Redefining Bronchioloalveolar Carcinoma

Lung cancer in never smokers

Lung cancer in never smokers (LCINS) has lately been recognized as a unique disease based on rapidly gained knowledge from genomic changes to treatment responses. The focus of this article is on current knowledge and challenges with regard to LCINS expanded from recent reviews highlighting five areas: (1) distribution of LCINS by temporal trends, geographic regions, and populations; (2) three well-recognized environmental risk factors; (3) other plausible environmental risk factors; (4) prior chronic lung diseases and infectious diseases as risk factors; and (5) lifestyles as risk or protective factors. This article will also bring attention to recently published literature in two pioneering areas: (1) histological characteristics, clinical features with emerging new effective therapies, and social and psychological stigma; and (2) searching for susceptibility genes using integrated genomic approaches.

Sclerosing variant of the bronchioloalveolar carcinoma: imaging findings in an atypical case

Bronchioloalveolar carcinoma remains one of the most enigmatic lung cancers, demonstrating varied growth patterns, mixed histological features, and confusing clinical manifestations. This paper reports a case of an unusual form of presentation: a sclerosing type associated with desmoplastic reaction and cicatrization. A 75-year-old woman was admitted with persistent dry cough and progressive dyspnea. Physical examination showed bilateral inspiratory crackles. A chest radiograph and high-resolution computed tomography demonstrated confluent airspace nodules, forming areas of consolidation in both lungs, with signs of architectural distortion. The lung biopsy revealed a nonmucinous sclerosing bronchioloalveolar carcinoma.

Clinical usefulness of the fluorodeoxyglucose (FDG)-PET maximal standardized uptake value (SUV) in combination with CT features for the differentiation of adenocarcinoma with a bronchioloalveolar carcinoma from other subtypes of non-small cell lung cancers

PURPOSE

To evaluate the clinical usefulness of fluorodeoxyglucose (FDG)-PET maximal SUV in combination with CT features for differentiation of adenocarcinoma with bronchioloalveolar carcinoma (BAC) from other subtypes of non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

This retrospective study included 125 patients (104 men and 21 women; mean age, 64 years) who underwent CT and subsequent FDG-PET examinations for preoperative evaluation and underwent curative intent operation with the final diagnoses of NSCLC made by surgical histopathology. We categorized NSCLC into adenocarcinoma with BAC feature and other subtypes. Finally, there were 16 cases of adenocarcinoma with BAC and 109 cases of other NSCLC subtypes included in the study. Several CT features of lung cancer were analyzed, including tumor size, presence of spiculation, margin (irregular or smooth), pattern of the mass (pure solid, pure ground glass opacity and mixed), associated pleural effusion and location (center, mid and periphery). Maximal SUV and visual scores of FDG uptakes of primary NSCLC were evaluated. The diagnostic performances of CT alone, PET alone, and combination of two modalities to predict adenocarcinoma with BAC from other subtypes of NSCLC were calculated.

RESULTS

A nodule with a mixed pattern with partly solid and ground glass opacity was significantly more frequent CT feature of an adenocarcinoma with BAC (8/16, 50%) as compared with the other subtypes (2/109, 1.8%) (p<0.0001). Maximal SUV of adenocarcinoma with BAC (mean=7.2) was significantly lower than that of other subtypes of NSCLC (mean=13.33) (p<0.0001). Sensitivity, specificity, PPV, and NPV of CT for differentiating adenocarcinoma with BAC from other subtypes was 50% (8/16), 98.2% (107/109), 80% (8/10), and 93% (107/115), respectively. Sensitivity, specificity, PPV, and NPV of FDG-PET was 68.8% (11/16), 86.2% (94/109), 42.3% (11/26), and 94.9% (94/99), respectively. Sensitivity, specificity, PPV, and NPV of combination of two modalities was 81.3% (13/16), 85.3% (93/109), 44.8% (13/29), 96.9% (93/96), respectively.

CONCLUSION

Careful combined assessment of the FDG-PET maximal SUV and CT findings have the potential to differentiate an adenocarcinoma with BAC from other NSCLC subtypes, such as a pure BAC. These findings might be useful for imaging interpretations and will help initial planning of NSCLC management.

Voltage-gated sodium channels potentiate the invasive capacities of human non-small-cell lung cancer cell lines

Ionic channel activity is involved in fundamental cellular behaviour and participates in cancerous features such as proliferation, migration and invasion which in turn contribute to the metastatic process. In this study, we investigated the expression and role of voltage-gated sodium channels in non-small-cell lung cancer cell lines. Functional voltage-gated sodium channels expression was investigated in normal and non-small-cell lung cancer cell lines. The measurement, in patch-clamp conditions, of tetrodotoxin-inhibitable sodium currents indicated that the strongly metastatic cancerous cell lines H23, H460 and Calu-1 possess functional sodium channels while normal and weakly metastatic cell lines do not. While all the cell lines expressed mRNA for numerous sodium channel isoforms, only H23, H460 and Calu-1 cells had a 250 kDa protein corresponding to the functional channel. The other cell lines also had another protein of 230 kDa which is not addressed to the membrane and might act as a dominant negative isoform to prevent channel activation. At the membrane potential of these cells, channels are partially open. This leads to a continuous entry of sodium, disrupting sodium homeostasis and down-stream signaling pathways. Inhibition of the channels by tetrodotoxin was responsible for a 40-50% reduction of in vitro invasion. These experiments suggest that the functional expression of voltage-gated sodium channels might be an integral component of the metastatic process in non-small-cell lung cancer cells probably through its involvement in the regulation of intracellular sodium homeostasis. These channels could serve both as novel markers of the metastatic phenotype and as potential new therapeutic targets.

Loss of Nkx2.8 deregulates progenitor cells in the large airways and leads to dysplasia

Nkx2.8, a homeodomain transcription factor, has been characterized in liver cancer and in the developing central nervous system. We now show that this factor is also expressed in the lung, where it localizes in adults to a discrete population of tracheobronchial basal cells. To target the mouse gene, the first exon was replaced by a LacZ marker gene joined to the intact 5'-untranslated region. Marker expression was observed throughout the lower respiratory tract, beginning on E11 in a few cells of the distal lung buds. The region of expression then spread upward. By neonatal day 1, expression was greatest in the large airways and the Nkx2.8-/- mice exhibited generalized tracheobronchial hyperplasia. Bromodeoxyuridine (BrdUrd) labeling studies showed that a higher rate of bronchial cell proliferation persisted at 6 to 8 months. In adults, Nkx2.8 marker expression decreased with progressive differentiation into ciliated and secretory cells. The cell localizations and patterns of coexpression with BrdUrd and differentiation markers suggest a progenitor relationship: the cells that most strongly express Nkx2.8 seem to function as tracheobronchial stem cells. Moreover, Nkx2.8 acts to limit the number of these progenitor cells because the marker-expressing population was greatly expanded in Nkx2.8-/- mice. Increased proliferation and an altered progenitor relationship caused progressive bronchial pathology, which manifested as widespread dysplasia in the large airways of 1-year-old Nkx2.8-/- mice.

Worldwide trends in lung cancer pathology

Molecular profiling studies serve to remind us that lung cancer is a complex disease, with different phenotypes that are characterized by variation in morphology as well as molecular composition. Over recent decades, there appear to be worldwide shifts in the relative frequencies of various phenotypic patterns of lung cancer, which are even more striking than changes in the overall incidence of lung cancer. This review summarizes major worldwide trends in lung cancer pathology, which can be explained in part, but not entirely, by changes in cigarette design. Characterizing these trends will be important for recognizing contributions of carcinogens other than tobacco smoke to the worldwide problem of lung cancer.

Synchronous multiple primary lung cancers with different response to gefitinib

Synchronous bronchiolo-alveolar cell carcinoma (BAC) in both lungs and squamous cell carcinoma in left lung were found in a 66-year-old male smoker. After two courses of chemotherapy with gemcitabine and carboplatin, the left lung mass had partially resolved, however, the extent of BAC had been increased. When gefitinib was used as a second-line chemotherapy, the consolidation lesions of BAC was improved while the mass of squamous cell carcinoma was aggravated. The analysis of epidermal growth factor receptor-tyrosine kinase (EGFR-TK) mutations showed that BAC had the deletion, delE746-A750 in exon 19, however, squamous cell carcinoma had no mutations. These synchronous tumors with different location, histology, status of EGFR-TK mutations and response to chemotherapy might be caused by different molecular pathogenesis.

Response to bortezomib (velcade) in a case of advanced bronchiolo-alveolar carcinoma (BAC)

A 65-year-old male with 40-pack year smoking history presented with exertional dyspnea and was subsequently diagnosed with bronchiolo-alveolar carcinoma (BAC). He did not respond to first line therapy with geftinib, but he achieved disease stabilization with gemcitabine and carboplatin for 4 months before developing symptomatic worsening requiring oxygen supplementation. He responded dramatically to bortezomib with rapid symptom improvement. The follow-up computerized tomography revealed partial response that was maintained for 11 months. Based on observations like this and those seen in phase I studies with bortezomib, this agent is being studied now in patients with bronchio-alevolar cancer.