P3.14.06 Attitude of Italian Physicians Towards Germline and Somatic Genetic Testing in Pleural Mesothelioma: Preliminary Results of a Nationwide Survey

Introduction Up to 10% of patients (PTS) with pleural mesothelioma (PM) harbor a pathogenic germline mutation in cancer predisposing genes, a condition generally associated with better overall survival at diagnosis. Conversely, less than 1% of PTS with PM present potentially actionable somatic mutations. The 2025 ASCO guidelines on PM recommend germline genetic testing for all PM PTS, while discouraging routine somatic testing. This survey aims to assess the attitude and current clinical practice of Italian physicians treating PM regarding genetic testing. Methods From March 1st, 2025 to March 31th, 2025, a nationwide survey was distributed to an expert network of Italian physicians treating PM (MEsothelioma Team Italy- MET-I). The questionnaire investigated clinical practice in genetic testing, barriers to its implementation and educational needs. Results Thirty-seven responders (RS) completed the survey. Most RS were female (23, 62%), aged 30-45 years (24, 65%), medical oncologists (26, 70%), working in academic hospitals (32, 87%) based in the North of Italy (31, 83%), and managing at least 20 PM cases per year (16, 43%).Most RS don’t recommend germline testing (22, 60%) or do it occasionally (12, 34%), and only three (8%) routinely recommend it in PM PTS. The main criteria for requesting germline testing include: a family history (FH) of PM (87%), FH of genetic mutations predisposing to PM (78%) and FH of tumors associated with PM (70%). In most cases, germline testing is available through genetic counselling (23, 62%), witheither monogenic BAP1 testing (11, 30%) or multigenic panelsincluding BAP1 (18, 49%).The main barriers to routine germline testing in PM include: cost (65%), limited access to dedicated genetic counselling (54%), and lack of physician awareness (51%). Proposed solutions involved increasing education on the topic (24, 65%), improving access to genetic counselling (21, 57%), and implementing dedicated institutional policies (54%).Somatic testing is routinely performed by four RS (11%), occasionally performed by 13 RS (35%), and never performed by 20 RS (54%). The main criteria for somatic testing in mesothelioma are the availability of a clinical trials with targeted agents (62%) and a young age (<50 years) at diagnosis (51%). Somatic test results influenced treatment decisions often or never in six RS (16%) and sometimes in nine RS (24%).Finally, 68% of RS were aware of the 2025 ASCO guidelines on PM, and 54% stated they would modify their clinical practice accordingly. Conclusions The survey highlights the underuse of germline testing among Italian physicians managing PM. High costs, limited access to genetic counselling, and lack of physician awareness are the primary barriers to germline testing. Implementing medical education programs on PM genetics, establishing dedicated genetic counselling services, and introducing institutional policies for germline testing could enhance the management of PM PTS in Italy.