Pathologic Findings and Long-Term Results After Surgical Treatment for Pulmonary Sarcomatoid Tumors: A Multicenter Analysis

Abstract

Pulmonary sarcomatoid carcinoma (PSC) is a very rare subtype of non-small cell lung cancer (NSCLC). The aim of this study was to clarify the pathologic characteristics and long-term survival after surgical treatment in patients with PSC. From January 2003 to December 2013, we retrospectively reviewed the clinical findings, surgical notes, and pathologic and follow-up data from 148 consecutive patients who underwent curative resection for PSC in 5 institutions. The Kaplan-Meier method, log-rank test, and Cox regression analysis were used. Mean age and male to female ratio were 66.6 ± 9.9 years and 120:28, respectively. Surgical resection (pneumonectomy in 8 patients, bilobectomy in 132 patients, and sublobar resection in 8 patients) was complete in 142 cases (96%). At pathologic evaluation, 36 patients (24%) had stage I, 69 patients (47%) had stage II, 33 patients (22%) had stage III, and 10 patients (7%) had stage IV disease. A "biphasic tumor" (PSC with an NSCLC component) was observed in 77 patients (52%). We detected a high rate of vascular emboli in the surgical specimens (overall, 68%; 57% in pathologic stage I tumors), whereas lymphatic emboli were found in 30% of cases (5% of pathologic stage I tumors). Overall median and 5-year long-term survival (LTS) was 19 months and 12.6% (LTS, 16.3% in pathologic stage I), respectively. Distant recurrences frequently occurred after surgical treatment (81%), even in pathologic stage I tumors that underwent R0 resection (62%). Multivariable survival analysis identified R+ resection (hazard ratio [HR],12.3; 95% confidence interval [CI], 3.67-41.28; p < 0.0001), advanced pathologic stage (HR, 5.75; 95% CI, 2.55-12.98; p< 0.0001), and the presence of vascular emboli (HR, 1.67; 95% CI, 1.05-2.67; p= 0.0327) as independent negative prognostic factors. PSCs have very aggressive behavior and high metastatic potential even in early stages. R+ resection, pathologic TNM status, and the presence of vascular emboli are independent prognostic factors.