Bronchioloalveolar Carcinoma in Small Pulmonary Nodules: Clinical Relevance

The Regimen of Computed Tomography Screening for Lung Cancer: Lessons Learned Over 25 Years From the International Early Lung Cancer Action Program

We learned many unanticipated and valuable lessons since we started planning our study of low-dose computed tomography (CT) screening for lung cancer in 1991. The publication of the baseline results of the Early Lung Cancer Action Project (ELCAP) in Lancet 1999 showed that CT screening could identify a high proportion of early, curable lung cancers. This stimulated large national screening studies to be quickly started. The ELCAP design, which provided evidence about screening in the context of a clinical program, was able to rapidly expand to a 12-institution study in New York State (NY-ELCAP) and to many international institutions (International-ELCAP), ultimately working with 82 institutions, all using the common I-ELCAP protocol. This expansion was possible because the investigators had developed the ELCAP Management System for screening, capturing data and CT images, and providing for quality assurance. This advanced registry and its rapid accumulation of data and images allowed continual assessment and updating of the regimen of screening as advances in knowledge and new technology emerged. For example, in the initial ELCAP study, introduction of helical CT scanners had allowed imaging of the entire lungs in a single breath, but the images were obtained in 10 mm increments resulting in about 30 images per person. Today, images are obtained in submillimeter slice thickness, resulting in around 700 images per person, which are viewed on high-resolution monitors. The regimen provides the imaging acquisition parameters, imaging interpretation, definition of positive result, and the recommendations for further workup, which now include identification of emphysema and coronary artery calcifications. Continual updating is critical to maximize the benefit of screening and to minimize potential harms. Insights were gained about the natural history of lung cancers, identification and management of nodule subtypes, increased understanding of nodule imaging and pathologic features, and measurement variability inherent in CT scanners. The registry also provides the foundation for assessment of new statistical techniques, including artificial intelligence, and integration of effective genomic and blood-based biomarkers, as they are developed.

Clinicopathologic features of resected subcentimeter lung cancer

BACKGROUND

Subcentimeter lung cancers are still rare, and their pathobiologic behavior and management have not yet been fully clarified.

METHODS

From 1993 through 2011, 291 patients with resected lung cancers 1.0 cm or less in diameter were studied regarding their clinicopathologic characteristics. According to appearance on high-resolution computed tomography (HRCT), the tumors were classified into four types: type 1 (n = 50), nonsolid ground-glass opacity (GGO) lesion; type 2 (n = 89), part-solid GGO lesion including 50% or more GGO within the lesion; type 3 (n = 62), part-solid GGO lesion including less than 50% GGO within the lesion, and type 4 (n = 90), solid lesion.

RESULTS

Although none of types 1 to 3 tumors had lymph node metastases, these were found in 10% of type 4 tumors. Recurrence was observed in 13 patients, almost all of whom had type 4 tumors. The lone exception was a patient with a type 3 tumor in whom local recurrence developed on a surgical staple line. The 5-year overall survival rates were 100% in type 1 and type 2, 98% in type 3, and 88% in type 4. Type 4 had a significantly worse prognosis than the other types.

CONCLUSIONS

Subcentimeter lung cancers with a GGO component on HRCT (types 1 to 3) can be considered "early" lung cancers. In these cases, limited resection may be warranted to achieve a cure because they had no lymph node metastasis. By contrast, lobectomy should still be considered the standard operation of choice for type 4 tumors.

Surveillance of the Remaining Nodules after Resection of the Dominant Lung Adenocarcinoma is an Appropriate Follow-Up Strategy

INTRODUCTION

Adenocarcinomas, commonly present as a dominant lesion (DL) with additional nodules in the ipsilateral or contralateral lung. We sought to determine the fate and management of the secondary nodules and to assess the risk of these nodules using the Lung CT Screening Reporting and Data System (Lung-RADS) criteria and the National Comprehensive Cancer Network (NCCN) Guidelines to determine if surveillance is an appropriate strategy.

METHODS

We retrospectively evaluated patients with lepidic growth pattern adenocarcinoma and secondary nodules from 2000 to 2013. Risk assessment of the additional lesions was completed with a simplified model of Lung-RADS and NCCN-Guidelines.

RESULTS

Eighty-seven patients underwent resection of 87 DLs (Group 1) concurrently with 60 additional pulmonary nodules (Group 2), while 157 non-DLs were radiologically surveyed over a median follow-up time of 3.2 years (Group 3). Malignancy was found in 29/60 (48%) nodules in Group 2. Whereas, only 9/157 (6%) of the lesions in Group 3 enlarged, 4 of which (2.5% of total) were found to be malignant, and then treated, while the remaining nodules continued surveillance. After applying the Lung-RADS and NCCN simplified models, nodules in Group 2 were at higher risk for lung cancer than those in Group 3.

CONCLUSION

In patients with lepidic growth pattern adenocarcinoma associated with multiple secondary nodules, surveillance of the remaining nodules, after resection of the DL, is a reasonable strategy since these nodules exhibited a slow rate of growth and minimal malignancy. In contrast, nodules resected from the ipsilateral lung at the time of the DL, harbor malignancy in 48%. Risk assessment models may provide a useful and standardized tool for clinical assessment of pulmonary nodules.

Localized mucinous bronchioloalveolar carcinoma of the lung: thin-section computed tomography and fluorodeoxyglucose positron emission tomography findings

PURPOSE

The aim of this study was to evaluate thinsection computed tomography (CT) and fluorodeoxyglucose positron emission tomography (FDG-PET) findings of localized pulmonary mucinous bronchioloalveolar carcinomas (BACs).

METHODS AND MATERIALS

From February 2000 to February 2009, there were seven patients with pulmonary localized mucinous BACs that were pathologically confirmed in the surgical specimens. Their CT findings were assessed regarding location, extent (percent) of groundglass opacity (GGO), margin characteristics, and the presence of air-containing spaces and contractive changes. We evaluated the presence of the "angiogram sign" in the patients who underwent enhanced CT. The maximum standardized uptake value (SUVmax) on FDG-PET was measured in four cases.

RESULTS

All tumors were located in the lower lobes. The percentages of GGOs ranged from 0% to 70% (average 20%). The tumor margins were well defined in five cases and ill-defined in two cases. Air-containing spaces were seen in all cases. Evidence of contractive change was seen in two of the seven cases. The angiogram sign was identified in one of five patients who underwent enhanced CT. The SUVmax on FDG-PET ranged from 0.93 to 1.97 (mean 1.53).

CONCLUSION

The imaging features of localized mucinous BACs include solid or partly solid attenuation, the presence of air-containing spaces, lack of contractive changes, and lower lobe predominance. Additionally, the SUVmax is markedly low on FDG-PET.

Early Detection of Lung Cancer

The overall 5-year survival of lung cancer is only 10% in Europe and 15% in the United States, and progress in curative treatments during the last 20 years has been modest. Late diagnosis of extensive disease is the main reason of failure. Early detection with low-dose spiral computed tomography (CT) is one of the most promising development of clinical research, and continuous improvements in technology can make this instrument more effective than mammography in breast cancer detection. In order to prove the benefit of early detection by reduction of lung cancer mortality, we need to enroll large numbers of high-risk individuals in multicentric prospective randomized trials combining primary prevention by smoking cessation with diagnostic intervention with low-dose spiral CT, optimal management of cancer and minimum damage for healthy individuals. Molecular biology research within early detection trials, combining genomic and proteomic analysis of blood and sputum, may improve the differential diagnosis, define the individual risk of cancer incidence and failure, and help target therapies on the basis of biologic profile.