Tumour standardized uptake value on positron emission tomography is a novel predictor of adenocarcinoma in situ for c-Stage IA lung cancer patients with a part-solid nodule on thin-section computed tomography scan

Predictive value of SUVmax in visceral pleural invasive lung adenocarcinoma with different diameters

OBJECTIVES

This study aimed to investigate predictive visceral pleural invasion (VPI) occurrence value of the maximum standardized uptake value (SUVmax) in patients with lung adenocarcinoma (LA).

PATIENTS AND METHODS

A total of 388 LA patients were divided into D1ab, D1c, D1, D2, D2a, D2b, D3, and all patient groups based on their tumor diameter (D). Patients were also classified into negative VPI (VPI-n) and positive VPI (VPI-p) groups according to VPI presence. SUVmax of patients was measured with 18F-fluorodeoxyglucose (FDG) by PET/computed tomography (18F-PET/CT). Receiver operating characteristic (ROC) analysis and the area under curve (AUC) of SUVmax were applied to determine optimal cut-off value for predicting VPI occurrence.

RESULTS

There were significant differences in SUVmax between VPI-n and VPI-p groups ( P  < 0.05) at the same tumor diameter. SUVmax cut-off value and sensitivity (Se,%) of VPI occurrence in each group were following: D1ab was 3.79 [AUC = 0.764, P  < 0.001], Se86.11%; D1c was 5.47 (AUC = 0.706, P  < 0.001), Se 93.75%; D1 was 5.49 (AUC = 0.731, P  < 0.001), Se 79.76%; D2 was 7.36 (AUC = 0.726, P  < 0.001), Se81.67%. All patient group was 7.26 (AUC = 0.735, P  < 0.001), Se74.19%.

CONCLUSION

In LA patients with the same diameter, SUVmax of the VPI-p group was significantly higher than that of the VPI-n group. The cut-off value of SUVmax for predicting VPI of T1 stage, T1 substages, and T2 stage LA could be determined through ROC curve. SUVmax measurement by PET/CT scan in stratified tumor size is helpful for predicting VPI occurrences of the physician.

Nomogram combining clinical and radiological characteristics for predicting the malignant probability of solitary pulmonary nodules measuring ≤ 2 cm

Background

At present, how to identify the benign or malignant nature of small (≤ 2 cm) solitary pulmonary nodules (SPN) are an urgent clinical challenge. This retrospective study aimed to develop a clinical prediction model combining clinical and radiological characteristics for assessing the probability of malignancy in SPNs measuring ≤ 2 cm.

Method

In this study, we included patients with SPNs measuring ≤ 2 cm who underwent pulmonary resection with definite pathology at Qilu Hospital of Shandong University from January 2020 to December 2021. Clinical features, preoperative biomarker results, and computed tomography characteristics were collected. The enrolled patients were randomized at a ratio of 7:3 into a training cohort of 775 and a validation cohort of 331. The training cohort was used to construct the predictive model, while the validation cohort was used to test the model independently. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors. The prediction model and nomogram were established based on the independent risk factors. The receiver operating characteristic (ROC) curve was used to evaluate the identification ability of the model. The calibration power was evaluated using the Hosmer-Lemeshow test and calibration curve. The clinical utility of the nomogram was also assessed by decision curve analysis (DCA).

Result

A total of 1,106 patients were included in this study. Among them, the malignancy rate of SPNs was 85.08% (941/1,106). We finally identified the following six independent risk factors by logistic regression: age, carcinoembryonic antigen, nodule shape, calcification, maximum diameter, and consolidation-to-tumor ratio. The area under the ROC curve (AUC) for the training cohort was 0.764 (95% confidence interval [CI]: 0.714-0.814), and the AUC for the validation cohort was 0.729 (95% CI: 0.647-0.811), indicating that the prediction accuracy of nomogram was relatively good. The calibration curve of the predictive model also demonstrated a good calibration in both cohorts. DCA proved that the clinical prediction model was useful in clinical practice.

Conclusion

We developed and validated a predictive model and nomogram for estimating the probability of malignancy in SPNs measuring ≤ 2 cm. With the application of predictive models, thoracic surgeons can make more rational clinical decisions while avoiding overtreatment and wasting medical resources.

Prognostic Significance of the Maximum Standardized Uptake Value on the Prognosis of Clinical Stage IA Lung Adenocarcinoma Based on the 8th Edition TNM Classification

BACKGROUND

There are few reports on the utility of the maximum standardized uptake value (SUVmax) for predicting the prognosis of early-stage lung adenocarcinoma based on the latest tumor-node-metastasis (TNM) classification. This study aimed to determine whether clinicopathologic factors, including the SUVmax, affect prognosis in these patients.

PATIENTS AND METHODS

We enrolled 527 patients with c-stage IA lung adenocarcinoma who underwent lobectomy or greater resection between 2011 and 2017. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using Kaplan-Meier curves and compared using the log-rank test. Factors associated with RFS and OS were determined using the Cox proportional hazards model.

RESULTS

RFS was significantly different based on tumor stage. In contrast, there was no significant difference in OS between patients with stage IA2 and IA3 disease (p = 0.794), although there were significant differences in OS between patients with stage IA1 and IA2 disease (p = 0.024) and between patients with stage IA1 and IA3 disease (p = 0.012). Multivariate analysis demonstrated that SUVmax was independently associated with both RFS and OS among patients with c-stage IA lung adenocarcinoma (RFS, p = 0.017; OS, p = 0.047). Further, even though there was no significant difference in OS between patients with stage IA2 and IA3 disease (n = 410), SUVmax was able to stratify patients with high and low RFS and OS among these patients (RFS, p < 0.001; OS, p < 0.001).

CONCLUSION

SUVmax was an important preoperative factor to evaluate prognosis among patients with c-stage IA lung adenocarcinoma as well as the current TNM classification.

A retrospective diagnostic test study on circulating tumor cells and artificial intelligence imaging in patients with lung adenocarcinoma

Background

Either tumor volume or folate-receptor-positive circulating tumor cells (FR⁺CTC) has been proven effective in predicting tumor cell invasion. However, it has yet to be documented to use FR⁺CTC along with artificial intelligence (AI) tumor volume to differentiate between pathological subtypes of lung adenocarcinoma (LUAD). Therefore, this study is aimed to evaluate the accuracy of FR⁺CTC and AI tumor volume for classifying the invasiveness of LUAD.

Methods

A total of 226 patients who were diagnosed with LUAD were enrolled. The inclusion criteria were: (I) FR⁺CTC detection and AI imaging before anticancer therapy, and (II) definite histopathologic diagnosis, which is the gold diagnosis of LUAD and its subtypes. Use the CytoploRare^® Detection Kit to quantify FR⁺CTC and the AI-assisted diagnosis system, ScrynPro, to measure tumor volume. The clinical data were used to construct univariate and multivariate logistic regression models. A nomogram was drawn based on the multivariate logistic regression model. The validity is evaluated by the calibration curve and Hosmer-Lemeshow goodness-of-fit test.

Results

The mean age of 146 patients (96 males, 49 females and 1 gender missing) retrospectively enrolled was 56.6. In the cohort, 41 and 105 patients were assigned to adenocarcinoma in situ (AIS) + minimally invasive adenocarcinoma (MIA) and invasive pulmonary adenocarcinoma (IPA), respectively. There was no significant difference between the sex distribution and smoking history of the two groups (P=0.155 and P=0.442, respectively). In univariate analysis, the nodules type, maximum density, tumor volume and FR⁺CTC level were statistically significant with the invasiveness of LUAD (P<0.05). The multivariate analysis showed significant differences in FR⁺CTC and AI tumor volume (P<0.001). The area under the curves (AUCs) of FR⁺CTC and AI tumor volume in diagnosing tumor invasiveness were 0.659 and 0.698, respectively. A predictive model combining FR⁺CTC with AI tumor volume showed a sensitivity of 86.89% and a specificity of 70.94%, and the AUC was 0.841. The nomogram had good agreement with actual observation, and the Hosmer-Lemeshow test yielded non-significant goodness-of-fit.

Conclusions

FR⁺CTC and/or AI tumor volume are independent indicators of the invasiveness of LUAD, and the nomogram based on them can be used for the preoperative screening of patients.

Folate receptor-positive circulating tumor cells in the preoperative diagnosis of indeterminate pulmonary nodules

BACKGROUND

The use of FR + CTC to distinguish lung cancer from benign lung disease has been well studied. However, the effective method to differentiate precursor glandular lesions from benign/malignant pulmonary diseases is rare.

METHODS

380 patients with indeterminate pulmonary nodules were prospectively recruited. Peripheral blood samples were collected from all participants before surgery for analyzing FR + CTC levels. The performance of FR + CTC to identify lung precursor lesions were analyzed by receiver operating characteristic (ROC) curve.

RESULTS

FR + CTC can effectively differentiate precursor from benign pulmonary diseases in all included patients (cutoff: 9.22 FU/3 ml, AUC = 0.807, (p < 0.0001, sensitivity: 69.17%, specificity: 82.46%) and patients with single pulmonary lesion (cutoff: 9.03 FU/3 ml, AUC = 0.842, p = 0.0001, sensitivity: 75.20%, specificity: 83.00%). However, FR + CTC cannot differentiate precursor from benign pulmonary diseases in multiple lesions patients (p = 0.110). FR + CTC neither differentiate precursor from malignant pulmonary lesions in all included patients (p = 0.715), single nor multiple lesions patients (p = 0.867, p = 0.692, respectively). Total number of pulmonary nodules, MTD, location (lower vs upper) were independent risk factors for malignancy (AOR, 95% CI: 3.104 (1.525, 6.316), 3.148 (1.722, 5.754), 2.098 (1.132, 3.888), respectively.

CONCLUSION

Preoperative FR + CTC can be identified in precursor glandular lesions and utilized to differentiate from benign pulmonary diseases. Total number of pulmonary nodules, MTD, location (lower vs upper) were independent risk factors for malignancy.

Managing screening-detected subsolid nodules-the Asian perspective

The broad application of low-dose computed tomography (CT) screening has resulted in the detection of many small pulmonary nodules. In Asia, a large number of these detected nodules with a radiological ground glass pattern are reported as lung adenocarcinomas or premalignant lesions, especially among female non-smokers. In this review article, we discuss controversial issues and conditions involving these subsolid pulmonary nodules that we often face in Asia, including a lack or insufficiency of current guidelines; the roles of preoperative biopsy and imaging; the location of lesions; appropriate selection of localization techniques; the roles of dissection and sampling of frozen sections and lymph nodes; multifocal lesions; and the roles of non-surgical treatment modalities. For these complex issues, we have tried to present up-to-date evidence and our own opinions regarding the management of subsolid nodules. It is our hope that this article helps surgeons and physicians to manage the complex issues involving ground glass nodules (GGNs) in a balanced manner in their daily practice and provokes further discussion towards better guidelines and/or algorithms.

Clinical Value of 18F-FDG PET/CT in Prediction of Visceral Pleural Invasion of Subsolid Nodule Stage I Lung Adenocarcinoma

RATIONALE AND OBJECTIVES

This study investigated the utility of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) for predicting visceral pleural invasion (VPI) of subsolid nodule (SSN) stage I lung adenocarcinoma.

MATERIALS AND METHODS

A retrospective analysis of ¹⁸F-FDG PET/CT data from 65 postsurgical cases with surgical pathology-confirmed SSN lung adenocarcinoma identified significant VPI predictors using multivariate logistic regression.

RESULTS

Nodule and solid component sizes, solid component-to-tumor ratios, pleural indentations, distances between nodules and pleura, and maximum standardized uptake values (SUVmax) differed significantly between VPI-positive (n = 30) and VPI-negative (n = 35) cases on univariate analysis. The distance between the nodule and pleura and SUVmax were significant independent VPI predictors on multivariate analysis. Areas under the curve of the distance between the nodule and pleura and SUVmax on receiver operating characteristic curves were 0.76 and 0.79, respectively; both factors were 0.90. The area under the curve of combined predictors was significantly superior to the distance between the nodule and pleura only but not SUVmax alone. The threshold of the distance between the nodule and pleura, to predict VPI was 4.50 mm, with 96.67% sensitivity, and 57.14% specificity. The threshold of SUVmax to predict VPI was 1.05, with 100% sensitivity and 60% specificity. The sensitivity and specificity of model 2 using the independent predictive factors were 96.67%, and 71.43%, respectively.

CONCLUSION

Distance between the nodule and pleura and SUVmax are independent predictors of VPI in SSN stage I lung adenocarcinoma. Further, combining these factors improves their predictive ability.

The Epidemiology of Ground Glass Opacity Lung Adenocarcinoma: A Network-Based Cumulative Meta-Analysis

Introduction: Due to the introduction of low-dose computed tomography (CT) and screening procedures, the proportion of early-stage lung cancer with ground glass opacity (GGO) manifestation is increasing in clinical practice. However, its epidemiological characteristics is still not fully investigated.

Methods: We retrieved all solitary GGO adenocarcinoma lung cancer (ADLC) on the PubMed, Cochrane Library, and Embase databases until January 1, 2019 and extracted the general information to perform the meta-analysis, mainly focusing on age, gender, and smoking status.

Results: A total of 8,793 solitary GGO ADLC patients from 53 studies were included in this analysis. The final pooled analysis showed that the female proportion, average diagnosis age, and non-smoking proportion of solitary GGO ADLC was 0.62 (95% CI, 0.60–0.64), 56.97 (95% CI, 54.56–59.37), and 0.72 (95% CI, 0.66–0.77), respectively. The cumulative meta-analysis and meta-trend analysis confirmed that the average age at diagnosis has been decreasing while the non-smoking proportion significantly increased in the past two decades.

Conclusions: From our epidemiological analysis, it demonstrates that the clinical characteristics of GGO lung cancer patients may be out of the high-risk factors. Therefore, we propose to reconsider the risk assessment and current lung cancer screening criteria.

Prognostic role of positron emission tomography and computed tomography parameters in stage I lung adenocarcinoma

Background

According to the current pathological classification, lung adenocarcinoma includes histological subtypes with significantly different prognoses, which may require specific surgical approaches. The aim of the study was to assess the role of CT and PET parameters in stratifying patients with stage I adenocarcinoma according to prognosis.

Patients and methods

Fifty-eight patients with pathological stage I lung adenocarcinoma who underwent surgical treatment were retrospectively reviewed. Adenocarcinoma in situ and minimally-invasive adenocarcinoma were grouped as non-invasive adenocarcinoma. Other histotypes were referred as invasive adenocarcinoma. CT scan assessed parameters were: ground glass opacity (GGO) ratio, tumour disappearance rate (TDR) and consolidation diameter. The prognostic role of the following PET parameters was also assessed: standardized uptake value (SUV) max, SUVindex (SUVmax to liver SUVratio), metabolic tumour volume (MTV), total lesion glycolysis (TLG).

Results

Seven patients had a non-invasive adenocarcinoma and 51 an invasive adenocarcinoma. Five-year disease-free survival (DFS) and cancer-specific survival (CSS) for non-invasive and invasive adenocarcinoma were 100% and 100%, 70% and 91%, respectively. Univariate analysis showed a significant difference in SUVmax, SUVindex, GGO ratio and TDR ratio values between non-invasive and invasive adenocarcinoma groups. Optimal SUVmax, SUVindex, GGO ratio and TDR cut-off ratios to predict invasive tumours were 2.6, 0.9, 40% and 56%, respectively. TLG, SUVmax, SUVindex significantly correlated with cancer specific survival.

Conclusions

CT and PET scan parameters may differentiate between non-invasive and invasive stage I adenocarcinomas. If these data are confirmed in larger series, surgical strategy may be selected on the basis of preoperative imaging.

A simple prediction model using fluorodeoxyglucose-PET and high-resolution computed tomography for discrimination of invasive adenocarcinomas among solitary pulmonary ground-glass opacity nodules

OBJECTIVE

To analyze the FDG-PET and high-resolution computed tomography (HRCT) features of early lung adenocarcinoma manifesting as solitary ground-glass opacity nodules (GGNs), and to establish a new risk model for predicting the invasiveness of early lung adenocarcinoma.

METHODS

We retrospectively analyzed the data of clinical stage IA lung adenocarcinoma patients who received preoperative PET/CT and HRCT examination. Patients were divided into invasive adenocarcinoma (IVA) group and preinvasive minimally invasive adenocarcinoma (MIA) group. The correlations between FDG-PET parameters, HRCT parameters and histopathological invasiveness, and their predictive efficacy were analyzed. A mathematical model for predicting histopathological invasiveness of early lung adenocarcinoma was established and assessed.

RESULTS

This study enrolled 56 patients, 48 were in IVA group and 8 were in preinvasive MIA group. Compared with those in preinvasive MIA group, GGNs in IVA group showed larger diameter, higher ground-glass opacity (GGO) density and more pleural indentation signs (70.8%) on HRCT; they also showed higher maximum standardized uptake value (SUV) and SUV index on FDG-PET (P = 0.001-0.037). Logistic regression analysis found a risk model for predicting IVA of solitary GGNs that were established by CTGGO and SUV index. Receiver operating characteristic curves showed that this model had the highest area under the curve (AUC), sensitivity, specificity and accuracy (AUC, 0.948; sensitivity, 95.8%; specificity, 87.5%; accuracy, 94.6%).

CONCLUSION

Using HRCT combined with FDG-PET to establish the corresponding mathematical prediction model has the potential to identify IVA in early lung adenocarcinoma preoperatively.

Lung Adenocarcinoma Manifesting as Ground-Glass Opacity Nodules 3 cm or Smaller: Evaluation With Combined High-Resolution CT and PET/CT Modality

OBJECTIVE. The purpose of this study is to evaluate high-resolution CT (HRCT) combined with PET/CT for preoperative differentiation of invasive adenocarcinoma (IAC) from preinvasive lesions and minimally invasive adenocarcinoma (MIA) (the combination of which is hereafter referred to as preinvasive-MIA) in lung adenocarcinoma manifesting as ground-glass opacity nodules (GGNs) 3 cm or smaller. MATERIALS AND METHODS. We retrospectively analyzed the data of patients with lung adenocarcinoma with GGNs that were 3 cm or smaller between November 2011 and November 2018. The HRCT and PET/CT parameters for GGNs were compared to differentiate between IAC and preinvasive-MIA. Qualitative and quantitative parameters were analyzed using univariate and multivariate logistic regression models. The diagnostic performance of different parameters was compared using ROC curves and the McNemar test. RESULTS. The study enrolled 89 patients (24 men and 65 women) with lung adenocarcinoma who had a mean (± SD) age of 60.1 ± 8.1 years (range, 36-78 years). The proportions of mixed GGN type, polygonal or irregular shape, lobulated or spiculated edge, and dilated, distorted, or cutoff bronchial sign were higher for IAC GGNs than for preinvasive-MIA GGNs, and the attenuation value of the ground-glass opacity component on CT (CT_GGO), maximum standardized uptake value, and the standardized uptake value (SUV) index (i.e., the ratio of the tumor maximum SUV to the liver mean SUV) for IAC GGNs were also higher (p = 0.001-0.022). Logistic regression analyses showed that the CT_GGO and SUV index were independent predictors for IAC GGNs. The accuracy of CT_GGO in combination with the SUV index for predicting IAC was 81.4% on a per-GGN basis and 85.4% on a per-patient basis. The combined HRCT and PET/CT modality had higher sensitivity and accuracy than did morphologic features, HRCT, and PET/CT measurement parameters alone (p < 0.001). CONCLUSION. The combined HRCT and PET/CT modality is an effective method to preoperatively identify IAC in lung adenocarcinoma manifesting as GGNs 3 cm or smaller.

New revisions and current issues in the eighth edition of the TNM classification for non-small cell lung cancer

In the eighth edition of the TNM classification of lung cancer, the prognostic impact of tumor size is emphasized as a descriptor of all T categories. Especially in lung cancer where tumor size is 5 cm or less, the 1-cm cutoff point significantly differentiated the survival outcome. In addition, the new staging categories were assigned, namely, Tis (adenocarcinoma in situ) and T1mi (minimally invasive adenocarcinoma). Furthermore, the measurement of a radiological solid component size excluding the ground glass opacity component or pathological invasive size without a lepidic component was proposed for deciding the cT/pT categories for lung adenocarcinoma. The N descriptors were kept the same as in the eventh edition on the whole, however, quantification of nodal disease had a prognostic impact based on the number of nodal stations involved in the eighth edition, i.e. N1a as a single N1 station, N1b as a multiple N1 station, N2a1 as a single N2 station without N1 (skip metastasis), N2a2 as a single N2 station with N1 disease, and N2b as a multiple N2 station. In the M descriptors, subclassification was performed based on the location or numbers of distantly metastatic lesions, i.e. M1a as any intrathoracic metastases, M1b as a single distant metastatic lesion in one organ, and M1c as multiple distant metastases in either a single organ or multiple organs. Survival analysis of the eighth edition of the TNM classification clearly separated the distinct groups, however, unsolved issues still remain that should be discussed and further revised for the forthcoming TNM staging system.

Expression of p53 in ground-glass nodule of lung cancer and non-lung cancer patients

The present study investigated the expression of p53 in ground-glass nodule (GGN) of lung cancer and non-lung cancer patients, and explored the correlation with prognosis. A total of 120 GGN patients admitted to the Department of Respiratory Medicine in the Second Affiliated Hospital of Zhejiang University School of Medicine during the period from March 2010 to March 2014 were selected. These patients included 60 lung cancer patients and 60 non-tumor patients. Biopsy or surgical specimens were collected. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) were used to detect p53 gene and protein expression in the two groups of GGN tissues. All patients were followed up for 3 years and the relationship between p53 protein expression and the overall survival (OS) of the two groups of patients was analyzed. In GGN cells of non-cancer patients, p53 absence was observed in 6 cases and the absence rate was 10.0%. In GGN cells of cancer patients, the absence rate was significantly higher than that of non-cancer GGN group (p<0.05). The positive rate of p53-positive cases in non-tumor patients GGN group was lower than that of in GGN tissues of lung cancer patients (p<0.05). There were no deaths in the GGN non-cancer group (n=60) within 3 years, while 43 deaths occurred in GGN lung cancer group. The median survival time and the 3-year survival rate of patients with p53 positive was lower than that of p53-negative patients (p<0.05). p53 was overexpressed in GGN of lung cancer patients, and p53 overexpression is significantly correlated with poor prognosis of lung cancer patients. p53 plays an important role in transformation from GGN to lung cancer. Detection of p53 expression in GGN tissue may provide guidance for the diagnosis and prognosis of lung cancer.

Statistical analysis of 18F-fluorodeoxyglucose positron-emission tomography/computed tomography ground-glass nodule findings

¹⁸F-fluorodeoxyglucose positron-emission tomography/computed tomography (¹⁸F-FDG-PET/CT) is important in lung cancer diagnosis; false negatives are often caused by ground-glass nodules (GGNs). PET/CT utility in GGN diagnosis is unknown. The associations between GGN CT findings (size, properties), the pathological diagnosis and maximum standardized uptake value (SUV_max) were explored. Sixty-six patients with pathological stage IA1-IIA lung adenocarcinoma underwent surgical resection and PET/CT between January 2010 and December 2014. Clinical characteristics, CT findings, pathological diagnoses and PET/CT findings were retrospectively examined. The age range was 47-86 years (median, 69 years), the female/male ratio was 38:28 and the pathological stage was IA1, IA2, IA3, IB and IIA in 5, 30, 21, 9 and 1, respectively. Total and solid-part lesion diameters ranged from 7.00-41.13 mm (median, 19.43 mm) and 0.00-23.23 mm (median, 4.55 mm), respectively; the solid-part ratio (solid-part diameter/total diameter) was 0-77% (median, 20%). SUV_max ranged from a value too low for evaluation to 3.9 (median, 1.0). Pathological diagnoses were adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), lepidic-predominant adenocarcinoma (LPA) and papillary predominant adenocarcinoma (PPA) in 17, 15, 32 and 2, respectively. Correlation coefficients for each factor and SUV_max for total and solid-part diameters were 0.513 (p<0.0001) and 0.461 (p<0.0001), respectively. All pure GGNs showed clinically unimportant SUV_max<2.5, even though some large GGNs were included (maximum, 40.0 mm). A total diameter ≥20 mm was significantly associated with FDG uptake (p<0.0001). SUV_max were <2.5 when the solid-part diameter was <4.55 mm. The AIS-MIA group showed significantly lower SUV_max than the LPA-PPA group (p=0.0008). There was no clinically important SUV_max with diagnostic value for pure or small part-solid GGNs. There were medium correlations for GGN total diameter, solid-part diameter, and SUV_max. We should note PET/CT's limitations in GGN diagnosis.

Comparison of different automated lesion delineation methods for metabolic tumor volume of 18F-FDG PET/CT in patients with stage I lung adenocarcinoma

The aim of the study was to investigate the suitable segmentation method in small, low uptake and heterogeneous nodules of stage I lung adenocarcinoma.133 stage I lung adenocarcinoma patients with F-FDG PET/CT scans were enrolled in this retrospective study. All lesions were divided into different groups according to nodule density, nodule size, and the maximum standard uptake value (SUVmax) level. Four different PET segmentation methods were performed, including percentage threshold of SUVmax (T42% and T42% × RC), gradient-based threshold (adaptive iterative algorithm, AT-AIA), and background-related threshold (adaptive thresholding at 40% SUVmax, AT40%) approaches. The MTVs were evaluated and compared with CT volume (CTV). Percentage volume error (%VE) compared to CTV was calculated and the correlations between MTVs and CTV were analyzed.AT-AIA had the highest accuracy in large, high uptake, and solid nodules (72.5%, 72.4%, and 65.6%, respectively). AT40% had the highest accuracy in small, low uptake and nonsolid nodules (56.6%, 56.1%, and 62.6%, respectively). In part-solid nodules, the accuracy of AT-AIA (60.0%) and AT40% (56.7%) were higher than that of T42% and T42% × RC. The MTV of AT-AIA was in excellent correlation with the CTV in solid nodules (R = 0.831, P < .001) and in high uptake nodules (R = 0.830, P < .001). The MTV of AT40% was in good correlation with the CTV in nonsolid nodules (R = 0.686, P = .003) and in part-solid nodules (R = 0.731, P < .001).AT40% showed best performance in small, low uptake, nonsolid and part-solid lesions. AT-AIA was suitable for large, high uptake, and solid lesions.

Solitary ground-glass opacity nodules of stage IA pulmonary adenocarcinoma: combination of 18F-FDG PET/CT and high-resolution computed tomography features to predict invasive adenocarcinoma

To investigate the performance of combined 18F-FDG Positron Emission Tomography/Computed Tomography with high-resolution CT for differentiating invasive adenocarcinoma from adenocarcinoma in situ (pre-invasive lesion) or minimally invasive adenocarcinoma in stage IA lung cancer patients with solitary ground-glass opacity nodules. This retrospective study enrolled 58 consecutive stage IA pulmonary adenocarcinoma patients with solitary ground-glass opacity nodules. The characteristics and measurements of the ground-glass opacity nodules as pure ground-glass opacity nodules and mixed ground-glass opacity nodules in the pre-invasive or minimally invasive adenocarcinoma and invasive adenocarcinoma groups on Positron Emission Tomography/Computed Tomography and high-resolution CT were compared and analyzed. Ground-glass opacity nodules in the pre-invasive or minimally invasive adenocarcinoma group preferentially manifested as pure ground-glass opacity nodule (p < 0.01) compared to the invasive adenocarcinoma group. While cystic appearance was more common in the invasive adenocarcinoma group (p < 0.05). Significant differences were found in the diameter of the ground-glass opacity nodule itself and its solid component, and consolidation/tumor ratio between the two groups. The sensitivity in predicting invasive adenocarcinoma was higher with a combined consolidation/tumor ratio > 0.38 and SUV_max > 1.46 in mixed ground-glass opacity nodule when compared to those of SUV_max > 0.95 alone or consolidation/tumor ratio> 0.39 alone (both p > 0.05). For a mixed ground-glass opacity nodule combined consolidation/tumor ratio > 0.38 and SUV_max > 1.46 appears to better predict invasive adenocarcinoma in stage IA lung cancer patients with solitary ground-glass opacity nodules.

Locoregional recurrence after segmentectomy for clinical-T1aN0M0 radiologically solid non-small-cell lung carcinoma

Objectives

We aimed to identify the clinicopathological features of loco-regional recurrence after segmentectomy for clinical-T1aN0M0 radiologically invasive non-small-cell lung carcinoma (NSCLC).

Methods

Between 2008 and 2014, 353 patients underwent pulmonary lobectomy or segmentectomy with nodal dissection for clinical-T1aN0M0 radiologically invasive NSCLC showing 0.5 ≤ consolidation tumour ratio (CTR)≤1.0 on thin-section computed tomography (CT). Radiological invasive NSCLC was divided into two groups, i.e. part-solid (0.5 ≤ CTR < 1.0) and pure-solid (CTR = 1.0). Significant prognostic factors for oncological outcomes were evaluated by multivariate analysis.

Results

Lobectomy was performed in 270 (76.5%) patients and segmentectomy in 83 (23.5%). Locoregional recurrence-free survival (LRFS) of clinical-T1a radiologically invasive NSCLC on the whole showed no significant differences between the lobectomy and segmentectomy arms (3-year LRFS, 93.0 vs 90.1%, P  = 0.2725). In contrast, the multivariate analysis revealed that radiologically pure-solid appearance and tumour size were significant predictors of loco-regional recurrence ( P  = 0.0106, 0.0408). Among 212 clinical-T1a radiologically pure-solid NSCLCs, frequency of loco-regional recurrence was high in the segmentectomy arm (20.7%) compared with that of lobectomy arm (8.2%). Furthermore, segmentectomy and larger tumour size were independent significant clinical factors of loco-regional recurrence based on the multivariate analysis ( P  = 0.0292, 0.0402). The 3-year LRFS of the segmentectomy arm was significantly worse than that of the lobectomy arm in the c-T1a disease (82.2 vs 90.6%, P  = 0.0488) provided the tumour showed a pure-solid appearance.

Conclusions

Even in cases of small-sized lung carcinoma, segmentectomy should be applied with great caution especially for a radiological pure-solid NSCLC on thin-section CT due to their high incidence of loco-regional recurrence.

[Advance in Diagnose and Treatment Strategies of Adenocarcinoma in Situ]

Adenocarcinoma in situ (AIS) is a new concept which was introduced to the 2011 The International Association for the Study of Cancer (IASLC)/ American Thoracic Society (ATS)/ European Respiratory Society (ERS) International Multidisciplinary Classification of Lung Adenocarcinoma firstly and an important supplement of The 2015 World Health Organization Classification of Lung Tumors. Because AIS is at an early stage of development of lung adenocarcinoma, the deepening understanding of its pathology, differential diagnosis, treatment strategies, has an important significance for the improvement of the prognosis of lung adenocarcinoma. This review will provide a systematic review of the main progress of occurrence and development, pathological characteristics, differential diagnosis and treatment strategy of AIS, in order to provide theoretical basis for the further research of AIS.

Correlation of EGFR or KRAS mutation status with 18F-FDG uptake on PET-CT scan in lung adenocarcinoma

Background

¹⁸F-fluoro-2-deoxy-glucose (¹⁸F-FDG) positron emission tomography (PET) is a functional imaging modality based on glucose metabolism. The correlation between EGFR or KRAS mutation status and the standardized uptake value (SUV) of ¹⁸F-FDG PET scanning has not been fully elucidated.

Methods

Correlations between EGFR or KRAS mutation status and clinicopathological factors including SUV_max were statistically analyzed in 734 surgically resected lung adenocarcinoma patients. Molecular causal relationships between EGFR or KRAS mutation status and glucose metabolism were then elucidated in 62 lung adenocarcinomas using cap analysis of gene expression (CAGE), a method to determine and quantify the transcription initiation activities of mRNA across the genome.

Results

EGFR and KRAS mutations were detected in 334 (46%) and 83 (11%) of the 734 lung adenocarcinomas, respectively. The remaining 317 (43%) patients had wild-type tumors for both genes. EGFR mutations were more frequent in tumors with lower SUV_max. In contrast, no relationship was noted between KRAS mutation status and SUV_max. CAGE revealed that 4 genes associated with glucose metabolism (GPI, G6PD, PKM2, and GAPDH) and 5 associated with the cell cycle (ANLN, PTTG1, CIT, KPNA2, and CDC25A) were positively correlated with SUV_max, although expression levels were lower in EGFR-mutated than in wild-type tumors. No similar relationships were noted with KRAS mutations.

Conclusions

EGFR-mutated adenocarcinomas are biologically indolent with potentially lower levels of glucose metabolism than wild-type tumors. Several genes associated with glucose metabolism and the cell cycle were specifically down-regulated in EGFR-mutated adenocarcinomas.

Neither Maximum Tumor Size nor Solid Component Size Is Prognostic in Part-Solid Lung Cancer: Impact of Tumor Size Should Be Applied Exclusively to Solid Lung Cancer

BACKGROUND

We aimed to investigate the prognostic impact of tumor size based on the consolidation status by thin-section computed tomography.

METHODS

We evaluated 1,181 surgically resected clinical N0 M0 non-small cell lung carcinomas. Consolidation tumor ratio (CTR) was evaluated for all, and tumors were classified into three groups, namely pure ground-glass opacity (CTR = 0; n = 168), part-solid (0 < CTR < 1.0; n = 448), and solid (CTR = 1.0; n = 565). The impact of tumor size was assessed based on CTR using Cox proportional hazards model.

RESULTS

Tumor size significantly differentiated the 5-year overall survival (≤20 mm; n = 638: 93.4%; 21-30 mm; n = 284: 84.2%; 31-50 mm; n = 193: 69.3%; ≥51 mm; n = 66: 43.5%; p < 0.0001). When we evaluated the impact of tumor size based on CTR, the 5-year overall survival differed significantly in patients with radiologic solid lung cancer (≤20 mm: 83.0%; 21-30 mm: 75.4%; 31-50 mm: 56.2%; ≥51 mm: 45.3%; p < 0.0001). In contrast, it did not affect the 5-year overall survival in patients with radiologic pure ground-glass opacity (100% regardless of the tumor sizes) and part-solid lung cancer (≤20 mm: 97.7%; 21-30 mm: 94.6%; 31-50 mm: 93.4%; p = 0.1028; 0 < CTR ≤ 0.5: 98.4%; 0.5 < CTR < 1.0: 95.0%; p = 0.1247). Furthermore, maximum tumor size (p = 0.6370), solid component size (p = 0.2340), and CTR (p = 0.1395) were not associated with poor overall survival in radiologic part-solid lung cancer.

CONCLUSIONS

The impact of maximum tumor size should be applied only to radiologic solid lung cancer without the ground-glass opacity component on thin-section computed tomography. On the other hand, we recommend that pure ground-glass opacity and part-solid lung cancers be described, respectively, as clinical-Tis and clinical-T1a, which are independent of maximum tumor size and solid component size on thin-section computed tomography.

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.

Partly solid pulmonary nodules: waiting for change or surgery outright?

OBJECTIVES

It has been assumed that if the prognosis and rate of lymph node metastases differ between two groups of patients being followed up for partly solid tumours, those with an increased solid component and those without change, these differences can help to decide on the time of surgery for patients with partly solid tumours. Therefore, this study compared the differences in pathological results and prognosis after surgical resection between patients with no change and and those with change in partly solid tumours during the preoperative period.

METHODS

Surgery was performed in patients who had an increased size of the solid component during the follow-up observation of partly solid tumours, as well as patients who had no change in the size of the solid component during a certain period of time. The 'No change group' in this study comprised those who had no change in at least two chest computed tomography scans during a minimum period of 6 months, but who underwent surgery.

RESULTS

Twenty-four patients were enrolled in this study. Among these patients, 14 were included in the No change group, and ten were included in the 'Change group'. There was no difference in the ratio of other postoperative pathological results, adenocarcinoma in situ, minimally invasive adenocarcinoma or invasive adenocarcinoma between the two groups. There was no difference in the pathological size of the tumour, including the in situ component between the two groups, but the size of the invasive component in the Change group was 2.5-fold that of the No change group, a statistically significant difference. During the median follow-up period of 59 months, neither recurrence nor cancer-related deaths occurred.

CONCLUSIONS

The pathological results and prognosis of lung cancer patients with persistent partly solid tumours who develop changes in their lesions after a certain period of follow-up time were not different from those of patients who did not develop any changes in the lesions. Therefore, surgery can be deferred until those lesions demonstrate changes in size or growth in their solid component when the overall size of ground-glass opacity (GGO) is less than 3 cm and the proportion of GGO is greater than 50%.