536P - The evaluation and long-term outcome of pulmonary metastasectomy for osteosarcoma: A 20-year experience of Shanghai Rujin Hospital

Background

We aim to evaluate the technical evolution and the long-term outcome of the surgical resection of the pulmonary metastases (PMs) in osteosarcoma.

Methods

We retrospectively reviewed patients with osteosarcoma who underwent pulmonary metastasectomy between Nov. 2002 and Nov. 2022 in our institution. We investigated the surgical techniques, post-metastasectomy overall survival (OS), as well as the clinicopathological factors associated with patients’ survival.

Results

230 cases of surgical resection of PMs were performed over the past 20 years in a total of 141 patients. The M:F ratio was 92:49, with a median age of 17 yro. During the two decades, the pulmonary metastasectomy has been continuously evolving, from the prototype of large- and oligo-metastases with upfront surgery of video-assisted lobectomy, toward the trend of small- and multiple metastases with thoracotomy, video-assisted manual palpation (VAMP) and wedge resection after a pre-operative non-progression disease control (the “Ruijin protocol”). The 3-yr and 5-yr OS of our group were 50.3% and 40.9%, respectively and reached a plateau in the recent years. Univariate analysis demonstrated that >=3 lesions (p<0.001), large-sized PM (p<0.001), CEA (p=0.0516), NSE (p=0.0166) and PLR (p=0.0587) were predictive factors associated with the surgical outcome. Surprisingly, the incidence of detecting extra tiny PMs during surgical exploration has increased from 11% to 55.7% over the two decades, and was found to a novel independent risk factor for the long-term survival(P=0.03). Of note, our premature experience suggested that post-operative early tumor rebound might be drastically reduced in patients treated with tyrosine-kinase inhibitors in the peri-operative setting (p<0.05).

Conclusions

Through the relentless effort of two decades, we have reached a “Ruijin protocol” of pulmonary metastasectomy of osteosarcoma, with a long-term survival of ∼30%. Such survival plateau might be further improved by adding novel biomarkers and therapeutic modalities (e.g. targeted therapy) into the armamentarium against such disease.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

National Science Foundation of China, grant No. 82141116; Natural Science Foundation of Shanghai, grant No. 20ZR1434000; Shanghai Municipal Health Commission, grant No. 202140124.

Disclosure

All authors have declared no conflicts of interest.