Allelic losses on chromosome 3p are accumulated in relation to morphological changes of lung adenocarcinoma

Pathologists' staging of multiple foci of lung cancer: poor concordance in absence of dramatic histologic or molecular differences

OBJECTIVES

A long-standing problem in lung cancer pathology has been to determine whether two anatomically distinct foci of lung carcinoma are independent primaries or intrapulmonary metastases. While several proposals exist with respect to this problem, it is not known how pathologists use these proposals in actual practice.

METHODS

We performed a voluntary survey of the Pulmonary Pathology Society, a self-selected group of pathologists with a specialty interest in pulmonary pathology, to determine their opinion on staging various specific scenarios of multiple foci of lung cancer.

RESULTS

We found that there was a great deal of disagreement and uncertainty in the approach to these scenarios unless there were also unambiguous molecular markers or a dramatic difference in histology.

CONCLUSIONS

Pathologists have a high degree of uncertainty and disagreement on staging multiple lung carcinomas. An improved pathologic method is required to distinguish separate primary tumors from intrapulmonary metastases. Until that is available, improved nomenclature is needed to convey the intrinsic uncertainty of the situation.

Approach to the ground-glass nodule

The detection of ground-glass opacity (GGO) is increasingly common. Sufficient data have been accumulated to formulate recommendations for observation, intervention, and treatment modalities. However, an understanding of many nuances and uncertainties in the available data is needed to avoid making management errors. This article discusses the range of possible entities, risk factors and characteristics that help make a presumptive clinical diagnosis, how often and for how long these should be followed when and how a biopsy should be done, how these lesions should be treated, and how multifocal GGOs should be approached.

Molecular profiling of lung carcinoma: identifying clinically useful tumor markers for diagnosis and prognosis

The overall survival of patients with lung cancer is dismal despite extensive effort in improvement of diagnosis and treatment. A better understanding of the multistep genetic and epigenetic alterations in lung cancer pathogenesis and progression is necessary for development of improved diagnostic approaches and new targeted therapies. Identification of molecular alterations in the early lung carcinogenesis, together with advanced molecular techniques, may facilitate development of rapid and effective methods for early diagnosis and prognosis of lung carcinoma. In this review, we discuss current understanding of lung carcinogenesis and prospective molecular markers in lung cancer diagnosis. Although the impact of translating new technologies into clinical practice on survival has not been completely determined, they offer a new avenue of exciting novel approaches to early diagnosis of this deadly disease.

Clinicopathologic significance of the mutations of the epidermal growth factor receptor gene in patients with non-small cell lung cancer

PURPOSE

It has been reported that the mutations of epidermal growth factor receptor (EGFR) are detected in lung cancers. Studies of EGFR mutations in large numbers of patients' tumors with clinical data including response to EGFR tyrosine kinase directed therapy are needed to develop a robust database for clinical use. The purpose of the present study is to gain further insights into the significance of EGFR mutation in non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

We investigated the clinicopathologic significance of tyrosine kinase domain (exons 18-21) EGFR mutations in 120 patients with primary NSCLC and the correlation between EGFR mutation and sensitivity to gefitinib in an additional 20 NSCLC patients treated with gefitinib. In addition, onocogenic KRAS mutations and RASSF1A promoter methylation were determined in the same samples.

RESULTS

EGFR mutation was detected in 29 of 120 (24%) tumors. All of the 29 (40%) mutations occurred in 72 adenocarcinomas. EGFR mutation was significantly more frequent in females (47%) than males (12%, P < 0.0001), in younger patients (38%) than older patients (10%, P = 0.0005), in nonsmokers (47%) than smokers (13%, P < 0.0001), and in well-differentiated tumors (39%) than moderately and poorly differentiated tumors (7%, P < 0.0001). Mutation of the EGFR gene was preferentially observed in advanced disease. Furthermore, EGFR mutations were detected in 11 of 14 (79%) responders, whereas none of six (0%) nonresponders had the mutation (P = 0.0022).

CONCLUSIONS

These results in Japanese (East Asian) patients indicated that EGFR mutation plays an important role in pathogenesis of lung adenocarcinoma.

Papillary adenocarcinoma of the lung is a more advanced adenocarcinoma than bronchioloalveolar carcinoma that is composed of two distinct histological subtypes

To clarify the clinicopathological nature of papillary adenocarcinoma (PA) of the lung, 20 cases of PA were collected consecutively from resected adenocarcinoma of the lung, studied immunohistochemically and, using molecular techniques, compared with bronchioloalveolar carcinoma (BAC). Clinicopathologically, PA occurred in 7.4% and dominantly in female patients. Morphologically, PA was divided into two subtypes according to the presence of residual alveolar structures, detected by elastica van Gieson stain. One of these subtypes was closely related to the morphology of BAC and might be diagnosed as adenocarcinoma with mixed subtypes. The other PA subtype was composed of tall columnar cells and grew compressively, which was similar to type F adenocarcinoma previously reported by Noguchi et al. Immunohistochemical studies using lung tissue-specific antigens, progression markers and tumor suppressor products found that PA seemed a more advanced adenocarcinoma than BAC, but no differences were observed among PA subtypes. Molecular biological analysis using three microsatellite markers at chromosome 3p revealed more frequent loss of heterozygosity in PA than BAC, with no differences among PA subtypes. These findings suggest that PA is a more advanced adenocarcinoma subtype than BAC. Further investigations are needed to clarify true PA as clinicopathologically and biologically independent from other histological subtypes of adenocarcinoma of the lung.

Genetic and epigenetic inactivation ofLTFgene at 3p21.3 in lung cancers

Allelic loss on the short arm of chromosome 3 is one of the most common events in the pathogenesis of lung cancer. The lactotransferrin gene (LTF, also referred to as the lactoferrin gene, LF) is located at 3p21.3 common eliminated region 1, which is frequently deleted in lung and other cancers. The expression of the LTF gene was absent in 16 (59%) of 27 small cell lung cancer cell lines, 33 (77%) of 43 nonsmall-cell lung cancer (NSCLC) cell lines and 7 (54%) of 13 primary NSCLC, while LTF mRNA was overexpressed in 3 (7%) of 43 NSCLC cell lines. Its expression was restored by treatment with 5-aza-2'-deoxycytidine (5-aza-dC), trichostatin A (TSA) or a combination of both in a subset of lung cancer cell lines without LTF expression. In addition, we found 8 different types of nucleotide substitutions and one frameshift mutation. These results indicate that the LTF gene is inactivated by genetic and epigenetic mechanisms in lung cancer.