Prognostic value of bronchiolo-alveolar carcinoma component of small lung adenocarcinoma

Vessel co-option in cancer

All solid tumours require a vascular supply in order to progress. Although the ability to induce angiogenesis (new blood vessel growth) has long been regarded as essential to this purpose, thus far, anti-angiogenic therapies have shown only modest efficacy in patients. Importantly, overshadowed by the literature on tumour angiogenesis is a long-standing, but continually emerging, body of research indicating that tumours can grow instead by hijacking pre-existing blood vessels of the surrounding nonmalignant tissue. This process, termed vessel co-option, is a frequently overlooked mechanism of tumour vascularization that can influence disease progression, metastasis and response to treatment. In this Review, we describe the evidence that tumours located at numerous anatomical sites can exploit vessel co-option. We also discuss the proposed molecular mechanisms involved and the multifaceted implications of vessel co-option for patient outcomes.

Controversies on lung cancers manifesting as part-solid nodules

PURPOSE

Summarise survival of patients with resected lung cancers manifesting as part-solid nodules (PSNs).

METHODS

PubMed/MEDLINE and EMBASE databases were searched for all studies/clinical trials on CT-detected lung cancer in English before 21 December 2015 to identify surgically resected lung cancers manifesting as PSNs. Outcome measures were lung cancer-specific survival (LCS), overall survival (OS), or disease-free survival (DFS). All PSNs were classified by the percentage of solid component to the entire nodule diameter into category PSNs <80% or category PSNs ≥80%.

RESULTS

Twenty studies reported on PSNs <80%: 7 reported DFS and 2 OS of 100%, 6 DFS 96.3-98.7%, and 11 OS 94.7-98.9% (median DFS 100% and OS 97.5%). Twenty-seven studies reported on PSNs ≥80%: 1 DFS and 2 OS of 100%, 19 DFS 48.0%-98.0% (median 82.6%), and 16 reported OS 43.0%-98.0% (median DFS 82.6%, OS 85.5%). Both DFS and OS were always higher for PSNs <80%.

CONCLUSION

A clear definition of the upper limit of solid component of a PSN is needed to avoid misclassification because cell-types and outcomes are different for PSN and solid nodules. The workup should be based on the size of the solid component.

KEY POINTS

• Lung cancers manifesting as PSNs are slow growing with high cure rates. • Upper limits of the solid component are important for correct interpretation. • Consensus definition is important for the management of PSNs. • Median disease-free-survival (DFS) increased with decreasing size of the nodule.

Predictors of False-Negative Results from Percutaneous Transthoracic Fine-Needle Aspiration Biopsy: An Observational Study from a Retrospective Cohort

PURPOSE

We investigated factors predictive of false-negative pulmonary lesions with nonspecific benign cytology results on percutaneous transthoracic fine-needle aspiration biopsy (FNAB).

MATERIALS AND METHODS

We included 222 pulmonary lesions that had a nonspecific benign result from percutaneous transthoracic FNAB between March 2005 and December 2012, and were confirmed by subsequent pathologic results or adequate clinical follow up over at least 2 years. Clinical, imaging, and biopsy procedure-related findings were compared between lesions with a final diagnosis of malignancy (false-negative) and lesions with a benign diagnosis (true-negative). Multivariate logistic regression analysis was performed to identify significant predictors of false-negatives.

RESULTS

Of 222 lesions, 115 lesions were proved to be false-negatives, and 107 were true-negatives. Compared with the true-negatives, false-negative lesions showed significantly older age (p=0.037), higher maximum standardized uptake value (SUVmax) on positron emission tomography (p=0.001), larger lesion size (p=0.007), and lesion characteristics of a subsolid nodule (p=0.007). On multivariate logistic regression analysis, SUVmax, lesion size, and lesion characteristics were significant predictors of false-negative results.

CONCLUSION

Among the clinical, radiologic, and procedure-related factors analyzed, high SUVmax, large lesion size, and subsolid lesions were useful for predicting malignancy in pulmonary lesions with nonspecific benign cytology results on FNAB.

The percentage of lepidic growth is an independent prognostic factor in invasive adenocarcinoma of the lung

Background

The literature is inconclusive as to whether the percentage of the lepidic component of an invasive adenocarcinoma (AC) of the lung influences prognosis. We studied a population-based series of selected, resected invasive pulmonary ACs to determine if incremental increases in the lepidic component were an independent, prognostic variable.

Methods

Patients undergoing resection for lung cancer reported to the Cancer Registry of Norway and diagnosed in the period 1993-2002 with a bronchioloalveolar carcinoma (BAC) (old terminology) (adenocarcinoma in situ, AIS in the new terminology) in the lung were selected. A pulmonary pathologist reviewed all sections and estimated the percentage of the lepidic component. Follow-up of survival was to the end of 2013.

Results

One hundred thirty-one patients were identified, 102 had AC with lepidic growth. Of these, 44 had AC with a component of lepidic growth less than 50 % and seven had AC with 95 % lepidic component or more. One of the latter cases was considered to be AIS. In regression analyses, superior survival was associated with a greater lepidic component (p = 0.041). Mucinous tumors had a worse prognosis than non-mucinous (p = 0.012) in regression analyses, as did increasing age and stage. The five-year observed survival was 69.0 % for non-mucinous cases and 66.7 % for the group with a lepidic component of 80 % or greater.

Conclusion

The percentage of the lepidic component appears to be an independent, significant prognostic factor in a selection of pulmonary AC.

Correlation of histological components with tumor invasion in pulmonary adenocarcinoma

Background

Pulmonary adenocarcinoma (PA) is the most common histologic type of primary lung cancer. Generally, adenocarcinoma was composed by five major components. The present study aimed to evaluate changes in the composition of adenocarcinoma components as the tumor grows; in addition, to analyze the correlation between the occupancy rates of histologic components of the tumor in regard to prognosis.

Methods

Pathologic data were retrospectively evaluated for 206 patients who underwent curative resection of PA. We investigated how histologic component occupancy rates changed as tumor size and N stage increased. To evaluate local invasiveness, the major components of the present group and absent group of pleural invasion, lymphatic invasion, and vascular invasion were compared.

Results

The mean percentages of acinar and solid components significantly increased with an increase in size (P = 0.006, P < 0.001) ; however, the percentage of lepidic components decreased (P < 0.001). In cases with a solid component and a micropapillary component, a gradual increase was found with an increase N stage (P = 0.001, P < 0.001); however the percentage of lepidic components decreased (P < 0.001). Average differences of histologic components dependent upon whether pleural, lympathic and vascular invasion were present, the difference of micropapillary and lepidic components were statistically significant. With logistic regression analysis, as the occupancy rate of the lepidic component increased, the probability of pleural invasion, lymphatic invasion, and vascular invasion decreased; in cases with a micropapillary component, as the occupancy rate of increased, the probability of lymphatic invasion and vascular invasion increased. In multivariate analysis using the Cox propotional hazards model, the occupancy rates of acinar(p = 0.043; odds ratio = 1.023), micropapillary(p = 0.002; odds ratio = 1.051) and lepidic (p = 0.005; odds ratio = 0.966) components were significantly associated with recurrence.

Conclusions

The lower the occupancy rate of a lepidic component and the higher the occupancy rates of acinar, solid, and micropapillary components, the likelihood of tumor progression increased. In addition, as the occupancy rate of a lepidic component decreased and a micropapillary component increased, local invasiveness and recurrence rate increased; thus, increasing the probability of a poor prognosis.

Nodule characterization: subsolid nodules

In this review, we focus on the radiologic, clinical, and pathologic aspects primarily of solitary subsolid pulmonary nodules. Particular emphasis will be placed on the pathologic classification and correlative computed tomography (CT) features of adenocarcinoma of the lung. The capabilities of fluorodeoxyglucose positron emission tomography-CT and histologic sampling techniques, including CT-guided biopsy, endoscopic-guided biopsy, and surgical resection, are discussed. Finally, recently proposed management guidelines by the Fleischner Society and the American College of Chest Physicians are reviewed.

Recommendations for the management of subsolid pulmonary nodules detected at CT: a statement from the Fleischner Society

This report is to complement the original Fleischner Society recommendations for incidentally detected solid nodules by proposing a set of recommendations specifically aimed at subsolid nodules. The development of a standardized approach to the interpretation and management of subsolid nodules remains critically important given that peripheral adenocarcinomas represent the most common type of lung cancer, with evidence of increasing frequency. Following an initial consideration of appropriate terminology to describe subsolid nodules and a brief review of the new classification system for peripheral lung adenocarcinomas sponsored by the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS), six specific recommendations were made, three with regard to solitary subsolid nodules and three with regard to multiple subsolid nodules. Each recommendation is followed first by the rationales underlying the recommendation and then by specific pertinent remarks. Finally, issues for which future research is needed are discussed. The recommendations are the result of careful review of the literature now available regarding subsolid nodules. Given the complexity of these lesions, the current recommendations are more varied than the original Fleischner Society guidelines for solid nodules. It cannot be overemphasized that these guidelines must be interpreted in light of an individual's clinical history. Given the frequency with which subsolid nodules are encountered in daily clinical practice, and notwithstanding continuing controversy on many of these issues, it is anticipated that further refinements and modifications to these recommendations will be forthcoming as information continues to emerge from ongoing research.

Clinicopathological characteristics of subcentimeter adenocarcinomas of the lung

BACKGROUND

Identification of subcentimeter adenocarcinoma is becoming easier due to recent advances in radiographic techniques. Pathological (p) T1a (≤20 mm) adenocarcinomas with a pure lepidic growth pattern have excellent prognosis, whereas invasive pT1a adenocarcinomas are associated with recurrence/metastasis despite their small size. Thus, an accurate pathological diagnosis is critical in such cases. This study examined the clinicopathological characteristics of subcentimeter adenocarcinomas, especially those associated with early invasive carcinomas.

METHODS

We retrospectively reviewed 595 adenocarcinomas including 66 subcentimeter carcinomas, which were then analyzed with reference to early invasive features.

RESULTS

Of the 66 subcentimeter tumors, 36 were invasive and 30 were noninvasive (adenocarcinoma in situ, AIS). Invasive carcinomas were significantly more frequent in males than females, and included 20 tumors with ≤5 mm invasion in greatest dimension (minimally invasive adenocarcinoma, MIA) and 16 tumors with >5mm invasion, 5 of which had no lepidic growth portions (entirely invasive carcinoma). Approximately half of the invasive carcinomas had no localized fibrous area ≥1 mm in diameter (LFA), and showed histological features of invasive carcinoma with localized lepidic growth including MIA (Noguchi's type C). Invasion was sometimes difficult to detect in these carcinomas. High-grade nuclear atypia was always associated with invasive carcinomas and aided the diagnosis. Moreover, invasive carcinoma with >5mm invasion was significantly associated with presence of metastasis in sensitivity analysis in patients followed for more than two years. Compared with adenocarcinomas of 11-20mm in diameter, subcentimeter carcinomas included significantly more AIS, fewer entirely invasive carcinomas, and fewer invasive carcinomas with LFA.

CONCLUSIONS

Familiarity with the histopathological characteristics of subcentimeter adenocarcinomas as described above could aid the accurate diagnosis of early invasive carcinomas.

Number of circulating endothelial progenitor cells and intratumoral microvessel density in non-small cell lung cancer patients: differences in angiogenic status between adenocarcinoma histologic subtypes

INTRODUCTION

Angiogenesis plays a significant role in tumor progression. This study examined the association between the number of circulating endothelial progenitor cells (EPCs), intratumoral microvessel density (MVD) (both of which may be markers for neovascularization), and lung cancer histological types, particularly adenocarcinoma histological subtypes.

METHODS

A total of 83 stage I non-small cell lung cancer (NSCLC) patients underwent complete tumor resection between November 2009 and July 2010. The number of EPCs from the pulmonary artery of the resected lungs was measured by assaying CD34/vascular endothelial growth factor receptor 2 positive cells, and the MVD was assessed immunohistochemically in tumor specimens by staining for CD34.

RESULTS

A statistically significant correlation between the number of EPCs from pulmonary artery and intratumoral MVD was found (p < 0.001). No statistically significant differences in the number of EPCs and the MVD were observed between the adenocarcinomas and the squamous cell carcinomas. Among the adenocarcinoma histological subtypes, a higher number of EPCs and MVD were found significantly more frequently in solid adenocarcinomas than in nonsolid adenocarcinomas (p < 0.001 and p = 0.011, respectively). In addition, solid adenocarcinomas showed higher levels of vascular endothelial growth factor using quantitative real-time polymerase chain reaction in the tumor tissue samples than in the nonsolid adenocarcinomas (p = 0.005).

CONCLUSION

The higher number of circulating EPCs and the MVD of solid adenocarcinoma may indicate the presence of differences in the tumor angiogenic status between early-stage adenocarcinoma histological subtypes. Among adenocarcinoma patients, patients with solid adenocarcinoma may be the best candidates for antiangiogenic therapies.

Small peripheral lung adenocarcinoma: CT and histopathologic characteristics and prognostic implications

Since the introduction of computed tomography (CT), detection of small lung cancer, especially small peripheral adenocarcinoma, is common. Recently, the morphological characteristics, including thin-section CT and pathologic findings, and prognosis of small peripheral lung adenocarcinomas have been studied extensively. The radiologic and microscopic findings correlate well with each other and are closely associated with tumour prognosis. Most importantly, some subtypes of small lung adenocarcinomas with specific CT or pathologic features are curable. Therefore, all defining characteristics (CT, pathologic and prognostic) of this kind of tumour should be integrated to improve our understanding, provide guidelines for management and accurately assess its prognosis.

The prognostic impact of cigarette smoking on patients with non-small cell lung cancer

INTRODUCTION

The purposes of this study are to investigate the association between cigarette smoking and clinicopathological characteristics of patients with non-small cell lung cancer (NSCLC) and to evaluate its significance as a predictor of recurrence after resection.

METHODS

A total of 2295 consecutive patients with NSCLC underwent complete resection with systematic node dissection between August 1992 and December 2006 at the National Cancer Center Hospital East.

RESULTS

A statistically significant difference in the 5-year overall survival rate was observed between never and ever smokers in patients with stage I (92% and 76%, respectively, p < 0.001) NSCLC, whereas no difference was observed in stage II (57% and 52%, respectively, p = 0.739) and stage III (30% and 33%, respectively, p = 0.897). In patients with stage I NSCLC, 5-year recurrence-free proportions (RFPs) for never and ever smokers were 89% and 80%, respectively (p < 0.001). In contrast, the 5-year RFPs for never smokers were lower than those for ever smokers in stage II (44% and 60%, respectively, p = 0.049) and stage III (17% and 31%, respectively, p = 0.004). In stage I patients, significant difference in 5-year RFP was observed between never and ever smokers (89% and 83%, respectively) in patients with adenocarcinoma, but not in patients with nonadenocarcinoma (82% and 76%, respectively).

CONCLUSIONS

Smoking history showed different impact on postoperative recurrence in patients with NSCLC between stage I and stages II and III, and depending on histology in stage I patients. Disease stages should be considered while evaluating smoking history as a predictor of recurrence.

Accuracy of CT parameters for assessment of tumour size and aggressiveness in lung adenocarcinoma with bronchoalveolar elements

Accurate determination of tumour size in lung adenocarcinoma with bronchoalveolar features (BAC) is important for the determination of TNM (tumour, nodes, metastasis) scores used in staging, prognosis and therapy response assessment. However, tumour sizes derived using lung window (LW) CT or soft-tissue/mediastinal window (MW) CT often give different results. This study examines which measurement correlates best with actual tumour size and which best identifies advanced disease. This retrospective study included 43 BAC patients who underwent surgical resection with mediastinal lymphadenectomy <4 weeks post CT scan. The largest unidimensional tumour diameter on each CT window was compared with actual histopathological tumour size (HP). LW, MW and HP size measurements and a recently described CT parameter - the modified tumour shadow disappearance rate (mTDR) = (1 - [MW/LW]) - were then used to determine which parameter best discriminated between the presence or absence of advanced disease. There was no difference between HP and LW sizes, but MW significantly underestimated HP size (p<0.0001). Unlike MW (p = 0.01) and mTDR (p = 0.001), neither HP (p = 0.14) nor LW (p = 0.10) distinguished between patients with or without advanced disease. On receiver operating characteristic (ROC) analysis at a cut-off of ≤0.13, the sensitivity and specificity of mTDR for detecting advanced disease were 69% and 89%, respectively. In patients with tumours ≤3 cm, only mTDR remained a significant predictor of advanced disease (p = 0.017), with best cut-off at ≤0.20, giving a sensitivity and specificity of 71% and 94%, respectively. MW better predicts advanced disease than LW and might also need to be recorded for RECIST (response evaluation criteria in solid tumours) assessment for T staging of BAC; however, mTDR appears to be an even better predictor and should also be used.

Prognostic impact of histology on early-stage non-small cell lung cancer

BACKGROUND

The purpose of this study is to evaluate the significance of histology as a predictor of recurrence after resection in patients with early-stage non-small cell lung cancer.

METHODS

A total of 1,870 consecutive patients in stage I and II with adenocarcinoma or squamous cell carcinoma (SCC) who underwent complete tumor resection with systematic lymph node dissection between August 1992 and December 2007 were included.

RESULTS

In patients with SCC, significantly more tumors were stage IB or higher. Ever smokers were more common in patients with SCC, and more patients with SCC died of other diseases. In stage IA, a statistically significant difference in the 5-year recurrence-free probability was observed between adenocarcinoma and SCC (91.4% and 82.6%, respectively; P < .001), whereas no such difference was observed in stage IB (74.4% and 73.6%, respectively; P = .934). In stage II, the 5-year recurrence-free probability for adenocarcinoma was significantly lower than that for SCC (47% and 73%, respectively; P < .001). In stage IA, patients with predominantly bronchioloalveolar carcinoma subtype were more common compared with stage IB or higher in patients with adenocarcinoma.

CONCLUSIONS

It is important to offset the prognostic impact of comorbidities associated with cigarette smoking because more patients with SCC died of other diseases. When evaluating its significance as a predictor of recurrence stratified by stage, histology showed a different impact on postoperative recurrence within different substages. Histologic subtype distribution was different among substages in patients with adenocarcinoma. Disease stages should be considered while evaluating histology as a predictor of recurrence.

[Detection of lymph node involvement and surgical treatment of pulmonary neoplastic processes. Current state of diagnostic and therapeutic procedures]

An analysis is made of different publications associated with the surgical staging and treatment of primary and metastasic pulmonary neoplastic processes. A suitable treatment program is essential to determine lymph node involvement in patients with bronchogenic carcinoma. The indication and sequence of the procedure to use (CT-PET, transbronchial puncture, videomediastinoscopic ultrasound guided transbronchial needle aspiration) is evaluated in accordance to the sensitivity, specificity and positive and negative predictive value of the different methods. Another interesting challenge is to define the criteria for indicating a sublobar resection in certain tumours and patients. Different factors, age, lung function, tumour location and type of sublobar resection, are analysed. Levels of evidence and recommendations of the procedure are also considered. Surgical resection is an accepted therapeutic option in the treatment of colorectal cancer lung metastases. Its indication is based on acceptable survival rates and knowledge of the impact of various factors (interval free of disease, number of metastases, presence of liver metastasis, presence of lymph node involvement, or increased pre-operative levels of carcinoembryonic antigen), is analysed in detail.

Small peripheral lung adenocarcinoma: clinicopathological features and surgical treatment

The clinical use of high-resolution computed tomography (CT) has greatly advanced diagnosis of small peripheral lesions of the lung. In CT images, these lesions often exhibit ground-glass opacity (GGO). Ground-glass opacity is typical of noninvasive bronchioloalveolar carcinoma (BAC), which is characterized by a lepidic pattern of cells that line the alveoli but do not invade neighboring structures. Bronchioloalveolar carcinoma is classified as a subset of lung adenocarcinoma, but has distinct clinical and pathological features and a favorable prognosis. Most small peripheral lung lesions, including BAC, probably originate in the epithelium of the peripheral airway. As with other subsets of non-small cell lung cancer, surgical resection is a potentially curative treatment. However, it is questionable whether a lobectomy is necessary for small lesions that exhibit GGO, particularly when they are <1 cm in diameter. Although several Japanese investigators have suggested that a limited resection, including a wedge resection and a segmentectomy without nodal dissection, is an appropriate treatment for small lung adenocarcinomas, this approach should be validated by clinical trials.

Subepithelial myofibroblast in lung adenocarcinoma: a histological indicator of excellent prognosis

We report here the presence of subepithelial myofibroblasts in pure bronchioloalveolar carcinoma and a subset of invasive lung adenocarcinoma. The subepithelial myofibroblasts we describe were observed in a peculiar location beneath the cancer cells in the alveolar septa. Immunohistochemically, they were positive for alpha-smooth muscle actin and calponin, but negative for desmin and h-caldesmon. To gain insight into their biological significance, we examined 116 surgically resected lung adenocarcinomas. The resected tumors included 13 bronchioloalveolar carcinomas, 20 mixed type adenocarcinomas with bronchioloalveolar carcinoma components, 57 papillary adenocarcinomas, 22 solid adenocarcinomas with mucin, and 4 acinar adenocarcinomas. All specimens were immunostained for alpha-smooth muscle actin to visualize the myofibroblasts. In all of the pure bronchioloalveolar carcinomas observed, the subepithelial myofibroblasts were completely preserved adjacent to the cancer cells. In mixed adenocarcinomas with bronchioloalveolar carcinoma components, subepithelial myofibroblasts were present in the bronchioloalveolar carcinoma components, but scanty in the invasive areas, where stromal myofibroblasts emerged between the cancer cell nests. Subepithelial myofibroblasts were retained, however, in the invasive areas of a subset of invasive adenocarcinomas. Survival analysis showed that the retention of subepithelial myofibroblasts in these invasive tumors was associated with low rates of lymphatic and vascular invasion, a low rate of lymph node involvement, and an excellent patient survival. These results suggest that subepithelial myofibroblasts increase in bronchioloalveolar carcinomas, but are gradually replaced by typical stromal myofibroblasts during progression into invasive cancer. A subset of invasive adenocarcinomas retains subepithelial myofibroblasts. Analysis of subepithelial myofibroblasts may be helpful in identifying a subset of lung adenocarcinoma with excellent prognosis.

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.

Treatment strategy for patients with small peripheral lung lesion(s): intermediate-term results of prospective study

BACKGROUND

This prospective study was undertaken to establish a novel management algorithm using new indicators to decide the type of lung resection for small peripheral lung lesions.

METHODS

Inclusion criteria were: (1) <or=20mm peripheral lung lesion(s) and (2) absence of significant lymph node swelling on preoperative CT. Along with the conventional criteria, the percentage of ground-glass opacity (GGO) (>or=50% as GGO type and <50% as solid type) on high-resolution CT scan was employed. In accordance with such indicators, a wide wedge resection (WWR), segmentectomy or lobectomy was planned for individual patients. The primary endpoint was to estimate the effectiveness of limited resection in patients with lung cancer by analyzing their locally disease-free survival rates at 5 and 10 years.

RESULTS

Of 179 patients enrolled between 1997 and 2002, 90 were male and 89 female. They were divided into 77 GGO types and 102 solid types. During surgery, conversions from limited resections to standard operations were performed on six patients to avoid the risk of local-regional recurrence. Finally, WWR was performed on 73 patients, segmentectomy on 26 and lobectomy on 80, respectively. There were 138 lung cancers and 41 non-cancers. Of 138 cancer patients, 114 patients are alive and 24 died. There were no local-regional recurrences among the 58 cancer patients who underwent limited resection.

CONCLUSIONS

This intermediate-term outcome suggests that the selection of the type for lung resection using this management algorithm for small peripheral lung lesions was effective for preventing both local-regional recurrences and the excessive resection of normal lung tissue.

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.

Clinicopathologic Analysis of Microscopic Extension in Lung Adenocarcinoma: Defining Clinical Target Volume for Radiotherapy

PURPOSE

To determine the gross tumor volume (GTV) to clinical target volume margin for non-small-cell lung cancer treatment planning.

METHODS

A total of 35 patients with Stage T1N0 adenocarcinoma underwent wedge resection plus immediate lobectomy. The gross tumor size and microscopic extension distance beyond the gross tumor were measured. The nuclear grade and percentage of bronchoalveolar features were analyzed for association with microscopic extension. The gross tumor dimensions were measured on a computed tomography (CT) scan (lung and mediastinal windows) and compared with the pathologic dimensions. The potential coverage of microscopic extension for two different lung stereotactic radiotherapy regimens was evaluated.

RESULTS

The mean microscopic extension distance beyond the gross tumor was 7.2 mm and varied according to grade (10.1, 7.0, and 3.5 mm for Grade 1 to 3, respectively, p < 0.01). The 90th percentile for microscopic extension was 12.0 mm (13.0, 9.7, and 4.4 mm for Grade 1 to 3, respectively). The CT lung windows correlated better with the pathologic size than did the mediastinal windows (gross pathologic size overestimated by a mean of 5.8 mm; composite size [gross plus microscopic extension] underestimated by a mean of 1.2 mm). For a GTV contoured on the CT lung windows, the margin required to cover microscopic extension for 90% of the cases would be 9 mm (9, 7, and 4 mm for Grade 1 to 3, respectively). The potential microscopic extension dosimetric coverage (55 Gy) varied substantially between the stereotactic radiotherapy schedules.

CONCLUSION

For lung adenocarcinomas, the GTV should be contoured using CT lung windows. Although a GTV based on the CT lung windows would underestimate the gross tumor size plus microscopic extension by only 1.2 mm for the average case, the clinical target volume expansion required to cover the microscopic extension in 90% of cases could be as large as 9 mm, although considerably smaller for high-grade tumors. Fractionation significantly affects the dosimetric coverage of microscopic extension.

Reliability of cytologic diagnosis of early lung cancer

BACKGROUND

Baseline screening for lung cancer of 2968 high-risk men and women utilizing HRCT enrolled in ELCAP (Early Lung Cancer Action Project) was performed between 1993-2002. Among them, 65 people had surgical resection of their screen-diagnosed lung cancer, 53 of them on the basis of a diagnosis of malignancy or atypical bronchioloalveolar proliferation (ABP) on fine needle aspiration (FNA) biopsy at Weill Medical College of Cornell University (WMC) prior to surgery. The authors compared the diagnosis obtained from the FNA with the subsequent diagnosis from the surgical specimen to assess the reliability of a cytologic diagnosis of lung cancer on FNA of these screen-diagnosed lung cancers.

METHODS

The FNA biopsies were performed with a 22-gauge Wescott needle by 1 radiologist (D.Y.), with preliminary on-site as well as final diagnosis rendered by a cytologist (M.V., J.K.). These results were correlated with histologic diagnoses obtained as a result of consensus diagnosis by a panel of 5 expert pulmonary pathologists.

RESULTS

Of the 53 cases of lung cancer resected following FNA, 4 were diagnosed as atypical bronchioloalveolar proliferation (ABP), 14 as adenocarcinoma with bronchioloalveolar features (ADC-BAC), 28 as adenocarcinoma, not otherwise specified (ADC-NOS), 1 as squamous cell carcinoma (SQCC), 4 as nonsmall-cell carcinoma (NSCC), and 2 as typical carcinoid. In the 49 cases with a malignant cytology and 4 cases of ABP, lung cancer was confirmed histologically. The tumor sizes ranged from 4 mm to 40 mm, mean size 13mm. The final expert panel histologic diagnosis was adenocarcinoma in 47 cases; of these, 42 were invasive (mixed subtype or acinar subtype), and 5 were a noninvasive (bronchioloalveolar carcinoma, BAC). Three of the 42 invasive adenocarcinoma that had a predominant BAC component and 1 case of BAC were diagnosed as ABP on FNA; all were sampled at the periphery of the tumor. Three of 4 cases of invasive adenocarcinoma of high nuclear grade were diagnosed as NSCC, and 1 was inaccurately classified as SQCC on FNA. One case of high-grade noninvasive BAC associated with a scar was diagnosed as NSCC on FNA. Two cases classified as nonkeratinizing SQCC and 2 cases of large cell neuroendocrine carcinoma on histology were misclassified as ADC-NOS by FNA. Two cases of typical carcinoid on histology were also diagnosed as typical carcinoid on FNA.

CONCLUSIONS

Preoperative diagnosis of lung cancer detected by screening with HRCT could be reliably made by FNA. Difficulty in classification occurs in carcinomas of high nuclear grade with prominent nucleoli, including poorly differentiated SQCC and large cell neuroendocrine carcinoma. These are best diagnosed as NSCC on cytomorphology with further subclassification based on immunohistochemistry, which these authors generally perform on cell-block material. A diagnosis of ABP on FNA may be indicative of noninvasive BAC or an invasive adenocarcinoma with prominent BAC features, usually sampled at its periphery.

Adenocarcinoma of the lung: current concepts in radiologic diagnosis and management

PURPOSE OF REVIEW

Since the introduction especially of multidetector computed tomography scanners, detection of peripheral pulmonary nodules as small as 2-3 mm is now a frequent event even in individuals without a significant smoking history. This preponderance of small indeterminate nodules has necessitated reconsideration of the natural history of malignant lung tumors, in particular peripheral adenocarcinomas, as well as current clinical and radiologic guidelines to aid in the management of these lesions.

RECENT FINDINGS

New information within the radiologic, pathologic and surgical literature is currently redefining nodule characterization. Most important has been the growing awareness of the prevalence of 'so-called' sub-solid pulmonary nodules, with important implications for revising our understanding of the natural history of these lesions as it impacts guidelines for nodule management.

SUMMARY

Reassessment of our approach to small pulmonary nodules, while controversial, is now requisite as newer insights into the computed tomography appearance and natural history of small adenocarcinomas of the lung become apparent. Recognition of suspicious morphology and accurate measurements of volume doubling time, in particular, should aid in the management of these lesions.

Diagnosis and treatment of bronchioloalveolar carcinoma

PURPOSE OF REVIEW

Bronchioloalveolar carcinoma accounts for 5% of lung cancers, although histologically mixed bronchioloalveolar carcinoma and adenocarcinoma account for up to 20%. Bronchioloalveolar carcinoma histology is present in a majority of tumors found on lung-cancer screening by computed tomography. We review issues surrounding the diagnosis and treatment of bronchioloalveolar carcinoma, which often differs from other types of lung cancer.

RECENT FINDINGS

A spectrum of disease from histologically pure bronchioloalveolar carcinoma to adenocarcinoma exists. The approach to treatment of diseases within this spectrum is still evolving. Evidence on the role of sub-lobar resection, resection of multifocal disease, and pulmonary transplantation is reviewed. We also discuss epidermal growth factor receptor tyrosine kinase inhibitors, and their role in patients with bronchioloalveolar carcinoma.

SUMMARY

An understanding of recent developments in the diagnosis and treatment of patients with bronchioloalveolar carcinoma histology is important as early detection of lung cancer becomes more common. Ongoing clinical trials will provide important information on the role of limited resection. The use of epidermal growth factor receptor tyrosine kinase inhibitors should currently be limited to patients with advanced or recurrent disease who have failed cytotoxic chemotherapy. New targeted therapies are emerging for patients with bronchioloalveolar carcinoma histology.

Differential diagnosis of ground-glass opacity nodules: CT number analysis by three-dimensional computerized quantification

OBJECTIVES

To differentiate among atypical adenomatous hyperplasia (AAH), bronchioloalveolar carcinoma (BAC), and adenocarcinoma showing ground-glass opacity (GGO) on CT scans, we conducted a study to determine the optimal parameter on CT number analysis using three-dimensional (3D) computerized quantification.

METHODS

From the CT numbers of GGO lesions obtained by 3D computerized quantification, CT number histogram pattern, peak CT number on the histogram, mean CT number, and the 5th to 95th percentile CT numbers were analyzed to determine the optimal parameter for differentiation among AAH (n = 10), BAC (n = 21), and adenocarcinoma (n = 12).

RESULTS

While the CT number histogram showed one peak in all 10 of the AAH lesions (100%), it showed two peaks in 8 of 21 BAC lesions (38%), and in 5 of 12 adenocarcinoma lesions (42%). For differentiation between AAH and BAC, the 75th percentile CT number with a cutoff value of -584 Hounsfield units (HU) was optimal, with a sensitivity of 0.90 and a specificity of 0.81. For differentiation between BAC and adenocarcinoma, a mean CT number with a cutoff value of -472 HU was optimal, with a sensitivity of 0.75 and a specificity of 0.81.

CONCLUSIONS

From the analysis of CT numbers of GGO lesions obtained by 3D computerized quantification, we conclude the following: (1) two peaks on the CT number histogram can rule out AAH; (2) the 75th percentile is the optimal CT number for differentiating between AAH and BAC; and (3) the mean CT number is the optimal CT number for differentiating between BAC and adenocarcinoma.

Controversy about Small Peripheral Lung Adenocarcinomas: How Should We Manage Them?

In recent years, the clinical use of high-resolution computed tomography has greatly advanced the diagnosis of small lesions of the peripheral lung. Such small lesions are often associated with ground-glass opacity in computed tomography findings. The noninvasive bronchioloalveolar carcinoma component with a replacement growth pattern of alveolar lining cells manifests as ground-glass opacity. Bronchioloalveolar carcinoma is classified as a subset of lung adenocarcinoma, but has a distinct clinical presentation, tumor biology, and favorable prognosis. Most small peripheral lung lesions including bronchioloalveolar carcinoma putatively originate from the peripheral airway epithelium, in which the epidermal growth factor receptor gene is frequently mutated. As with other subsets of non-small cell lung cancer, surgical resection is a potentially curative treatment. For the ground-glass opacity type of tiny lesions, particularly those less than 1 cm in their greatest dimension, the question has been raised whether lobectomy is really needed. Although several authors in Japan suggest the suitability of limited resection including segmentectomy and wedge resection without any nodal dissections for these small lung adenocarcinomas, this procedure should be validated in future clinical trials.

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.

Clinical characteristics and survival of patients with surgically resected, incidentally detected lung cancer

BACKGROUND

There is little information on the clinical characteristics and outcomes of patients with surgically resected, incidentally detected lung cancers. Our hypothesis was that among patients with surgically resected non-small cell lung cancer (NSCLC), incidentally detected cancers were common, were less likely to require pneumonectomy, and were associated with better stage-adjusted survival.

METHODS

Two hundred seventy-four patients with NSCLC who underwent surgical resection between 1999 and 2004 were studied. The clinical characteristics of patients with incidentally detected and symptomatic NSCLC were compared. A proportional hazards model was used to compare the stage-adjusted mortality rate of patients with incidentally detected and symptomatic NSCLC.

RESULTS

One hundred patients (36%) had incidentally detected NSCLC. Patients with incidentally detected NSCLC had smaller and earlier-stage cancers, were less likely to undergo pneumonectomy (3% versus 13%, p = 0.005), and were more likely to have bronchioloalveolar carcinoma (15% versus 5%, p = 0.003). Patients with incidentally detected cancers had a stage-adjusted hazards ratio (HR) of mortality of 0.9 compared with symptomatic patients (0.6-1.4, p = 0.64). Patients with cancers detected incidentally on computed tomography (CT) had a stage-adjusted HR of 0.5 (0.2-1.5, p = 0.15).

CONCLUSIONS

Early-stage NSCLC is commonly detected incidentally. Patients with incidentally detected lung cancers are more likely to have bronchioloalveolar carcinoma histology, less likely to undergo pneumonectomy, and overall have similar stage-adjusted survival compared with symptomatic patients. Patients with cancers detected incidentally by CT scan may have better stage-adjusted survival, but our study was not sufficiently powered to detect this effect.

Impalpable pulmonary nodules with ground-glass opacity: Success for making pathologic sections with preoperative marking by lipiodol

BACKGROUND

The developments in high-resolution CT scanning have increased the chance of detecting small bronchioloalveolar carcinoma (BAC) or atypical adenomatous hyperplasia (AAH) that appears as a ground-glass opacity (GGO). However, these lesions are not only difficult to localize during surgery, but they are also hard to make pathologic sections of because they are usually impalpable. Here, we report a method of making pathologic sections for impalpable GGO lesions.

METHODS

Twenty-nine impalpable GGO lesions < 1 cm in size were marked by 0.4 to 0.5 mL of lipiodol under CT scan before surgery. The lesions were resected under C-arm fluoroscopy. The radiopaque areas marked by lipiodol within the formalin-fixed specimens were cut serially under conventional fluoroscopy for pathologic examinations.

RESULTS

The mean (+/- SD) size of the lesions was 0.5 +/- 0.2 cm (range, 0.2 to 1 cm), and the mean depth from the pleural surface was 1.6 +/- 1.4 cm (range, 0.2 to 6 cm). The mean number of sections submitted for pathologic examinations was 2.3 +/- 1.7 per lesion (range, 1 to 7 per lesion). While 11 of the 29 lesions (38%) were invisible even on the cut surface of the specimens, all were demonstrated in hematoxylin-eosin sections. The pathologic diagnosis was BAC in 17 lesions, AAH in 10 lesions, and organized pneumonia in 2 lesions. The use of lipiodol did not affect the pathologic findings.

CONCLUSIONS

The use of fluoroscopy to cut sections from resected specimens after preoperative marking with lipiodol was useful for making pathologic sections of impalpable GGOs < 1 cm in size.

Clinical impact of concomitant surgical diagnosis and subsequent lobectomy for preoperatively undiagnosed lung cancer

OBJECTIVES

We conducted a retrospective study of the clinical impact of a concomitant diagnostic and therapeutic procedure for patients with histologically unproven pulmonary nodules.

METHODS

Between January 2001 and December 2003, we performed 150 consecutive surgical biopsy procedures for histologically indeterminate pulmonary nodules. We compared the clinical impact of the concomitant diagnostic wedge resection followed by lobectomy (U group, n=50) with that of a scheduled standard lobectomy in those with preoperatively proven clinical stage I lung cancer during the same period (C group, n=60).

RESULTS

There were no significant differences in dichotomous variables, whereas we found significant differences in tumor size, operative time and blood loss between the 2 groups. Complication developed in 9 in the U group and 3 in the C group (p=0.030). Hospital mortality was 2% in the U group and 0% in the C group (p=0.11).

CONCLUSION

Morbidity and mortality following a concomitant diagnostic and therapeutic procedure in patients with preoperatively undiagnosed lung cancer was acceptable, however, staged operations should be indicated for patients with considerable co-morbidity.

Bronchioloalveolar carcinoma: a review

Bronchioloalveolar carcinoma (BAC) is classified as a subset of lung adenocarcinoma but has a distinct clinical presentation, tumor biology, response to therapy, and prognosis compared with other subtypes of non-small-cell lung carcinoma (NSCLC). Bronchioloalveolar carcinoma disproportionately affects women, never-smokers, and Asians and is characterized by growth along alveolar septae without evidence of stromal, vascular, or pleural invasion. Although pure BAC accounts for approximately 4% of lung cancers, tumors with histologically mixed BAC and adenocarcinoma account for > 20% of all NSCLCs, and the incidence of BAC might be increasing. Bronchioloalveolar carcinoma histology is most commonly found in small lesions identified incidentally on chest radiographs or computed tomography scans and might represent a precursor lesion to invasive adenocarcinoma. As with other subsets of NSCLC, surgical resection is the only potentially curative treatment. Patients with unresectable BAC are more likely to respond to the epidermal growth factor receptor tyrosine kinase inhibitors gefitinib and erlotinib than patients with other subtypes of NSCLC. Stage for stage, patients with BAC have a higher rate of long-term survival but might have an increased rate of intrathoracic recurrence than patients with other subtypes of NSCLC.

Prognosis and morphometrical features of non-bronchioloalveolar cell adenocarcinoma: an assessment of the non-alveolar replacing area and high grade atypical area

AIM

It has become obvious that the prognosis of bronchioloalveolar cell carcinoma (BAC) in small peripheral adenocarcinoma of the lung is good, but most cases actually treated as pulmonary adenocarcinoma in hospitals tend to be non-bronchioloalveolar cell carcinoma (non-BAC). The prognoses of non-BAC are greatly varied. We studied the relationships between the morphometrical features and the prognoses of non-BAC.

METHODS

In total, 69 cases of non-BAC measuring <or=20 mm in diameter across their greatest dimension were evaluated. We considered that the non-alveolar replacing area and the high grade atypical area were related to the prognosis, and therefore defined the ratio of both areas to the total area at the maximum face of the tumours as the non-alveolar replacing area ratio (NAAR) and the high grade atypical area ratio (HAAR), respectively. We thereafter analysed the relationships between both ratios and the prognosis.

RESULTS

The NAAR and HAAR were significantly higher in the recurrent cases than in the recurrence free cases. We divided the non-BAC cases at the centre of both ratios into two groups, high and low. The 5 year survival rate of the high NAAR and high HAAR group was 48.3%, while that of the low NAAR and low HAAR group was 72.2%. The groups showing high rates for both ratios had significantly worse prognoses. A multivariate analysis indicated that the HAAR contributes most to the prognosis.

CONCLUSIONS

These results suggest that the NAAR and HAAR are closely associated with the prognosis of non-BAC.