Primary pulmonary osteosarcoma: a case report, literature review and pooled analysis

Primary pulmonary osteosarcoma (PPOS) is an exceptionally rare malignant tumor that arises within the lung parenchyma. Fewer than 40 cases of PPOS have been reported to date. Owing to its rarity, the clinical features and prognostic factors of PPOS remain poorly defined. To report a new case of PPOS and perform a pooled retrospective analysis of published cases to identify clinical profiles and potential prognostic determinants. A comprehensive literature review was conducted using the PubMed, Medline, and Cochrane Library databases. Thirty-eight reported cases of PPOS were identified. Among these, sufficient clinical and survival data of 25 patients, including one from our institution, were available for analysis. Overall survival (OS) was assessed using the Kaplan–Meier method and Cox proportional hazards models. The median age of the pooled cohort was 64 years. Kaplan-Meier and multivariable Cox analyses demonstrated that older age (> 64 years) was associated with poorer OS and that surgical resection significantly improved survival. Among surgical patients, adjuvant chemotherapy was associated with a trend toward prolonged OS, although the difference was not statistically significant ( P = 0.053). Age-stratified analysis revealed a survival benefit of surgery in both the ≤ 64-year age group and the > 64-year age group ( P = 0.003 and P < 0.001, respectively), and no significant difference in OS was observed according to tumor size among surgically treated patients ( P = 0.89). PPOS is an aggressive malignancy with poor prognosis. Age and surgical resection were found to be crucial prognostic factors. A combination of surgery and chemotherapy may offer additional survival benefits to selected patients. Given that the benefits of surgery were observed across all age groups and that no difference in survival was observed according to tumor size among surgically treated patients, advanced age and larger tumor size alone should not preclude consideration of surgical intervention in patients with adequate performance status. Larger multi-institutional studies are needed to validate these findings.