The impact of visceral pleural invasion on survival in non-small cell lung cancer

<bold>Introduction:</bold> In lung cancer (LC), TNM stage determines survival. Visceral pleural invasion (VPI) upgrades T1 to T2 in LC tumors <3 cm, requiring adjuvant chemotherapy. VPI is crucial for staging and treatment decisions. We studied VPI impact on survival and progression in operable tumors ≤3 cm. <bold>Materials and Methods:</bold> NSCLC patients (01/01/2015–31/12/2021) were screened. Tumors ≤3 cm with negative nodal staging were included. VPI degree (PL0, PL1, PL2, PL3) was recorded. Clinicopathological features and survival were analyzed by VPI groups. <bold>Results:</bold> Among 3600 patients, 239 met criteria. Demographics were similar, except for tumor location. PL0 tumors were mostly central, PL2 peripheral (p=0.019). 179 had PL0, 46 PL1, 9 PL2, and 5 PL3. No significant difference in PFS and OS between PL0 and PL1 or PL1 and PL2. However, PL0 and PL3 showed significant OS and PFS differences (112.7 vs 30.2, p=0.03 in OS, 57 vs 22, p=0.001 in PFS). <bold>Discussion:</bold> In tumors ≤3 cm, VPI degree determines T stage, necessitating adjuvant chemotherapy. 9th TNM proposal lacks new VPI recommendations. Studies show no PFS and OS difference between PL0 and PL1. PL3 correlates with worse survival outcomes than PL0