How Should Primary Pulmonary Sarcoma be Staged? Results of an International Multicentre Analysis

Primary pulmonary sarcomas (PPS) are rare, accounting for 1% of all pulmonary malignancies. No dedicated staging system for PPS is available. We tested the value of lung cancer and Trunk and Extremity Soft Tissue Sarcoma (STS) staging systems for PPS.

An international multicentre retrospective study including patients with PPS was performed through a network of sarcoma expert centres. Data on demographics, staging, multimodality treatment including surgery, and outcomes were retrieved. Patients were staged according to TNM for lung cancer (eighth edition) and American Joint Committee on Cancer (AJCC) Staging for Trunk and Extremity STS. Overall survivals (OS) were compared.

A total of 173 patients with PPS from 18 centres from 9 European countries were included. Of these, 115 patients (66%) underwent curative-intent surgery. Median tumour size was 85 mm. Sixty-nine patients had grade 3 PPS (72%). Eleven patients had nodal involvement (16%). Five-year OS was 49%. Median follow-up was 33 months. According to TNM for lung cancer, 15 (13%) patients had stage I, 15 (13%) had stage II, 45 (40%) had stage III, and 22 (19%) had stage IV. Five-year OS were 90%, 55%, 48%, and 22%, respectively (P = .001). According to AJCC staging for Trunk and Extremity STS 3 (3.4%) patients had stage I, 19 (21.6%) had stage II, 39 (44.3%) had stage III, and 27 (30.7%) had stage IV (Table 1). Five-year OS were 100% 74% 50%, and 24%, respectively (P = .005).

In our cohort of patients with curative-intent surgery for PPS, AJCC staging for Trunk and Extremity STS is more reliable than lung cancer staging system.