade and non-high-grade malignant SPLs, the AUCs of MD, ADC, MTV, and TLG were 0.729, 0.680, 0.693, and 0.711, respectively.

Conclusion

DWI, DKI, and PET in PET/MRI are all effective methods to distinguish benign from malignant SPLs, and are also helpful in evaluating the pathological grading of malignant SPLs.

Relationships between SUVmax of lung adenocarcinoma and different T stages, histological grades and pathological subtypes: a retrospective cohort study in China

OBJECTIVES

Cancer cell has aberrant metabolism. The purpose of this study aimed to investigate relationships between maximum standard uptake value (SUVmax）of ¹⁸fluoro-2-deoxy-d-glucose and T stages, histological grades and pathological subtypes of lung adenocarcinoma.

DESIGN

Retrospective cohort study, employing the Kruskal-Wallis, Bonferroni-Dunn and Mann-Whitney tests to compare SUVmax of different T stages, histological grades and pathological subtypes of lung adenocarcinoma.

SETTING

The outpatients who had aberrant positron emission tomography/CT (PET/CT) images in chest were enrolled this study from August 2016 to November 2018 in Shanghai, China.

PARTICIPANT

Initial 11 270 patients with suspected lung cancer who underwent PET/CT examinations were surveyed. A total of 1454 patients who were diagnosed as lung adenocarcinoma by pathologist were included in this project.

PRIMARY OUTCOME MEASURES

SUVmax value at different tumour-node-metastasis stages of lung adenocarcinoma before surgery.

RESULTS

The mean SUVmax of patients with lung adenocarcinoma was significantly elevated with the increase in T stages. There were significant evident differences in SUVmax among T1a-T1c (p<0.05). However, after the staging of patients was more than T1 stage, SUVmax of T2a, T2b, T2 visceral pleural invasion, T3 and T4 had not dramatic changes. SUVmax value of lung adenocarcinoma in the same T stage group was the highest in patients with the high grade of malignancy and solid-predominant invasive adenocarcinoma.

CONCLUSIONS

SUVmax value was significantly associated with T stages, grades of malignancy and pathological subtypes of lung adenocarcinoma.

Cytomorphometric and flow cytometric analyses using liquid-based cytology materials in subtypes of lung adenocarcinoma

BACKGROUND

The histological classifications of invasive lung adenocarcinoma subtypes are considered to predict patient prognosis after surgical treatment. The objectives of this study were to evaluate cytomorphological characteristics and proliferative activities among the histological predominant patterns by performing cytomorphometric and flow cytometric analyses using liquid-based cytology materials.

METHODS

Cytological samples fixed by liquid-based cytology preservatives from 53 surgically-resected lung adenocarcinoma specimens were obtained between August 2018 and November 2019. The Papanicolaou-stained and paired Ki-67-stained slides were analyzed for calculating nuclear morphology (nuclear area, nuclear perimeter and nuclear circularity) and Ki-67 labeling index using software. The cell proliferation index (CPIx) was calculated and cellular information including cell cycle stage of tumor cells was obtained by flow cytometry.

RESULTS

The 53 cases included papillary (n = 29), acinar (n = 8), lepidic (n = 5), and solid (n = 4) subtypes, and invasive mucinous adenocarcinoma (n = 7) were also included. In the lepidic pattern, nuclear area (79.6 ± 28.8 μm² ) and perimeter (34.1 ± 6.1 μm) were relatively larger and longer than those of the other predominant patterns. The Ki-67 labeling index of the solid pattern (27.9 ± 12.5%) was highest compared with those of other predominant patterns. There were statistically significant differences in the lepidic versus solid patterns and the papillary versus solid patterns (p = .013 and p = .039, respectively). The calculated mean CPIx of the lepidic and the acinar patterns were approximately two-fold higher than those of the other predominant patterns.

CONCLUSION

By revealing the differences of cytomorphological characteristics, these methodologies might be used for diagnosing cytopathological materials using digital cytopathology.

The Role of Histogram-Based Textural Analysis of 18F-FDG PET/CT in Evaluating Tumor Heterogeneity and Predicting the Prognosis of Invasive Lung Adenocarcinoma

Objectives:

This study aimed to investigate the contributory role of histogram-based textural features (HBTFs) extracted from ¹⁸fluorinefluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) in tumoral heterogeneity (TH) evaluation and invasive lung adenocarcinoma (ILA) prognosis prediction.

Methods:

This retrospective study analyzed the data of 72 patients with ILA who underwent ¹⁸F-FDG PET/CT followed by surgical resection. The maximum standardized uptake value (SUV_max), metabolic tumor volume, and total lesion glycolysis values were calculated for each tumor. Additionally, HBTFs were extracted from ¹⁸F-FDG PET/CT images using the software program. ILA was classified into the following five histopathological subtypes according to the predominant pattern: Lepidic adenocarcinoma (LA), acinar adenocarcinoma, papillary adenocarcinoma, solid adenocarcinoma (SA), and micropapillary adenocarcinoma (MA). Differences between ¹⁸F-FDG PET/CT parameters and histopathological subtypes were evaluated using non-parametric tests. The study endpoints include overall survival (OS) and progression-free survival (PFS). The prognostic values of clinicopathological factors and ¹⁸F-FDG PET/CT parameters were evaluated using the Cox regression analyses.

Results:

The median SUV_max and entropy values were significantly higher in SA-MA, whereas lower in LA. The median energy-uniformity value of the LA was significantly higher than the others. Among all parameters, only skewness and kurtosis were significantly associated with lymph node involvement status. The median values for follow-up time, PFS, and OS were 31.26, 16.07, and 20.87 months, respectively. The univariate Cox regression analysis showed that lymph node involvement was the only significant predictor for PFS. The multivariate Cox regression analysis revealed that higher SUV_max (≥11.69) and advanced stage (IIB-IIIA) were significantly associated with poorer OS [hazard ratio (HR): 3.580, p=0.024 and HR: 7.608, p=0.007, respectively].

Conclusion:

HBTFs were tightly associated with clinicopathological factors causing TH. Among the ¹⁸F-FDG PET/CT parameters, only skewness and kurtosis were associated with lymph node involvement, whereas SUV_max was the only independent predictor of OS. TH measurement with HBTFs may contribute to conventional metabolic parameters in guiding precision medicine for ILA.

Relationship between 18F-FDG PET/CT Semi-Quantitative Parameters and International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society Classification in Lung Adenocarcinomas

Objective

To investigate the relationship between ¹⁸F-FDG PET/CT semi-quantitative parameters and the International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histopathologic classification, including histological subtypes, proliferation activity, and somatic mutations.

Materials and Methods

This retrospective study included 419 patients (150 males, 269 females; median age, 59.0 years; age range, 23.0–84.0 years) who had undergone surgical removal of stage IA–IIIA lung adenocarcinoma and had preoperative PET/CT data of lung tumors. The maximum standardized uptake values (SUVmax), background-subtracted volume (BSV), and background-subtracted lesion activity (BSL) derived from PET/CT were measured. The IASLC/ATS/ERS subtypes, Ki67 score, and epidermal growth factor/anaplastic lymphoma kinase (EGFR/ALK) mutation status were evaluated. The PET/CT semi-quantitative parameters were compared between the tumor subtypes using the Mann–Whitney U test or the Kruskal–Wallis test. The optimum cutoff values of the PET/CT semi-quantitative parameters for distinguishing the IASLC/ATS/ERS subtypes were calculated using receiver operating characteristic curve analysis. The correlation between the PET/CT semi-quantitative parameters and pathological parameters was analyzed using Spearman’s correlation. Statistical significance was set at p < 0.05.

Results

SUVmax, BSV, and BSL values were significantly higher in invasive adenocarcinoma (IA) than in minimally IA (MIA), and the values were higher in MIA than in adenocarcinoma in situ (AIS) (all p < 0.05). Remarkably, an SUVmax of 0.90 and a BSL of 3.62 were shown to be the optimal cutoff values for differentiating MIA from AIS, manifesting as pure ground-glass nodules with 100% sensitivity and specificity. Metabolic-volumetric parameters (BSV and BSL) were better potential independent factors than metabolic parameters (SUVmax) in differentiating growth patterns. SUVmax and BSL, rather than BSV, were strongly or moderately correlated with Ki67 in most subtypes, except for the micropapillary and solid predominant groups. PET/CT parameters were not correlated with EGFR/ALK mutation status.

Conclusion

As noninvasive surrogates, preoperative PET/CT semi-quantitative parameters could imply IASLC/ATS/ERS subtypes and Ki67 index and thus may contribute to improved management of precise surgery and postoperative adjuvant therapy.

Is It Possible to Establish a Reliable Correlation between Maximum Standardized Uptake Value of 18-Fluorine Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography and Histological Types of Non-Small Cell Lung Cancer? Analysis of the Italian VATS Group Database

BACKGROUND

Although positron emission tomography/computed tomography, often integrated with 2-deoxy-2-[fluorine-18] fluorine-D-glucose (18F-FDG-PET/CT), is fundamental in the assessment of lung cancer, the relationship between metabolic avidity of different histotypes and maximum standardized uptake value (SUVmax) has not yet been thoroughly investigated. The aim of the study is to establish a reliable correlation between Suvmax and histology in non-small cell lung cancer (NSCLC), in order to facilitate patient management.

METHODS

We retrospectively assessed the data about lung cancer patients entered in the Italian Registry of VATS Group from January 2014 to October 2019, after establishing the eligibility criteria of the study. In total, 8139 patients undergoing VATS lobectomy were enrolled: 3260 females and 4879 males. The relationship between SUVmax and tumor size was also analyzed.

RESULTS

The mean values of SUVmax in the most frequent types of lung cancer were as follows: (a) 4.88 ± 3.82 for preinvasive adenocarcinoma; (b) 5.49 ± 4.10 for minimally invasive adenocarcinoma; (c) 5.87 ± 4.18 for invasive adenocarcinoma; and (d) 8.85 ± 6.70 for squamous cell carcinoma. Processing these data, we displayed a statistically difference (p < 0.000001) of FDG avidity between adenocarcinoma and squamous cell carcinoma. Moreover, by classifying patients into five groups based on tumor diameter and after evaluating the SUVmax value for each group, we noted a statistical correlation (p < 0.000001) between size and FDG uptake, also confirmed by the post hoc analysis.

CONCLUSIONS

There is a correlation between SUVmax, histopathology outcomes and tumor size in NSCLC. Further clinical trials should be performed in order to confirm our data.

Frequent EGFR Mutations and Better Prognosis in Positron Emission Tomography-Negative, Solid-Type Lung Cancer

BACKGROUND

The differential diagnosis of a solitary solid-type lung nodule is diverse. 18F-fluorodeoxyglucose positron emission tomography (PET) has a high sensitivity in the diagnosis of solid-type lung cancers; however, PET-negative, solid-type lung cancers are rarely observed. In this study, we analyzed the clinical/genetic features and prognosis of PET-negative, solid-type lung cancers.

PATIENTS AND METHODS

Between January 2007 and February 2020, 709 patients with solid-type lung cancers (tumor size ≥2.0 cm) underwent pulmonary resection. Clinical, genetic, and prognostic features were evaluated in 27 patients (3.8%) with tumors showing negative PET results defined as SUVmax <2.0.

RESULTS

All 27 patients had lung adenocarcinoma; 23 had invasive adenocarcinomas and 4 had invasive mucinous adenocarcinomas. The PET-negative group showed high frequencies of females and never-smokers. Recurrence-free survival was significantly better in the PET-negative group compared with PET-positive counterparts extracted using propensity score matching from patients who underwent pulmonary resection during the same period (P = .0052). Furthermore, 83% of PET-negative, solid-type invasive lung adenocarcinoma patients harbored EGFR mutation, which was significantly higher than that of PET-positive, solid-type invasive lung adenocarcinoma patients (38%, n = 225) who received EGFR mutation testing in our cohort (P < .0001). PET-negative, solid-type lung adenocarcinoma patients with EGFR mutations had significantly better recurrence-free survival compared with PET-positive, solid-type lung adenocarcinoma patients with EGFR mutations extracted using propensity score matching (P = .0030).

CONCLUSION

PET-negative, solid-type lung cancers are characterized with a high incidence of EGFR mutation and a better prognosis compared with PET-positive, solid-type lung cancer.

The Effect of GLUT1 on Survival Rate and the Immune Cell Infiltration of Lung Adenocarcinoma and Squamous Cell Carcinoma: A Meta and Bioinformatics Analysis

BACKGROUND

Lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC) are two major subtypes of non-small cell lung cancer (NSCLC). Studies have shown that abnormal expression of glucose transport type 1 (GLUT1) in NSCLC patients has been associated with progression, aggressiveness, and poor clinical outcome. However, the clinical effect of GLUT1 expression on LUAD and LUSC is unclear.

OBJECTIVE

This study aims to learn more about the character of GLUT1 in LUAD and LUSC.

METHODS

A meta-analysis was performed to evaluate the GLUT1 protein level, and bioinformatics analysis was used to detect the GLUT1 mRNA expression level, survival differences, and the infiltration abundance of immune cells in samples from TCGA. Meanwhile, functional and network analysis was conducted to detect important signaling pathways and key genes with the Gene Expression Omnibus (GEO) dataset.

RESULTS

Our results showed that GLUT1 was over-expressed both in LUAD and LUSC. LUAD patients with high GLUT1 expression had a poor prognosis. Additionally, GLUT1 was related to B cell and neutrophil infiltration of LUAD. In LUSC, GLUT1 was correlated with tumor purity, B cell, CD8⁺ T cell, CD4⁺ T cell, macrophage, neutrophil, and dendritic cell infiltration. The GEO dataset analysis results suggested GLUT1 potentially participated in the p53 signaling pathway and metabolism of xenobiotics by cytochrome P450 and was associated with KDR, TOX3, AGR2, FOXA1, ERBB3, ANGPT1, and COL4A3 gene in LUAD and LUSC.

CONCLUSION

GLUT1 might be a potential biomarker for aggressive progression and poor prognosis in LUAD, and a therapeutic biomarker in LUSC.

FDG-PET/CT for pretherapeutic lymph node staging in non-small cell lung cancer: A tailored approach to the ESTS/ESMO guideline workflow

OBJECTIVES

In patients with NSCLC, current ESTS and ESMO guidelines recommend invasive lymph node (LN) staging with EBUS-TBNA even if FDG-PET/CT is negative for mediastinal LNs if at least one of three risk factors is present (cN1, non-peripheral primary or primary >3 cm). Modified workflows to avoid unnecessary invasive procedures were evaluated.

MATERIALS AND METHODS

Monocentric retrospective analysis of pretherapeutic FDG-PET/CT in 247 patients with NSCLC (62 % male; age, 68 [43-88] years) using an analog or digital PET/CT scanner. PET windowing was standardized. LNs were positive if 'LN uptake > mediastinal blood pool' or short axis >10 mm. Surgery or EBUS-TBNA served as reference for diagnostic accuracy per LN station. In all patients with negative mediastinal LNs by PET/CT, LN histology from surgery was available.

RESULTS

Among 700 L N stations analyzed, 180 were malignant. Sensitivity and specificity of PET/CT per LN station were 93 % and 71 %. Following current guidelines, 76 patients with mediastinal negative PET/CT required confirmatory invasive staging. Only 5/76 patients had unexpected pN2 (all had adenocarcinoma). In a modified approach, confirmatory invasive staging was confined to patients with mediastinal negative PET/CT who showed all three risk factors. Using this modification, EBUS-TBNA could have been omitted in 62 (82 %) of the 76 patients who required EBUS-TBNA based on current recommendation. Among these 62 patients, only one patient had unsuspected pN2 (single-level) while the remaining 61 of 62 omitted EBUS-TBNA were deemed unnecessary because mediastinal LNs were confirmed to be negative. No multi-level pN2 would have been missed.

CONCLUSION

In the current analysis, 82 % of EBUS-TBNA procedures in patients with mediastinal negative PET/CT could have been omitted by modifying the current guideline workflow as proposed (i.e., restricting EBUS-TBNA in patients with cN0/1 to those with all three risk factors). This was consistent with different PET/CT scanners. Prospective confirmation is required.

Can dynamic imaging, using 18F-FDG PET/CT and CT perfusion differentiate between benign and malignant pulmonary nodules?

BACKGROUND

The aim of the study was to derive and compare metabolic parameters relating to benign and malignant pulmonary nodules using dynamic 2-deoxy-2-[fluorine-18]fluoro-D-glucose (¹⁸F-FDG) PET/CT, and nodule perfusion parameters derived through perfusion computed tomography (CT).

PATIENTS AND METHODS

Twenty patients with 21 pulmonary nodules incidentally detected on CT underwent a dynamic ¹⁸F-FDG PET/CT and a perfusion CT. The maximum standardized uptake value (SUV_max) was measured on conventional ¹⁸F-FDG PET/CT images. The influx constant (K_i ) was calculated from the dynamic ¹⁸F-FDG PET/CT data using Patlak model. Arterial flow (AF) using the maximum slope model and blood volume (BV) using the Patlak plot method for each nodule were calculated from the perfusion CT data. All nodules were characterized as malignant or benign based on histopathology or 2 year follow up CT. All parameters were statistically compared between the two groups using the nonparametric Mann-Whitney test.

RESULTS

Twelve malignant and 9 benign lung nodules were analysed (median size 20.1 mm, 9-29 mm) in 21 patients (male/female = 11/9; mean age ± SD: 65.3 ± 7.4; age range: 50-76 years). The average SUV_max values ± SD of the benign and malignant nodules were 2.2 ± 1.7 vs. 7.0 ± 4.5, respectively (p = 0.0148). Average K_i values in benign and malignant nodules were 0.0057 ± 0.0071 and 0.0230 ± 0.0155 min^-1, respectively (p = 0.0311). Average BV for the benign and malignant nodules were 11.6857 ± 6.7347 and 28.3400 ± 15.9672 ml/100 ml, respectively (p = 0.0250). Average AF for the benign and malignant nodules were 74.4571 ± 89.0321 and 89.200 ± 49.8883 ml/100g/min, respectively (p = 0.1613).

CONCLUSIONS

Dynamic ¹⁸F-FDG PET/CT and perfusion CT derived blood volume had similar capability to differentiate benign from malignant lung nodules.

Cell-free DNA concentration and fragment size fraction correlate with FDG PET/CT-derived parameters in NSCLC patients

PURPOSE

The aim of our study was to investigate the correlation between cfDNA concentration and fragment size fraction with FDG PET/CT- and CT-derived parameters in untreated NSCLC patient.

METHODS

Fifty-three patients diagnosed of locally advanced or metastatic NSCLC who had undergone FDG PET/CT, CT and cfDNA analysis prior to any treatment were included in this retrospective study. CfDNA concentration was measured by fluorometry and fragment size fractions were determined by microchip electrophoresis. [¹⁸F]F-FDG PET/CT was performed and standardised uptake values (SUV), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were calculated for primary, extrapulmonary and total disease. CT scans were evaluated according to RECIST 1.1 criteria.

RESULTS

CfDNA concentration showed a positive correlation with extrapulmonary MTV (r² = 0.36, P = 0.009), and extrapulmonary TLG (r² = 0.35, P = 0.009) and their whole-body (wb) ratios. Higher concentrations of total cfDNA were found in patients with liver lesions. Short fragments of cfDNA (100-250 bp) showed a positive correlation with extrapulmonary MTV (r² = 0.49, P = 0.0005) and extrapulmonary TLG (r² = 0.39, P = 0.006) and their respective wb ratios, and a negative correlation with SUVmean (r² = -0.31, P = 0.03) and SUVmean/SUVmax ratio (r² = -0.34, P = 0.02). A higher fraction of short cfDNA fragments was found in patients with liver and pleural lesions.

CONCLUSIONS

This study supports the hypothesis that cfDNA concentration and short cfDNA fragment size fraction reflect the tumour burden as well as metabolic activity in advanced NSCLC patients. This suggests their suitability as complementary tests for a more accurate diagnosis of tumour metabolic behaviour and to allow personalised therapies.

SUVmax of 18FDG PET/CT Predicts Histological Grade of Lung Adenocarcinoma

OBJECTIVES

The relationship between the ¹⁸FDG PET-CT maximum standard uptake value (SUVmax) and the type of lung adenocarcinoma is still not established. The aim of this study was to investigate the relationship between SUVmax value and histological grade and pathological subtype of lung adenocarcinoma, and to determine the optimum SUVmax cutoffs for distinguishing different histological grades.

MATERIALS AND METHODS

The data of 618 lung adenocarcinoma patients were retrospectively analyzed. The relationship between SUVmax measured on preoperative ¹⁸FDG-PET-CT and the histological grade and pathological subtype was examined. The Kruskal-Wallis test was used to compare differences among groups, and the Bonferroni-Dunn test for pairwise comparison among groups. ROC analysis was applied to determine the optimal cut-off values for distinguishing different groups. In addition, the cut-off value was verified in an independent cohort of 85 consecutive lung adenocarcinoma cases.

RESULTS

The SUVmax was significantly different between the low, intermediate, and high-grade groups(p < .001). SUVmax value increased with increase in the degree of malignancy. The optimal cut-off value for identifying low-grade tumors was 2.01 (sensitivity 90.4%, specificity 86.9%, area under the curve [AUC] = 0.928, 95% confidence interval: 0.91-0.95; p < .001). The optimal cutoff SUVmax value for identifying high-grade tumors was 7.41 (sensitivity 79.8%, specificity 73.5%, AUC = 0.830, 95% confidence interval: 0.79-0.87; p < .001). The validation experiment showed that the coincidence rate was 88.89% in the low-level group, 64.15% in the middle-level group, and 78.57% in the high-level group.

CONCLUSION

SUVmax can be used to predict pathological subtype and histological grade of lung adenocarcinoma. Thus, ¹⁸FDG PET-CT can serve as a noninvasive tool for precise diagnosis and help in the preoperative formulation of patient-specific treatment strategies.

Differences in PET/CT standardized uptake values involvement and survival compared to histologic subtypes of lung adenocarcinoma

PURPOSE

Lung adenocarcinoma is histologically diverse but has distinct histologic growth patterns. There is no consensus on the clinical benefit of this histologic model. We aimed to evaluate the differences in the distribution of the preoperative primary tumor positron emission tomography (PET)/computed tomography (CT) standardized uptake values (SUVs) and survival in the lung adenocarcinoma subtypes.

METHODS

We retrospectively evaluated the data of 107 patients with resected lung adenocarcinoma who had preoperative PET/CT between 2005 and 2017 in a single center. Patients had lepidic, acinar, papillary, micropapillary, and solid histologic subtypes. We compared fluorodeoxyglucose SUVs and survival data of histologic subtypes.

RESULTS

The median age of the patients was 62 years (40-75), 76.4% were male, the median SUVmax was 9.4 (1-36.7), and the median follow-up time was 29 months (3-135 months). The median overall survival (OS) was 71 months and the median progression-free survival (PFS) was 33 months. SUVmax was significantly different in histologic subtypes: values for papillary, micropapillary, solid, acinar, and lepidic subtypes were 9.7, 8, 12, 9.1, and 3.9, respectively (p = 0.000). Solid predominant adenocarcinoma had significantly higher SUVmax than the other subtypes (p = 0.001). Lepidic predominant adenocarcinoma had significantly lower SUVmax than the other subtypes (p = 0.000). There was no significant difference in OS between histologic subtypes (p = 0.66), but PFS was significantly different between the groups (p = 0.017), and the solid subtype had a shorter PFS than the other histologic subtypes.

CONCLUSION

Lung adenocarcinoma consists of a diverse group of diseases. Different SUVmax values are seen in different histologic subtypes of nonmetastatic lung adenocarcinoma. Solid predominant types have high SUVmax values while lepidic predominant types have lower SUVmax values. The solid subtype had a shorter PFS than the other histologic subtypes.

Role of PET/CT in Management of Early Lung Adenocarcinoma

OBJECTIVE. The purpose of this study was to explore the value of FDG PET combined with high-resolution CT (HRCT) in predicting the pathologic subtypes and growth patterns of early lung adenocarcinoma. MATERIALS AND METHODS. A retrospective analysis was conducted on the PET/CT data on ground-glass nodules (GGNs) resected from patients with stage IA lung adenocarcinoma. The efficacy of PET maximum standardized uptake value (SUV_max) combined with HRCT signs in prediction of histopathologic subtype and growth pattern of lung adeno-carcinoma was evaluated. RESULTS. SUV_max was significantly higher in GGNs with invasive HRCT signs. The diameter of GGN (odds ratio, 1.660; p = 0.000) and the difference in attenuation value (odds ratio, 1.012; p = 0.011) between ground-glass components and adjacent lung tissues were independent predictors of FDG uptake by GGNs. SUV_max was higher in invasive adenocarcinoma than in adenocarcinoma in situ (AIS)-minimally invasive adenocarcinoma (MIA) (median SUV_max, 2.0 vs 1.1; p = 0.008). An SUV_max of 2.0 was the optimal cutoff value for differentiating invasive adenocarcinoma from AIS-MIA. Acinar-papillary adenocarcinoma had a higher SUV_max than lepidic adenocarcinoma (median SUV_max, 2.1 vs 1.3; p = 0.037). An SUV_max of 1.4 was the optimal cutoff value for differentiating the growth pattern of adenocarcinoma. Use of PET/CT with HRCT significantly improved efficacy for differentiating invasive adeno-carcinoma from AIS-MIA. However, use of HRCT cannot significantly improve the diagnostic efficacy of FDG PET in the evaluation of tumors with different growth patterns. CONCLUSION. FDG PET can be used to predict the histopathologic subtypes and growth patterns of early lung adenocarcinoma. Combined with HRCT, it has value for predicting invasive histopathologic subtypes but no significance for predicting invasive growth patterns.

Associations between GLUT expression and SUV values derived from FDG-PET in different tumors-A systematic review and meta analysis

Purpose

Fluorodeoxyglucose-Positron-emission tomography (FDG-PET), quantified by standardized uptake values (SUV), is one of the most used functional imaging modality in clinical routine. It is widely acknowledged to be strongly associated with Glucose-transporter family (GLUT)-expression in tumors, which mediates the glucose uptake into cells. The present systematic review sought to elucidate the association between GLUT 1 and 3 expression with SUV values in various tumors.

Methods

MEDLINE library was screened for associations between FDG-PET parameters and GLUT correlation cancer up to October 2018.

Results

There were 53 studies comprising 2291 patients involving GLUT 1 expression and 11 studies comprising 405 patients of GLUT 3 expression. The pooled correlation coefficient for GLUT 1 was r = 0.46 (95% CI 0.40–0.52), for GLUT 3 was r = 0.35 (95%CI 0.24–0.46). Thereafter, subgroup analyses were performed. The highest correlation coefficient for GLUT 1 was found in pancreatic cancer r = 0.60 (95%CI 0.46–0.75), the lowest was identified in colorectal cancer with r = 0.21 (95% CI -0.57–0.09).

Conclusion

An overall only moderate association was found between GLUT 1 expression and SUV values derived from FDG-PET. The correlation coefficient with GLUT 3 was weaker. Presumably, the underlying mechanisms of glucose hypermetabolism in tumors are more complex and not solely depended on the GLUT expression.

Computed Tomography Histogram Approach to Predict Lymph Node Metastasis in Patients With Clinical Stage IA Lung Cancer

BACKGROUND

Quantitative computed tomography (CT) histogram analysis of tumors is reported to help distinguish between invasive and less invasive lung cancers. This study aimed to clarify whether CT histogram analysis of tumors can be used to classify patients with clinical stage 0 to IA non-small cell lung cancer according to pathologic lymph node (pN) status.

METHODS

Predictive factors associated with pN metastasis were identified from the derivation dataset including 629 patients with clinical stage 0 to IA non-small cell lung cancer who underwent complete resection with lymph node dissection (surgeries between 2008 and 2013). The validation dataset including 238 patients (surgeries between 2014 and 2015) were subsequently reevaluated. Clinicosurgical factors, including CT histogram analysis of tumors (CT value percentiles 2.5, 25, 50, 75, and 97.5, skewness, and kurtosis) were assessed.

RESULTS

Seventy-three patients (12%) in the derivation cohort and 35 patients (15%) in the validation cohort had positive nodes. The pN status significantly affected survival in the entire population: 5-year overall survival of 93.1% vs 71.1% and 5-year disease-free survival of 85.9% vs 43.1% for negative vs positive (both P < .001). On multivariate analysis in the derivation cohort, the 75th percentile CT value (P < .001), age (P = .003), and comorbidities (P = .006) were significantly associated with pN metastasis. The area under the curve and the cutoff level of the 75th percentile CT value relevant to pN metastasis were 0.729 and 1.5 HU, respectively, and the threshold value provided accuracy of 71% for the validation cohort.

CONCLUSIONS

Histogram analysis of CT imaging metrics of tumors contributes to noninvasive prediction of pN metastasis in patients with clinical stage 0 to IA non-small cell lung cancer.

Predictive accuracy of lepidic growth subtypes in early-stage adenocarcinoma of the lung by quantitative CT histogram and FDG-PET

OBJECTIVES

The aim of this study was to analyze the accuracy of computed tomography (CT) and F-18 fluorodeoxyglucose-positron emission tomography/CT (FDG-PET/CT) to distinguish lepidic growth adenocarcinoma (LGA), including adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and lepidic-predominant adenocarcinoma, all of which have favorable survival outcomes, from the more aggressive and invasive non-LGA subtypes.

MATERIALS AND METHODS

We identified 225 patients with c-0/I adenocarcinoma of the lung who underwent PET/CT and 3DCT followed by complete resection. Maximum standardized uptake values (SUVmax) of FDG and several histogram parameters were analyzed. Histological grades were classified according to the predominant subtype (G1: lepidic; G3: micropapillary or solid; and G2: subtypes other than G1/G3).

RESULTS

The proportion of pathological invasive factors (lymphatic vessel involvement/blood vessel invasion/pleural invasion/lymph node metastasis) of patients with preinvasive adenocarcinoma, G1, G2, and G3 tumors were 0%, 3.6%, 48.0%, and 100%, respectively; p <  0.001). Multivariate analysis with CT-related parameters demonstrated that 75^th percentile CT attenuation value (75^th%, p <  0.001) and maximum CT attenuation value (maxCT, p =  0.009) were associated with incidence of non-LGA, whereas the value of SUVmax demonstrated a significant correlation (p <  0.001). When all patients were dichotomized according to ground-glass opacities (GGO)/solid-dominancy for CT maximum diameter, a significant correlation with non-LGA was shown in patients with solid-dominant tumor on SUVmax (p <  0.001) and with GGO-dominant tumor on 75^th% (p =  0.006) and maxCT (p =  0.007). The combination of one of the two significant histogram parameters and SUVmax revealed higher predictive performance for pathological high malignant features (positive pathological invasive factors, non-LGA, and the highly malignant subtype covering G2 with moderately or poorly-differentiated carcinoma and G3) than the individual use of either factor.

CONCLUSION

The 75^th%, maxCT, and SUVmax were highly useful in distinguishing LGA from non-LGA in c-0/I adenocarcinoma.

Updating the role of FDG PET/CT for evaluation of lung cancer manifesting in nonsolid nodules

PURPOSE

To assess the feasibility of using CT to correct specific uptake values (SUVs) for fluorodeoxyglucose (FDG) in patients with nonsolid nodules.

METHODS

Patients with FDG-PET/CT and thin-section CT were included in this pilot study. Thirty-five adenocarcinomas manifesting as nonsolid nodules were classified into two groups; 90-100% and 1-89% lepidic component. SUVmax was corrected based on the CT determination of the proportion of soft tissue component within the cancer (SUVatt).

RESULTS

Both SUVmax and SUVatt increased as the percentage of the lepidic component decreased. SUVmax and SUVatt were significantly different between the groups.

CONCLUSION

Extent of invasiveness of nonsolid cancers (as a marker of aggressiveness) can potentially be quantified by PET/CT using a correction method that accounts for the proportion of soft tissue within the tumor.

Differences of tumor microenvironment between stage I lepidic-positive and lepidic-negative lung adenocarcinomas

OBJECTIVE

Lepidic growth is a noninvasive component of lung adenocarcinoma. Many adenocarcinoma cases contain coexistent lepidic and nonlepidic (invasive) components (lepidic-growth positive [Lep+] adenocarcinoma); however, some cases comprise only nonlepidic components (lepidic-growth negative [Lep-] adenocarcinoma). The aim of this study was to investigate the biological differences between the invasive components of Lep+ and Lep- adenocarcinoma.

METHODS

We investigated the clinicopathologic characteristics of 232 adenocarcinomas (116 size-matched tumor pairs from Lep+ and Lep- adenocarcinomas). We then evaluated the cancer cell-specific expression levels of cancer stem cell, hypoxia, and invasion molecules in these lesions. The number of tumor-promoting stromal cells, including podoplanin-positive cancer-associated fibroblasts and CD204-positive tumor-associated macrophages, was also analyzed.

RESULTS

Among cases with size-matched invasive components, significant differences were shown in total tumor size and predominant subtype in invasive component between Lep+ and Lep- adenocarcinomas. The expression levels of hypoxia-related molecules were significantly lower in Lep+ adenocarcinomas (glucose transporter 1: 0 vs 10, P < .01; carbonic anhydrase IX: 0 vs 0 [mean, 4.7 vs 14.1], P = .01). The number of podoplanin-positive cancer-associated fibroblasts and CD204-positive tumor-associated macrophages was significantly lower in Lep+ adenocarcinomas (podoplanin-positive cancer-associated fibroblasts: 0 vs 0 [mean: 1.6 vs 11.6], P < .01; CD204-positive tumor-associated macrophages: 8.7 vs 24.7, P < .01).

CONCLUSIONS

Our results indicated that lower cancer cell-specific expression levels of hypoxia markers and a smaller number of tumor-promoting stromal cells in invasive component were characteristic features of Lep+ adenocarcinomas.

Value of combining serum carcinoembryonic antigen and PET/CT in predicting EGFR mutation in non-small cell lung cancer

Background

We sought to investigate the associations between pretreatment serum Carcinoembryonic antigen (CEA) level, ¹⁸F-Fluoro-2-deoxyglucose (¹⁸F-FDG) uptake value of primary tumor and epidermal growth factor receptor (EGFR) mutation status in non-small cell lung cancer (NSCLC).

Methods

We retrospectively reviewed medical records of 210 NSCLC patients who underwent EGFR mutation test and ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) scan before anti-tumor therapy. The associations between EGFR mutations and patients' characteristics, serum CEA, PET/CT imaging characteristics maximal standard uptake value (SUVmax) of the primary tumor were analyzed. Receiver-operating characteristic (ROC) curve was used to assess the predictive value of these factors.

Results

EGFR mutations were found in 70 patients (33.3%). EGFR mutations were more common in high CEA group (CEA ≥7.0 ng/mL) than in low CEA group (CEA <7.0 ng/mL) (40.4% vs. 27.6%; P=0.05). Females (P<0.001), non-smokers (P<0.001), patients with adenocarcinoma (P<0.001) and SUVmax <9.0 (P=0.001) were more likely to be EGFR mutation-positive. Multivariate analysis revealed that gender, tumor histology, pretreatment serum CEA level, and SUVmax were the most significant predictors for EGFR mutations. The ROC curve revealed that combining these four factors yielded a higher calculated AUC (0.80).

Conclusions

Gender, histology, pretreatment serum CEA level and SUVmax are significant predictors for EGFR mutations in NSCLC. Combining these factors in predicting EGFR mutations has a moderate diagnostic accuracy, and is helpful in guiding anti-tumor treatment.

Standardized uptake value and radiological density attenuation as predictive and prognostic factors in patients with solitary pulmonary nodules: our experience on 1,592 patients

BACKGROUND

Multislice computed tomography (MSCT) increased detection of solitary pulmonary nodules (SPNs), changing the management based on radiological and clinical factors. When 18-fluorine fluorodeoxyglucose positron emission tomography combined with computed tomography (¹⁸F-FDG-PET/CT) was considered for the evaluation of nodules, the maximum standardized uptake value (SUVmax) more than 2.5 is used frequently as a cut off for malignancy. The purpose of this study is to evaluate SUVmax PET/CT and pulmonary attenuation patterns at MSCT in patients with SPN according to morphological and pathological characteristics of the lesion.

METHODS

A retrospective study on 1,592 SPN patients was carried out following approval by the Italian Registry of VATS Lobectomies.

RESULTS

All patients underwent VATS lobectomy. On histologic examination, 98.1% had primary or second metachronous primary lung cancers. In addition, 10.7% presented occult lymph node metastases (pN1 or pN2) on histological examination. Nodule attenuation on CT was associated with the histology of the lesion (p= 0.030); in particular, pure ground glass opacities (pGGOs) and partially solid nodules were related to adenocarcinomatous histotypes. Conversely, a significant relationship between SUVmax and age, nodule size, pathological node status (pN) was found (P=0.007, P=0.000 and P=0.002 respectively).

CONCLUSIONS

Nodule attenuation can predict the histology of the lesion whereas SUVmax may relate to the propensity to lymph node metastases.

The distinct metabolic phenotype of lung squamous cell carcinoma defines selective vulnerability to glycolytic inhibition

Adenocarcinoma (ADC) and squamous cell carcinoma (SqCC) are the two predominant subtypes of non-small cell lung cancer (NSCLC) and are distinct in their histological, molecular and clinical presentation. However, metabolic signatures specific to individual NSCLC subtypes remain unknown. Here, we perform an integrative analysis of human NSCLC tumour samples, patient-derived xenografts, murine model of NSCLC, NSCLC cell lines and The Cancer Genome Atlas (TCGA) and reveal a markedly elevated expression of the GLUT1 glucose transporter in lung SqCC, which augments glucose uptake and glycolytic flux. We show that a critical reliance on glycolysis renders lung SqCC vulnerable to glycolytic inhibition, while lung ADC exhibits significant glucose independence. Clinically, elevated GLUT1-mediated glycolysis in lung SqCC strongly correlates with high ¹⁸F-FDG uptake and poor prognosis. This previously undescribed metabolic heterogeneity of NSCLC subtypes implicates significant potential for the development of diagnostic, prognostic and targeted therapeutic strategies for lung SqCC, a cancer for which existing therapeutic options are clinically insufficient.

Adenocarcinoma and squamous cell carcinoma are distinct subtypes of non-small cell lung cancer. Here, the authors show that increased glycolytic flux, via increased glucose transporter Glut1 expression, is a core metabolic feature of squamous cell carcinoma that renders it sensitive to glycolysis inhibition.

Interstitial lung disease pattern turned out to be a predominantly lepidic lung adenocarcinoma

We report a case of a 46-year-old woman without any medical history who presented to our Respiratory Department with exertional dyspnoea for the last 6 weeks associated with non-productive cough. Chest radiography showed bilateral diffuse interstitial opacity. Bronchoalveolar lavage and transbronchial biopsies performed during flexible bronchoscopy as a step in the diagnostic workup of idiopathic interstitial pneumonia showed cells of pulmonary adenocarcinoma.

Comparison of Prognosis of Solid and Part-Solid Node-Negative Adenocarcinoma With the Same Invasive Component Size

BACKGROUND

Our study compared the prognosis of solid node-negative adenocarcinoma sized less than 20 mm with that of part-solid node-negative adenocarcinoma with an invasive tumor size of less than 20 mm.

METHODS

From 2003 to 2012, 191 patients were selected with a diagnosis of solid or part-solid pathologic node-negative adenocarcinoma with an invasive component sized less than 20 mm. The enrolled patients were categorized into two groups: group 1 had solid adenocarcinoma consisting only of the invasive component, and group 2 had part-solid adenocarcinoma consisting of both an in situ and an invasive component. Recurrence-free survival and overall survival at 5 years were compared using Kaplan- Meier survival analysis and the log-rank test.

RESULTS

The mean size of the invasive component was 15.9 mm in group 1 (n = 92) and 15.2 mm in group 2 (n = 99; p = 0.06), and the mean total lesion size was 15.9 mm in group 1 and 21.0 mm in group 2 (p < 0.001). The median follow-up duration was 54.2 months. The 5-year overall survival rates were 90.3% in group 1 and 93.8% in group 2 (p = 0.160), and the recurrence-free survival rates were 84.0% in group 1 and 93.7% in group 2 (p = 0.037). Lymphovascular invasion and high maximum standardized uptake values were significantly more common in group 1.

CONCLUSIONS

Although the total size of the part-solid adenocarcinoma lesions was larger than that of the solid adenocarcinoma lesions, the prognosis of part-solid adenocarcinoma was better than that of solid adenocarcinoma in cases of node-negative adenocarcinoma with invasive components sized less than 20 mm.

Association between histopathological subtype, 18F-fluorodeoxyglucose uptake and epidermal growth factor receptor mutations in lung adenocarcinoma

The aim of the present study was to investigate the association between histopathological subtypes, epidermal growth factor receptor (EGFR) mutations and ¹⁸F-fluorodeoxyglucose (FDG) uptake in patients with lung adenocarcinoma (ADC). The cases of 97 patients with lung ADC who underwent ¹⁸F-FDG positron emission tomography-computed tomography prior to surgical resection were retrospectively reviewed. The patients were stratified according to the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification, and graded using a histopathological scoring system. EGFR mutations were identified. Clinicopathological characteristics associated with EGFR mutation status were evaluated using univariate and multivariate analyses. EGFR mutation was identified in 45.4% of the patients and was associated with gender, smoking history, maximum standardized uptake value (SUVmax) and histopathological score. ADC patients with a low SUVmax were more likely to exhibit EGFR mutations compared with patients with a high SUVmax (P=0.018). Patients with a lower histopathological score possessed a significantly lower SUVmax compared with patients with a higher score (P<0.001). Furthermore, the histopathological score and smoking history of the patients were identified to be independent predictors for EGFR mutations, according to multivariate logistic regression analysis. In conclusion, SUVmax and EGFR mutations were associated with lung ADC patients stratified according to the IASLC/ATS/ERS classification. Overall, SUVmax has the potential to be a useful marker in stratifying pre-operative patients with lung ADC and identifying EGFR mutations.

Clinical Correlation Between Tumor Maximal Standardized Uptake Value in Metabolic Imaging and Metastatic Tumor Characteristics in Advanced Non-small Cell Lung Cancer

This study aimed to elucidate whether the maximal standardized uptake value (SUVmax) of primary tumors in metabolic imaging correlated with pathological or metastatic characteristics and whether it was prognostic in stage IV nonsmall cell lung cancer (NSCLC).We retrospectively reviewed the medical records of 412 eligible patients between June 2007 and January 2013. All enrolled patients fulfilled the following criteria: they were newly diagnosed with stage IV NSCLC without any previous treatment and had undergone a systemic evaluation, including 18(F)-Fluoro-2-deoxyglucose positron emission tomography/computed tomography, to assess synchronous metastatic sites. Patient and tumor characteristics were analyzed, and clinical correlations between SUVmax and metastatic features were investigated.The median age of the study population was 65 years (range, 30-94), and 259 (62.9%) patients were male. The median SUVmax was statistically higher in males, in tumors with squamous cell histology, and in poorly differentiated tumors. Multivariate logistic regression analysis revealed that SUVmax ≥ 11.4 (top 30 percentiles) were significantly correlated with positive lymph node status (odds ratio [OR] 3.473), abdomen/pelvis metastasis (OR 1.949), and the absence of bone metastasis (OR 0.399) in the subgroup of nonsquamous NSCLC (n = 343). In Kaplan-Meier survival analysis, overall survival was significantly lower among cohorts with high SUVmax (≥11.4) than with low SUVmax (<11.4) (P < 0.001, median 7.4 months vs 12.1 months).The tumors with different SUVmax have distinctive metastatic and biological features in stage IV NSCLC. The underlying mechanisms of this unique metabolic biology need to be resolved in future studies.

Advances in lung adenocarcinoma classification: a summary of the new international multidisciplinary classification system (IASLC/ATS/ERS)

Due to advances in the understanding of lung adenocarcinoma since the advent of its 2004 World Health System classification, an international multidisciplinary panel [sponsored by the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS)] has recently updated the classification system for lung adenocarcinoma, the most common histologic type of lung cancer. Here, we summarize and highlight the new criteria and terminology, certain aspects of its clinical relevance and its potential treatment impact, and future avenues of research related to the new system.

Oncogenic mutations are associated with histological subtypes but do not have an independent prognostic value in lung adenocarcinoma

Lung adenocarcinomas have diverse genetic and morphological backgrounds and are usually classified according to their distinct oncogenic mutations (or so-called driver mutations) and histological subtypes (the de novo classification proposed by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society [IASLC/ATS/ERS]). Although both these classifications are essential for personalized treatment, their integrated clinical effect remains unclear. Therefore, we analyzed 981 lung adenocarcinomas to detect the potential correlation and combined effect of oncogenic mutations and histological subtype on prognosis. Analysis for oncogenic mutations included the direct sequencing of EGFR, KRAS, HER2, BRAF, PIK3CA, ALK, and RET for oncogenic mutations/rearrangements, and a rereview of the IASLC/ATS/ERS classification was undertaken. Eligible tumors included 13 atypical adenomatous hyperplasia/adenocarcinoma in situ, 20 minimally invasive adenocarcinomas, 901 invasive adenocarcinomas, 44 invasive mucinous adenocarcinomas, and three other variants. The invasive mucinous adenocarcinomas had a lower prevalence of EGFR mutations but a higher prevalence of KRAS, ALK, and HER2 mutations than invasive adenocarcinomas. Smoking, a solid predominant pattern, and a mucinous component were independently associated with fewer EGFR mutations. The ALK rearrangements were more frequently observed in tumors with a minor mucinous component, while the KRAS mutations were more prevalent in smokers. In addition, 503 patients with stage I-IIIA tumors were analyzed for overall survival (OS) and relapse-free survival. The stage and histological pattern were independent predictors of relapse-free survival, and the pathological stage was the only independent predictor for the OS. Although patients with the EGFR mutations had better OS than those without the mutations, no oncogenic mutation was an independent predictor of survival. Oncogenic mutations were associated with the novel IASLC/ATS/ERS classification, which facilitates a morphology-based mutational analysis strategy. The combination of these two classifications might not increase the prognostic ability, but it provides essential information for personalized treatment.

Pathologic classification of adenocarcinoma of lung

Recently, the 1999/2004 World Health Organization (WHO) classification of adenocarcinoma became less useful from a clinical standpoint as most adenocarcinomas belonged to the mixed subtype and the term bronchioloalveolar carcinoma (BAC) gave rise to much confusion among clinicians. For these reasons a new adenocarcinoma classification was introduced in 2011 by a joint working group of the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS). This represents an international, multidisciplinary effort joining pathologists, molecular biologists, pulmonary physicians, thoracic oncologists, radiologists, and thoracic surgeons. Currently, a distinction is made between pre-invasive lesions, minimally invasive and invasive lesions. The confusing term BAC is not used anymore and new subcategories include adenocarcinoma in situ and minimally invasive adenocarcinoma. Several aspects of this classification are discussed with main emphasis on its correlation with imaging techniques and its impact on diagnosis, treatment and prognosis. On chest computed tomography (CT) a distinction is made between solid and subsolid nodules, the latter comprising ground glass opacities (GGO), and partly solid lesions. Several studies incorporating CT and positron emission tomographic (PET) data show a good imaging-pathologic correlation. With the implementation of screening programs early lung cancer has become a hotly debated topic and sublobar resection is currently reconsidered for early lesions without lymph node involvement. This new classification will also have an impact on the TNM classification. Thoracic surgeons will continue to play a major role in the application, evaluation and further refinement of this new adenocarcinoma classification.

The correlation of SUVmax with pathological characteristics of primary tumor and the value of Tumor/ Lymph node SUVmax ratio for predicting metastasis to lymph nodes in resected NSCLC patients

Background

We aimed to investigate the correlation of maximum standardized uptake value (SUVmax) with pathological characteristics of primary tumor and to determine a Tumor/ Lymph node (T/LN) SUVmax ratio predicting metastasis to lymph nodes in NSCLC patients.

Methods

Eighty-one NSCLC patients who had PET/CT examination at initial staging and subsequently underwent surgical resection were retrospectively evaluated. There were 100 PET/CT positive mediastinal or hilar lymph node stations. Pathological characteristics of the tumor such as largest tumor diameter, tumor histology, differentiation, number of mitosis, degree of stromal inflammation, necrosis; etiology of PET/CT positive lymph node stations; SUVmax of primary tumor and positive lymph node stations were recorded. A T/LN SUVmax ratio was calculated for each lymph node station.

Results

SUVmax of the primary tumor was positively correlated with the largest tumor diameter (p = 0.001, r = 0.374), number of mitosis (p < 0.001, r = 0.405), and postoperative pathological stage (p = 0.007, r = 0.298). Patients with squamous cell carcinoma had a statistically significant higher mean SUVmax, number of mitosis and advanced N stages compared to adenocarcinoma. The etiology of 100 PET/CT positive lymph node stations were metastasis in 14, anthracosis in 40, reactive in 39, granulomatous in 4, and silicosis in 3 patients. A T/LN SUVmax ratio of 5 or lower was suggestive for a malignant lymph node with a sensitivity of 92.8% and specificity of 47%.

Conclusions

SUVmax of a primary tumor is related to certain pathological characteristics, such as largest diameter, histology, and number of mitosis. A T/LN SUVmax ratio lower than 5 predicts the metastasis to lymph nodes with a high sensitivity.

Evaluation of integrated positron emission tomography and computed tomography accuracy in detecting lymph node metastasis in patients with adenocarcinoma vs squamous cell carcinoma

OBJECTIVES

The aim of our study was to analyze the specificity and sensitivity of integrated positron emission tomography and computed tomography (PET/CT) in detecting nodal metastasis according to histology (adenocarcinoma vs squamous cell carcinoma), and to identify the factors related to false-negative findings.

METHODS

A retrospective, single-institution review of 353 consecutive patients with suspected or pathologically proven, potentially resectable non-small-cell lung cancer (NSCLC) who had integrated PET/CT scanning at the same centre. Lymph node staging was pathologically confirmed on tissue specimens obtained at mediastinoscopy and/or thoracotomy. Statistical evaluation of PET/CT results was performed on a per-patient and per-nodal-station basis.

RESULTS

A total of 2286 nodal stations (1643 mediastinal, 333 hilar and 310 intrapulmonary) were evaluated. Adenocarcinoma was the final diagnosis in 244 patients and squamous carcinoma in 109 patients. Nodes were positive for malignancy in 80 (32.8%) of 244 patients with adenocarcinoma (N1 = 31; N2 = 48 and N3 = 1) and in 32 (29.3%) of 109 with squamous carcinoma (N1 = 21 and N2 = 11). PET/CT in the adenocarcinoma group had a sensitivity, specificity and accuracy of 53.8, 91.5 and 79.1%, and in the squamous cell group, of 87.5, 81.8 and 83.5%, respectively in a per-patient analysis. In the analysis for N2 disease on a per-patient basis, the sensitivity, specificity and accuracy were 38.8, 97.4, and 85.7% for the adenocarcinoma group and 81.8, 91.8 and 90.8% in the squamous cell group. In the adenocarcinoma group, the mean diameter of false-negative lymph nodes was 7 mm (standard deviation [SD] ± 2.5 mm) compared with the diameter of true-positive lymph nodes of 12.5 (SD ± 4 mm; P < 0.00001). In the squamous cell group, the mean diameter of false-negative lymph nodes was 7.4 mm (SD ± 2.8 mm) compared with the diameter of true-positive lymph nodes of 14.7 (SD ± 6 mm; P < 0.005). In the adenocarcinoma group, false-negative lymph nodes were statistically correlated with the presence of vascular invasion and in the squamous cell group only with the maximum standardized uptake value (SUV(max)) < 5.4.

CONCLUSIONS

The sensitivity of PET/CT in detecting nodal metastasis in patients with adenocarcinoma is too low to avoid any further invasive staging procedure. Ultrasound-guided needle biopsy or mediastinoscopy is still necessary in staging patients undergoing lung resection for adenocarcinoma.

[Application of ¹⁸F-FDG PET/CT in pulmonary disease: a report of 419 cases]

背景与目的

我国是肺癌的高发国家，PET/CT在我国的肺外科临床应用价值仍处在探索阶段。本研究总结病理证实的419例肺部肿瘤或肿瘤样病变的患者资料，探讨PET/CT在这一领域的应用价值。

方法

2007年12月-2011年8月北京大学肿瘤医院胸外一科单个医疗组对594例肺部肿瘤或肿瘤样病变的患者在诊治过程的不同阶段进行了PET/CT检查，以获得病理的419例患者为研究对象，结合临床、病理及随访，分析PET/CT在良恶性定性，肺癌TNM分期，疗效评价及疗后随访中的应用价值。

结果

全组419例患者中病理证实为良性者63例，恶性者356例，其中原发性肺癌338例，肺转移瘤18例。PET/CT对恶性肿瘤定性诊断（SUVmax＞2.5）的敏感性为85.0%，特异性为52.4%，准确性79.2%，阳性预测值89.2%，阴性预测值42.9%。338例患者中治疗前行PET/CT者275例，共发现远处转移46例（46/275, 16.7%），较传统检查（38/275, 13.8%）多发现8例。对临床怀疑术后复发者（89例）行PET/CT，发现复发43例（43/89, 48.3%），较传统检查（37/89, 41.6%）多发现6例。对手术的168例患者作了T及N分期相关性的研究，发现SUVmax与肿瘤直径正相关（P＜0.05）。清扫淋巴结共计610组，PET/CT诊断肺癌淋巴结转移的敏感性为36.3%，特异性为93.9%，准确性为84.3%，阳性预测值为54.4%，阴性预测值为88.0%。全组有10例患者化疗前后均作了PET/CT，SUVmax随肿瘤降期而下降，下降平均百分比为37.5%（P＜0.05）。

结论

PET/CT是现阶段除组织学外另一种可选的判断肺部良恶性病变的方法。PET/CT在肺癌M分期中的作用优于传统检查；也可作为术后复查的常规手段之一。PET/CT对淋巴结转移的诊断特异性较好，但敏感性不高。PET/CT在肺癌化疗评效中有积极意义。