At the Laboratory for Molecular and Cellular Therapy (LMCT) of the Vrije Universiteit Brussel, Belgium, we study resistance mechanisms that hamper effective immunotherapy for solid cancer patients. To perform clinically relevant research, we apply autologous human material for functional assessment. The latter requires viable tumor and immune cells.

Solid cancer patients with pleural metastasis often develop pleural effusion. Notably, upon pleural drainage, residual material is obtained that consists of histocompatible tumor and immune cells. Hence with this study, we want to obtain blood and pleural effusion fluid drawn from solid cancer patients with pleural metastases to:

1. Collect, enrich and store primary cells derived from residual pleural effusion fluid and blood at the LMCT (VUB, Belgium)
2. Evaluate characteristics of the cells (phenotype, function,...) and compare content of pleural effusate with blood and clinicopathologic features of the patients.

Malignant pleural effusion (MPE) is characterized by the presence of malignant cells in the pleural cavity and develops in about 15% of patients with malignant disease. Two-thirds of all cases have a pleural effusion as one or sole initial manifestation of malignant disease. Primary tumors that most frequently develop MPE as metastatic disease are lung, breast cancer, and lymphoma accounting for 75% of all cases. Discomforting symptoms of MPE can include chest pain, cough, wheezing, hemoptysis, general discomfort, uneasiness, or ill feeling (malaise), shortness of breath and weight loss. To relief these discomforting symptoms, pleural drainage (evacuation) is routinely performed.

A significant number of solid cancer patients are currently being treated with immunotherapeutic drugs in first or second line or in the framework of a clinical trial. Aside from tumor cell intrinsic mechanisms, we and others previously found that non-malignant tumor infiltrated cells can also install immunotherapy resistance. Hence it remains of utmost importance to study the functional interactions between tumor cells and their non-malignant (solid) micro-environment to increase our current understanding of molecular profiles that predict responsiveness to immunotherapy. By exploiting patient-derived material, we aspire to perform more clinically relevant fundamental and translation research. The primary objective is to collect and compare blood, tumor and MPE-derived cell fractions. The secondary objective is to correlate cellular profiles with clinico-pathologic data.

Inclusion Criteria:

• All solid cancer patients with pleural metastases undergoing pleural drainage with available tumor biopsy (upon informed consent)
• >18 years of age

Exclusion Criteria:

• pregnancy

Healthy volunteers will be included for collection of control blood samples (upon informed consent).

Samples will be pseudonymized and processed via RedCAP