The role of pulmonary metastasectomy for non-primary lung cancer: Umbrella review of meta-analysis.

Abstract

8639 Background: Lungs are the most common metastatic area for many cancers. Due to heterogeneous characteristics of primary cancers, the benefit of pulmonary metastasectomy (PM) has not been investigated other than colorectal cancers. Furthermore, well-designed trials in this field are difficult to undertake due to diverse clinical scenarios and therapy related to primary cancers. This study aims to investigate the clinical outcomes of PM for non-primary lung cancer by synthesizing existing literature. Methods: A systematic search for meta-analyses on PM for non-primary lung cancers was conducted, encompassing publications up to January 3, 2024. The analysis included eight primary cancer types: colorectal, renal cell, breast, adrenocortical, head and neck cancers, melanoma, and sarcoma. Primary outcomes, overall survival, and recurrence rates post-PM were assessed using random-effect models to account for study heterogeneity. Subgroup analysis categorized the survival rates based on primary cancer types, and a proportion meta-analysis was performed for comparison. Results: This study included 44 systematic-review articles and 157 individual studies, involving 23,694 patients who underwent PM for non-primary lung cancer. Patients had a mean age of 48.0 [95% CI 43.9-52.0] years, with 68.4% [95% CI 65.0-71.7] being male. About half of patients (47.1% [95% CI 40.8-53.5] had multiple metastatic lesions and 26.6% had bilateral involvement of lung. Sublobar resection was mostly performed (82%), and complete R0 resection was achieved in 87.2% [95% CI 83.0-90.8]. The pooled 5-year overall survival rate after PM was 41.2% [95% CI, 37.1-45.4%], with specific rates for each primary cancer type listed (Table). Patients with germ cell tumor demonstrated significantly higher survival rate than other cancers (p<0.05), while patients with melanoma had worst outcome (p<0.05). During follow-up, 57.6% [95% CI 46.4-68.1] had recurrence: 48% of them had intrathoracic only recurrence and 52% had extra-thoracic recurrence. Conclusions: The findings affirm that PM yields survival benefit. Overall survival rates following PM do not significantly differ based on primary cancer types, except for germ cell tumors and melanoma. Additionally, the recurrence rates are comparable to that of stage 4 advanced cancers other than germ cell tumor and is not significantly influenced by the primary cancer type. This highlights the importance of recognizing and incorporating PM in clinical practice when appropriate. [Table: see text]