The Role of Primary Tumor Resection in Patients with Pleural Metastasis Encountered at the Time of Surgery.

Background: Evidence is lacking on whether the resection of lung parenchymal cancer improves the survival of patients with unexpected pleural metastasis encountered during surgery. We conducted a single-center retrospective study to determine the role of lung resection in the long-term survival of these patients.

Methods: Among 4683 patients who underwent lung surgery between 1995 and 2014, 132 (2.8%) had pleural metastasis. After excluding 2 patients who had incomplete medical records, 130 patients' data were collected. Only a diagnostic pleural and/or lung biopsy was performed in 90 patients, while the lung parenchymal mass was resected in 40 patients.

Results: The mean follow-up duration was 29.8 months. The 5-year survival rate of the resection group (34.7%±9.4%) was superior to that of the biopsy group (15.9%±4.3%, p=0.016). Multivariate Cox regression analysis demonstrated that primary tumor resection (p=0.041), systemic treatment (p<0.001), lower clinical N stage (p=0.018), and adenocarcinoma histology (p=0.009) were significant predictors of a favorable outcome. Interestingly, primary tumor resection only played a significant prognostic role in patients who received systemic treatment.

Conclusion: When pleural metastasis is unexpectedly encountered during surgical exploration, resection in conjunction with systemic treatment may improve long-term survival, especially in adenocarcinoma patients without lymph node metastasis.