Should we distinguish between intra and extrapericardial pulmonary artery involvement in NSCLC? A multicenter retrospective case-control study

Background: T4 tumours comprise a heterogeneous group of locally invasive non-small cell lung cancers (NSCLC). Intrapericardial and extrapericardial involvement of the pulmonary artery (PA) may have a different prognosis. We compared the short and long-term surgery outcomes for NSCLC of the PA with intrapericardial or extrapericardial involvement. Methods: This is a multicenter retrospective study that included 129 patients who received an anatomical resection with PA resection and reconstruction in our centres between January 2000 and December 2018. Extrapericardial group included 70 patients, while the intrapericardial included 59. Results: Differences in outcomes were found in terms of left side surgery (more common in extrapericardial, p = 0.010), type of lung resection (p < 0.001), Clavien-Dindo score (p = 0.012) and 90-day mortality (1.4 vs 16.9%, p = 0.002). Overall survival (OS, 91.11 ± 63.78 vs 63.78 ± 58.241 months, p = 0.008) and tumour-free survival (TFS, 68.17 ± 71.57 vs 45.44 ± 61.32 months, p = 0.007) were statistically different. OS stratification for performed pneumonectomy, pathological lymph node status and pattern of recurrence were statistically different (p = 0.017, 0.040, <0.001). Differences were found in terms of recurrence months stratified for recurrence pattern (p < 0.001). Conclusions: According to our results, the difference between PA involvement is significant in terms of survival and complications. A T4 subset or a shift to T3 for extrapericardial involvement of the PA may lead to a change in staging and surgical approach for these patients.