Evolution of peripheral lung adenocarcinomas: CT findings correlated with histology and tumor doubling time

Thin-section computed tomography-histopathologic comparisons of pulmonary focal interstitial fibrosis, atypical adenomatous hyperplasia, adenocarcinoma in situ, and minimally invasive adenocarcinoma with pure ground-glass opacity

OBJECTIVE

To retrospectively compare focal interstitial fibrosis (FIF), atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), and minimally invasive adenocarcinoma (MIA) with pure ground-glass opacity (GGO) using thin-section computed tomography (CT).

MATERIALS AND METHODS

Sixty pathologically confirmed cases were reviewed including 7 cases of FIF, 17 of AAH, 23of AIS, and 13 of MIA. All nodules kept pure ground glass appearances before surgical resection and their last time of thin-section CT imaging data before operation were collected. Differences of patient demographics and CT features were compared among these four types of lesions.

RESULTS

FIF occurred more frequently in males and smokers while the others occurred more frequently in female nonsmokers. Nodule size was significant larger in MIA (P<0.001, cut-off value=7.5mm). Nodule shape (P=0.045), margin characteristics (P<0.001), the presence of pleural indentation (P=0.032), and vascular ingress (P<0.001) were significant factors that differentiated the 4 groups. A concave margin was only demonstrated in a high proportion of FIF at 85.7% (P=0.002). There were no significant differences (all P>0.05) in age, malignant history, attenuation value, location, and presence of bubble-like lucency.

CONCLUSION

A nodule size >7.5mm increases the possibility of MIA. A concave margin could be useful for differentiation of FIF from the other malignant or pre-malignant GGO nodules. The presence of spiculation or pleural indentation may preclude the diagnosis of AAH.

Early detection of lung cancer

Most patients with lung cancer are diagnosed when they present with symptoms, they have advanced stage disease, and curative treatment is no longer an option. An effective screening test has long been desired for early detection with the goal of reducing mortality from lung cancer. Sputum cytology, chest radiography, and computed tomography (CT) scan have been studied as potential screening tests. The National Lung Screening Trial (NLST) demonstrated a 20% reduction in mortality with low-dose CT (LDCT) screening, and guidelines now endorse annual LDCT for those at high risk. Implementation of screening is underway with the desire that the benefits be seen in clinical practice outside of a research study format. Concerns include management of false positives, cost, incidental findings, radiation exposure, and overdiagnosis. Studies continue to evaluate LDCT screening and use of biomarkers in risk assessment and diagnosis in attempt to further improve outcomes for patients with lung cancer.

Quantitative CT Scanning Analysis of Pure Ground-Glass Opacity Nodules Predicts Further CT Scanning Change

BACKGROUND

We sought to determine whether quantitative analysis of lung adenocarcinoma manifesting as a ground-glass opacity (GGO) nodule (GGN) on initial CT scans can predict further CT scanning change or rate of growth.

METHODS

This retrospective study included patients with lung adenocarcinoma manifesting as pure GGN on initial CT scans who were followed up with interval CT scanning until resection. All pure GGNs were classified based on CT scanning interval change in three subgroups as follows: group A (development of solid component), group B (growth of GGO component), and group C (no change in size). Nodule size, volume, density, mass, and CT scanning attenuation values were assessed from initial CT data sets.

RESULTS

Fifty-four pure GGNs were enrolled and classified into group A (n = 9), group B (n = 25), and group C (n = 20). Nodule size, volume, mass, and density of the GGNs in each subgroup were not significantly different. The 97.5th percentile CT scanning attenuation value and slope of CT scanning attenuation values from the 2.5th to the 97.5th percentile were significantly different among the three subgroups (P = .02, P < .00). Three of nine (33%) pure GGNs showing a new solid component developed a solid component within 6 months.

CONCLUSIONS

The 97.5th percentile CT scanning attenuation value and slope of CT scanning attenuation values from the 2.5th to the 97.5th percentile could be helpful in predicting future CT scanning change and growth rate of pure GGNs. Pure GGNs showing higher 97.5th percentile CT scanning attenuation values and steeper slopes of CT scanning attenuation values may require more frequent follow-up than the usual interval of 6 months.

Chemoprevention studies within lung cancer screening programmes

While aggressive tobacco control and help to stop smoking are essential weapons in the fight against lung cancer, screening with low-dose computed tomography (LDCT) in high-risk populations and chemoprevention may also contribute to reducing lung cancer deaths. Persons undergoing LDCT screening are an ideal population to be tested for agents potentially able to prevent the development of lung cancer by the regression of precancerous lesions, which are routinely monitored as part of the screening process. Peripheral subsolid nodules appear as particularly suitable targets, since many are adenocarcinoma precursors.

A study on inhaled budesonide (a potential chemopreventive drug) for 1 year found that the mean size of non-solid lung nodules was significantly reduced over 5 years of follow-up, compared to inhaled placebo, in a population of high-risk individuals with indeterminate lung nodules not requiring immediate specific investigation for lung cancer and detected as part of a lung cancer screening program with LDCT.

A new randomised placebo-controlled phase-II trial to test the ability of aspirin to induce the regression of non-solid and partially solid nodules detected by LDCT screening has been started. The effect of aspirin on a miRNA signature able to predict the presence of both cancer and precancerous lesions in high-risk asymptomatic individuals is also being monitored in the trial. This signature was previously shown to predict the presence of both lung cancer and non-solid lung nodules in asymptomatic individuals.

Pulmonary ground-glass nodules diagnosis: mean change rate of peak CT number as a discriminative factor of pathology during a follow-up

OBJECTIVE

We aimed to analyse the peak CT number (PEAK) in CT number histogram of ground-glass nodules (GGN), meaning the most frequent density of pixels in the image of pulmonary nodule, based on three-dimensional (3D) reconstructive model pre-operatively, and the mean rate of PEAK change (V-PEAK) during a follow-up of GGN for differential diagnosis between pre-invasive adenocarcinoma (PIA) and invasive adenocarcinoma (IAC).

METHODS

CT number histogram of pixels in GGN was made automatically by 3D measurement software. Diameter, total volume, PEAK and V-PEAK were measured from CT data sets of different groups classified by pathology, subtype and number of GGN, respectively.

RESULTS

Among all 102 cases, 47 were PIA, including atypical adenomatous hyperplasia (n = 29) and adenocarcinoma in situ (n = 18), and 55 were IAC, including minimally IAC (MIA, n = 4). By Wilcoxon test, PEAK of IAC was significantly higher than that of PIA (p < 0.001). By receiver operating curve analysis, area under the curve (AUC) was 0.857 and threshold -820.50 Hounsfield units (HU) for differentiation between PIA and IAC. V-PEAK of IAC was unexpectedly remarkably smaller than that of PIA (p < 0.001) with AUC and threshold being 0.810 and -0.829 HU day(-1), respectively.

CONCLUSION

Pre-operative PEAK and V-PEAK, which interpret and evaluate the change of volume and density of pulmonary nodule simultaneously from both exterior and interior perspectives, can help to distinguish IAC from PIA.

ADVANCES IN KNOWLEDGE

This study provided researchers of GGN another perspective, taking both volume and density of nodules into consideration for pathological evaluation.

[Advances of mediastinal lymph node metastasis and the extent of lymph node dissection in patients with stage T1 non-small cell lung cancer]

肺癌是我国发病率和死亡率最高的恶性肿瘤。非小细胞肺癌（non-small cell lung cancer, NSCLC）约占肺癌80%。临床上，早期NSCLC以手术治疗为主要治疗方式，淋巴结分期及手术中清扫程度直接影响着患者的预后。不同肺叶原发NSCLC的淋巴结转移区域存在一定规律。解剖性肺叶切除加系统性淋巴结清扫一直以来被认为是NSCLC的标准手术方式，但近年来T1期NSCLC手术中纵隔淋巴结清扫的程度存在较大争议，选择性淋巴结清扫已逐渐被大多数学者所重视。

Management of subsolid pulmonary nodules in CT lung cancer screening

The distinct appearance and behavior of subsolid pulmonary nodules (SSNs) has resulted in separate recommendations for the management of solitary SSNs, both for incidentally detected as well as for screen detected nodules. However, these guidelines have been based primarily on expert opinion. Recently two studies were published regarding SSNs detected in low-dose computed tomography (LDCT) lung cancer screening, including management advices.

Preoperative Prediction of Ki-67 Labeling Index By Three-dimensional CT Image Parameters for Differential Diagnosis Of Ground-Glass Opacity (GGO)

The aim of this study was to predict Ki-67 labeling index (LI) preoperatively by three-dimensional (3D) CT image parameters for pathologic assessment of GGO nodules. Diameter, total volume (TV), the maximum CT number (MAX), average CT number (AVG) and standard deviation of CT number within the whole GGO nodule (STD) were measured by 3D CT workstation. By detection of immunohistochemistry and Image Software Pro Plus 6.0, different Ki-67 LI were measured and statistically analyzed among preinvasive adenocarcinoma (PIA), minimally invasive adenocarcinoma (MIA) and invasive adenocarcinoma (IAC). Receiver operating characteristic (ROC) curve, Spearman correlation analysis and multiple linear regression analysis with cross-validation were performed to further research a quantitative correlation between Ki-67 labeling index and radiological parameters. Diameter, TV, MAX, AVG and STD increased along with PIA, MIA and IAC significantly and consecutively. In the multiple linear regression model by a stepwise way, we obtained an equation: prediction of Ki-67 LI=0.022*STD+0.001* TV+2.137 (R=0.595, R’s square=0.354, p<0.001), which can predict Ki-67 LI as a proliferative marker preoperatively. Diameter, TV, MAX, AVG and STD could discriminate pathologic categories of GGO nodules significantly. Ki-67 LI of early lung adenocarcinoma presenting GGO can be predicted by radiologic parameters based on 3D CT for differential diagnosis.

Pulmonary subsolid nodules: what radiologists need to know about the imaging features and management strategy

Pulmonary subsolid nodules (SSNs) refer to pulmonary nodules with pure ground-glass nodules and part-solid ground-glass nodules. SSNs are frequently encountered in the clinical setting, such as screening chest computed tomography (CT). The main concern regarding pulmonary SSNs, particularly when they are persistent, has been lung adenocarcinoma and its precursors. The CT manifestations of SSNs help radiologists and clinicians manage these lesions. However, the management plan for SSNs has not previously been standardized. Recently, the Fleischner Society published recommendations for the management of incidentally detected SSNs. The guidelines reflect the new lung adenocarcinoma classification system proposed by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) and include six specific recommendations according to the nodule size, solid portion and multiplicity. This review aims to increase the understanding of SSNs and the imaging features of SSNs according to their histology, natural course, possible radiologic interventions, such as biopsy, localization prior to surgery, and current management.

Imaging the solitary pulmonary nodule

The development of widespread lung cancer screening programs has the potential to dramatically increase the number of thoracic computed tomography (CT) examinations performed annually in the United States, resulting in a greater number of newly detected, indeterminate solitary pulmonary nodules (SPNs). Additional imaging studies, such as fluorodeoxyglucose F 18 (FDG)-positron emission tomography (PET), have been shown to provide valuable information in the assessment of indeterminate SPNs. Newer technologies, such as contrast-enhanced dual-energy chest CT and FDG-PET/CT, also have the potential to facilitate diagnosis of potentially malignant SPNs.

Management of ground-glass opacities: should all pulmonary lesions with ground-glass opacity be surgically resected?

Pulmonary nodules with ground-glass opacity (GGO) are frequently observed and will be increasingly detected. GGO can be observed in both benign and malignant conditions, including lung cancer and its preinvasive lesions. Atypical adenomatous hyperplasia and adenocarcinoma in situ are typically manifested as pure GGOs, whereas more advanced adenocarcinomas may include a larger solid component within the GGO region. The natural history of GGOs has been gradually clarified. Approximately 20% of pure GGOs and 40% of part-solid GGOs gradually grow or increase their solid component, whereas others remain unchanged for years. Therefore, it remains unclear whether all pulmonary lesions with GGO should be surgically resected or whether lesions without changes may not require resection. To distinguish GGOs with growth from those without growth, a 3-year follow-up observation period is a reasonable benchmark based on the data that the volume-doubling time (VDT) of pure GGOs ranges from approximately 600 to 900 days and that of part-solid GGOs ranges from 300 to 450 days. Future studies on the genetic differences between GGOs with growth and those without growth will help establish an appropriate management algorithm.

Long-term effects of inhaled budesonide on screening-detected lung nodules

BACKGROUND

A previously carried out randomized phase IIb, placebo-controlled trial of 1 year of inhaled budesonide, which was nested in a lung cancer screening study, showed that non-solid and partially solid lung nodules detected by low-dose computed tomography (LDCT), and not immediately suspicious for lung cancer, tended to regress. Because some of these nodules may be slow-growing adenocarcinoma precursors, we evaluated long-term outcomes (after stopping the 1-year intervention) by annual LDCT.

PATIENTS AND METHODS

We analyzed the evolution of target and non-target trial nodules detected by LDCT in the budesonide and placebo arms up to 5 years after randomization. The numbers and characteristics of lung cancers diagnosed during follow-up were also analyzed.

RESULTS

The mean maximum diameter of non-solid nodules reduced significantly (from 5.03 mm at baseline to 2.61 mm after 5 years) in the budesonide arm; there was no significant size change in the placebo arm. The mean diameter of partially solid lesions also decreased significantly, but only by 0.69 mm. The size of solid nodules did not change. Neither the number of new lesions nor the number of lung cancers differed in the two arms.

CONCLUSIONS

Inhaled budesonide given for 1 year significantly decreased the size of non-solid nodules detected by screening LDCT after 5 years. This is of potential importance since some of these nodules may progress slowly to adenocarcinoma. However, further studies are required to assess clinical implications.

CLINICAL TRIAL NUMBER

NCT01540552.

Mesenchymal properties of SJL mice-stem cells and their efficacy as autologous therapy in a relapsing-remitting multiple sclerosis model

Introduction

Mesenchymal stem cells (MSCs) are a multipotent population of adult stem cells, which may represent a promising therapeutic approach for neurological autoimmune diseases such as multiple sclerosis. The mouse is the most used species for obtaining and studying the characteristics of MSC and their potential as autologous transplants in pre-clinical models. However, conflicting data have been published disclosing intraspecies variations. The choice of the mouse strain and the tissue source appear, among others, as important factors in the experimental application of MSCs.

Methods

Adipose tissue-derived MSCs obtained from the SJL/JCrl mouse strain (SJL-AdMSC) have been cultured for a long time (from passage 0 up to 15) under controlled experimental conditions, and their growth rate, morphology, stromal and haematopoietic marker expression profiles and differentiation capacity towards adipocytes, osteocytes and chondrocytes have been determined. Moreover, their preclinical efficacy has been assessed by autologous transplant in relapsing-remitting experimental autoimmune encephalomielitis (RR-EAE)-induced SJL mice (a well established mice model for the study of RR-multiple sclerosis).

Results

We demonstrate that SJL-AdMSCs show the same fibroblastic shape, growth rate, profile of markers expression and multipotency described for MSCs in every passage evaluated (up to passage 15). Additionally, SJL-AdMSCs ameliorate the RR-EAE course, suggesting that they could modulate disease progression. Moreover, their features studied are fully comparable with the standardized Ad-MSCs obtained from the C57BL/6 mouse strain, which strengthens their use in cell therapy.

Conclusion

SJL-AdMSCs might be a suitable source of Ad-MSCs for studies related to the properties of MSCs and their application as promising therapeutic tools in autologous transplants in experimental medicine.

Towards a close computed tomography monitoring approach for screen detected subsolid pulmonary nodules?

Pulmonary subsolid nodules (SSNs) have a high likelihood of malignancy, but are often indolent. A conservative treatment approach may therefore be suitable. The aim of the current study was to evaluate whether close follow-up of SSNs with computed tomography may be a safe approach. The study population consisted of participants of the Dutch-Belgian lung cancer screening trial (Nederlands Leuvens Longkanker Screenings Onderzoek; NELSON). All SSNs detected during the trial were included in this analysis. Retrospectively, all persistent SSNs and SSNs that were resected after first detection were segmented using dedicated software, and maximum diameter, volume and mass were measured. Mass doubling time (MDT) was calculated. In total 7135 volunteers were included in the current analysis. 264 (3.3%) SSNs in 234 participants were detected during the trial. 147 (63%) of these SSNs in 126 participants disappeared at follow-up, leaving 117 persistent or directly resected SSNs in 108 (1.5%) participants available for analysis. The median follow-up time was 95 months (range 20-110 months). 33 (28%) SSNs were resected and 28 of those were (pre-) invasive. None of the non-resected SSNs progressed into a clinically relevant malignancy. Persistent SSNs rarely developed into clinically manifest malignancies unexpectedly. Close follow-up with computed tomography may be a safe option to monitor changes.

Evidence based imaging strategies for solitary pulmonary nodule

Solitary pulmonary nodule (SPN) is defined as a rounded opacity ≤3 cm in diameter surrounded by lung parenchyma. The majority of smokers who undergo thin-section CT have SPNs, most of which are smaller than 7 mm. In the past, multiple follow-up examinations over a two-year period, including CT follow-up at 3, 6, 12, 18, and 24 months, were recommended when such nodules are detected incidentally. This policy increases radiation burden for the affected population. Nodule features such as shape, edge characteristics, cavitation, and location have not yet been found to be accurate for distinguishing benign from malignant nodules. When SPN is considered to be indeterminate in the initial exam, the risk factor of the patients should be evaluated, which includes patients' age and smoking history. The 2005 Fleischner Society guideline stated that at least 99% of all nodules 4 mm or smaller are benign; when nodule is 5-9 mm in diameter, the best strategy is surveillance. The timing of these control examinations varies according to the nodule size (4-6, or 6-8 mm) and the type of patients, specifically at low or high risk of malignancy concerned. Noncalcified nodules larger than 8 mm diameter bear a substantial risk of malignancy, additional options such as contrast material-enhanced CT, positron emission tomography (PET), percutaneous needle biopsy, and thoracoscopic resection or videoassisted thoracoscopic resection should be considered.

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%.

Screening for lung cancer with low-dose computed tomography: a review of current status

Screening using low-dose computed tomography (CT) represents an exciting new development in the struggle to improve outcomes for people with lung cancer. Randomised controlled evidence demonstrating a 20% relative lung cancer mortality benefit has led to endorsement of screening by several expert bodies in the US and funding by healthcare providers. Despite this pivotal result, many questions remain regarding technical and logistical aspects of screening, cost-effectiveness and generalizability to other settings. This review discusses the rationale behind screening, the results of on-going trials, potential harms of screening and current knowledge gaps.

Volume and mass doubling times of persistent pulmonary subsolid nodules detected in patients without known malignancy

PURPOSE

To evaluate volume doubling time (VDT) and mass doubling time (MDT) of persistent pulmonary subsolid nodules (SSNs) followed-up with low-dose (LD) computed tomography (CT) in patients without a history of malignancy.

MATERIALS AND METHODS

This retrospective institutional review board-approved study, with waiver of patient informed consent, included 97 SSNs in 97 patients (45 men, 52 women; median age, 58 years; range, 37-87 years) in whom at least two LD CT scans were obtained, with 3-month or longer follow-up interval and median follow-up of 633 days. SSNs were categorized into pure ground-glass nodules (GGNs) (group A), part-solid GGNs with solid components of 5 mm or smaller (group B), and part-solid GGNs with solid components larger than 5 mm (group C). Three-dimensional manual segmentation for all SSNs was performed on initial and latest follow-up LD CT scans; subsequently, VDTs and MDTs were calculated and were compared among groups by using Kruskal-Wallis test, followed by the Dunn procedure with Bonferroni correction for volume-growing SSNs and mass-growing SSNs.

RESULTS

Volume growth was thus: 12 of 63 SSNs (19%), group A; nine of 23 SSNs (39%), group B; and eight of 11 SSNs (73%), group C. Median VDT was thus: 1832.3 days (range, 1230.7-4537.3 days), group A; 1228.5 days (range, 934.7-4617.7 days), group B; and 759.0 days (range, 376.4-941.5 days), group C. Mass growth was thus: 17 of 63 SSNs (27%), group A; 11 of 23 SSNs (48%), group B; and nine of 11 SSNs (82%), group C. Median MDT was 1556.1 days (range, 642.5-3564.5 days) for group A, 1199.9 days (range, 838.6-2578.7 days) for group B, and 627.7 days (range, 340.0-921.2 days) for group C. Median VDTs and MDTs of groups A and B were significantly longer than those of group C (P < .01).

CONCLUSION

Pure GGNs and part-solid GGNs with solid components of 5 mm or smaller show significantly longer VDTs and MDTs than do part-solid GGNs with solid components larger than 5 mm. Online supplemental material is available for this article.

Lung cancer imaging

Lung cancer remains the leading cause of cancer-related deaths in the US. Imaging plays an important role in the diagnosis, staging, and follow-up evaluation of patients with lung cancer. With recent advances in technology, it is important to update and standardize the radiological practices in lung cancer evaluation. In this article, the authors review the main clinical applications of different imaging modalities and the most common radiological presentations of lung cancer.

A decrease in the size of ground glass nodules may indicate the optimal timing for curative surgery

OBJECTIVES

Although ground glass nodules (GGNs) are generally considered to grow slowly to a large size, their natural progression remains unclear, and a decrease in tumor size has been reported in a few previous studies. The study aimed to retrospectively review the radiologic and pathological characteristics of resected ground glass nodules (GGNs) followed with chest computed tomography (CT) for at least a year before surgery to clarify the natural progression of GGNs.

PATIENTS AND METHODS

The chest CT cans and clinical charts of 32 GGNs in 31 patients who underwent pulmonary resection between January 2006 and March 2013 were retrospectively reviewed. The definitions of pure GGNs and part-solid nodules were based on the tumor shadow disappearance rate. The tumor size was measured twice, and the mean size was used for evaluation.

RESULTS

The mean GGN size before surgery was 15.2 mm, and the median follow-up period before surgery was 21 months. In the follow-up period, 15 (58%) of 26 pure GGNs at the initial CT remained pure GGNs at the last CT. However, a solid component appeared in the remaining 11 tumors (42%) of the 26 initial pure GGNs. Furthermore, 1 GGN of the 15 GGNs that remained pure and 10 of the 11 GGNs with solid component also showed a size decrease. In addition, 6 part-solid nodules were observed at the initial CT. Of these, 3 showed a decrease in size during follow-up. Overall, 47% of the GGNs showed a size reduction on follow-up chest CT.

CONCLUSIONS

A size reduction was observed in nearly half of the GGNs and suggested the progression to an invasive adenocarcinoma. When a mild collapse of the GGNs is observed, a careful follow-up is necessary to identify a solid component. Tumor size decreases may represent the optimal timing of pulmonary resection for curative treatment.

In compressed lung tissue microscopic sections of adenocarcinoma in situ may mimic papillary adenocarcinoma

CONTEXT

Surgical removal and pathologic handling of lung tissue has a compressive effect upon its architecture. The effect of surgical atelectasis on morphology has not been examined in depth, especially with respect to lung adenocarcinomas.

OBJECTIVE

To examine the influence of surgical atelectasis on morphologic lepidic growth pattern, mimicking papillary adenocarcinoma pattern.

DESIGN

In 2 cases serial sections of resected pulmonary adenocarcinoma were used, as was a 3-dimensional reconstruction. Elastin stains were performed on primary and metastatic adenocarcinomas.

RESULTS

Perfusion fixation of another case showed marked morphologic differences of less compressed peripheral lung tissue, emphasizing the preexisting alveolar structure. An elastic stain may help identify true lesional architecture.

CONCLUSIONS

We demonstrate that microscopic sections of adenocarcinoma in situ in compressed/collapsed tissue may give rise to a pseudopapillary pattern mimicking invasive adenocarcinoma. Accurate appreciation of different tumor architecture in lung adenocarcinoma has important biologic and clinical implications. Pathologists should be aware of the possibility of misclassification of adenocarcinoma pattern due to tissue artifacts caused by lung tissue handling.

Computed tomography quantitative analysis of components: a new method monitoring the growth of pulmonary nodule

BACKGROUND

The estimation of the growth of solitary pulmonary nodules by using non-invasive methods is increasingly gaining clinical importance for performing the timely adequate treatment of these nodules.

PURPOSE

To evaluate the application value of computed tomography (CT) quantitative analysis of components for dynamic assessment of the growth of solitary pulmonary nodules, and compare this approach with three-dimensional (3D) volumetric measurement of pulmonary nodules.

MATERIAL AND METHODS

The imaging data of 21 patients who had undergone multiple follow-up CT scans for solitary pulmonary nodules were retrospectively analyzed, and the total volume of pulmonary nodules and the percentage change in the total volume of pulmonary nodules after multiple follow-up CT scans were measured using 3D volume measurement software. The volume of solid components in pulmonary nodules was measured using CT quantitative analysis; the percentage change in the volume of solid components across examinations was calculated; and the percentage change in the total volume of pulmonary nodules was compared and contrasted with the percentage change in the volume of solid components in the pulmonary nodules.

RESULTS

All 21 cases were malignant adenocarcinomas. In the 21 cases of malignant nodules, the 3D volumes of the nodules and solid components were both increased, with the percentage change in the volume of the solid components (115.78-418.91%, 130.45 ± 119.48) significantly different from the percentage change in the total volume of the nodules (78.56-105.73% , 42.34 ± 32.17) (P = 0.02).

CONCLUSION

By measuring volume changes in solid components in the nodules, CT quantitative analysis offers more sensitive and earlier evaluation of the dynamic growth of the nodules than measurement of volume changes in the nodules alone.

The proangiogenic phenotype of natural killer cells in patients with non-small cell lung cancer

The tumor microenvironment can polarize innate immune cells to a proangiogenic phenotype. Decidual natural killer (dNK) cells show an angiogenic phenotype, yet the role for NK innate lymphoid cells in tumor angiogenesis remains to be defined. We investigated NK cells from patients with surgically resected non-small cell lung cancer (NSCLC) and controls using flow cytometric and functional analyses. The CD56(+)CD16(-) NK subset in NSCLC patients, which represents the predominant NK subset in tumors and a minor subset in adjacent lung and peripheral blood, was associated with vascular endothelial growth factor (VEGF), placental growth factor (PIGF), and interleukin-8 (IL-8)/CXCL8 production. Peripheral blood CD56(+)CD16(-) NK cells from patients with the squamous cell carcinoma (SCC) subtype showed higher VEGF and PlGF production compared to those from patients with adenocarcinoma (AdC) and controls. Higher IL-8 production was found for both SCC and AdC compared to controls. Supernatants derived from NSCLC CD56(+)CD16(-) NK cells induced endothelial cell chemotaxis and formation of capillary-like structures in vitro, particularly evident in SCC patients and absent from controls. Finally, exposure to transforming growth factor-β(1) (TGFβ(1)), a cytokine associated with dNK polarization, upregulated VEGF and PlGF in peripheral blood CD56(+)CD16(-) NK cells from healthy subjects. Our data suggest that NK cells in NSCLC act as proangiogenic cells, particularly evident for SCC and in part mediated by TGFβ(1).

Low-dose CT scan screening for lung cancer: comparison of images and radiation doses between low-dose CT and follow-up standard diagnostic CT

OBJECTIVES

This study aim to compare image quality and radiation doses between low-dose CT and follow-up standard diagnostic CT for lung cancer screening.

METHODS

In a single medical institution, 19 subjects who had been screened for lung cancer by low-dose CT before going through follow-up standard diagnostic CT were randomly selected. Both CT image sets for all subjects were independently evaluated by five specialized physicians.

RESULTS

There were no significant differences between low-dose CT screening and follow-up standard diagnostic CT for lung cancer screening in all 11 criteria. The concordance rate for the diagnoses was approximately 80% (p < 0.001) for all categories. Agreement of the evaluation of all categories in the final diagnosis exceeded 94% (p < 0.001). Five physicians detecting and characterizing the pulmonary nodules did not recognized the difference between low-dose CT screening and follow-up standard diagnostic CT. With low-dose CT, the effective dose ranged between 1.3 and 3.4 mSv, whereas in the follow-up diagnostic CT, the effective dose ranged between 8.5 and 14.0 mSv.

CONCLUSION

This study suggests that low-dose CT can be effectively used as a follow-up standard diagnostic CT in place of standard-dose CT in order to reduce the radiation dose.

Overestimated lead times in cancer screening has led to substantial underestimation of overdiagnosis

Background:

Published lead time estimates in breast cancer screening vary from 1 to 7 years and the percentages of overdiagnosis vary from 0 to 75%. The differences are usually explained as random variations. We study how much can be explained by using different definitions and methods.

Methods:

We estimated the clinically relevant lead time based on the observed incidence reduction after attending the last screening round in the Norwegian mammography screening programme. We compared this estimate with estimates based on models that do not take overdiagnosis into account (model-based lead times), for varying levels of overdiagnosis. Finally, we calculated overdiagnosis adjusted for clinical and model-based lead times and compared results.

Results:

Clinical lead time was about one year based on the reduction in incidence in women previously offered screening. When overdiagnosed tumours were included, the estimates increased to 4–9 years, depending on the age at which screening begins and the level of overdiagnosis. Including all breast cancers detected in women long after the end of the screening programme dilutes the level of overdiagnosis by a factor of 2–3.

Conclusion:

When overdiagnosis is not taken into account, lead time is substantially overestimated. Overdiagnosis adjusted for model-based lead time is a function tending to zero, with no simple interpretation. Furthermore, the estimates are not in general comparable, because they depend on both the duration of screening and duration of follow-up. In contrast, overdiagnosis adjusted for clinically relevant tumours is a point estimate (and interpreted as percentage), which we find is the most reasonable method.

How long should small lung lesions of ground-glass opacity be followed?

INTRODUCTION

Pulmonary ground-glass nodules are frequently encountered. The purpose of this study was to evaluate the natural history of them and to gain some insights on how to follow them up.

METHODS

We retrospectively studied patients with pulmonary nodules that met the following criteria: (1) tumor diameter of 3 cm or less, (2) ground-glass opacity proportion of 50% or more, and (3) observation without treatment for 6 months or more. Between 1999 and 2012, 108 pulmonary lesions in 61 patients fulfilled these criteria. We reevaluated their computed tomography images and analyzed changes in their size.

RESULTS

The tumors were 1 cm or lesser in size in 69 lesions, 1.1 cm to 2 cm in 34, and 2.1 cm to 3 cm in five. The proportion of solid lesions was 0% for 82 lesions, 1% to 25% for 19, and 26% to 50 % for seven. At the median observation period of 4.2 years, 29 lesions had become larger, whereas the remaining 79 had persisted without changing in size (±1 mm). The median size change in the nodules that grew was 7 mm (range, 2-32 mm). All 29 tumors began to grow within 3 years of their first observation: 1 year or lesser in 13 lesions, after 1.1 years to 2 years in 12, and after 2.1 years to 3 years in four.

CONCLUSIONS

Some small lung lesions exhibiting ground-glass opacity persisted without changes in size, whereas others grew gradually. The tendency to grow was clear within the first 3 years in all cases. Therefore, we conclude that these lesions should be followed for at least 3 years.

Evaluation of individuals with pulmonary nodules: when is it lung cancer? Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

OBJECTIVES

The objective of this article is to update previous evidence-based recommendations for evaluation and management of individuals with solid pulmonary nodules and to generate new recommendations for those with nonsolid nodules.

METHODS

We updated prior literature reviews, synthesized evidence, and formulated recommendations by using the methods described in the "Methodology for Development of Guidelines for Lung Cancer" in the American College of Chest Physicians Lung Cancer Guidelines, 3rd ed.

RESULTS

We formulated recommendations for evaluating solid pulmonary nodules that measure > 8 mm in diameter, solid nodules that measure ≤ 8 mm in diameter, and subsolid nodules. The recommendations stress the value of assessing the probability of malignancy, the utility of imaging tests, the need to weigh the benefits and harms of different management strategies (nonsurgical biopsy, surgical resection, and surveillance with chest CT imaging), and the importance of eliciting patient preferences.

CONCLUSIONS

Individuals with pulmonary nodules should be evaluated and managed by estimating the probability of malignancy, performing imaging tests to better characterize the lesions, evaluating the risks associated with various management alternatives, and eliciting their preferences for management.

Clinical and organizational factors in the initial evaluation of patients with lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

This guideline is intended to provide an evidence-based approach to the initial evaluation of patients with known or suspected lung cancer. It also includes an assessment of the impact of timeliness of care and multidisciplinary teams on outcome.

METHODS

The applicable current medical literature was identified by a computerized search and evaluated using standardized methods. Recommendations were framed using the approach described by the Guidelines Oversight Committee of the American College of Chest Physicians. Data sources included MEDLINE and the Cochrane Database of Systematic Reviews.

RESULTS

Initial evaluation should include a thorough history and physical examination; CT imaging; pulmonary function tests; and hemoglobin, electrolyte, liver function, and calcium levels. Additional testing for distant metastases and paraneoplastic syndromes should be determined on the basis of these results. Paraneoplastic syndromes may have an adverse impact on cancer treatment, so they should be controlled rapidly with the goal of proceeding with definitive cancer treatment in a timely manner. Although the relationship between timeliness of care and survival is difficult to quantify, efforts to deliver timely care are reasonable and should be balanced with the need to attend to other dimensions of health-care quality (eg, safety, effectiveness, efficiency, equality, consistency with patient values and preferences). Quality care will require multiple disciplines. Although it is difficult to assess the impact, we suggest that a multidisciplinary team approach to care be used, particularly for patients requiring multimodality therapy.

CONCLUSIONS

The initial evaluation of patients with lung cancer should include a thorough history and physical examination, pulmonary function tests, CT imaging, basic laboratory tests, and selective testing for distant metastases and paraneoplastic syndromes.

Limited resection and two-staged lobectomy for non-small cell lung cancer with ground-glass opacity

Background

Lung tumors showing ground-glass opacities on high-resolution computed tomography indicate the presence of inflammation, atypical adenomatous hyperplasia, or localized bronchioloalveolar carcinoma. We adopted a two-staged video-assisted thoracoscopic lobectomy strategy involving completion lobectomy for localized bronchioloalveolar carcinoma with an invasive component according to postoperative pathological examination by permanent section after partial resection.

Methods

Forty-one patients with undiagnosed small peripheral ground-glass opacity lesions underwent partial resection from 2001 to 2007 in Hokkaido University Hospital. Localized bronchioloalveolar carcinoma was classified according to the Noguchi classification for adenocarcinoma. Malignant lesions other than Noguchi types A and B were considered for completion lobectomy and systemic mediastinal lymphadenectomy. Perioperative data of completion video-assisted thoracoscopic lobectomies were compared with data of 67 upfront video-assisted thoracoscopic lobectomies for clinical stage IA adenocarcinoma performed during the same period.

Results

Postoperative pathological examination revealed 35 malignant and 6 non-malignant diseases. Histologically, all of the malignant diseases were adenocarcinomas of Noguchi type A (n = 7), B (n = 9), C (n = 18), and F (n = 1). Eleven of 19 patients (58%) with Noguchi type C or F underwent two-staged video-assisted thoracoscopic lobectomy. Three patients refused a second surgery. There was no cancer recurrence. The two-staged lobectomy group had a significantly longer operative time and more blood loss than the upfront lobectomy group. There was no surgical mortality or cancer recurrence.

Conclusions

Two-staged lobectomy for undiagnosed small peripheral ground-glass opacity lesions showed satisfactory oncological results. However, low compliance for and invasiveness of the second surgery are concerns associated with this strategy.

Early diagnosis of lung cancer

A large randomized controlled trial, The National Lung Screening Study (NLST), has demonstrated that screening with low-dose spiral computed tomography saved lives from lung cancer when compared with screening with chest radiographs. This is the first test showing efficacy in screening for lung cancer as previous trials of chest radiographs and sputum cytology failed to result in fewer deaths with screening. This review will examine the problem of lung cancer, the issues presented by screening, and the results of computed tomography (CT) studies for lung cancer screening. Now that CT screening has been shown to be effective, implementation of screening becomes the next step.

The long-term course of ground-glass opacities detected on thin-section computed tomography

BACKGROUND

Focal ground-glass opacity (GGO) is becoming a major concern because of its possible association with lung cancer. In this study, we analyzed the long-term progression of GGOs that persisted for more than 2 years.

METHODS

We reviewed focal GGOs identified by thin-section computed tomography that persisted for more than 2 years.

RESULTS

We enrolled a total of 114 patients with 175 GGO lesions. The median patient age was 61 years (range, 37-92 years) and 42 (36.8%) patients were male. Mean initial GGO size was 7.8 ± 4.4 mm. Median follow-up duration was 45 months. Forty-six (26.3%) GGOs had significant size increases (≥2 mm in the longest diameter) with a mean volume doubling time of 1041 days. In a multivariate analysis, large size (≥10 mm), the presence of a solid portion (mixed GGO) and old age (≥65 years) were risk factors for significant size increase, with odds ratios (95% CI) of 6.46 (2.69-15.6), 2.69 (1.11-6.95) and 2.55 (1.13-5.77), respectively. GGOs with character changes from pure to mixed or mixed to solid showed more rapid volume expansion.

CONCLUSIONS

GGOs which persisted for several years showed an indolent course. Large lesions with a solid portion and GGOs in male or elderly individuals may be cause for more concern, as these factors were associated with size increase. Resection should be considered if GGOs show character changes, as these may be associated with rapid size progression.

Low-dose CT: technique, reading methods and image interpretation

The National Lung Cancer Screening Trial has recently demonstrated that screening of high-risk populations with the use of low-dose computed tomography (LDCT) reduces lung cancer mortality^[1]. Based on this encouraging result, the National Comprehensive Cancer Network guidelines recommended LDCT for selected patients at high risk of lung cancer^[2]. This suggests that an increasing number of CT screening examinations will be performed. The LDCT technique is relatively simple but some CT parameters are important and should be accurately defined in order to achieve good diagnostic quality and minimize the delivered dose. In addition, LDCT examinations are not as easy to read as they may initially appear; different approaches and tools are available for nodule detection and measurement. Moreover, the management of positive results can be a complex process and can differ significantly from routine clinical practice. Therefore this paper deals with the LDCT technique, reading methods and interpretation in lung cancer screening, particularly for those radiologists who have little experience of the technique.