Accurate characterization of malignant cells obtained via thoracocentesis is of paramount importance in the management of cancer patients. The identification of novel biomarkers may in that regard considerably improve the diagnostic approach of these pleural effusions, guide therapeutic decisions, particularly with respect to targeted therapies, and offer helpful prognostic information. Nuclear anomalies represent the cornerstone of the cytologic and/or histopathologic diagnosis of malignant cells. The nuclear matrix is a fundamental constituent of the nuclear architecture via its interaction with the nuclear membrane, but is also directly involved with DNA and RNA processing. Prior studies have suggested that in some cancers, the lamins, a major constituent of the nuclear matrix, have different patterns of expression or nuclear localization that could potentially have prognostic implications. Our project aims at studying the constituents of the nuclear matrix of malignant cells isolated for pleural fluid in patients with metastatic disease, both of bronchogenic or non-bronchogenic origin, which, to our knowledge, has not yet been done. Both proteomic (localization by immunofluorescence and expression by Western-Blot) and genomic (microarray, CGH type) analyses will be undertaken to identify microrearrangements in the genes of interest. The primary aim is to identify specific biomarkers to more accurately characterize malignant cells in metastatic pleural disease.

Inclusion Criteria:

• sign consent approval
• patients with metastatic disease, both of bronchogenic or non-bronchogenic origin
• 50% or more of malignant cells

Exclusion Criteria:

• patients with tumoral treatment during thoracocentesis
• 50% or less of malignant cells

patients with metastatic disease