Incidence, survival, and associated factors estimation in osteosarcoma patients with lung metastasis: a single-center experience of 11 years in Tianjin, China.

BACKGROUND: Osteosarcoma is the most common primary malignant bone tumor. The current study was conducted to describe the general condition of patients with primary osteosarcoma in a single cancer center in Tianjin, China and to investigate the associated factors in osteosarcoma patients with lung metastasis.

METHODS: From February 2009 to October 2020, patients from Tianjin Medical University Cancer Institute and Hospital, China were retrospectively analyzed. The Kaplan-Meier method was used to evaluate the overall survival of osteosarcoma patients. The Cox proportional hazard regression analysis was performed to analyze the prognostic factors of all osteosarcoma patients and those patients with lung metastasis, respectively. Furthermore, risk factors for developing lung metastasis were identified in synchronous lung metastasis (SLM) and metachronous lung metastasis (MLM) patients.

RESULTS: A total of 203 patients were involved and 150 patients were successfully followed up for survival status. The 5-year survival rate of osteosarcoma was 70.0% and the survival months for patients with SLM and MLM were 33.3 ± 12.6 and 45.8 ± 7.4 months, respectively. The presence of lung metastasis was one of the independent prognostic factors for prognosis of osteosarcoma. In patients with lung metastasis, twenty-one (10.3%) showed lung metastasis at the diagnosis of osteosarcoma and 67 (33%) were diagnosed with lung metastases during the later course. T3 stage (OR = 11.415, 95%CI 1.362-95.677, P = 0.025) and bone metastasis (OR = 6.437, 95%CI 1.69-24.51, P = 0.006) were risk factors of SLM occurrence. Bone metastasis (OR = 1.842, 95%CI 1.053-3.224, P = 0.032), good necrosis (≥ 90%, OR = 0.032, 95%CI 0.050-0.412, P < 0.001), elevated Ki-67 (OR = 2.958, 95%CI 1.098-7.969, P = 0.032) and elevated LDH (OR = 1.791, 95%CI 1.020-3.146, P = 0.043) were proved to be independent risk factors for developing MLM.

CONCLUSION: The overall survival, prognostic factors and risk factors for lung metastasis in this single center provided insight about osteosarcoma management.