Prognostic impact of pathologically confirmed rib invasion in patients with lung cancer requiring chest wall resection.

Background: Primary lung cancer that invades the chest wall is classified as T3 regardless of the depth of invasion. This study assessed the prognostic impact of pathologically confirmed rib invasion in patients with pT3N0-1 lung cancer requiring chest wall resection. Methods: We retrospectively analyzed the records of patients with non-small cell lung cancer (NSCLC) who underwent combined lung and chest wall resection with rib involvement from 2006 to 2019. The median follow-up period was 64.0 months. Results: In total, 42 patients (41 men, 1 woman) were enrolled. The median patient age was 64 years (range, 42-79 years). The median tumor size before treatment was 56.5 mm (range, 21-80 mm), and an osteolytic sign was identified on computed tomography (CT) in 42.9% (18/42). Among 27 patients who received induction chemoradiotherapy, 5 (18.5%) achieved a complete pathological response. The operations comprised 36 lobectomies, 5 segmentectomies, and 1 wedge resection with resection of 2.5 ribs on average. Pathological examination revealed rib invasion in 18 (42.9%) patients. The 5-year disease-free and overall survival rates with pathological rib invasion were 44.4% and 77.4% (P=0.0114), respectively and those without pathological rib invasion were 44.7% and 81.3% (P=0.0222), respectively. Pathologically confirmed rib invasion was the only factor identified to have a prognostic impact in the univariate and multivariate analyses [hazard ratio (HR), 5.98; 95% confidence interval (CI): 1.37-26.1]. Locoregional recurrence and distant metastases were more common in patients with than without pathologically confirmed rib invasion [4 (22.2%) and 6 (33.3%), respectively, among 18 patients with pathological rib invasion; 2 (8.3%) and 3 (12.5%), respectively, among 24 patients without pathological rib invasion] (P=0.0073). Conclusions: Pathologically confirmed rib invasion was found to have a significant unfavorable prognostic impact in patients with pT3N0-1 lung cancer requiring chest wall resection. Multimodal therapy may be preferable in these patients to prevent local and distant relapse.