Immune- and Microenvironment- Proteogenomics Profiling for Classifying Lung Cancer Patients

The excessive accumulation of fluid between the membranes surrounding the lung, a clinical condition commonly referred to as "pleural effusion", is caused by one of three factors: increased production of pleural fluid, decreased ability to reabsorb pleural fluid or a mixture both.

The basis of pleural effusion accumulation may originate from multiple pathologies: from benign and extrapulmonary conditions to intrinsic pleural pathology (inflammatory or neoplastic primary or metastatic) in which the accumulation of fluid in the pleural space is mainly due to changes in the structure of the pleural membrane (loss of integrity and / or infiltration by neoplastic cells).

An example of extrapulmonary conditions is the pleural effusion observed in patients with congestive heart failure in which there is increase in hydrostatic capillary pressure, due to failure of the cardio circulatory pump.

The distinction between benign and malignant causes is currently a diagnostic challenge that usually requires the collection of material (cells immersed in the pleural fluid or even a histological sample).

The first step of this investigation is currently the cytological evaluation of the pleural fluid, that is, the observation of cells, of an initial sample of the pleural fluid. This procedure is associated with an average sensitivity of 62% while a second sample through thoracentesis improves the sensitivity of the diagnosis by 10%. In certain cases, however, it is not possible to diagnose by analyzing the pleural fluid and, as a rule, a more invasive diagnostic method is recommended, such as pleural biopsy (collected by puncture with a "blind" needle, echo guided or computed tomography guided or obtained by means of direct visualization of the pleural cavity through pleuroscopy).

The diagnostic yield of this approach can reach up to 97% (in the case of pleural biopsy obtained by medical thoracoscopy). However, it implies greater morbidity and greater consumption of resources (material and human). The development of a more sensitive and specific and at the same time less invasive diagnostic method for pleural fluid may contribute to a more effective screening of patients, limiting the use of more invasive methods to only patients with a higher risk of malignant pathology.