Surgically curable "early" adenocarcinoma in the periphery of the lung

Psoas muscle mass in patients undergoing lung cancer surgery: a prognostic difference between squamous cell carcinoma and adenocarcinoma

BACKGROUND

Psoas muscle mass is a surrogate marker for sarcopenia: a depletion of skeletal muscle mass. This study was conducted to elucidate the prognostic significance of the psoas muscle index (PMI: cross-sectional area of the bilateral psoas muscle at the umbilical level on computed tomography/height² [cm²/m²]) in patients undergoing surgery for lung squamous cell carcinoma (SCC) and lung adenocarcinoma (ADC).

METHODS

One hundred and sixty-five patients with SCC and 556 patients with ADC who underwent R0 resection between 2007 and 2014 were reviewed for analysis. In SCC patients, the mean value (standard deviation) of the PMI was 6.15 (1.49) in men and 4.65 (1.36) in women. Among ADC patients, the PMI was 7.12 (1.60) in men and 5.29 (1.22) in women. Clinicopathological characteristics as well as the survival were evaluated.

RESULTS

The PMI was associated with the age, body mass index (BMI), and serum albumin. In the multivariable Cox regression analysis, after adjusting for age, BMI, serum albumin, sex, pathological stage, and diffusing capacity for carbon monoxide, the PMI showed a significant association with the overall survival (OS) and disease-free survival (DFS) in SCC patients (hazard ratios 0.50 and 0.56, 95% confidence intervals 0.39-0.65 and 0.45-0.71, respectively). On the other hand, in ADC patients, the PMI had no impact on the OS or DFS.

CONCLUSIONS

The PMI was significantly associated with the survival of lung SCC patients, but not of lung ADC patients, suggesting the presence of a previously unidentified relationship between skeletal muscle and lung SCC progression.

Mitosis count and number of cancer cells in cases of primary pulmonary adenocarcinoma: Correlations among phosphorylated histone 3, number of cancer cells, nuclear grade, pathologic features and prognosis

Immunohistochemistry findings for the phosphorylated form of histone 3 (pHH3) have been shown to be a reliable mitosis-specific marker. We evaluated the correlation between pHH3-stained mitotic figures (PHMFs) and clinical outcome, and compared the results with findings for numbers of PHMFs and cancer cells. The primary tumor was obtained from 113 patients with pulmonary adenocarcinomas (≤2 cm maximum dimension). All specimens were stained with pHH3, then the number of cancer cells in each was determined. Cases with a cancer-cell index ≥1000 showed worse recurrence-free survival as compared to those with a value <1000 (P < 0.001). Also, cases with a pHH3 index ≥0.27 showed worse recurrence-free survival as compared to <0.27 (P = 0.001) and cases with a pHH3/cancer-cell index ≥0.001 showed worse recurrence-free survival as compared to <0.001 (P = 0.002). Multivariate analysis demonstrated that pHH3/cancer-cell index was significantly correlated with prognosis, but not Ki-67 index. The number of cancer cells was also strongly correlated with progression of Noguchi's classification and WHO pathologic type. pHH3/cancer-cell index was correlated with prognosis, and those were useful for prognostic evaluation of pulmonary adenocarcinoma patients. Furthermore, cancer cell number was correlated with Noguchi's classification and WHO pathologic type.

A Grading System Combining Tumor Budding and Nuclear Diameter Predicts Prognosis in Resected Lung Squamous Cell Carcinoma

For lung squamous cell carcinomas, there are no histologic findings that have been universally accepted as prognostic factors. Tumor budding and nuclear grade have been recognized as prognostic factors in other carcinomas. In this study, we investigated whether pathologic findings could determine clinical outcome in Japanese patients with lung squamous cell carcinomas. Tumor slides from surgically resected lung squamous cell carcinomas (1999 to 2012) were reviewed (n=216). Tumors were evaluated for histologic subtypes, differentiation, tumor budding, nuclear diameter, and mitosis. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using the log-rank test and the Cox proportional hazards model. Tumor budding and large nuclei were independent prognostic factors of a worse RFS (P<0.001 and P=0.002, respectively) and a worse OS (P<0.001 and P=0.038, respectively) on multivariate analysis after adjustment for pathologic stage and lymphatic invasion. However, histologic subtypes, differentiation, and mitotic count did not correlate with prognosis. A grading system combining tumor budding and nuclear diameter was an independent prognostic factors of a worse RFS (grade 2 vs. 1, hazard ratio [HR]=2.91; P<0.001, and grade 3 vs. 1, HR=7.60, P<0.001) and a worse OS (grade 2 vs. 1, HR=2.15; P=0.014, and grade 3 vs. 1, HR=4.54, P<0.001). We found that a grading system combining tumor budding and nuclear diameter was a significant prognostic factor among Japanese patients with resected lung squamous cell carcinoma.

Adenocarcinoma in situ, minimally invasive adenocarcinoma, and invasive pulmonary adenocarcinoma--analysis of interobserver agreement, survival, radiographic characteristics, and gross pathology in 296 nodules

The International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society and 2015 World Health Organization classifications of lung adenocarcinoma recommend designating tumors showing entirely lepidic growth as adenocarcinoma in situ (AIS) and lepidic tumors with invasion less than or equal to 5 mm as minimally invasive adenocarcinoma (MIA), both of which have superior outcome to conventional invasive adenocarcinoma (IA). Data on interobserver variability within this classification are limited, and further validation of the superior survival of AIS and MIA is needed. A total of 296 surgically excised pulmonary adenocarcinomas were reviewed from 254 patients (1997-2009). Slides were independently reviewed by 2 pulmonary pathologists who categorized tumors as AIS, MIA, or IA. Of 296 nodules, 244 (82.4%) were agreed upon by both observers: 10 AIS, 61 MIA, and 173 IA (κ = 0.63, good agreement). In 6 cases (2%), there was disagreement between AIS and MIA; in 45 cases (15%), there was disagreement between MIA and IA; and in 1 case, there was disagreement between AIS and IA. Overall survival was significantly different among categories as determined by both observers. Cases with disagreement between MIA and IA had similar survival to agreed MIA. Disease-specific 10-year survival was 100% for AIS (both observers) and 97.3% and 97.6% for MIA, although this did not reach statistical significance compared to IA for either observer. Good agreement was present between observers when classifying tumors as AIS, MIA, and IA. Significant differences in overall survival were present between the 3 groups for both observers, and interobserver variability was evident. Patients with AIS and MIA experienced excellent DSS.

Comprehensive pathological analyses in lung squamous cell carcinoma: single cell invasion, nuclear diameter, and tumor budding are independent prognostic factors for worse outcomes

INTRODUCTION

For lung squamous cell carcinomas, there are no pathological findings that have been universally accepted as prognostic factors, with the exception of pathological stage. Tumor budding and nuclear grade have been recognized as a poor prognostic factor in other carcinomas. In this study, we investigated whether pathological findings could determine prognosis in lung squamous cell carcinomas.

METHODS

All available tumor slides from patients with surgically resected, solitary lung squamous cell carcinomas (1999-2009) were reviewed (n = 485; stage I/II/III, 281/136/68). Tumors were evaluated for differentiation, subtypes (keratinizing, nonkeratinizing, basaloid pattern, papillary growth, and clear cell feature), tumor nest size (tumor budding and single cell invasion), and nuclear grade (nuclear diameter and mitosis). Overall survival (OS) was estimated using the Kaplan-Meier method (stratified by pathological stage), and group differences were investigated using the stratified log-rank test and the Cox proportional hazards model.

RESULTS

OS was significantly decreased in patients with versus without single cell invasion (p = 0.002 for the entire tumor and p = 0.001 for tumor edge), with large versus small nuclei (p = 0.011), and with high versus low grade tumor budding (p < 0.001 for maximum and p = 0.007 for total). In multivariate analyses, single cell invasion (hazard ratio [HR], 1.47-1.49), nuclear diameter (HR, 1.09-1.33), and tumor budding (HR, 1.04) were independent prognostic factors of OS. However, histologic subtyping including keratinizing, nonkeratinizing, basaloid, and clear cell subtypes did not show prognostic significance.

CONCLUSIONS

Pathological factors can help stratify prognosis in patients with lung squamous cell carcinomas.

Prognostic significance of adenocarcinoma in situ, minimally invasive adenocarcinoma, and nonmucinous lepidic predominant invasive adenocarcinoma of the lung in patients with stage I disease

According to the IASLC/ATS/ERS classification, the lepidic predominant pattern consists of 3 subtypes: adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and nonmucinous lepidic predominant invasive adenocarcinoma. We reviewed tumor slides from 1038 patients with stage I lung adenocarcinoma, recording the percentage of each histologic pattern and measuring the invasive tumor size. Tumors were classified according to the IASLC/ATS/ERS classification: 2 were AIS, 34 MIA, and 103 lepidic predominant invasive. Cumulative incidence of recurrence (CIR) was used to estimate the probability of recurrence. Patients with AIS and MIA experienced no recurrences. Patients with lepidic predominant invasive tumors had a lower risk for recurrence (5-y CIR, 8%) than nonlepidic predominant tumors (n=899; 19%; P=0.003). Patients with >50% lepidic pattern tumors experienced no recurrences (n=84), those with >10% to 50% lepidic pattern tumors had an intermediate risk for recurrence (n=344; 5-y CIR, 12%), and those with ≤10% lepidic pattern tumors had the highest risk (n=610; 22%; P<0.001). CIR was lower for patients with ≤2 cm tumors than for those with >2 to 3 cm tumors (for both total and invasive tumor size), with the difference more pronounced for invasive tumor size (5-y CIR, 13% vs. 21% [total size; P=0.022] and 12% vs. 27% [invasive size; P<0.001]). Most patients with lepidic predominant adenocarcinoma who experienced a recurrence had potential risk factors, including sublobar resection with close margins (≤0.5 cm; n=2), 20% to 30% micropapillary component (n=2), and lymphatic or vascular invasion (n=2). It therefore may be possible to identify lepidic predominant adenocarcinomas that carry a low or high risk for recurrence.

Completely resected n0 non-small cell lung cancer: prognostic factors affecting long-term survival

Background. Although early stage non-small cell lung cancer (NSCLC) has an excellent outcome and correlated with good long-term survival, up to 15 percent of patients still relapse postoperatively and die. This study is conducted to identify prognostic factors that may affect the long-term survival in completely resected N0 NSCLC. Methods. Medical records of 124 patients with completely resected N0 NSCLC were retrospectively reviewed. Prognostic factors affecting long-term survival were analyzed by the Kaplan-Meier method and Cox proportional hazards analysis. Results. Overall five-year survival rate was 48 percent. Multivariable analysis revealed stage of disease, tumor necrosis, tumor recurrence, brain metastasis, adrenal metastases, and skin metastases as significant prognostic factors affecting long-term survival. The hazard ratio (HR) of tumor necrosis, tumor recurrence, brain metastasis, adrenal metastases, and skin metastases was 2.0, 2.3, 7.6, 4.1, and 8.3, respectively, and all P values were less than 0.001. Conclusions. Our study shows stage of disease, tumor necrosis, tumor recurrence, brain metastasis, adrenal metastasis, and skin metastasis as the independent prognostic factors of long-term survival in pathological N0 NSCLC. Early stage NSCLC patients without nodal involvement or presented with tumor necrosis should benefit from adjuvant chemotherapy, and sites of metastasis could predict the long-term survival as described.

The utility of the proposed IASLC/ATS/ERS lung adenocarcinoma subtypes for disease prognosis and correlation of driver gene alterations

BACKGROUND

The present study aimed to determine the ability of the revised International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification of lung adenocarcinoma to predict patient survivals and driver gene alterations.

PATIENTS AND METHODS

A reclassification of 904 surgically resected adenocarcinomas was performed. The results were statistically analyzed to examine the correlation between the classification and overall survival (OS) using Cox regression analyses, and integrated discrimination improvement (IDI) analyses.

RESULTS

The 5-year OS rates for adenocarcinomas in situ (AIS) or minimally invasive adenocarcinoma (MIA) were 98%. Five-year OS rates of Lepidic-, acinar-, papillary-, micropapillary-, and solid-predominant adenocarcinomas was 93%, 67%, 74%, 62%, and 58%, respectively. The IDI estimates revealed that classification of ADC into the 7 subgroups had a higher estimated (0.0175) than did the combined histological grouping (AIS + MIA, lepidic + acinar + papillary, micropapillary + solid + others) (0.0111). Epidermal growth factor receptor mutations, KRAS gene mutations, and anaplastic lymphoma kinase gene alterations were statistically prevalent in papillary-predominant (P = 0.00001), invasive mucinous (P = 0.00001), and micropapillary- and acinar-predominant (P = 0.00001) adenocarcinomas, respectively.

CONCLUSIONS

The new classification reflects disease prognosis, and was also associated with driver gene alterations.

A grading system combining architectural features and mitotic count predicts recurrence in stage I lung adenocarcinoma

The International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) has recently proposed a new lung adenocarcinoma classification. We investigated whether nuclear features can stratify prognostic subsets. Slides of 485 stage I lung adenocarcinoma patients were reviewed. We evaluated nuclear diameter, nuclear atypia, nuclear/cytoplasmic ratio, chromatin pattern, prominence of nucleoli, intranuclear inclusions, mitotic count/10 high-power fields (HPFs) or 2.4 mm(2), and atypical mitoses. Tumors were classified into histologic subtypes according to the IASLC/ATS/ERS classification and grouped by architectural grade into low (adenocarcinoma in situ, minimally invasive adenocarcinoma, or lepidic predominant), intermediate (papillary or acinar), and high (micropapillary or solid). Log-rank tests and Cox regression models evaluated the ability of clinicopathologic factors to predict recurrence-free probability. In univariate analyses, nuclear diameter (P=0.007), nuclear atypia (P=0.006), mitotic count (P<0.001), and atypical mitoses (P<0.001) were significant predictors of recurrence. The recurrence-free probability of patients with high mitotic count (≥5/10 HPF: n=175) was the lowest (5-year recurrence-free probability=73%), followed by intermediate (2-4/10 HPF: n=106, 80%), and low (0-1/10 HPF: n=204, 91%, P<0.001). Combined architectural/mitotic grading system stratified patient outcomes (P<0.001): low grade (low architectural grade with any mitotic count and intermediate architectural grade with low mitotic count: n=201, 5-year recurrence-free probability=92%), intermediate grade (intermediate architectural grade with intermediate-high mitotic counts: n=206, 78%), and high grade (high architectural grade with any mitotic count: n=78, 68%). The advantage of adding mitotic count to architectural grade is in stratifying patients with intermediate architectural grade into two prognostically distinct categories (P=0.001). After adjusting for clinicopathologic factors including sex, stage, pleural/lymphovascular invasion, and necrosis, mitotic count was not an independent predictor of recurrence (P=0.178). However, patients with the high architectural/mitotic grade remained at significantly increased risk of recurrence (high vs low: P=0.005) after adjusting for clinical factors. We proposed this combined architectural/mitotic grade for lung adenocarcinoma as a practical method that can be applied in routine practice.

Internal growth of nonsolid lung nodules: radiologic-pathologic correlation

PURPOSE

To determine whether computed tomographic (CT) attenuation values correlate with the histologic measurements of a lung cancer manifesting as a nonsolid nodule and to quantify the extent to which the tumor replaces the airspace within the nodule.

MATERIALS AND METHODS

Informed consent was obtained to analyze images from CT and pathologic examination under an institutional review board-approved protocol. Fifteen patients who had undergone resection of nonsolid lung cancer were evaluated. On the basis of the CT attenuation values of nonsolid nodules, nonneoplastic lung, soft tissue, and air, the overall proportion of soft tissue in the nodule and nonneoplastic lung and the difference between these two measures were calculated. The analogous measures were obtained from a representative digitized histologic slide. The area of each nodule and the proportion of air within it were measured, and the proportion of soft tissue in the nodule and nonneoplastic lung and the difference between the two were calculated. The difference between the two proportions at CT and histologic examination are the proportions attributable to the cancer on the basis of CT and histologic examinations, respectively. Linear regression was performed to assess the relationship between these measures.

RESULTS

The average proportions of soft tissue in the nodule at CT and histologic examination were 48% and 69%, respectively, and they showed significant correlation with each other (P = .02); in addition, each showed significant correlation with the attenuation of the nodule (P < .0001 and P = .02, respectively). The difference between the proportions of soft tissue in nodule and nonneoplastic lung at CT and histologic examination were 37% and 30%, respectively, and both were independent of the tumor diameter (P = .26 and P = .41).

CONCLUSION

The proportion of soft tissue within a nonsolid nodule is correlated with attenuation at CT. This allows for measurement of change within the nodule. An increase of 100 HU in nodule attenuation represents an approximately 10% increase in tumor volume.

Histologic patterns and molecular characteristics of lung adenocarcinoma associated with clinical outcome

BACKGROUND

Lung adenocarcinoma is histologically heterogeneous and has 5 distinct histologic growth patterns: lepidic, acinar, papillary, micropapillary, and solid. To date, there is no consensus regarding the clinical utility of these patterns.

METHODS

The authors performed a detailed semiquantitative assessment of histologic patterns of 240 lung adenocarcinomas and determined the association with patients' clinicopathologic features, including recurrence-free survival (RFS) and overall survival (OS) rates. In a subset of tumors, expression levels of 2 prognostic molecular markers were evaluated: thyroid transcription factor-1 (TTF-1) (n = 218) and a panel of 5 proteins (referred as the FILM signature index) (n = 185).

RESULTS

Four mutually exclusive tumor histology pattern groups were identified: 1) any solid (38%), 2) any papillary but no solid (14%), 3) lepidic and acinar but no solid or papillary (30%), and 4) acinar only (18%). Patients in group 3 had a higher RFS rate than patients in group 1 (hazard ratio [HR], 0.4510; P = .0165) and group 2 (HR, 0.4253; P = .0425). Solid pattern tumors (group 1) were associated with a lower OS rate than nonsolid pattern tumors (all stages: HR; 1.665; P = .0144; stages I and II: HR, 2.157; P = .008). In the patients who had tumors with a nonsolid pattern, high TTF-1 expression was associated significantly with higher RFS (HR, 0.994; P = .0017) and OS (HR, 0.996; P = .0276) rates in all stages, and a high FILM signature index score was associated with lower RFS and OS rates in all stages (RFS: HR, 1.343; P = .0192; OS: HR, 1.371; P = .0156) and in stages I and II (RFS: HR, 1.419; P = .0095; OS: HR, 1.315; P = .0422).

CONCLUSIONS

The presence of a solid histologic pattern was identified as a marker of unfavorable prognosis in patients with primary lung adenocarcinoma. High TTF-1 expression and low FILM signature index scores were associated with a better prognosis for patients who had tumors with a nonsolid pattern.

Prognostic impact of nm23-H1 and PCNA expression in pathologic stage I non-small cell lung cancer

INTRODUCTION

The purpose of this study was to evaluate the value of nm23-H1 and proliferating cell nuclear antigen (PCNA) expression as well as other confirmed prognostic factors in predicting the clinical outcome after definitive surgery of pathologic stage I non-small cell lung cancer (NSCLC).

METHODS

Four hundred fifty-two consecutive and non-selected patients who underwent definitive surgery for stage I NSCLC were included in this study. Formalin-fixed paraffin-embedded specimens were stained for nm23-H1 and PCNA, the correlation between the staining and its clinicopathological parameters, and its prognostic power were analyzed statistically.

RESULTS

Of the 452 patients studied, 320 cases (70.8%) were high expression for nm23-H1. A total of 182 carcinomas (40.3%) were PCNA high expression tumors. PCNA expression correlated with serum CEA level (P < 0.001), and differentiation (P < 0.001). In univariate analysis by log-rank test, serum CEA level, pT stage, differentiation, nm23-H1 expression, and PCNA expression were significant prognostic factors (P = 0.037, 0.021, <0.001, 0.042, and 0.014, respectively). In multivariate analysis, pT stage and nm23-H1 expression maintained its independent prognostic influence on overall survival (P = 0.041 and 0.003, respectively).

CONCLUSIONS

nm23-H1 may be a good biomarker to be applied in clinic to predict the prognosis of patients with completely resected pathologic stage I NSCLC.

A grading system of lung adenocarcinomas based on histologic pattern is predictive of disease recurrence in stage I tumors

Currently no objective grading system for pulmonary adenocarcinomas exists. To determine whether specific histologic patterns or combinations thereof could be linked to an objective grading system, the histologic patterns in metastatic tumor deposits was compared with the patterns seen in the corresponding 73 primary tumor to determine whether a specific pattern had higher propensity to metastasize. The concordance of the predominant histologic pattern in the primary tumor and the metastases was of 100% for micropapillary, 86% for solid, 42% for acinar, and 23% for papillary types of adenocarcinoma. Informed by these results, a 3-tier grading system based on the histologic subtypes was established. Grade I, a pattern with low metastatic potential (BAC); Grade II, patterns with intermediate metastatic potential (acinar and papillary); and Grade III, patterns with high metastatic potential (solid and micropapillary). These grades were combined into a number of different scoring systems, whose ability to predict recurrence or death from disease was tested in 366 stage 1 adenocarcinomas. A score based on the 2 most predominant grades was able to stratify patients into low-to-high risk for recurrence or death of disease (P=0.001). The 5-years disease-free survival for patients in the highest score group was of 0.73, compared with 0.84 and 0.92 in the intermediate and lowest score groups. Concordance probability estimate was 0.65 (95% confidence interval 0.57-0.73). Therefore, this scoring system provides valuable information in discriminating patients with different risk of disease-recurrence in a highly homogeneous population of patients with stage I cancer.

Prognostic significance of grading in lung adenocarcinoma

BACKGROUND

Although grading has prognostic significance for many tumor types, a prognostically significant grading system for lung adenocarcinoma has not yet been established. The aim of this study was to evaluate histologic characteristics included in tumor grading systems, establish optimal cutoff values that have the strongest association with overall survival, and develop a grading system incorporating the histopathologic characteristics that the authors found to have prognostic significance in patients with lung adenocarcinoma.

METHODS

The authors studied lung adenocarcinomas from 85 consecutive patients, and evaluated the percentage of solid pattern (as a reflection of tumor architecture), the degree of cytologic atypia, and the mitotic count.

RESULTS

In univariate analysis, overall survival was associated significantly with sex (P = .045), age (P = .0008), tumor status (P < .0001), lymph node status (P = .02), solid pattern (P = .046), and cytologic atypia (P = .01), but not with mitotic count (P = .26). On the basis of optimal cutoff values, the authors found that a solid pattern > or = 90% and severe cytologic atypia were the best discriminators of worse outcome. A grading score, computed as the sum of the architecture score and cytologic atypia score (2 = well differentiated, 3 = moderately differentiated, 4 = poorly differentiated), was a significant predictor of overall survival in univariate analysis (median overall survival times, 72.4, 39.5, and 8.7 months for well, moderately, and poorly differentiated adenocarcinoma, respectively; P = .0001). Moreover, grading was an independent predictor of survival in multivariate analysis (P = .002).

CONCLUSIONS

The authors describe a grading system that incorporates the percentage of solid pattern and degree of the cytologic atypia that is an independent predictor of survival in patients with lung adenocarcinoma.

[Localized pure or mixed ground-glass lung opacities]

Localized ground-glass opacities (GGOs) have been recently individualized and account for between 2.9% and 19% of all pulmonary nodules detected in high-risk patients included in CT screening series for lung cancer. These opacities, nodular, lobular or flat, correspond to benign lesions (localised infectious and inflammatory diseases, focal interstitial fibrosis, and atypical alveolar hyperplasia) or malignant lesions (bronchioloalveolar carcinoma, early-stage adenocarcinoma and sometimes metastases). Localized GGOs are more likely to be malignant than solid nodules and prognosis is related to the percentage of the ground-glass component. However, doubling time of pure localized malignant GGOs is longer than mixed localized malignant GGOs and even longer than the doubling time of solid malignant nodules. Therefore, localized GGOs warrant a dedicated diagnostic workup.

Small cluster invasion: a possible link between micropapillary pattern and lymph node metastasis in pT1 lung adenocarcinomas

Lung adenocarcinomas with micropapillary pattern (MPP) are associated with frequent nodal metastasis. However, little is known about the mechanisms that underlie MPP-associated nodal metastasis. In this study, we investigated how small micropapillary clusters of carcinoma cells present in tumoral alveolar spaces lead to increased lymph node metastasis. We analyzed 146 cases of pT1 lung adenocarcinomas with reference to the presence of MPP, small cluster invasion (SCI), and lymphatic involvement. SCI was defined as markedly resolved acinar-papillary tumor structures with single or small clusters of carcinoma cells invading stroma within fibrotic foci. The MPP-positive group (88/146 cases) was associated with significantly more frequent nodal metastasis and significantly worse survival. Moreover, SCI was significantly more frequent in the MPP-positive group (71/88 cases) than MPP-negative group (10/58 cases) and was significantly associated with lymphatic involvement (p < 0.0001) and nodal metastasis (p = 0.0073). The SCI-positive group showed significantly worse survival (5-year survival, 70%) than the SCI-negative group (91%, p = 0.0017). Carcinoma cells undergoing SCI demonstrated the same characteristic MUC-1 expression on the outer surface of cell clusters as those undergoing MPP. Thus, SCI could link MPP to nodal metastasis; carcinoma cells with MPP tend to undergo SCI in scars and invade lymphatics in pT1 lung adenocarcinomas.

Pulmonary adenocarcinomas with ground-glass attenuation on thin-section CT: Quantification by three-dimensional image analyzing method

PURPOSE

The purpose of this study was to evaluate software designed to calculate whole tumor volumes and the ratio of the solid component to whole volume (%solid) in pulmonary nodules with ground-glass opacity in three dimensions.

METHODS

The study included 49 patients with histologically diagnosed adenocarcinomas smaller than 2 cm in diameter. The %solid was calculated both automatically using new software, and by manual measurement of the following four parameters by two observers: the ratio of the largest diameter (a) and the area (b) at the mediastinal window to those at the lung window, and the ratio of the largest diameter (c) and the area (d) of the solid component to those of the ground-glass component at the lung window. Agreement of intra- and inter-observer data by both Spearman's rank correlation test and Bland-Altman's method, and a comparison by Spearman's rank correlation test of the %solid in both Noguchi sub-classifications and vessel invasion in histologic specimens, between the software and manual methods, were assessed.

RESULTS

Of the 49 nodules, 48 were successfully measured and assessed. The agreement of the observers with the software was better (Bland-Altman's method; mean difference, -0.3%; 95% limits of agreement, -3.1 to 2.5%) than with the manual measurements (a: 5.3%, -17.6 to 28.3%; b: 8.3%, -10.6 to 26.9%; c: 10.7%, -17.6 to 39%; d: 6.4%, -22 to 34.8%). The correlation between %solid and the histological group was worse with the software (Spearman's rank correlation test; r=0.487, p<0.001) than with the manual method (a, r=0.534; b, r=0.557; c, r=0.552; d, r=0.545).

CONCLUSION

Although the software requires improvement in the calculation of %solid with volumetric analysis, this is a reproducible and promising quantitative method for determining the grades of malignancy of small lung cancers.

Prognostic significance of thin-section CT scan findings in small-sized lung adenocarcinoma

OBJECTIVES

The purpose of this study is to evaluate the prognostic importance of thin-section (TS) CT scan findings in small-sized lung adenocarcinomas.

PATIENTS AND METHODS

We reviewed TS-CT scan findings and pathologic specimens from 359 consecutive patients who underwent surgical resection for peripheral lung adenocarcinomas <or= 20 mm in diameter during the period from July 1997 to May 2006. By using TS-CT scan images, tumors were defined as air-containing types if the maximum diameter of tumor opacity on mediastinal window images was less than or equal to half of that seen on lung window images, and as a solid-density type if the maximum diameter on the mediastinal window images was more than half of that on lung window images. We compared TS-CT scan findings to pathologic findings (ie, lymph node metastasis, pleural invasion, vessel invasion, and lymphatic invasion) and prognosis. The following prognostic factors were analyzed by chi2 test and Cox proportional hazard model: age; gender; tumor size; pathologic stage; TS-CT scan findings; histologic subtypes defined by Noguchi et al (ie, Noguchi type); pleural involvement; lymphatic invasion; and vascular invasion.

RESULTS

No pathologic invasive findings or recurrence were found in patients with air-containing-type tumors. Pathologic invasive findings and recurrence were found in 10 to 30% of patients with solid-density-type tumors. The air-containing type tumors seen on TS-CT scans and Noguchi type A or B tumors were demonstrated as prognostic factors for good outcome by chi2 test (p < 0.001). Multivariate analyses revealed lymphatic permeation as a significant prognostic factor.

CONCLUSION

The TS-CT scan findings were important predictive factors for postsurgical outcome in patients with lung adenocarcinoma.

Micropapillary pattern and grade of stromal invasion in pT1 adenocarcinoma of the lung: usefulness as prognostic factors

Recently, the stromal invasion grading system was proposed for small adenocarcinomas of < or =2.0 cm. The system is based on the presence or absence of a fibrotic focus, and the extent of invasion into the fibrotic focus. Although stromal invasion grading system closely correlated with the prognosis, stromal invasion grade 3, representing stromal invasion into the center of a fibrotic focus, was the largest group of tumors and showed variable prognosis. In this study, we investigated whether stromal invasion grading system could be applied to and validated in pT1 adenocarcinomas as the TNM classification is the most universally used system. Furthermore, we investigated whether stromal invasion grade 3 cases could be subclassified according to the presence and absence of micropapillary pattern. The study included 120 cases of pT1 lung adenocarcinomas, of which 81 (68%) cases were stromal invasion grade 3. Micropapillary pattern was positive in 80% of grade 3 cases. For stromal invasion grade 3 cases, the 5-year survival rate of patients with micropapillary pattern-positive carcinomas was 63%, which was significantly worse than 94% of those with micropapillary pattern-negative carcinomas (P=0.0196). The latter was very close to that for patients with stromal invasion grade 0-2 (95%). Moreover, small cluster invasion was observed at sites of stromal invasion significantly more often in micropapillary pattern-positive cases than negative cases. Thus, the stromal invasion grading system is reproducible and correlates with prognosis even in pT1 lung adenocarcinomas. Moreover, among patients with stromal invasion grade 3 carcinomas, favorable prognosis is noted in micropapillary pattern-negative cases. The micropapillary pattern subclassification provides an advantage to the stromal invasion grading system and reconfirms the importance of micropapillary pattern as a prognostic marker. Our study is the first to point to the possible association of micropapillary pattern-positive carcinomas and small cluster invasion.

Cytopathologic factors can predict invasion in small-sized peripheral lung adenocarcinoma with a bronchioloalveolar carcinoma component

BACKGROUND

Patients with noninvasive, small-sized primary adenocarcinomas of the lung have excellent prognosis after lobectomy. Several researchers have suggested that limited resection could be an acceptable alternative for these patients. Therefore, a preoperative or intraoperative judgment of invasiveness would be one of the critical determinants of the surgical procedure in each case. Cytopathologic findings that can distinguish invasive from noninvasive adenocarcinomas remain to be elucidated.

METHODS

Imprint smears were obtained from 60 resected adenocarcinomas with nonmucinous bronchioloalveolar features. Thirteen cytologic factors were evaluated: the presence of necrosis, fibrovascular tissue, proportion of macrophages, the presence of large tumor cell clusters, nuclear grooves, nuclear overlapping, variation in nuclear size, chromatin pattern, presence of a nucleolus, intranuclear inclusions, multinucleated cells, spindle cells, and mitosis. Each factor was examined by univariate analysis for correlation with the presence of histopathologic invasion.

RESULTS

In the univariate analysis, 5 cytologic factors--presence of tumor cell clusters consisting of more than 50 tumor cells (P < .001), nuclear overlapping in more than 3 layers (P < .001), presence of nuclear grooves (P = .007), more than 3-fold variation in nuclear size (P < .001), and 1 mitotic cell per 1000 tumor cells (P = .035)--were associated significantly with invasion. Among these, nuclear overlapping in more than 3 layers (P = .003) and more than 3-fold variation in nuclear size (P = .005) were found to be independent predictive factors for invasion by multivariate analysis.

CONCLUSIONS

Using imprint smears, the presence of invasion in small-sized primary adenocarcinomas of the lung is predictable by the 2 above-mentioned cytologic findings. Imprint smear cytology may effectively aid intraoperative judgement of invasion in cases where frozen section histology is difficult to interpret.

Cytoplasmic localization of p63 is associated with poor patient survival in lung adenocarcinoma

AIMS

To determine the significance of p63 protein expression in the development and progression of lung adenocarcinoma.

METHODS AND RESULTS

The expression of p63 was immunohistochemically investigated in 92 cases of lung adenocarcinoma with a maximum diameter of 30 mm or less. p63 expression was observed not only in the nuclei (46/92 cases, 50%), but also in the cytoplasm of neoplastic cells (47/92, 51%). Nuclear localization of p63 was correlated with nuclear accumulation of p53 (P=0.0120), whereas the presence of nuclear p63 had no apparent effect on patient survival. Cytoplasmic localization of p63 was found to be correlated with shorter survival periods by univariate and multivariate analyses (P=0.0486 and P=0.0488, respectively) and the relation was independent of clinicopathological factors. Cytoplasmic localization of p63 was further confirmed by immunoblots of the cytoplasmic fraction of HLC-1, a lung adenocarcinoma cell line which predominately expressed DeltaNp63alpha transcript relative to TAp63 transcript by quantitative reverse transcriptase-polymerase chain reaction.

CONCLUSIONS

Cytoplasmic expression of p63 is an adverse prognostic factor in patients with adenocarcinoma of the lung.

Small adenocarcinoma of the lung: prognostic significance of central fibrosis chiefly because of its association with angiogenesis and lymphangiogenesis

To clarify the reason why central fibrosis (CF) is an important histological prognostic factor in small adenocarcinoma (SA) of the lung, tumor tissues from 50 patients with SA < or = 2 cm in diameter were investigated using immunohistochemical and in situ hybridization analysis for factors relating to extracellular matrix and vessels. CF was observed in 33/50 cases (66%). In adenocarcinoma areas, positive activity was observed with both primary antibodies and probes for matrix metalloproteinase-2 (MMP-2) in 11/50 patients (22%), membrane-type 1 matrix metalloproteinase (MT1-MMP) in 39/50 patients (78%) and tissue inhibitor of metalloproteinase-2 (TIMP-2) in 49/50 patients (98%). In CF areas, the positive activity of fibroblastic cells was seen for only TIMP-2 in 32/33 patients (97%). In CF areas, both CD34-positive (blood and lymphatic) vessels and D2-40-positive lymphatic vessels were semiquantitatively increased in 16/33 patients (48.5%) by immunohistochemistry. Tumors with increased vessel density were associated with statistically lower disease-free survival curves compared with tumors without increased vessels. Lymphatic vessels in some CF showed intravasation by carcinoma cells. In conclusion, CF could be an important histological prognostic factor in SA chiefly because of its association with angiogenesis and lymphangiogenesis.

Pleural lavage cytology before and after lung resection in non-small cell lung cancer patients

BACKGROUND

The aim of this study was to analyze on a multivariate basis the prognostic significance of pre-resection and post-resection pleural lavage cytologies in surgically resected primary non-small cell lung cancer (NSCLC) patients, in relation to pathologic TNM factors in a large cohort of almost 1,200 patients.

METHODS

From August 1992 through March 2001, pleural lavage cytology (PLC) was performed in 1,214 NSCLC patients without pleural effusion or dissemination undergoing pulmonary resection. The cytologic evaluation was classified into three categories: negative, suggestive, and positive. To investigate the impact on patient survival, PLC results were analyzed with conventional clinicopathologic factors.

RESULTS

Definitive pre-resection PLC result was obtained in 1,194 patients and 38 had a positive result. The 5-year survival rates were 27% if pre-resection PLC was positive and 71% if negative. Of 1,198 patients 54 had a positive post-resection PLC result. The 5-year survival rates were 10% if post-resection PLC was positive and 73% if negative. On multivariate analysis, post-resection PLC was an independent prognostic factor as significant as established clinicopathologic factors.

CONCLUSIONS

Pre-resection and post-resection PLC should be recognized as an essential prognostic factor and should be performed in NSCLC patients without pleural effusion and dissemination. Post-PLC, compared with pre-PLC, had a greater and independent impact on survival and needs to be incorporated in the pathologic staging of NSCLC in the future.

CT screening for lung cancer: significance of diagnoses in its baseline cycle

PURPOSE

The aim of this study was to assess the significance of Stage I diagnoses of lung cancer in the baseline cycle of screening for this disease, with special reference to the potential for overdiagnosis.

METHODS

We reviewed all 69 cases of Stage I lung cancer diagnosis resulting from our baseline CT screening. Among these 69 cases of lung cancer, 24 presented as solid, 30 as part-solid, and 15 as nonsolid nodules. The extent to which these represented genuine malignancy was assessed by a panel of experts on lung pathology, and the "aggressiveness" of these cases was addressed by the criterion of the tumor's volume doubling time being less than 400 days.

RESULTS

The expert panel confirmed all 69 cases as representing genuine malignancy. Among the 69 cases without evidence of metastases, the proportion that satisfied the aggressiveness criterion was 60/69=87%. The corresponding proportions by presentation as solid, part-solid, and nonsolid nodule were 23/24 (96%), 27/30 (90%), and 10/15 (67%), respectively.

CONCLUSIONS

In baseline CT screening for lung cancer, overdiagnosis of the disease is uncommon, with cases presenting as a nonsolid nodule a possible exception to this.

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.

Micropapillary pattern: a distinct pathological marker to subclassify tumours with a significantly poor prognosis within small peripheral lung adenocarcinoma (<=20 mm) with mixed bronchioloalveolar and invasive subtypes (Noguchi's type C tumours)

AIMS

A micropapillary pattern (MPP) in lung adenocarcinoma, characterized by papillary structures with epithelial tufts lacking a central fibrovascular core, has been reported to be a new pathological marker of poor prognosis. However, its clinicopathological and prognostic significance in small lung adenocarcinomas (</=20 mm) remains undetermined. A new histological classification of small lung adenocarcinoma proposed by Noguchi et al. has been found to be useful since it has defined surgically curable bronchioloalveolar carcinoma (BAC)-type tumours (Noguchi's type A and B) based on the absence of active fibroblastic proliferation. However, BAC-type tumours with active fibroblastic proliferation (Noguchi's type C), which is adenocarcinoma with mixed subtypes including BAC and invasive carcinoma in the new World Health Organization (WHO) classification, account for most of the small adenocarcinomas and represent a heterogeneous group ranging from minimal to overtly invasive cancer with variable prognoses. Therefore, in this study the aim was to investigate whether MPP can be an additional histological marker(s) to subclassify this heterogeneous group in small lung adenocarcinoma.

METHODS AND RESULTS

One hundred and twenty-two cases of small lung adenocarcinomas (</=20 mm in maximum dimension) classified according to the new WHO classification and Noguchi's proposal were analysed with reference to the presence of MPP. Of the 122 cases, 67 (55%) were MPP-positive and 55 (45%) were MPP-negative. Lymph node metastasis and pleural invasion were significantly more frequent in the MPP-positive group: 74% and 66% in the positive group versus 26% and 34% in the negative group, respectively. The 5-year survival of the MPP-positive group was 54%, whereas that of the MPP-negative group was 81% (P=0.024). The 5-year survival rates of BAC (Noguchi's type A and B) (n=14), mixed BAC and invasive adenocarcinoma (Noguchi's type C) (n=85) and invasive adenocarcinoma (Noguchi's type D and F) (n=23) were 100%, 68% and 36%, respectively. In patients with mixed BAC and invasive adenocarcinoma (Noguchi's type C tumours), the 5-year survival of the MPP-positive group (n=51) was 54%, significantly lower than that of the MPP-negative group (n=23) of 100% (P=0.02).

CONCLUSIONS

MPP is a simple and distinct pathological marker to subclassify tumours with a significantly poor prognosis within small (</=20 mm) mixed BAC and invasive adenocarcinoma (Noguchi's type C tumours).

EGFR Mutation Is Specific for Terminal Respiratory Unit Type Adenocarcinoma

We have previously reported that terminal-respiratory-unit (TRU) type adenocarcinoma is a distinct subset of lung adenocarcinoma in terms of molecular pathway for carcinogenesis and phenotypic profiles. This type of cancer shows TRU features, characterized by distinct cellular morphology and the expression of TTF-1 and surfactant proteins. Recently, two groups published novel mutations of the epidermal growth factor receptor (EGFR) that are closely associated with clinical response to gefitinib. The clinicopathologic features of gefitinib responders overlap with those of TRU-type adenocarcinoma, and the characteristics of TRU are likely to correspond to the bronchioloalveolar features reported as a predictor of gefitinib response. We therefore examined the characteristics of EGFR-mutated pulmonary adenocarcinomas with special reference to TRU-type adenocarcinoma. EGFR mutation was detected in 97 of 195 adenocarcinomas, 91 of 149 TRU-type adenocarcinomas and 6 of 46 tumors of other types. Conversely, 91 of 97 EGFR-mutated adenocarcinomas were categorized as TRU-type adenocarcinomas. This type-specific involvement was confirmed by logistic regression model. In addition, EGFR mutation was detected in some cases of atypical adenomatous hyperplasia, a preinvasive lesion of TRU-type adenocarcinoma. These findings further confirm that TRU-type-adenocarcinoma is a distinct adenocarcinoma subset in which a particular molecular pathway is involved.

Grade of Stromal Invasion in Small Adenocarcinoma of the Lung

The pathologic features of invasion such as stromal disruption and pleural/vascular involvement have been shown to be of prognostic value in adenocarcinoma. However, the relationship between the degree of invasion, histologic subtype of adenocarcinoma, and prognosis remains unclear. We retrospectively studied 380 peripheral adenocarcinomas of < or = 2.0 cm in diameter with regard to histology and clinical profiles. Their degree of invasive growth was classified into four grades as follows according to the structural deformity and its location in the adenocarcinoma lesion: Grade 0 had a pure bronchioloalveolar growth pattern and no evidence of stromal invasion. Grade 1 had stromal invasion in the area of bronchioloalveolar growth. Grade 2 had stromal invasion localized on the periphery of a fibrotic focus. Grade 3 had stromal invasion into the center of a fibrotic focus. The clinicopathological data were obtained from medical records. The distribution of the histologic grade of invasion was as follows: grade 0 in 85 tumors (22%), grade 1 in 37 (10%), grade 2 in 46 (12%), and grade 3 in 212 (56%). This histologic grade of invasion was closely related to other indicators of tumor spread. Vascular/lymphatic permeation was seen in none of grade 0, in 1 lesion each of grade 1 and grade 2, and 144 (68%) of grade 3. Lymph node metastasis was seen in 57 (27%) lesions of grade 3 but not in grades 0, 1, or 2. The 5-year disease-free survival rates were 100%, 100%, 100%, and 59.6% for tumors with grade 0, grade 1, grade 2, and grade 3 invasion, respectively. Tumors with grade 1 and grade 2 invasion, like tumors with grade 0 invasion (bronchioloalveolar carcinoma), showed an excellent prognosis. Therefore, tumors with grade 1 and grade 2 invasion could be considered "minimally invasive" or "early" adenocarcinomas.

Discrepancy of computed tomographic image between lung and mediastinal windows as a prognostic implication in small lung adenocarcinoma

BACKGROUND

There have been no proven preoperative indicators for postoperative survival of patients with an adenocarcinoma, the incidence of which has been increasing lately.

METHODS

Of 952 consecutive patients operated on for primary lung cancer between 1995 and 2002, 167 patients with a proven adenocarcinoma 3 cm or less in diameter underwent complete removal of the primary tumor. We examined their computed tomographic scans to estimate tumor shadow disappearance rate (TDR), which was defined as the ratio of the tumor area of the mediastinal window to that of the lung window, reviewed the clinical records, and evaluated their relation to prognosis.

RESULTS

On univariate analyses, size of the tumor (p = 0.0380), TDR (p = 0.0018), carcinoembryonic antigen (p = 0.0001) pathologic stage (p < 0.0001), nodal involvement (p < 0.0001), lymphatic invasion (p = 0.0001), and vascular invasion (p = 0.0017) were significantly associated with prognosis. Also, the outcomes of multivariate analyses for preoperative factors indicated that TDR (p = 0.0340) and carcinoembryonic antigen (p = 0.0047) are significant independent prognostic determinants. The 5-year survival was 48% in cases with a TDR of 0% to 25%, 87% in those with a TDR of 26% to 50%, 97% in those with a TDR of 51% to 75%, and 100% in those with a TDR of 76% to 100%. The incidence of lymphatic, vascular invasion, and nodal metastases was lower in patients with a higher TDR.

CONCLUSIONS

Small-sized adenocarcinomas with a higher TDR showed less lymphatic, vascular vessel invasion, or nodal involvement, and demonstrated longer survival, suggesting that TDR was associated with clinical-pathologic characteristics and tumor aggressiveness. Preoperative assessment of TDR may be useful to identify an appropriate candidate for a lesser pulmonary resection.

Clinicopathologic relevance of apoptotic and proliferative factors in human lung adenocarcinoma: Fas expression correlates with the histologic subtype, but not with the degree of apoptosis

We immunohistochemically examined 141 surgically resected peripheral lung adenocarcinomas for the expression of Fas, single stranded (ss-) DNA and Ki-67, and statistically evaluated the relationship of these parameters with other clinicopathologic variables, including clinical stage, nodal involvement, and histopathologic subtypes classified according to WHO criteria. Fas expression by cancer cells was characteristically localized in the cytoplasm, and the extent of expression correlated well with the degree of Ki-67 reactivity (p = 0.0004), but not with the degree of apoptic occurrence, as assessed by ss-DNA reactivity. Cancer cells of the bronchioloalveolar carcinoma (BAC) subtype without invasive growth exhibited a significantly lower Fas expression than those of other subtypes (p < 0.0001). Positive expression of Fas was frequently associated with a high incidence of nodal involvement and advanced clinical stage, as compared with cases of negative expression (p = 0.0111 and p = 0.0439, respectively). Multivariate analysis revealed that Fas expression significantly correlated with the histologic subtype, but not with tumor size, nodal involvement, or clinical stage. Survival analysis determined by the log-rank test revealed that clinical stage and Ki-67 reactivity were poor prognostic variables, and Fas expression was not statistically significant. Based on these data, intracytoplasmic expression of Fas in cancer cells may participate in the development of resistance to fas-mediated apoptosis.

Modified scar grade: a prognostic indicator in small peripheral lung adenocarcinoma

BACKGROUND

Several studies have shown the prognostic value of desmoplasia for lung adenocarcinomas. The authors evaluated the density and extent of desmoplasia by modifying the scar grade, as well as the prognostic impact on patient survival.

METHODS

Modified scar grade was defined as follows: Grade 1, no desmoplasia; Grade 2, sparse desmoplastic reaction; Grade 3, dense desmoplastic reaction with diameter of 10 mm or less; Grade 4, dense desmoplastic reaction with diameter exceeding 10 mm. In addition, the prognostic impact of conventional histologic factors and modified scar grade was analyzed in 239 cases of small peripheral lung adenocarcinoma (maximum dimension, </= 30 mm) for which long-term follow-up data were available.

RESULTS

The 5 and 10-year survival rates according to the modified scar grade were 100% and 100% for Grade 1 lung adenocarcinoma (n = 29); 91.7% and 83.7% for Grade 2 (n = 61); 67.6% and 52.7% for Grade 3 (n = 78); and 50.0% and 37.5% for Grade 4 (n = 71), respectively. A significant difference in patient survival was found between Grade 1 or 2 versus Grade 3 or 4 (P < 0.0001, by log rank test). Multivariate analysis showed that modified scar grade was an independent prognostic factor (P = 0.0176), as were pathologic stage (P = 0.0293), lymph node metastasis (P = 0.0191), lymphatic permeation (P = 0.0022), and pleural involvement (P = 0.0452). Modified scar grade also had a significant impact on survival in various subsets of patients, including those with pathologic Stage IA disease, patients with tumors of diameter 20 mm or less, or patients with mixed subtype tumors with a bronchioloalveolar component.

CONCLUSIONS

Modified scar grade is a useful prognostic factor in patients with small lung adenocarcinomas. Tumors with a sparse fibroblastic reaction (modified scar Grade 2) may represent early invasive cancers or invasive cancers with low malignant potential, which should be distinguished from frankly invasive cancers (modified scar Grade 3 or 4).

"Early" peripheral lung cancer: prognostic significance of ground glass opacity on thin-section computed tomographic scan

BACKGROUND

The number of peripherally located lung cancers with an excellent prognosis has been increasing, possibly due to the introduction of computed tomography for lung cancer screening in Japan. The concept of peripherally located "early lung cancer" remains controversial.

METHODS

A retrospective study was conducted on 1,540 lung cancers resected at our institute between May 1992 and December 2000. The sizes of solid attenuation and ground glass opacity were evaluated radiologically and the relationships between radiologic findings and clinicopathologic features were investigated to define peripheral early lung cancer.

RESULTS

Sixty-nine (4.4%) lung cancers showed a large ground glass opacity component on thin-section computed tomographic scan. The maximum tumor dimension ranged from 6 to 41 mm, and all tumors were clinical stage I. Forty-seven patients were diagnosed as having bronchioloalveolar carcinoma pathologically. None of the tumors showed lymph node involvement or lymphatic invasion. Only two showed vascular invasion, but all were pathologic stage I disease. Most of the lung cancers that showed pure ground glass opacity were bronchioloalveolar carcinoma.

CONCLUSIONS

Peripheral lung nodules with a large ground glass opacity component on thin-section computed tomographic scan, which do not disappear during follow-up, tend to be bronchioloalveolar carcinomas or minimally invasive adenocarcinomas of the lung. These findings warrant a feasibility study of limited surgical resection for such lung tumors.

Lung: feasibility of a method for changing tube current during low-dose helical CT

A method for changing the tube current during helical scanning was applied to low-dose computed tomography (CT) in the lung. The changing method resulted in significant equalization of image noise in various lung sections compared with that at scanning with constant tube current. Detectability of nodules was equivalent between 60 mA and the changing method, whereas degradation occurred at 20 mA. This method seems feasible for the low-dose CT of lung cancer screening.

Detection of lung cancer on chest radiographs: analysis on the basis of size and extent of ground-glass opacity at thin-section CT

PURPOSE

To evaluate the detection of small peripheral lung tumors on chest radiographs on the basis of the size of the tumor and its extent of ground-glass opacity (GGO) at thin-section computed tomography (CT).

MATERIALS AND METHODS

Chest radiographs of 75 patients with peripheral carcinomas 20 mm in diameter or smaller (26 localized bronchioloalveolar carcinomas [BACs], 49 other carcinomas) and 60 normal chest radiographs were retrospectively reviewed individually by 10 radiologists. The extent of GGO within the lesions at thin-section CT was reviewed retrospectively. The detection rates for localized BAC and other carcinomas on chest radiographs were calculated and were correlated with tumor size and extent of GGO.

RESULTS

The mean sensitivity for detection of small peripheral carcinomas was 58.5% +/- 8.8 (standard error) for localized BAC and was 78.6% +/- 5.1 for other carcinomas (P =.024). Lesions that were smaller than 15 mm in diameter and had an extent of GGO of 70% or greater at thin-section CT were more difficult to detect than tumors that had larger diameters or less extensive GGO (chi(2) = 8.13, df = 1, P =.004).

CONCLUSION

The detection of small peripheral carcinomas on chest radiographs is influenced by tumor size and extent of GGO as seen at thin-section CT.

Bronchioloalveolar carcinoma and adenocarcinoma with bronchioloalveolar features presenting as ground-glass opacities on CT

OBJECTIVE

As bronchioloalveolar carcinoma (BAC) is noninvasive but, in its later stages, has a worse prognosis than adenocarcinoma with bronchioloalveolar features (ACB), early identification and differentiation is important for therapeutic and prognostic purposes. We wanted to identify features of BAC, which differentiated it from ACB when both presented as ground-glass opacities (GGOs) on CT.

MATERIALS AND METHODS

We reviewed all pathologic specimens of patients who were diagnosed with BAC and ACB in the lung from 1991 to 1999 in our institution and whose malignancy presented as a GGO on CT. This yielded 29 patients, 15 with BAC and 14 with ACB with GGOs on CT. Both univariate frequency table and multivariate logistic regression approaches were used to analyze the CT characteristics of these GGOs (location, GGO pattern, size, shape, margin, presence and type of air bronchogram and pseudocavitation).

RESULTS

BAC most frequently had a "GGO halo" around a solid opacity, often was a GGO "mixed with consolidation" with the smallest BACs being "pure GGO." Air bronchograms were frequently present in the largest GGOs. Pseudocavitations were rare. ACB, on the other hand, most frequently presented as a GGO "mixed with consolidation," less frequently with a "GGO halo" and rarely with "superimposed lymphangitis." The air bronchograms, frequently present, were usually tortuous and ectatic. Pseudocavitation was present in about one-third of the cases. The most useful CT features of GGO in separating those due to BAC from those due to ACB were pure (uniform) ground-glass attenuation and absence of lymphangitis.

CONCLUSION

The CT features of BAC and ACB presenting as GGO reflect the histologic descriptions of these carcinomas.

Detection of early invasion on the basis of basement membrane destruction in small adenocarcinomas of the lung and its clinical implications

To evaluate the correlation between the degree of basement membrane (BM) preservation and clinicopathological characteristics in the replacement-growth type (lepidic growth type) of small peripheral adenocarcinomas of the lung, the BM components of 72 surgically resected replacement-growth type adenocarcinomas of the lung, 2 cm or less in diameter, were evaluated immunohistochemically by using a monoclonal antibody to Type IV collagen and polyclonal antibodies to 7S collagen and laminin. The tumors were classified into the following three distinctive histological types according to the condition of the elastic framework: Type I, bronchioloalveolar carcinoma without fibrotic foci; Type II, sclerosing bronchioloalveolar carcinoma without elastic framework destruction; and Type III, sclerosing bronchioloalveolar carcinoma with elastic framework destruction. The BM was well preserved in the area of bronchioloalveolar spread along fully expanded alveoli in all tumor types; however, BM preservation was significantly lost in the areas of collapsed alveoli in Type III tumors. There were no BM component staining reactions in the scarred regions of Type III tumors. In addition, lymph node metastasis was significantly greater in Type III tumors and BM-destroyed tumors. We concluded that the BM was largely destroyed by tumor cell invasion in the scarred region of Type III adenocarcinomas. Type III tumors had discontinuous BMs in the area of collapsed alveoli, indicating that this BM-destructive pattern must be the first step in tumor invasion. Type I and II tumors were concluded to be noninvasive adenocarcinomas, because their BM components were well preserved and they had a good outcome.

Staging of non-small cell lung cancer: consensus, controversies and challenges

Stage is with performance status, the most potent prognostic factor in non-small cell lung cancer. In the past decades, much effort has been directed towards the definition, description, development and implementation of staging guidelines. This has undoubtedly resulted in improvements in therapy and insight in the biology of the disease. The new millennium sees us confronted with an increasing epidemic of lung cancer. Hence, the need for further improvements in staging accuracy and cost effectiveness, in order to use the available therapeutic armament at its best and provide the patient with a treatment that is best adjusted to his or her condition. Current controversies and future challenges in staging will be addressed.

Prognostic significance of thrombomodulin expression and vascular invasion in stage I squamous cell carcinoma of the lung

Thrombomodulin (TM) is an important modulator of intravascular coagulation. TM exists on endothelial cells and on several types of tumor cells, especially squamous cell carcinoma cells. Tumor cell TM is thought to be associated with progression and metastasis of the tumor. To evaluate the prognostic significance of TM in lung cancer, we examined TM expression and vascular invasion in surgical specimens obtained from 90 patients with completely resected stage I non-small cell lung cancer (NSCLC). In addition, we correlate these pathologic data to other clinicopathologic data, including the outcome of the patients. Squamous cell carcinomas had a significantly higher incidence (P<0.0001) of TM expression (22/36 cases, 61%) than adenocarcinomas (9/54 cases, 17%). In 36 squamous cell carcinoma patients, both vascular invasion (P=0.0153; risk ratio 6.507) and TM non-expression (P=0.0282; risk ratio 3.584) were significant for a poor prognosis. Univariate analysis of patient survival rates also revealed that vascular invasion and TM expression were significant prognostic factors (P=0.0036 and 0.012, respectively). Further, combination analysis of vascular invasion and TM expression in the squamous cell carcinoma patients showed that the 5-year survival rate was 90% in patients with TM expression and without vascular invasion, but 21% in patients with vascular invasion and without TM expression (P=0.0004). Since our results suggest that vascular invasion and TM expression are independent prognostic factors of stage I squamous cell carcinoma of the lung, and since the two factors play different roles in the metastatic process of cancers (promotion of metastasis by vascular invasion and inhibition of metastasis by TM expression), the combination evaluation of vascular invasion and TM expression may be very significant in evaluating the prognosis of patients with completely resected stage I squamous cell carcinoma.

Predictors of lymph node and intrapulmonary metastasis in clinical stage IA non-small cell lung carcinoma

BACKGROUND

The feasibility of limited surgical resection for clinical stage IA non-small cell lung cancer still remains controversial.

METHODS

From July 1987 through April 1998, 389 patients with clinical stage IA disease underwent major lung resection and complete mediastinal lymph node dissection. Univariate and multivariable analyses were performed to determine predictors of local or regional tumor spread: pathologic lymph node involvement, intrapulmonary metastases, and lymphatic invasion.

RESULTS

Of the 389 patients, 88 (23%) had lymph node involvement or intrapulmonary metastases pathologically. According to multivariable analyses, grade of differentiation and pleural involvement were significant predictors of local or regional tumor spread (p < 0.01). Based on these results, more than 40% of clinical stage IA non-small cell lung cancer patients showed pathologic lymph node involvement or intrapulmonary metastases, or both, if the patients had both of the predictors of pathologic local or regional involvement: moderate or poor differentiation of the primary tumor and pleural involvement by tumor cells.

CONCLUSIONS

Limited surgical resection is not feasible for clinical stage IA non-small cell lung cancer, especially when the tumor shows moderate or poor differentiation, or pleural involvement.

Heterogeneous distribution of P53 immunoreactivity in human lung adenocarcinoma correlates with MDM2 protein expression, rather than with P53 gene mutation

Although the tumor suppressor p53 protein (P53) immunoreactivity and its gene (p53) mutation were reported to be significant prognostic indicators for human lung adenocarcinomas, little is known regarding the relationship between the heterogeneous distribution of P53 and its genetic status in each tumor focus and the clinicopathological significance. To determine how P53 is heterogeneously stabilized in patients, we compared P53 expression to both the p53 allelic mutation in exon 2 approximately 9 by polymerase chain reaction-single strand conformation polymorphism using microdissected DNA fractions, and the immunohistochemical MDM2 expression. Of the 48 positive to P53 in 118 lung adenocarcinomas examined, 10 with heterogeneous P53 expression were closely examined. The higher P53 expression foci in 7 of 10 cases were less differentiated, histologically in respective cases, and were frequently associated with fibrous stroma. Two had genetic mutations in exon 7 of the p53 gene in both the high and low P53 expression foci of cancer tissue indicating no apparent correlation between heterogeneous P53 expression and the occurrence of gene mutation. Immunohistochemical expression of MDM2 was significantly lower in high P53 expression areas (p < 0.05, the mean labeling indices of high and low P53 expression areas being 4.2 +/- 5.4% and 13.6 +/- 12.2%, respectively). In addition, among all the 118 cases examined, MDM2 expression was significantly suppressed in cases of p53 gene mutation, simultaneously with P53 overexpression, as compared with cases without both the p53 mutation and expression (p < 0.001). These findings suggest that the heterogeneous stabilization of P53 in human lung adenocarcinomas could be partly due to suppressed MDM2 expression. The overexpression of non-mutated P53 may afford a protective mechanism in human lung adenocarcinomas.

Early results of a prospective study of limited resection for bronchioloalveolar adenocarcinoma of the lung

BACKGROUND

We reported that bronchioloalveolar adenocarcinoma (BAC) without active fibroblastic proliferation of the lung had no lymph node and pulmonary metastasis and had a favorable prognosis. However, there has been no prospective trial regarding limited pulmonary resection for this type of BAC. The purpose of this study is to confirm the effectiveness of limited resection for histologically confirmed BAC without active fibroblastic proliferation.

METHODS

From 1996 through 1999, 42 patients who had small peripheral lung tumors (< or = 20 mm), suspected of being BAC, were enrolled in this trial. The patient population consisted of 24 men and 18 women with a mean age of 58.4 years. Limited resection was completed when BAC, without both active fibroblastic proliferation and lymph node metastasis, was confirmed histologically by intraoperative pathologic examination.

RESULTS

Limited resection was completed in 36 patients, wedge resection in 34, and segmentectomy in 2 patients. In 6 patients, the procedure was converted into lobectomy because of pathologic invasive sign in 3, active fibroblastic proliferation in 1, and for other reasons in 2 patients. All patients have been followed for a median follow-up period of 30 months and are alive without sign of recurrence.

CONCLUSIONS

Our early results indicate that limited resection may be an acceptable alternative to lobectomy for histologically confirmed BAC without active fibroblastic proliferation.