Primary Lung Cancer Lesions Research Articles

Diagnostic yield of cone beam CT based navigation bronchoscopy in patients with metastatic lesions: A propensity score matched case-control study

BackgroundCone beam CT based Navigation Bronchoscopy (CBCT-NB) has predominantly been investigated as a diagnostic tool in (suspected) primary lung cancers. Small metastatic lesions are clinically considered more challenging to diagnose, but no study has explored the yield of navigation bronchoscopy in patients with pulmonary metastatic lesions (ML) compared to primary lung cancers (PL), correcting for known lesion characteristics affecting diagnostic yield. Materials and methodsThis is a single-center, retrospective, propensity score-matched case-control study. We matched a subset of patients who underwent CBCT-NB and received a final diagnosis of pulmonary metastases of solid tumors between December 2017 and 2021 against confirmed primary lung cancer lesions subjected to CBCT-NB in the same time period. The lesions were propensity score matched based on known characteristics affecting yield, including location (upper lobe, lower lobe), size, bronchus sign, and lesion solidity. ResultsFifty-six metastatic pulmonary lesions (mean size 14.7 mm) were individually case-matched to a selection of 297 available primary lung cancer lesions. Case-matching revealed non-significant differences in navigation success rate (PL: 89.3 % vs. ML: 82.1 %, 95%CI on differences: −21.8 to +7.5) and yield (PL: 60.7 % vs. ML: 55.4 %, 95%CI on differences: −25.4 to +14.7). The overall complication rate was comparable (5.4 % in PL vs. 5,4 % in ML). ConclusionAfter matching primary and metastatic lesions based on CT assessable lesions characteristics, CBCT-NB showed no clinically relevant or significantly different navigation success or yield in either group. We recommend a careful assessment of CT characteristics to determine procedural difficulty rather than selecting based on the suspicion of lesion origin.

Characteristics of whole-body dynamic 18F-FDG PET/CT Patlak multi-parametric imaging in lung cancer and the influence of different delineation methods on quantitative parameters.

Dynamic course of flourine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) Patlak muti-parametric imaging spatial distribution in the targeted tissues may reveal highly useful clinical information about the tissue's metabolic properties. The characteristics of the Patlak multi-parametric imaging in lung cancer and the influence of different delineation methods on quantitative parameters may provide reference for the clinical application of this new technology. A total of 27 patients with pathologically diagnosed lung cancer underwent whole-body dynamic 18F-FDG PET/CT examination before treatment. Parametric images of metabolic rate of FDG (MRFDG) and Patlak intercept (or distribution volume; DV) were generated using Patlak reconstruction. The values of primary lung cancer lesions, target-to-background ratio (TBR), and contrast-to-noise ratio (CNR) were investigated using contour delineation and boundary delineation. Statistical analysis was performed to analyze the relationship between multi-parametric images and clinicopathological features, and to compare the effects of contour delineation and boundary delineation on quantitative parameters. MRFDG images showed higher TBR and CNR than did standardized uptake value (SUV) images. There were significant differences in MRFDG-max, MRFDG-mean, and MRFDG-peak among groups with different tumor diameters and pathology types (P<0.05). Moreover, the metabolic parameters of MRFDG were higher in patients with tumor diameters ≥3 cm and squamous carcinoma. The differences of the maximum and peak values of MRFDG and DV were not statistically significant in the different outlining method subgroups (all P>0.05). However, the difference of the mean values of MRFDG and DV were statistically significant in the different outline method groupings (all P<0.05). Dynamic 18F-FDG PET/CT Patlak multi-parametric imaging can obtain quantitative values for lung cancer with high TBR and CNR. Moreover, the multi-parameters are various from different pathology types to tumor size. Different delineation methods have a greater influence on the mean value of quantitative parameters.

Performance of [18F]FDG PET/CT versus FAPI PET/CT for lung cancer assessment: a systematic review and meta-analysis.

This article aims to compare the diagnostic performance of 18-fluorodeoxyglucose ([18F]FDG) PET/CT and fibroblast activating protein inhibitor (FAPI) PET/CT in the assessment of primary tumors, lymph nodes, and distant metastases in lung cancer patients. A systematic search was conducted on the Cochrane Library, Embase, and PubMed/MEDLINE databases from inception until November 1, 2022. Included studies assessed the use of FAPI PET/CT and [18F]FDG PET/CT in patients with lung cancer. The Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool was used to evaluate the risk of bias. A random variable model was used to analyze the diagnostic tests of the two imaging modalities. The sensitivity of FAPI PET/CT in detecting primary lung cancer lesions was 0.98 (95% CI: 0.88-1.00), while the sensitivity of [18F]FDG PET/CT was 0.99 (95% CI: 0.74-1.00). For the detection of metastatic lesions (lymph node metastases and distant metastases), FAPI PET/CT had a sensitivity of 0.99 (95% CI: 0.90-1.00), while the sensitivity of [18F]FDG PET/CT was 0.77 (95% CI: 0.66-0.85). However, the specificity of the two imaging modalities could not be assessed due to the lack of sufficient information on pertinent true negatives. In the diagnosis of metastatic lung cancer lesions, FAPI PET/CT demonstrated a higher sensitivity compared to [18F]FDG PET/CT. Therefore, FAPI PET/CT may be considered an alternative imaging modality for the assessment of primary lung cancer tumors, lymph node metastases, and distant metastases. FAPI may be an alternative to [18F]FDG in the assessment of primary lung cancer tumors, lymph node metastases, and distant metastases, which plays a very important role in treatment. • This article is to compare the performance of [18F]FDG PET/CT withFAPI PET/CT in the assessment of primary tumors, lymph nodes, and distant metastases in lung cancer. • However,FAPI PET/CT has a higher sensitivity for the diagnostic assessment of metastatic lung cancer lesions.

Results of intention-to-treat pulmonary metastasectomies in northern Finland revealing significant number of new lung primary carcinomas: time to move on from wedge resections?

A considerable proportion of intended pulmonary metastasectomies is known to turn out as new incidental primary lung cancers in final pathology. We aimed to analyse the trends and results of pulmonary metastasectomies using the intention-to-treat approach with an emphasis on final histopathological findings. All intention-to-treat pulmonary metastasectomies performed in Oulu University Hospital between 2000 and 2020 were included in the study. Long term survival was analysed with the Kaplan-Meier method and log-rank tests. A binary logistic regression analysis was performed to calculate odds ratios for incidental primary lung cancer in final histology. A total of 154 intended pulmonary metastasectomies were performed to 127 individual patients. There was an increasing trend in pulmonary metastasectomies during the study period. Despite the increasing trend in comorbidities of the operated patients, the length of hospital stays decreased, and the postoperative complication rates remained stable. In final pathology reports, 9.7% were new primary lung cancers and 13.0% were benign nodules. A long disease-free interval (≥24 months) and smoking history were associated with incidental primary lung cancer in final histology. The short-term 30- and 90-day mortalities after pulmonary metastasectomy were 0.7%. The 5-year survival after pulmonary metastasectomy from all histologies was 52.8%, and from colorectal cancer metastasectomies (n=34) it was 73.5%. The significant amount of new primary lung cancer lesions in pulmonary metastasectomy specimens highlight the diagnostic importance of pulmonary metastasectomy. A segmentectomy could be considered as a primary procedure in pulmonary metastasectomy in patients with a long disease-free interval and a heavy smoking history.

Performance and Prospects of [68Ga]Ga-FAPI PET/CT Scans in Lung Cancer.

Fibroblast activation protein (FAP) could be a promising target for tumor imaging and therapy, as it is expressed in &gt;90% of epithelial cancers. A high level of FAP-expression might be associated with worse prognosis in several cancer types, including lung cancer. FAPI binds this protein and allows for labelling to Gallium-68, as well as several therapeutic radiopharmaceuticals. As FAP is only expressed at insignificant levels in adult normal tissue, FAPI provides a highly specific tumor-marker for many epithelial cancers. In this review, current information on the use of [68Ga]Ga-FAPI PET/CT in lung cancer is presented. [68Ga]Ga-FAPI shows a high uptake (standardized uptake value = SUVmax) and tumor-to-background ratio (TBR) in primary lung cancer lesions, as well as in metastatic lesions of other tumor types located in the lung and in lung cancer metastases located throughout the body. Where a comparison was made to [18F]FDG PET/CT, [68Ga]Ga-FAPI showed a similar or higher SUVmax and TBR. In brain and bone metastases, [68Ga]Ga-FAPI PET/CT outperformed [18F]FDG PET/CT. In addition to this strong diagnostic performance, a possible prognostic value of [68Ga]Ga-FAPI PET/CT in lung cancer is proposed.

Glutathione peroxidase 4-dependent glutathione high-consumption drives acquired platinum chemoresistance in lung cancer-derived brain metastasis.

BackgroundPlatinum‐based chemotherapy is effective in inducing shrinkage of primary lung cancer lesions; however, it shows finite therapeutic efficacy in patients suffering from brain metastasis (BM). The intrinsic changes of BM cells, which contribute to the poor results remain unknown.MethodsPlatinum drug‐sensitivity was assessed by utilizing a preclinical BM model of PC9 lung adenocarcinoma cells in vitro and in vivo. High consumption of glutathione (GSH) and two associated upregulated proteins (GPX4 and GSTM1) in BM were identified by integrated metabolomics and proteomics in cell lines and verified by clinical serum sample. Gain‐of‐function and rescue experiments were implemented to reveal the impact and mechanism of GPX4 and GSTM1 on the chemosensitivity in BM. The interaction between GPX4 and GSTM1 was examined by immunoblotting and immunoprecipitation. The mechanism of upregulation of GPX4 was further uncovered by luciferase reporter assay, immunoprecipitation, and electrophoretic mobility shift assay.ResultsThe derivative brain metastatic subpopulations (PC9‐BrMs) of parental cells PC9 developed obvious resistance to platinum. Radically altered profiles of BM metabolism and protein expression compared with primary lung cancer cells were described and GPX4 and GSTM1 were identified as being responsible for the high consumption of GSH, leading to decreased chemosensitivity by negatively regulating ferroptosis. Besides, GSTM1 was found regulated by GPX4, which was transcriptionally activated by the Wnt/NR2F2 signaling axis in BM.ConclusionsCollectively, our findings demonstrated that Wnt/NR2F2/GPX4 promoted acquired chemoresistance by suppressing ferroptosis with high consumption of GSH. GPX4 inhibitor was found to augment the anticancer effect of platinum drugs in lung cancer BM, providing novel strategies for lung cancer patients with BM.

Mutational characteristics of bone metastasis of lung cancer

Roughly 30-40% of lung cancer (LC) patients develop bone metastasis during the course of disease. The genetic differences between primary LC and matched bone metastasis are not yet fully understood. A total of 40 LC patients with bone metastasis were collected and 450 targeted cancer-related genes were sequenced for genomic-alteration (GA) identification. Among the 40 LC patients, 33 had adenocarcinomas and 7 had squamous cell carcinomas. The metastatic sites of the 33 lung adenocarcinomas (LUADs) were the pelvis (6 patients), spine (16 patients), and limbs (11 patients). A total of 425 and 422 GAs were detected in the primary and metastatic lesions, respectively. The most common GAs were epidermal growth factor receptor (EGFR) mutations, which had mutation rates of 85.0% and 72.5% in the primary and metastatic lesions, respectively, and tumor protein 53 (TP53) mutations, which had mutation rates of 52.5% and 67.5% in the primary and metastatic lesions, respectively. Metastases to the pelvis and spine were most commonly accompanied by factor receptor substrate 2 (FRS2), cyclin-dependent kinase 4 (CDK4), and murine double minute 2 (MDM2) amplification, and cyclin-dependent kinase inhibitor 2A (CDKN2A) deletion. The concordance between primary lung squamous cell carcinoma (LUSC) and corresponding metastasis was significantly higher than that of primary LUAD and corresponding metastasis (P=0.033). Compared to limb and pelvis metastases, the shared mutation in spine metastasis was significantly lower (P=0.016 and P=0.023, respectively). In matched primary LUSCs and bone metastasis lesions, there was no significant difference in the distribution of the tumor mutational burden (TMB) (P=0.9). Conversely, a significant difference of the TMB distribution was detected in pairs of primary LUAD and corresponding bone metastasis lesions (P=0.021). The consistency of mutation patterns between primary LC lesions and matched bone metastases may vary in terms of metastatic sites, but is very high in general. There was a significant difference in the TMB between primary LUAD and matched bone metastatic lesions. Our findings contribute to molecular understandings of primary LC and matched bone metastatic lesions.

Inconsistent Intersample ALK FISH Results in Patients with Lung Cancer: Analysis of Potential Causes.

ALK FISH analyses of multiple specimens occasionally yield inconsistent intersample results in lung cancer patients, posing clinical challenges requiring intensive analysis of all potential causative pre- and post- analytic factors. In this study, 19 patients (8M/11F) with inconsistent intersample ALK FISH results were analyzed, representing 4.9% of patients assessed ≥ twice in our institution. Fifteen patients received ALK tyrosine kinase inhibitor(s) (TKIs). Nine patients died, and ten were alive for 8 to 74-month follow-ups (median, 40 months). Through strict and stringent laboratory and case-review policies, all postanalytic factors were excluded. Correlating clinical information, ALK results obtained by RNA sequencing (RNA-seq) and other concurrent tests, several pre-analytic factors were determined. A suboptimal specimen was likely the cause in three patients, supported by the failure of one or more concurrent tests or discrepant results between FISH and RNA-seq. ALK inhibition by TKIs might have been responsible for the change of ALK status from positive to negative in eight patients. Other potential explanations include the existence of multiple primary lung cancer lesions, tumor heterogeneity, and the clonal evolution of tumor cells, related or not to ALK TKI therapy. This study is helpful for both pathologists and clinicians encountering inconsistent and/or discrepant intersample results.

A rare family case study of multiple siblings with multiple synchronous primary lung cancers.

e21028 Background: Familial lung cancer is rare, let alone inherited lung cancer with multiple synchronous primary lung cancer lesions. Study of inherited lung cancer may facilitate the understanding of the molecular mechanism of the tumorigenesis. Methods: We identified an extremely rare family of five siblings, four with multiple primary lung adenocarcinomas by pathological examination. DNA samples were extracted from the patient tumor tissues and libraries were prepared for next-generation sequencing (NGS) analysis using a custom 500-gene cancer panel. Results: EGFR L858R or 19DEL mutations were identified in at least one lesion in all of the four lung cancer patients. Interestingly, lung cancer patient L1 had EGFR 19DEL in one lesion and L858R in the other, lung cancer patient L2 had EGFR L858R and KRAS G12C mutation in lesion 1 and lesion 2, respectively. The mutation statuses of EGFR and KRAS were confirmed by ARMS-PCR. The mutational spectrum of the two lesions from the same patient distinguished significantly based on the 500-gene NGS panel analysis, further demonstrating the heterogeneity of cancer mutations. Taken together, these results indicate that patients L1 and L2 both had synchronous primary lung cancers. Due to the small lesions, the two lesions for patient L3 were mixed together; the concurrent EGFR L858R and 19DEL mutations in the tissue sample implicated different drivers in the two different lesions since co-occurring of these two mutations was very rare. For patient L4, EGFR L858R was identified in one lesion and uncommon mutations with low frequencies were observed in the other lesion, consistent with different driving mechanisms for the two lesions. Conclusions: To our knowledge, this is the first study identifying a family of multiple siblings with multiple synchronous primary lung cancers and using NGS to reveal the genetics. Together with germline mutation analysis, this study may shed light on the tumorigenesis of familial lung cancer.

Diffusion-Weighted MR Imaging of Primary and Secondary Lung Cancer: Predictive Value for Response to Transpulmonary Chemoembolization and Transarterial Chemoperfusion.

To examine predictive value of apparent diffusion coefficient (ADC) in diffusion-weighted imaging (DWI) for response of patients with primary and secondary lung neoplasms undergoing transpulmonary chemoembolization (TPCE) and transarterial chemoperfusion (TACP) treatment. Thirty-one patients (mean age ± SD 64 ± 12.4 y) with 42 lung target lesions (13 primary and 29 secondary) underwent DWI and subsequent ADC analysis on a 1.5T MR imaging scanner before and 30.3 days ± 6.4 after first session of TPCE or TACP. After 3.1 treatment sessions ± 1.4 performed in 2- to 4-week intervals, morphologic response was analyzed by comparing tumor diameter and volume before and after treatment on unenhanced T1-weighted MR images. On a per-lesion basis, response was classified according to Response Evaluation Criteria In Solid Tumors. Threshold ADC increase of 20.7% indicated volume response with 88% sensitivity and 78% specificity (area under the curve [AUC]= 0.84). Differences between ADC changes in volume response groups were significant (P= .002). AUC for volume response predicted by ADC before treatment was 0.77. Median ADC before treatment and mean ADC change were 1.09× 10-3 mm2/second and 0.36× 10-3 mm2/second ± 0.23, 1.45× 10-3 mm2/second and 0.14× 10-3 mm2/second ± 0.16, and 1.30× 10-3 mm2/second and 0.06× 10-3 mm2/second ± 0.19 in partial response, stable disease, and progressive disease groups. In primary lung cancer lesions, strong negative correlation of ADC change with change in diameter (ρ=-.87, P < .001) and volume (ρ=-.66, P= .016) was found. In metastases, respective correlation coefficients were ρ=-.18 (P= .356) and ρ=-.35 (P= .061). ADC quantification shows considerable diagnostic value for predicting response and monitoring TPCE and TACP treatment of patients with primary and secondary lung neoplasms.

Imaging Features and Clinical Decision Analysis of 110 Cases of Intrapulmonary Lymph Nodes.

Through the summary and analysis of large samples, the characteristic imaging manifestations of intrapulmonary lymph nodes (IPLNs) were quantified, and two corresponding rating tables were developed. These rating tables could be used to distinguish the IPLNs from primary lung cancer, so as to improve the diagnostic accuracy and help clinicians make correct judgments and decisions. A total of 82 patients with 110 IPLNs and 35 patients with primary lung cancer lesions were collected from June 2017 to December 2018. All lesions were solid nodules of less than 12 mm in diameter, which were confirmed by pathology. Observation indicators included location, size, shape, density, border and internal vacuoles of nodules, linear high-density shadow around the nodules, distance from the pleura, pleural indentation, and so on. There were statistically significant differences in the location, size, shape, internal vacuole of the nodules, and distance from the pleura (p < 0.05). The diagnostic scoring table of the nature of solid nodules and the malignant risk table were drawn. The nodule corresponding to Level A was most likely the primary lung cancer, and surgical resection was recommended. The nodule corresponding to Level C was most likely IPLNs, and it was better to receive no treatment currently. The positive predictive value was 81% (23/28), the negative predictive value was 97% (89/92), the sensitivity was 63% (23/35), and the specificity was 81% (89/110). For the pulmonary solid nodules of less than 12 mm in diameter and unknown nature, the evaluation in accordance with the Score Table and the Risk Level Table of this study can be more accurate and faster than the original judgment, which will help clinicians in diagnosis and treatment decisions.

P3.17-08 Assessing Primary Lung Cancer Lesion Using Ratio Metrics of T1 and T2-Weighted Images in Magnetic Resonance Imaging

P3.17-08 Assessing Primary Lung Cancer Lesion Using Ratio Metrics of T1 and T2-Weighted Images in Magnetic Resonance Imaging

Programmed Death-Ligand 1 Expression and EGFR Mutations in Multifocal Lung Cancer

Little is known about the programmed death-ligand 1 (PD-L1) expression in multifocal lung cancer, such as the expression in multiple primary lung cancer and pulmonary metastasis. In this translational study, we investigated PD-L1 expression and its relationship with the epidermal growth factor receptor (EGFR) mutation status in resected multifocal lung cancer. The PD-L1 expression in 152 samples of multifocal lung cancer from 59 patients was evaluated by an immunohistochemical analysis. Among the 152 lung cancer lesions of 59 patients, PD-L1 expression was observed in 29 lesions (19.1%) of 20 patients (33.9%). Among 43 patients with 112 multiple primary lung cancer lesions, 15 lesions (13.4%) of 13 patients (30.2%) were PD-L1 positive; and among 16 patients with 40 pulmonary metastatic lesions, 14 lesions (35.0%) of 7 patients (43.8%) were PD-L1-positive. Among 43 patients with multiple primary lung cancer, there was disagreement of PD-L1 expression in 12 patients (27.9%, κ= 0.104). On the contrary, among 16 patients with pulmonary metastasis, disagreement of PD-L1 expression was observed only in 1 patient (6.3%, κ= 0.871). In pulmonary metastatic lesions, the frequency of PD-L1 positivity among lesions with wild-type EGFR was significantly higher than among lesions with mutated EGFR (66.7% versus 0%: p < 0.001). This study provides important evidence of higher levels of agreement of PD-L1 expression in pulmonary metastasis compared with in multiple primary lung cancer, and high positivity of PD-L1 expression in pulmonary metastatic lesions with wild-type EGFR in an Asian population.

Complete remission through icotinib treatment in Non-small cell lung cancer epidermal growth factor receptor mutation patient with brain metastasis: A case report.

Brain metastasis (BM) has been universally recognized as a poor prognostic factor in non-small cell lung cancer (NSCLC). Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have shown efficacy in treating BM with an EGFR mutation. This paper reports a case of BM patient with EGFR-mutated NSCLC. According to the findings, a complete remission (CR) of the BM was achieved by icotinib treatment without conducting a radiotherapy, which was followed by a resection of the primary lung cancer lesion and lymph nodes. After one-year follow-up, the disease progressed to liver metastasis and liver lesion biopsy showed a T790M mutation. The patient responded well to the combination treatment of AZD9291 and icotinib after the failure of transcatheter arterial chemoembolization (TACE). This case report suggests that icotinib has a sustainable anticancer response to BM and the combination with icotinib and AZD9291 is effective for liver metastasis with T790M.

Test–Retest Reproducibility Analysis of Lung CT Image Features

Quantitative size, shape, and texture features derived from computed tomographic (CT) images may be useful as predictive, prognostic, or response biomarkers in non-small cell lung cancer (NSCLC). However, to be useful, such features must be reproducible, non-redundant, and have a large dynamic range. We developed a set of quantitative three-dimensional (3D) features to describe segmented tumors and evaluated their reproducibility to select features with high potential to have prognostic utility. Thirty-two patients with NSCLC were subjected to unenhanced thoracic CT scans acquired within 15 min of each other under an approved protocol. Primary lung cancer lesions were segmented using semi-automatic 3D region growing algorithms. Following segmentation, 219 quantitative 3D features were extracted from each lesion, corresponding to size, shape, and texture, including features in transformed spaces (laws, wavelets). The most informative features were selected using the concordance correlation coefficient across test-retest, the biological range and a feature independence measure. There were 66 (30.14%) features with concordance correlation coefficient ≥ 0.90 across test-retest and acceptable dynamic range. Of these, 42 features were non-redundant after grouping features with R (2) Bet ≥ 0.95. These reproducible features were found to be predictive of radiological prognosis. The area under the curve (AUC) was 91% for a size-based feature and 92% for the texture features (runlength, laws). We tested the ability of image features to predict a radiological prognostic score on an independent NSCLC (39 adenocarcinoma) samples, the AUC for texture features (runlength emphasis, energy) was 0.84 while the conventional size-based features (volume, longest diameter) was 0.80. Test-retest and correlation analyses have identified non-redundant CT image features with both high intra-patient reproducibility and inter-patient biological range. Thus making the case that quantitative image features are informative and prognostic biomarkers for NSCLC.

Planning of segmentectomy using three-dimensional computed tomography angiography with a virtual safety margin: Technique and initial experience

ObjectivesIn preoperative segmentectomy simulation for primary lung cancer, it is important to identify the intersegmental pulmonary veins and the relationship between them and the surgical safety margin. We have adopted a method that incorporates a virtual safety margin into three-dimensional computed tomography angiography images in order to plan adequate segmentectomy for lung cancer patients. In this study, we describe the new preoperative planning technique and review cases in which we performed segmentectomy based on its results. MethodsWe reviewed clinical, radiological, and pathological records and selected patients who underwent segmentectomy for a primary lung cancer lesion with a diameter of 2cm or less. These segmentectomies were planned using preoperative three-dimensional computed tomography angiography with a virtual safety margin. ResultsA total of 17 primary lung cancers in 16 patients (11 male and 5 female, aged 52–82 years) were removed by segmentectomy, planned using the new technique. In 6 of 17 tumors (35%) were non-solid type adenocarcinomas, 3 tumors (18%) were partly solid type adenocarcinomas, 6 tumors (35%) were solid type adenocarcinomas and 2 tumors (12%) were squamous cell carcinomas. Pathological examination revealed no positive surgical margins and no lymph node metastases in any patients. ConclusionsThree-dimensional computed tomography angiography with a virtual safety margin was able to non-invasively visualize the three-dimensional distances and the relationships between the primary tumor and intersegmental pulmonary veins. It was able to aid in the preoperative planning of a suitable segmentectomy procedure for patients with a primary lung cancer lesion of 2cm or less in diameter.

Prognosis for non-small cell lung cancer patients with brain metastases.

Brain metastasis has a poor prognosis in patients with advanced non-small cell lung cancer (NSCLC). In this study, we evaluated the prognosis of NSCLC patients with brain metastases. We analyzed a total of 313 NSCLC patients with brain metastasis. We compared the prognoses between a group of less than four (group A) and a group of more than four or equal to four (≥4) (group B) brain metastases. The median survival time was 334 days (group A, 164 patients, 52.4%) and 234 days (group B, 149 patients, 47.6%). Univariate analysis showed that the number of metastases, age at diagnosis of brain metastasis, smoking history, histologic type, and former stage of primary lung cancer before brain metastasis, had a significant influence. In addition, treatment for primary lung cancer lesions and brain metastasis also affected the overall survival (p < .0001). However, there was no difference in the overall survival between the two groups in the multivariate analysis. Our results show that the number of brain metastases, classified by group A (<4) or group B (≥4) did not influence the overall survival of NSCLC patients. However, the overall survival in group A was better than in group B when analyzed, except for local brain treatment modalities in sub-group analysis, suggesting that non-optimized local treatment strategies might cause an unexpected prognosis result in this retrospective study. We suggest that more prospective studies might be needed for the optimal standard treatment for brain metastasis.

Feasibility of perfusion CT technique integrated into conventional 18FDG/PET-CT studies in lung cancer patients: clinical staging and functional information in a single study

To assess the additional functional vascular information and the relationship between perfusion measurements and glucose metabolism (SUVmax) obtained by including a perfusion CT study in a whole-body contrast-enhanced PET/CT protocol in primary lung cancer lesions. Enrolled in this prospective study were 34 consecutive patients with a biopsy-proven diagnosis of lung cancer who were referred for contrast-enhanced PET/CT staging. This prospective study was approved by our institutional review board, and informed consent was obtained from all patients. Perfusion CT was performed with the following parameters: 80 kV, 200 mAs, 30 scans during intravenous injection of 50 ml contrast agent, flow rate 5 ml/s. Another bolus of contrast medium (3.5 ml/s, 80 ml, 60-s delay) was administered to ensure a full diagnostic contrast-enhanced CT scan for clinical staging. The perfusion CT data were used to calculate a range of tumour vascularity parameters (blood flow, blood volume and mean transit time), and tumour FDG uptake (SUVmax) was used as a metabolic indicator. Quantitative and functional parameters were compared and in relation to location, histology and tumour size. The nonparametric Kruskal-Wallis rank sum test was used for statistical analysis. A cut-off value of 3 cm was used according to the TNM classification to discriminate between T1 and T2 tumours (i.e. T1b vs. T2a). There were significant perfusion differences (lower blood volumes and higher mean transit time) between tumours with diameter >30 mm and tumours with diameter <30 mm (p < 0.05; blood volume 5.6 vs. 7.1 ml/100 g, mean transit time 8.6 vs. 3.9 s, respectively). Also there was a trend for blood flow to be lower in larger lesions (p < 0.053; blood flow 153.1 vs. 98.3 ml/100 g tissue/min). Significant inverse correlations (linear regression) were found between blood volume and SUVmax in tumours with diameter >30 mm in diameter. Perfusion CT combined with PET/CT is feasible technique that may provide additional functional information about vascularity and tumour aggressiveness as a result of lower perfusion and higher metabolism shown by larger lesions.

A case of primary lung cancer lesion demonstrated by F-18 FDG positron emission tomography/computed tomography (PET/CT) one year after the detection of metastatic brain tumor

Cancer of unknown primary origin (CUP) is an aggressive disease with a poor prognosis. Metastatic brain tumors occur in approximately 15% of all cancer patients. F-18 2'-deoxy-2fluoro-D-glucose (FDG) positron emission tomography (PET) combined with computed tomography (PET/CT) contributes to the evaluation of cancer staging, although the benefits of PET/CT for detection of CUP origins has yet to be determined. In this study, we present a 37-year-old man with a brain tumor detected by magnetic resonance imaging. Surgical biopsy indicated a metastatic undifferentiated carcinoma, while clinical examination and a CT scan did not detect any abnormalities, with the exception of brain metastases. PET/CT did not reveal abnormal FDG uptake. PET/CT revealed abnormal intense FDG uptake in a small nodular lesion in the right lung 1 year following the detection of brain metastasis, and no other abnormal FDG uptake was observed elsewhere in the body. Right upper lobectomy and dissection of mediastinal lymph nodes were performed. The pathological diagnosis was poorly differentiated adenocarcinoma, which was similar to the brain metastatic lesion, and there was no lymph node metastasis. This case revealed an extremely rare lung cancer with primary lesions demonstrated by PET/CT 1 year after the detection of brain metastasis. This case reveals that F-18 FDG PET/CT imaging of CUP origin is capable of positively impacting on the identification of small primary tumor foci.

An siRNA screen identifies RSK1 as a key modulator of lung cancer metastasis

We performed a kinome-wide siRNA screen and identified 70 kinases altering cell migration in A549 lung cancer cells. In particular, ribosomal S6 kinase 1 (RSK1) silencing increased, whereas RSK2 and RSK4 downregulation inhibited cell motility. In a secondary collagen-based three-dimensional invasion screen, 38 of our hits cross-validated, including RSK1 and RSK4. In two further lung cancer cell lines, RSK1 but not RSK4 silencing showed identical modulation of cell motility. We therefore selected RSK1 for further investigation. Bioinformatic analysis followed by co-immunoprecipitation-based validation revealed that the actin regulators VASP and Mena interact with RSK1. Moreover, RSK1 phosphorylated VASP on T278, a site regulating its binding to actin. In addition, silencing of RSK1 enhanced the metastatic potential of these cells in vivo using a zebrafish model. Finally, we investigated the relevance of this finding in human lung cancer samples. In isogenically matched tissue, RSK1 was reduced in metastatic versus primary lung cancer lesions. Moreover, patients with RSK1-negative lung tumours showed increased number of metastases. Our results suggest that the findings of our high-throughput in vitro screen can reliably identify relevant clinical targets and as a proof of principle, RSK1 may provide a biomarker for metastasis in lung cancer patients.