Clinical features, treatment and prognosis of primary pulmonary rhabdomyosarcoma: A systemic review.

Background: Primary pulmonary rhabdomyosarcoma (RMS), a rare soft tissue sarcoma, is characterized by a high recurrence rate and a poor prognosis. This systematic review aims to summarize the clinical characteristics, pathological features, treatment, and clinical outcomes of primary pulmonary RMS, and to analyze prognostic-related risk factors to provide robust evidence for future treatment strategies.

Methods: Five databases (MEDLINE, Scopus, the Cochrane Central Register of Controlled Trials, EMBASE, and Web of Science) were searched using the relevant terms including "pulmonary", "lung", "alveolar", "ERMS", "ARMS", "RMS" and "rhabdomyosarcoma". Cases with a definitive pathological diagnosis of RMS, complete treatment information, a minimum follow-up period of at least three months, and detailed follow-up records were included. The primary study endpoints were cancer-specific survival (CSS) and progression-free survival (PFS).

Results: 22 articles spanning from 1955 to 2023 met the inclusion criteria for the systematic review. The median patient age was 10.5 (2.0, 52.5) years. 22 cases (78.6%) presented with respiratory symptoms due to pulmonary masses at the initial diagnosis. 10 cases were diagnosed with the embryonal type, and the majority (n = 20, 71.4%) underwent surgical treatment. The average PFS time was 60.9 ± 14.8 months. Patients at TNM stage IV were more prone to progression, and CSS was associated with factors including age ≥ 18 years, primary tumor size ≥ 10 cm, and non-surgical treatment. Surgery was identified as an independent factor that could shorten progression time (HR = 4.58 (1.32-15.90), P = 0.017) and improve tumor-related survival (HR = 8.11 (1.45-45.50), P = 0.017).

Conclusions: Patients with higher TNM stages who did not undergo surgery tended to have more aggressive tumors, whereas primary tumors ≥ 10 cm and ages ≥ 18 years were associated with increased tumor-related mortality. Surgery, the primary treatment modality, independently improved CSS rates. Exploring optimal comprehensive treatment strategies that combine surgery, radiotherapy, and chemotherapy represents the principal direction for future research.