Lymph node metastasis in small peripheral adenocarcinoma of the lung

Lymph node metastasis outside of a tumor-bearing lobe in primary lung cancer and the status of interlobar fissures: The necessity for removing lymph nodes from an adjacent lobe

The new Tumor Node Metastasis staging system does not recognize fissure status with respect to adjacent lobe invasion (ALI) in lung cancer. Furthermore, no specific surgical strategies have been recommended for lymph node dissections around adjacent nontumor-bearing lobes (NTBLs) according to fissure status. Therefore, this study was undertaken to investigate the necessity of removing additional adjacent lobe lymph nodes in patients with nonsmall cell lung cancer (NSCLC) for lesions limited to in the vicinity of the interlobar fissure.From August 2013 to March 2015, the records of 332 patients, who underwent systematic mediastinal lymph node dissection, were reviewed in this retrospective study. The bronchial lymph nodes had been subjected to pathological examination, and the status of the fissures was also recorded. A statistical analysis was performed to identify the significant predictors of lymph node metastasis.The patients were divided into a nonadjacent lobe invasion (NALI) group (n = 295) and an ALI group (n = 37). There was a significant difference in tumors with pN2 disease between the ALI and NALI groups (37.8% vs 8.8%, P = .001). ALI tumors had significantly more frequent pleural involvement than NALI tumors (62.2% vs 43.1%, P = .035). The frequency of N2 involvement among tumors invading across the complete fissure was higher than that of the tumors invading across the incomplete fissure (44.4% vs 14.3%, P = .015). However, the frequency of N1 involvement among tumors invading across the incomplete fissure was not statistically different than that of tumors not invading across incomplete fissure (32.1% vs 24.2%, P = .357). Regarding lymph node metastasis in NTBL, 15 (12.7%) patients had lymph node metastases in NTBLs. Pleural involvement was an independent predictor of lymph node metastasis in an NTBL.A greater frequency of N2 lymph nodes existed in NSCLC with invading adjacent lobe across complete fissure, extensive lymphatic resection within the hilum, and NTBL in tumors with pleural involvement are justifiable and necessary.

A Texture Analysis-Based Prediction Model for Lymph Node Metastasis in Stage IA Lung Adenocarcinoma

BACKGROUND

Some clinical N0 lung adenocarcinomas have been pathologically diagnosed as N1 or N2. To improve the preoperative diagnostic accuracy of lymph node disease, we developed a prediction model for lymph node metastasis in cT1 N0 M0 lung adenocarcinoma based on computed tomography texture analysis and clinical characteristics to estimate the probability of lymph node metastasis.

METHODS

The records of 501 consecutive patients with cT1 N0 M0 lung adenocarcinoma who underwent computed tomography scan and pulmonary resection with systematic lymph nodes dissection or lymph nodes sampling were reviewed. Each nodule was manually segmented, and its computerized texture features were extracted. Multivariate logistic regression with fivefold validation was used to estimate independent predictors and build the prediction model. The prediction model was then externally validated. A nomogram was developed based on logistic regression results.

RESULTS

Among 501 patients, 41 were diagnosed with positive lymph nodes (8.18%). Four independent predictors were identified: the skewness and 90th percentile of computed tomography number, nodule compactness, and carcinoembryonic antigen level. This model showed good calibration (Hosmer-Lemeshow test, p = 0.337), with an area under the curve of 0.883 (95% confidence interval, 0.842 to 0.924; p < 0.001). The area under the curve was 0.808 (95% confidence interval, 0.735 to 0.880) when validated with independent data.

CONCLUSIONS

A model based on computerized textures and carcinoembryonic antigen level can assess the lymph node status of patients with cT1 N0 M0 lung adenocarcinoma preoperatively, which could assist surgeons in making subsequent clinical decisions.

Peripheral lung adenocarcinomas harboring epithelial growth factor receptor mutations with microRNA-135b overexpression are more likely to invade visceral pleura

Lung adenocarcinoma, characterized by its early and aggressive local invasion and high metastatic potential, is the most frequently observed histological type of non-small-cell lung cancer (NSCLC). Visceral pleural invasion (VPI) caused by peripheral lung adenocarcinomas is closely associated with the poor prognosis of patients with NSCLC. The association between VPI and some clinicopathological characteristics has been observed in the past few decades. However, the molecular mechanism of VPI in lung adenocarcinomas is unknown. In the present, the expression level of microRNA (miR-)135b and epidermal growth factor receptor (EGFR) mutations using the reverse transcription-quantitative polymerase chain reaction and DNA sequencing, respectively. In addition, the present study aimed at exploring the association between the miR-135b level, EGFR mutations and VPI in peripheral lung adenocarcinoma. The results of the present study demonstrated that miR-135b was significantly upregulated in lung adenocarcinoma compared with adjacent normal tissue and positively associated EGFR mutations in peripheral lung adenocarcinoma. Furthermore, it was identified that lung adenocarcinomas with EGFR mutations and miR-135b overexpression were more likely to invade visceral pleura. Taken together, these findings indicate that miR-135b overexpression is positively associated with mutations to EGFR, which may promote the development of peripheral lung adenocarcinomas by the formation of VPI. This indicates that the two factors may serve as prognostic markers and molecular targets for the treatment of peripheral lung adenocarcinomas.

Are There Any Additional Benefits to Performing Positron Emission Tomography/Computed Tomography Scans and Brain Magnetic Resonance Imaging on Patients with Ground-Glass Nodules Prior to Surgery?

Background

A ground-glass nodule (GGN) represents early-stage lung adenocarcinoma. However, there is still no consensus for preoperative staging of GGNs. Therefore, we evaluated the need for the routine use of positron emission tomography/computed tomography (PET)/computed tomography (CT) scans and brain magnetic resonance imaging (MRI) during staging.

Methods

A retrospective analysis was undertaken in 72 patients with 74 GGNs of less than 3 cm in diameter, which were confirmed via surgery as malignancy, at the Samsung Medical Center between May 2010 and December 2011.

Results

The median age of the patients was 59 years. The median GGN diameter was 18 mm. Pure and part-solid GGNs were identified in 35 (47.3%) and 39 (52.7%) cases, respectively. No mediastinal or distant metastasis was observed in these patients. In preoperative staging, all of the 74 GGNs were categorized as stage IA via chest CT scans. Additional PET/CT scans and brain MRIs classified 71 GGNs as stage IA, one as stage IIIA, and two as stage IV. However, surgery and additional diagnostic work-ups for abnormal findings from PET/CT scans classified 70 GGNs as stage IA, three as stage IB, and one as stage IIA. The chest CT scans did not differ from the combined modality of PET/CT scans and brain MRIs for the determination of the overall stage (94.6% vs. 90.5%; kappa value, 0.712).

Conclusion

PET/CT scans in combination with brain MRIs have no additional benefit for the staging of patients with GGN lung adenocarcinoma before surgery.

Nanotechnology applications in thoracic surgery

Nanotechnology is an emerging, rapidly evolving field with the potential to significantly impact care across the full spectrum of cancer therapy. Of note, several recent nanotechnological advances show particular promise to improve outcomes for thoracic surgical patients. A variety of nanotechnologies are described that offer possible solutions to existing challenges encountered in the detection, diagnosis and treatment of lung cancer. Nanotechnology-based imaging platforms have the ability to improve the surgical care of patients with thoracic malignancies through technological advances in intraoperative tumour localization, lymph node mapping and accuracy of tumour resection. Moreover, nanotechnology is poised to revolutionize adjuvant lung cancer therapy. Common chemotherapeutic drugs, such as paclitaxel, docetaxel and doxorubicin, are being formulated using various nanotechnologies to improve drug delivery, whereas nanoparticle (NP)-based imaging technologies can monitor the tumour microenvironment and facilitate molecularly targeted lung cancer therapy. Although early nanotechnology-based delivery systems show promise, the next frontier in lung cancer therapy is the development of 'theranostic' multifunctional NPs capable of integrating diagnosis, drug monitoring, tumour targeting and controlled drug release into various unifying platforms. This article provides an overview of key existing and emerging nanotechnology platforms that may find clinical application in thoracic surgery in the near future.

Intra-Alveolar Intestinal Epithelium: A Reappraisal of the So-Called Mucinous Goblet-Cell Rich Carcinoma Apropos of Two Cases With Prolonged Follow-up and Literature Review

Primary pulmonary mucin-rich lesions with abundant goblet cells growing within alveolar spaces are either classified as mucinous adenocarcinoma (previously called mucinous bronchioloalveolar carcinoma) or colloid carcinoma. Some of these lesions display a morphologic pattern characterized by paucicellular discontinuous patches of nonatypical colonic type epithelium attached to alveolar walls without evidence of invasion. Immunohistochemically, these epithelial patches express an intestinal immunophenotype (CD20+, CDX-2+, CK7-, TTF-1-). None of the lesions so far reported with these histological and immunohistochemical characteristics have recurred or metastasized. Herein we describe 2 patients with this type of intra-alveolar mucinous lesions who have been meticulously followed-up for 9 and 14 years, respectively, without evidence of disease progression. Based on their histologic appearance, immunoreactivity, and on the presence of occasional CDX-2 expressing cells in terminal airways adjacent to the lesions, we propose alternative interpretations of the mucin-producing epithelium. More important, a separate provisional category for these lesions is suggested that eliminates their force inclusion as adenocarcinomas.

Recent evidence, advances, and current practices in surgical treatment of lung cancer

In the last 10-15 years, strategies and modalities of lung cancer treatment have changed dramatically. Meanwhile, the treatment objectives, the lung cancers themselves, have also changed, probably owing to early detection by computed tomography and aging of the population. In particular, the proportions of smaller lung cancers, lung adenocarcinomas with ground-glass opacity, and lung cancers in older patients are increasing. Along with these changes, surgeons have innovated and evaluated novel procedures for pulmonary resection. These include the application of minimally invasive surgical techniques, such as video-assisted thoracoscopic surgery (VATS) and robotic surgery, and sub-lobar resection, such as wedge resection and segmentectomy, for small peripheral lung cancers. Currently, VATS has gained wide acceptance and several institutions in Japan have started using robotic surgery for lung cancers. Two important clinical trials of sub-lobar resection for small peripheral lung cancers are now underway in Japan. In addition, surgery itself is of growing importance in lung cancer treatment. In particular, recent evidence supports the use of surgery in strictly selected patients with locally advanced disease, lung cancers with N2 lymph node metastases, small cell lung cancers, recurrent oligo-metastasis after pulmonary resection, or relapsed tumors after drug treatment. Surgical treatment also provides abundant tumor samples for molecular analysis, which can be used for drug selection in the adjuvant setting or after disease relapse. In the era of personalized treatment, surgery is still one of the most important treatment modalities to combat lung cancer.

Reclassification of early stage pulmonary adenocarcinoma and its consequences

The classification of pulmonary adenocarcinoma has recently undergone several proposed changes. Among these, the most striking pertains to the discontinuation of the term "bronchioloalveolar carcinoma (BAC)" and its replacement by the terms "adenocarcinoma in situ (AIS)" or "minimally invasive adenocarcinoma (MIA)" for small solitary adenocarcinomas with either pure bronchiolalveolar growth or predominant bronchioloalveolar growth and ≤5 mm invasion, respectively, in resection specimens. The recommendation for these new concepts was based on discussion and review of the literature by a panel of experts from multiple disciplines. However, the results of a recent study investigating the topic of early stage adenocarcinoma (pT1N0M0) which was based on an actual series of cases, have raised questions as to the concept, validity and justification of such new terminology and have reinforced the need to evaluate actual cases that meet the newly proposed definitions and compare them in terms of patient outcome. This is even more important when proposing terminology that implies benign behavior and that could result in a false sense of security putting patients at risk for suboptimal treatment approaches. The controversies surrounding these issues are the subject of this work.

Pulmonary adenocarcinoma T1N0M0 and its classification

Over the last decade, use of the term bronchioloalveolar carcinoma (BAC) has come under constant scrutiny as some consider it an anachronism or a term that provides incorrect information about this neoplasm. To that extent, it has recently been suggested to replace the term BAC with that of in situ adenocarcinoma (AIS) or minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure bronchioloalveolar growth (AIS) or predominant bronchioloalveolar growth and ≤5-mm invasion (MIA). However, as of today, there is no comprehensive study of these tumors, and most of what has been published in this context is based on a review of the literature that focused on scattered short series of cases describing either small adenocarcinomas or BAC. More recently, a large series of cases of a more comprehensive nature that included all early-stage adenocarcinomas (T1N0M0) has cast some doubt regarding the need for the proposed change in nomenclature. At the same time, it was suggested that if indeed that notion is maintained, a more serious and comprehensive study of actual cases must be undertaken. The details of the issues surrounding this subject are presented in this review.

Why do pathological stage IA lung adenocarcinomas vary from prognosis?: a clinicopathologic study of 176 patients with pathological stage IA lung adenocarcinoma based on the IASLC/ATS/ERS classification

BACKGROUND

Patients with pathological stage IA adenocarcinoma (AC) have a variable prognosis, even if treated in the same way. The postoperative treatment of pathological stage IA patients is also controversial.

METHODS

We identified 176 patients with pathological stage IA AC who had undergone a lobectomy and mediastinal lymph node dissection at the Shanghai Chest Hospital, Shanghai, China, between 2000 and 2006. No patient had preoperative treatment. The histologic subtypes of all patients were classified according to the 2011 International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary lung AC classification. Patients' 5-year overall survival (OS) and 5-year disease-free survival (DFS) were calculated using Kaplan-Meier and Cox regression analyses.

RESULTS

One hundred seventy-six patients with pathological stage IA AC had an 86.6% 5-year OS and 74.6% 5-year DFS. The 10 patients with micropapillary predominant subtype had the lowest 5-year DFS (40.0%).The 12 patients with solid predominant with mucin production subtype had the lowest 5-year OS (66.7%). Univariate and multivariate analysis showed that sex and prognositic groups of the IASLC/ATS/ERS histologic classification were significantly associated with 5-year DFS of pathological stage IA AC.

CONCLUSION

Our study revealed that sex was an independent prognostic factor of pathological stage IA AC. The IASLC/ATS/ERS classification of lung AC identifies histologic categories with prognostic differences that could be helpful in clinical therapy.

Early-stage pulmonary adenocarcinoma (T1N0M0): a clinical, radiological, surgical, and pathological correlation of 104 cases. The MD Anderson Cancer Center Experience

The recent proposal for histological subtyping of pulmonary adenocarcinoma by predominant pattern and introduction of the terms adenocarcinoma in situ and minimally invasive adenocarcinoma to replace the term bronchioloalveolar carcinoma by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society has led us to conduct a study of 104 patients with early-stage primary pulmonary adenocarcinoma (T1N0M0), with a view to histological subtype as defined by the new proposal and clinical outcome. None of the clinical parameters of our patient population (type of surgery, age, gender, tumor size, and comorbidities) showed any statistically significant correlation with outcome, except for associated malignancies, which not surprisingly appeared to have a negative impact on survival. In addition, statistical analyses of the histological characteristics to include tumor differentiation and the percentage of a lepidic or bronchioloalveolar component did not show any statistically significant values in terms of survival. Our results failed to show any statistically significant difference of survival between those T1N0M0 adenocarcinomas with a lepidic component and those without, thus questioning the use of terms such as in situ or minimally invasive adenocarcinoma. On the basis of our results, we consider that the outcome for patients with T1N0M0 disease is still best determined by appropriate staging rather than by changes in the pathology nomenclature of adenocarcinoma.

Identification of metastatic nodal disease in a phase 1 dose-escalation trial of intraoperative sentinel lymph node mapping in non-small cell lung cancer using near-infrared imaging

OBJECTIVES

Early-stage non-small cell lung cancer (NSCLC) has a high recurrence rate and poor 5-year survival, particularly if lymph nodes are involved. Our objective was to perform a dose-escalation study to assess safety and feasibility of intraoperative near-infrared (NIR) fluorescence imaging to identify the first tumor-draining lymph nodes (ie, sentinel lymph nodes [SLNs] in patients with NSCLC).

METHODS

A-dose escalation phase 1 clinical trial assessing real-time NIR imaging after peritumoral injection of 3.8 to 2500 μg indocyanine green (ICG) was initiated in patients with suspected stage I/II NSCLC. Visualization of lymphatic migration, SLN identification, and adverse events were recorded.

RESULTS

Thirty-eight patients underwent ICG injection and NIR imaging via thoracotomy (n = 18) or thoracoscopic imaging (n = 20). SLN identification increased with ICG dose, with fewer than 25% SLNs detected in dose cohorts of 600 μg or less versus 89% success at 1000 μg or greater. Twenty-six NIR(+) SLNs were identified in 15 patients, with 7 NIR(+) SLNs (6 patients) harboring metastatic disease on histologic analysis. Metastatic nodal disease was never identified in patients with a histologically negative NIR(+) SLN. No adverse reactions were noted.

CONCLUSIONS

NIR-guided SLN identification with ICG was safe and feasible in this initial dose-escalation trial. ICG doses greater than 1000 μg yielded nearly 90% intrathoracic SLN visualization, with the presence or absence of metastatic disease in the SLN directly correlating with final nodal status of the lymphadenectomy specimen. Further studies are needed to optimize imaging parameters and confirm sensitivity and specificity of SLN mapping in NSCLC using this promising imaging technique.

Preclinical study of near-infrared-guided sentinel lymph node mapping of the porcine lung

BACKGROUND

The presence of lymph node metastasis is the most important prognostic factor in early non-small cell lung cancer. Our objective was to develop a rapid, simple, and reliable method for thoracic sentinel lymph node (SLN) identification using near-infrared fluorescence imaging and clinically available contrast agents.

METHODS

Indocyanine green (ICG) reconstituted in saline, human serum albumin, human fresh frozen plasma, and autologous porcine plasma was evaluated for optimal formulation and dosing for SLN within porcine lungs. Animals were imaged using the fluorescence-assisted resection and exploration for surgery imaging system. The SLN identification rate, time to identification and fluorescence intensity of the SLN, bronchus, and background were measured.

RESULTS

The SLN identification rates varied widely, ranging from 33% to 100% as a function of the carrier used for ICG reconstitution. No significant difference was noted in SLN fluorescence intensity; however, bronchial intensity was significantly higher with ICG: albumin, which resulted in the lowest rate of SLN identification. Subsequent evaluation with 125 μM and 250 μM ICG:porcine plasma resulted in identification of strongly fluorescent SLNs, with identification rates of 93% and 100% and median signal-to-background ratios of 8.5 and 12.15, respectively, in less than 2 minutes in situ.

CONCLUSIONS

Near-infrared fluorescence imaging with ICG is a reliable method for SLN mapping in the lung with high sensitivity. Mixing of ICG with plasma resulted in strong SLN fluorescence signal with reliable identification rates.

Developing intrathoracic sentinel lymph node mapping with near-infrared fluorescent imaging in non-small cell lung cancer

With poor survival and high recurrence rates, early-stage lung cancer currently appears to be understaged or undertreated, or both. Although sentinel lymph node biopsy is standard for patients with breast cancer and melanoma, its success has been unreliable in non-small cell lung cancer. Sentinel lymph node biopsy might aid in the identification of lymph nodes at the greatest risk of metastasis and allow for more detailed analysis to select for patients who might benefit from adjuvant therapy. The early results in our recent clinical trial of patients with early-stage lung cancer have suggested that near-infrared imaging might offer a platform for reliable sentinel lymph node identification in these patients.

The significance of visceral pleural surface invasion in 321 cases of non-small cell lung cancers with pleural retraction

BACKGROUND

In order to improve prognostic applications and treatment decisions, we report our experiences of visceral pleural surface invasion (VPSI) in non-small cell lung cancers (NSCLCs) with pleural retraction.

METHODS

A total of 321 NSCLCs with pleural retraction were identified by carefully inspecting surgically resected specimens. The extent of pleural invasion, including the use of elastic stain, was evaluated. Patients with and without VPSI were compared for clinicopathologic parameters and survival.

RESULTS

VPSI was identified in 170 (53.0 %) of the stage I-III cases and 98 (43.4 %) of the patients with stage I disease. VPSI was associated with a higher frequency of tumor size greater than 3 cm, moderate/poor differentiation, vascular invasion, mediastinal lymph node metastasis, extranodal involvement, and higher TNM stages. Multivariate analysis revealed VPSI to be a significant independent predictor of unfavorable prognosis. The 5-year survival of patients with and without VPSI was 57.9 and 83.0 %, respectively (P = 0.001), and was 74.3 and 88.5 % (P = 0.005) in stages I-III and stage I disease, respectively.

CONCLUSIONS

VPSI is an independent factor for poor prognosis in NSCLCs, regardless of lymph node status. Stage IB NSCLCs with PL1 pleural invasion are associated with a survival rate similar to that of stage IA NSCLCs and could be classified as T1 lesions. While surgical treatment is adequate in these patients, stage IB NSCLCs with VPSI have poor prognosis, and these patients should be considered for adjuvant chemotherapy.

Are elastic stain and specialty sign out necessary to evaluate pleural invasion in lung cancers?

The seventh edition of American Joint Committee on Cancer (AJCC) staging system assigns lung cancers with visceral pleural invasion in the tumor size of 3 cm or less than 3 cm as T2 and without pleural invasion as T1. However, it may be difficult to distinguish with certainty between PL0 (no pleural invasion) and PL1 (extends through the elastic layer) on routine hematoxylin and eosin (H&E) stain. In this study, 25 cases of peripherally located lung adenocarcinoma were retrieved from the surgical pathology archives at the Asan Medical Center from May through June 2009. One representative H&E-stained slide was selected from each case and circulated to 31 pathology trainees and board-certified pathologists at Asan Medical Center who evaluated presence or absence of pleural invasion on H&E-stained slides. Elastic stain was used to determine the final status of pleural invasion for each case. The concordance rate of all pathologists with elastic stain results was, overall, 60.5%. The concordance rate of 2 lung specialists was 64%, better than the remaining faculty (54.7%). Fellows' and residents' evaluations were slightly more concordant than those of faculty responses (faculty overall, 56.4%; fellows, 62%; residents, 63.6%), but this difference was not statistically significant (P = .228). Our results confirm that pleural invasion status is difficult to discern with certainty on H&E-stained sections alone. Therefore, we recommend the routine use of elastic stain in evaluation of pleural invasion in all peripherally located lung cancers. Furthermore, our study indicates that subspecialty sign out may be preferable in evaluation of pleural invasion status.

A clinicopathological study of resected non-small cell lung cancers 2 cm or less in diameter: a prognostic assessment

The detection and diagnosis of small-sized (2 cm or less) non-small cell lung cancer (NSCLC) has increased with the development of computed tomography (CT). Over 80% of 5-year survival rate has been reported in surgically treated peripheral lung cancer. There are systematic mediastinal and hilar lymph node involvement pleural invasion and intrapulmonary metastasis even with tumor diameter less than 2 cm. The appropriate surgical procedure for such kinds of lung cancer is lobectomy with mediastinal lymph node dissection. To evaluate the prognostic factors and establish the optimal surgical strategy, we analyzed the clinicopathologic features and survival benefit in different tumor size of peripheral small-sized NSCLC. Among the resected lung cancer cases between January 1999 and July 2001, 185 patients were retrospectively analyzed in surgical methods, lymph node involvement, CT scan findings and survival rates. Survival was analyzed by Kaplan-Meier method and log-rank test. Lymph node involvement was recognized in 26(14.05%) patients. There was no statistically significant difference in the incidence of lymph node involvement between tumors 1.6-2.0 cm (17.82%) in diameter than in those 1.0-1.5 cm (11.94%). There was no lymph node metastasis in tumors less than 1.0 cm in diameter. The 5-year survival rates with or without lymph node involvement were 89.98 and 46.15%, respectively, showing significant difference (P=0.000). The overall 5-year survival rate was 83.78%. The 5-year survival rate in tumors 1.6-2.0 cm, 1.0-1.5 cm and less than 1.0 cm in diameter was 80.20, 85.07 and 100%, respectively, and showing significant difference (P=0.035). The 5-year survival rate of 19 patients showing ground-glass opacity (GGO) on CT scan was 94.74% without any metastasis and recurrence after operation. There are systematic mediastinal and hilar lymph node involvement even with tumor diameter less than 2 cm. The results of the present study suggested that systematic lymph node dissection is necessary even for cases with tumor diameter less than 2 cm. However, if the tumor is within 1.0 cm in diameter with obvious GGO showing on chest CT scan, these are good candidates for partial resection without mediastinal lymph node dissection.

Nanotechnology in thoracic surgery

Nanotechnology is an exciting and rapidly progressing field offering potential solutions to multiple challenges in the diagnosis and treatment of lung cancer, with the potential for improving imaging and mapping techniques, drug delivery, and ablative therapy. With promising preclinical results in many applications directly applicable to thoracic oncology, it is possible that the frontiers of minimally invasive thoracic surgery will eventually be explored at the nanoscale.

Proton beam therapy for patients with medically inoperable stage I non-small-cell lung cancer at the university of tsukuba

PURPOSE

To evaluate in a retrospective review the role of proton beam therapy for patients with medically inoperable Stage I non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

From November 2001 to July 2008, 55 medically inoperable patients with Stage I NSCLC were treated with proton beam therapy. A total of 58 (T1/T2, 30/28) tumors were treated. The median age of study participants was 77 years (range, 52-86 years). A total dose of 66 GyE in 10 fractions was given to peripherally located tumors and 72.6 GyE in 22 fractions to centrally located tumors.

RESULTS

The rates (95% confidence interval) of overall and progression-free survival of all patients and of local control of all tumors at 2 years were 97.8% (93.6-102.0%), 88.7% (77.9-99.5%), and 97.0% (91.1-102.8%), respectively. There was no statistically significant difference in progression-free rate between T1 and T2 tumors (p = 0.87). Two patients (3.6%) had deterioration in pulmonary function, and 2 patients (3.6%) had Grade 3 pneumonitis.

CONCLUSION

Proton beam therapy was effective and well tolerated in medically inoperable patients with Stage I NSCLC.

Limited resection for noninvasive bronchioloalveolar carcinoma diagnosed by intraoperative pathologic examination

BACKGROUND

The establishment of limited resection procedures for non-small cell lung cancer is expected. Many groups have suggested noninvasive bronchioloalveolar carcinoma (BAC) to be a potential indication for limited resection.

METHODS

We designed a prospective phase II study evaluating limited resection for noninvasive BAC diagnosed by intraoperative pathologic examination. From 1999 to 2007, limited resection was the procedure in 46 patients (16 men and 30 women; median age, 69 years; range, 49 to 83) who were diagnosed intraoperatively as having noninvasive BAC. The first end point was the predictive value of the intraoperative pathologic examination for noninvasive BAC diagnosis. The second end point was overall survival, disease-free survival, and cancer-specific survival, calculated using the Kaplan-Meier method.

RESULTS

We performed wedge resections for 44 patients and segmentectomy for 2 patients. Permanent pathologic examination revealed 3 patients had primary lung adenocarcinomas other than noninvasive BAC. The predictive value of intraoperative pathologic examination for noninvasive BAC diagnosis was 94%. During a median 51-month follow-up, there were only 2 cancer unrelated deaths. The 5-year overall survival rate and the disease-free survival rate were 93%, and the 5-year cancer-specific survival rate was 100%.

CONCLUSIONS

The results of our prospective phase II study indicate that limited resection, mainly by wedge resection, is a potentially curative surgical procedure and may be an acceptable alternative to lobectomy for patients with noninvasive BAC. Furthermore, an intraoperative pathologic diagnosis of noninvasive BAC is strongly predictive and allows for an intraoperative decision to perform a limited resection in these patients.

Point: Clinical stage IA non-small cell lung cancer determined by computed tomography and positron emission tomography is frequently not pathologic IA non-small cell lung cancer: the problem of understaging

OBJECTIVE

There is an increase in interest in limited resection for clinical stage IA non-small cell lung cancer. The purpose of this study was to evaluate the accuracy of the diagnosis of clinical stage IA non-small cell lung cancer when determined by both computed tomography and positron emission tomography scans and to determine factors associated with understaging.

METHODS

A retrospective review of a prospectively maintained database of patients with non-small cell lung cancer was performed. Patients with clinical stage IA cancer determined by preoperative computed tomography and positron emission tomography scan were reviewed. The influence of the following factors was analyzed with regard to accuracy of clinical staging: tumor size, location, histology, and positron emission tomography positivity.

RESULTS

Of the 266 patients identified, cancer was correctly staged in 65%. Final pathologic stages also included IB (15%), IIA (2.6%), IIB (4.1%), IIIA (4.9%), IIIB (7.5%), and IV (.08%). Positive lymph nodes were found in 11.7% of patients. Pathologic T classification changed in 28.2% of patients. Cancer in patients with clinical tumor size greater than 2 cm (n = 68) was significantly more likely to be understaged than in patients with tumors 2 cm or less (49% vs 29%, P = .003). Cancer in patients with a positron emission tomography-positive (positron emission tomography +VE) primary evaluation (n = 218) was also more likely to be understaged (39% vs 15%, P = .001). Of patients with positron emission tomography +VE tumors greater than 2 cm, cancer was clinically understaged in 55%, compared with 32% for positron emission tomography +VE tumors 2 cm or less, and only 17% for positron emission tomography negative (-VE) tumors less than 2 cm.

CONCLUSION

Clinical stage IA lung cancer is frequently understaged in patients. Size greater than 2 cm and positron emission tomography positivity are risk factors for understaging. Limited resection should be undertaken with caution in such patients.

Results of surgical treatment for small (2 cm or under) adenocarcinomas of the lung

PURPOSE

The objectives of this study were to identify the clinicopathologic characteristics and prognostic factors of small (2 cm or less in diameter) adenocarcinomas, and furthermore to assess the acceptability of performing a limited pulmonary resection in such patients.

METHODS

We retrospectively reviewed 523 cases of cT1N0M0 peripheral adenocarcinoma measuring 2 cm or less on diagnostic images treated by a complete resection between 1991 and 2004.

RESULTS

The overall 5-year survival rate of the patients with small adenocarcinomas was 83.6%. Univariate and multivariate analyses identified an older age, male sex, wedge resection, advanced stage, and Noguchi classification of C, D, E, or F as independent prognostic factors that adversely affected overall survival. However, there were no significant differences in the survival according to surgical procedure in the patients whose tumors had a maximum diameter of 1.0 cm or less or in Noguchi type A and B cases.

CONCLUSIONS

Age, sex, surgical procedure, p-stage, and Noguchi classification were independent prognostic factors for survival in patients with small adenocarcinomas. A segmentectomy is therefore considered to be an acceptable alternative to a lobectomy for adenocarcinomas of 2 cm or less in diameter. A wedge resection may be acceptable for tumors measuring 1 cm or less in diameter or Noguchi type A and B tumors.

Prognostic factors in resected stage I non-small cell lung cancer with a diameter of 3 cm or less: visceral pleural invasion did not influence overall and disease-free survival

OBJECTIVE

Resection is the treatment of choice for patients with stage I non-small cell lung cancer. Stage I non-small cell lung cancer has been further subdivided into IA (T1N0M0, tumor size < or = 3 cm without visceral pleural invasion) and IB (T2N0M0, tumor size > 3 cm or any size with visceral pleural invasion). The aim of this study was to evaluate the prognostic factors in patients with resected stage I non-small cell lung cancer with a diameter of 3 cm or less.

METHODS

We retrospectively reviewed the clinicopathologic characteristics of 445 patients with resected stage I non-small cell lung cancer with a diameter of 3 cm or less who were treated at Taipei Veterans General Hospital between 1980 and 2000. Disease-free survival, overall survival, and their predictors were analyzed.

RESULTS

The 5- and 10-year overall survivals were 61.4% and 40.0%, respectively. The 5- and 10-year disease-free survivals were 74.5% and 73.4%, respectively. Tumor size, smoking index, and number of mediastinal lymph nodes dissected were significant predictors for both disease-free survival (P = .009, P = .002, and P = .006, respectively) and overall survival (P = .004, P < .001, and P = .001, respectively) in multivariate analyses. Visceral pleural invasion did not influence overall survival or disease-free survival.

CONCLUSIONS

Tumor size, smoking index, and number of mediastinal lymph nodes dissected were prognostic factors for both overall survival and disease-free survival in resected stage I non-small cell lung cancer with a diameter of 3 cm or less. Small tumors (<3 cm) of stage IB (T2N0M0) non-small cell lung cancer with visceral pleural invasion should be treated as T1 disease and not T2 disease.

Impact of Elastic Staining on the Staging of Peripheral Lung Cancers

Accurate staging of lung cancer has a profound impact on patient management. For stage I nonsmall cell lung carcinomas (NSCLCs), the absence (stage IA) or presence (stage IB) of visceral pleural invasion represents a critical therapeutic branch point: patients with stage IB NSCLC benefit from adjuvant chemotherapy, whereas patients with stage IA NSCLC do not. Elastic staining has been advocated as a simple method for visualizing pleural invasion. The purpose of this study was to determine whether routine elastic staining of the resected peripheral NSCLCs alters tumor staging in a meaningful way. The study cases consisted of 100 consecutive peripheral NSCLCs resections that were pathologically staged as IA based on routine histologic assessment. Each case was stained with the Movats pentachrome elastic stain to aid identification of visceral pleural invasion. To assess current standards of surgical pathology practice, members of the American Association of Directors of Anatomic and Surgical Pathology were asked whether they never, sometimes, or always order elastic stains for peripheral NSCLCs that abut the pleura. Elastic staining resulted in a change of tumor stage from IA to IB in 19 (19%) cases. Of the 49 pathologists that responded to the survey, 25 (51%) never, 14 (29%) sometimes, and 10 (20%) always order an elastic stain for NSCLCs abutting the pleura. Elastic staining is currently not standard surgical pathology practice for the evaluation of peripheral NSCLCs, but it should be. Invasion of the pleura is an elusive finding that is best appreciated with an elastic stain. Our experience suggests that routine elastic tissue staining should be performed as a standard method of assessing pleural involvement for pleural-based nonsmall cell lung carcinomas.

Clinically predictive factors of pathologic upstaging in patients with peripherally located clinical stage IA non-small cell lung cancer

OBJECTIVE

Post-surgical pathologic examination often reveals a more advanced state than clinically defined in non-small cell lung cancer (NSCLC), posing the need for careful consideration of a lesser resection. We investigated the predictive factors for the pathologic upstaging in clinical stage IA NSCLC.

METHODS

The clinical features of 253 consecutive patients with peripherally located T1N0M0 NSCLC who underwent complete resection between 1991 and 2004 were investigated in relation to pathologic T- and N-factors.

RESULTS

Of the 253 patients, 46 (18.2%) were upstaged after surgery, due to T-factor in 12 patients, N-factor in 32, M-factor in 2 and both T- and N-factors in 1. Among the clinical parameters, a higher level of serum CEA (p=0.0378) and larger tumor size (p=0.0276) were observed in the upstaged patients. Multivariable analysis revealed that tumor size and positive serum CEA were independently associated with pathologic upstaging. When tumor size was greater than 10mm, patients with positive serum CEA (>2.0 ng/ml) showed a significantly higher incidence of pathologic upstaging (29.2%) than the rest (15.5%, p=0.0461).

CONCLUSION

Clinically defined peripheral stage IA NSCLC should be carefully indicated for a lesser resection when positive serum CEA and/or tumors greater than 10mm in size are observed.

Intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration

OBJECTIVE

The aim of this study was to assess the adequacy of our intentional limited resection for small peripheral lung cancer based on intraoperative pathologic exploration.

METHODS

Patients who had stage IA non-small cell lung cancer (NSCLC) with a maximum tumor diameter of 2 cm or less were candidates for limited resection. If bronchioloalveolar carcinoma (BAC) was suspected on computed tomography and intraoperative pathologic exploration revealed the lesion as BAC without foci of active fibroblastic proliferation (Noguchi type A and B), wedge resection was performed. If the tumor was not suspected of being Noguchi type A or B, extended segmentectomy with intraoperative lymph node exploration was performed.

RESULTS

Limited resection was performed in 34 patients, wedge resection in 14, and extended segmentectomy in 20. The median follow-up period after wedge resection was 36 months, and all patients are alive with no signs of recurrence. The median follow-up period after extended segmentectomy was 54 months. No local recurrences were found, but distant metastasis was diagnosed in one patient. The 5-year survival rate after extended segmentectomy was 93%. In the same period, lobectomy was performed in 57 patients with stage IA NSCLC with a maximum tumor diameter of 2 cm or less, and the 5-year survival rate was 84%. There were no significant differences in 5-year survival between extended segmentectomy and lobectomy.

CONCLUSIONS

Careful selection of patients based on high-resolution computed tomography findings and intraoperative pathologic exploration makes intentional limited resection an acceptable option for the treatment of small peripheral NSCLC.

Visceral pleural invasion is an invasive and aggressive indicator of non-small cell lung cancer

OBJECTIVE

Although visceral pleural invasion by non-small cell lung cancer is considered a poor-prognostic factor, further information is lacking, especially in relation to other clinicopathologic prognostic factors. We assessed the relationship between visceral pleural invasion and other clinicopathologic characteristics and evaluated its significance as a prognostic factor.

METHODS

We reviewed 1074 patients with surgically resected T1/2 non-small cell lung cancer for their clinicopathologic characteristics and prognoses. The patients were divided into 2 groups according to visceral pleural invasion status (visceral pleural invasion group and non-visceral pleural invasion group). Both groups were compared with regard to age, sex, histology, tumor size, tumor differentiation, lymph node involvement, lymphatic invasion, vascular invasion, scar grade, nuclear atypia, mitotic index, serum carcinoembryonic antigen level, and survival. Univariate and multivariate analyses were conducted.

RESULTS

Visceral pleural invasion was identified in 288 (26.8%) of the resected specimens. Survival was 76.0% at 5 years and 53.2% at 10 years in the non-visceral pleural invasion group and was 49.8% at 5 years and 37.0% at 10 years in the visceral pleural invasion group. The difference between groups was highly significant ( P < .0001). Visceral pleural invasion was also significantly associated with a higher frequency of lymph node involvement. However, regardless of N status (N0 or N1/2), there was a significant difference in survival when the visceral pleura was invaded. Visceral pleural invasion was observed significantly more frequently in tumors with factors indicative of tumor aggressiveness/invasiveness: moderate/poor differentiation, lymphatic invasion, vascular invasion, high scar grade, high nuclear atypia grade, high mitotic index, and high serum carcinoembryonic antigen level. By multivariate analysis, visceral pleural invasion proved to be a significant independent predictor of poor prognosis in non-small-cell lung cancer patients with or without lymph node involvement.

CONCLUSIONS

Visceral pleural invasion is a significant poor-prognostic factor, regardless of N status. Our analyses indicated that visceral pleural invasion is an independent indicator of non-small cell lung cancer invasiveness and aggressiveness.

Surgical mediastinal staging in daily practice

STUDY OBJECTIVES

An adequately staged mediastinum remains obligatory in patients with NSCLC prior to surgery. In this study, we investigated the accuracy of preoperative surgical mediastinal staging procedures in four hospitals.

SETTING

Non-university teaching hospital and three surrounding community hospitals in Eindhoven, The Netherlands.

PATIENTS, MEASUREMENTS AND RESULTS

Patients with NSCLC who underwent mediastinoscopy and/or thoracotomy, between 1993 and 1999. Adherence to guidelines for indicating and performing mediastinoscopy were investigated and compared in four hospitals. Guidelines for indicating mediastinoscopy were adequately followed in two-thirds of cases. Mediastinoscopy was performed according to gold standards in 40% of cases. The hospital with the smallest number of evaluated patients scored the worst. Postoperatively, 17% of patients appeared to have "unforeseen N2-3 disease". In approximately 18% of these "upstaged" patients, thoracotomy could have been prevented, if guidelines had been followed adequately.

CONCLUSIONS

In clinical practice the adherence to staging guidelines with respect to mediastinoscopy is insufficient in one-third of patients. Furthermore, mediastinoscopy was performed according to gold standards in 40% of patients.

What is early lung cancer? A review of the literature

The dismal cure rate of patients with lung cancer and the stage shift hypothesis have propelled the interest to perform screening at large, despite that previous randomized clinical trials failed to show any mortality benefit and the controversial issue of overdiagnosis. Due to early detection programs, a larger number of individuals at risk will be found to harbor small and potentially malignant early stage lesions. The application of non- and minimal invasive techniques for early detection, staging and treatment will become increasingly important. This review deals with the available clinical, surgical and pathological data focusing on early lung cancer lesions < or =1 cm. Literature data from both centrally located and parenchymal lesions < or =3 cm. have been analyzed. For all sub-centimeter lesions, minimal invasive staging and treatment approaches must still be considered inappropriate. Less invasive and less extensive treatment methods may be considered in high risk individuals with < or =1 cm. peripheral lesion showing > or =50 ground glass opacity on high resolution CT scan and those with superficial lesion in their central airways without deeper tumor invasion in the bronchial wall. Caution is necessary, however, as clinical staging remains inferior to pathological staging which is based on tissue samples collected after complete tumor removal and mediastinal lymph nodes dissection have been performed.

Video-assisted thoracoscopic surgery (VATS) segmentectomy for small peripheral lung cancer tumors: intermediate results

BACKGROUND

We investigated the feasibility and suitability of video-assisted thoracoscopic surgery (VATS) segmentectomy for curing selected non-small cell lung cancer (NSCLC) with this less invasive technique.

METHODS

We performed VATS segmentectomy for small (< 20 mm) peripherally located tumors and pathologically confirmed lobar lymph node-negative disease by frozen-section examination during surgery. Of the 34 patients who underwent this limited resection, 22 were treated with complete hilar and mediastinal lymph node dissection (intentional group), whereas 12 patients who were deemed to be high risk in their toleration for lobectomy underwent VATS segmentectomy with incomplete hilar and mediastinal lymph node dissection (compromised group). The surgical and clinical parameters were evaluated and compared with those of segmentectomy under standard thoracotomy to evaluate the technical feasibility of VATS segmentectomy.

RESULTS

We found that VATS segmentectomy could be performed safely with a nil mortality rate and acceptably low morbidity. The mean period of observation was relatively short at 656.7 +/- 572.1 and 783.4 +/- 535.8 days in the intentional and compromised groups, respectively. At the time of writing, all intentional patients remain alive and free of recurrence. There were two cases of non-cancer-related death in the compromised group. Clinical data indicated that VATS segmentectomy caused the same number or fewer surgical insults compared with segmentectomy under standard thoracotomy.

CONCLUSIONS

The present results are intermediate only; the rate of long-term survival and the advantages of the less invasive procedure still need further investigation. Nevertheless, we believe that VATS segmentectomy with complete lymph node dissection is a reasonable treatment option for selected patients with small peripheral NSCLC.

Segmental resection spares pulmonary function in patients with stage I lung cancer

BACKGROUND

Segmental resection for stage I non-small cell lung cancer remains controversial. Reports suggest that segmentectomy confers no advantage in preserving lung function and compromises survival. This study was undertaken to assess the validity of those assertions.

METHODS

We retrospectively analyzed patients undergoing lobectomy (n = 147) or segmentectomy (n = 54) for stage I non-small cell lung cancer between March 1996 and June 2001. All patients were included in the survival analysis. Pulmonary function testing was obtained preoperatively and at 1 year and included forced vital capacity, forced expiratory volume in 1 second, maximum voluntary ventilation, diffusing capacity, and stair-stepper exercise. Patients with recurrent disease (lobectomy, n = 32; segmentectomy, n = 10) were excluded in the pulmonary function testing analysis to avoid the confounding variables of tumor or treatments.

RESULTS

Preoperative pulmonary function tests in segmentectomy patients were significantly reduced compared with lobectomy (forced expiratory volume in 1 second, 75.1% versus 55.3%; p < 0.001). At 1 year, lobectomy patients experienced significant declines in forced vital capacity (85.5% to 81.1%), forced expiratory volume in 1 second (75.1% to 66.7%), maximum voluntary ventilation (72.8% to 65.2%), and diffusing capacity (79.3% to 69.6%). In contrast, a decline in diffusing capacity was the only significant change seen after segmental resection. Oxygen saturations at rest and with exercise were maintained in both groups. Actuarial survival in both groups was similar (p = 0.406) with a 1-year survival of 95% for lobectomy and 92% for segmentectomy. Four-year survivals were 67% and 62%, respectively.

CONCLUSIONS

For patients with stage I non-small cell lung cancer, segmental resection offers preservation of pulmonary function compared with lobectomy and does not compromise survival. Segmentectomy should be considered whenever permitted by anatomic location.

Computerized Tomographic Nodule Heterogeneity: Present and Future Impact on Indications for Sublobar Resections

With the advent of lung cancer screening, many nodules are being detected that are subsequently proven to be lung cancer. These nodules have different radiographic appearances and different biologic characteristics regarding their invasiveness and propensity for metastasis. These solid and part-solid nodules are now having surgeons reassess issues of lung sparing for early-stage lung cancer by not only considering smaller nodules as potentially appropriate for wedge resection or segmentectomies, but are also requiring surgeons to stratify these lesions by radiographic appearance. Data that argue for considering lesser resection of selected early-stage lung cancers, as well as the need for more prospectively accumulated facts that arise from trial designs like the original randomized Lung Cancer Study Group Trial, are discussed.

Visceral pleural involvement in nonsmall cell lung cancer: prognostic significance

BACKGROUND

A tumor of any size that invades the visceral pleura is classified in the T2 category; however, the definition of the visceral pleural involvement has remained somewhat ambiguous. It is unclear whether the T2 category includes the p2 status alone or incorporates the extent of the p1 status.

METHODS

We retrospectively analyzed the survival of 474 patients with T1 and T2 nonsmall cell lung cancer to evaluate the influence of the degree of visceral pleural involvement (p0, p1, and p2) on the prognosis and to clarify the definition of the visceral pleural involvement.

RESULTS

The 5-year survival rates according to the degree of visceral pleural involvement were 68.0% in p0 (n = 345), 43.9% in p1 (n = 110), and 54.9% in p2 (n = 19; p0 versus p1, p = 0.0004; p0 versus p2, p = 0.013; and p1 versus p2, p = 0.61). The degree of visceral pleural involvement (p0 versus p1/p2) was a significant independent prognostic factor from tumor size and lymph node involvement, by multivariate analysis (relative risk = 1.47, p = 0.033). The prognosis of pN0 patients with p1 and tumor size 3 cm or less was significantly poorer than that of those with p0 and tumor size 3 cm or less (p = 0.0004), and the prognosis of patients with p1 and tumor size more than 3 cm was significantly poorer than that of those with p0 and tumor size more than 3 cm (p = 0.024).

CONCLUSIONS

The degree of visceral pleural involvement (p0 versus p1/p2) is an important component of the lung cancer staging system. Tumors with p1 and p2 status should be regarded as representing visceral pleural involvement and T2 disease.